https://www.coastalwiki.org/w/index.php?title=Possible_consequences_of_eutrophication&feed=atom&action=historyPossible consequences of eutrophication - Revision history2024-03-29T13:11:42ZRevision history for this page on the wikiMediaWiki 1.31.7https://www.coastalwiki.org/w/index.php?title=Possible_consequences_of_eutrophication&diff=80815&oldid=prevDronkers J at 09:05, 20 February 20242024-02-20T09:05:18Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 09:05, 20 February 2024</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l9" >Line 9:</td>
<td colspan="2" class="diff-lineno">Line 9:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Increased biomass of phytoplankton resulting in [[algal bloom]]s===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Increased biomass of phytoplankton resulting in [[algal bloom]]s===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Plentiful_plankton.jpg|250px|thumb|right|<small>Fig. 1. Envisat satellite image of an algal bloom captured with MERIS (Photo Credit: ESA, 2009)</small>]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:Plentiful_plankton.jpg|250px|thumb|right|<small>Fig. 1. Envisat satellite image of an algal bloom captured with MERIS (Photo Credit: ESA, 2009)</small>]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[Phytoplankton]] or microalgae are [[photosynthesizing]] microscopic organisms. They contain chlorophyll and require sunlight in order to live and grow. Most phytoplankton are buoyant and float in the upper part of the ocean where sunlight penetrates the water. In a balanced ecosystem they provide food for a wide range of organisms such as whales, shrimp, snails and jellyfish.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[Phytoplankton]] or microalgae are [[<ins class="diffchange diffchange-inline">photosynthesis|</ins>photosynthesizing]] microscopic organisms. They contain chlorophyll and require sunlight in order to live and grow. Most phytoplankton are buoyant and float in the upper part of the ocean where sunlight penetrates the water. In a balanced ecosystem they provide food for a wide range of organisms such as whales, shrimp, snails and jellyfish.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Among the more important groups are the diatoms, cyanobacteria, dinoflagellates and coccolithophores (see: [[Marine Plankton]]).  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Among the more important groups are the diatoms, cyanobacteria, dinoflagellates and coccolithophores (see: [[Marine Plankton]]).  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Phytoplankton species require inorganic [[Nutrient|nutrients]] such as nitrates, phosphates, and sulfur which they convert into proteins, fats and carbohydrates. When '''too many''' of these '''nutrients''' (by natural or [[Anthropogenic|anthropogenic]] cause) are available in the water, phytoplankton may grow and multiply very fast forming algal blooms (see [[Algal bloom dynamics]]). Algal blooms may occur in freshwater as well as marine environments. Only one or a small number of phytoplankton species are involved and some blooms discolor (green, yellow-brown or red) the water due to their high density of pigmented cells. Blooms in the ocean may cover a large area and are easily visible in satellite images (Fig. 1) – see the article [[Plankton remote sensing]]. Enclosed and semi-enclosed water bodies (e.g., coastal lagoons) are particularly sensitive to increased nutrient loads (especially nitrogen input from agricultural effluents), potentially leading to ecosystem collapse<ref>Ouaissa, S., Gómez-Jakobsen, F., Yebra, L., Ferrera, I., Moreno-Ostos, E., Dolores Belando, M., Ruiz, J.M. and Mercado, J.M. 2023. Phytoplankton dynamics in the Mar Menor, a Mediterranean coastal lagoon strongly impacted by eutrophication. Marine Pollution Bulletin 192, 115074</ref>.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Phytoplankton species require inorganic [[Nutrient|nutrients]] such as nitrates, phosphates, and sulfur which they convert into proteins, fats and carbohydrates. When '''too many''' of these '''nutrients''' (by natural or [[Anthropogenic|anthropogenic]] cause) are available in the water, phytoplankton may grow and multiply very fast forming algal blooms (see [[Algal bloom dynamics]]). Algal blooms may occur in freshwater as well as marine environments. Only one or a small number of phytoplankton species are involved and some blooms discolor (green, yellow-brown or red) the water due to their high density of pigmented cells. Blooms in the ocean may cover a large area and are easily visible in satellite images (Fig. 1) – see the article [[Plankton remote sensing]]. Enclosed and semi-enclosed water bodies (e.g., coastal lagoons) are particularly sensitive to increased nutrient loads (especially nitrogen input from agricultural effluents), potentially leading to ecosystem collapse<ref>Ouaissa, S., Gómez-Jakobsen, F., Yebra, L., Ferrera, I., Moreno-Ostos, E., Dolores Belando, M., Ruiz, J.M. and Mercado, J.M. 2023. Phytoplankton dynamics in the Mar Menor, a Mediterranean coastal lagoon strongly impacted by eutrophication. Marine Pollution Bulletin 192, 115074</ref>.</div></td></tr>
</table>Dronkers Jhttps://www.coastalwiki.org/w/index.php?title=Possible_consequences_of_eutrophication&diff=80713&oldid=prevDronkers J at 16:05, 12 February 20242024-02-12T16:05:32Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 16:05, 12 February 2024</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l11" >Line 11:</td>
<td colspan="2" class="diff-lineno">Line 11:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Phytoplankton]] or microalgae are [[photosynthesizing]] microscopic organisms. They contain chlorophyll and require sunlight in order to live and grow. Most phytoplankton are buoyant and float in the upper part of the ocean where sunlight penetrates the water. In a balanced ecosystem they provide food for a wide range of organisms such as whales, shrimp, snails and jellyfish.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Phytoplankton]] or microalgae are [[photosynthesizing]] microscopic organisms. They contain chlorophyll and require sunlight in order to live and grow. Most phytoplankton are buoyant and float in the upper part of the ocean where sunlight penetrates the water. In a balanced ecosystem they provide food for a wide range of organisms such as whales, shrimp, snails and jellyfish.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Among the more important groups are the diatoms, cyanobacteria, dinoflagellates and coccolithophores (see: [[Marine Plankton]]).  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Among the more important groups are the diatoms, cyanobacteria, dinoflagellates and coccolithophores (see: [[Marine Plankton]]).  </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Phytoplankton species require inorganic [[Nutrient|nutrients]] such as nitrates, phosphates, and sulfur which they convert into proteins, fats and carbohydrates. When '''too many''' of these '''nutrients''' (by natural or [[Anthropogenic|anthropogenic]] cause) are available in the water, phytoplankton may grow and multiply very fast forming algal blooms (see [[Algal bloom dynamics]]). Algal blooms may occur in freshwater as well as marine environments. Only one or a small number of phytoplankton species are involved and some blooms discolor (green, yellow-brown or red) the water due to their high density of pigmented cells. Blooms in the ocean may cover a large area and are easily visible in satellite images (Fig. 1) – see the article [[<del class="diffchange diffchange-inline">Determining coastal water constituents from space</del>]]. Enclosed and semi-enclosed water bodies (e.g., coastal lagoons) are particularly sensitive to increased nutrient loads (especially nitrogen input from agricultural effluents), potentially leading to ecosystem collapse<ref>Ouaissa, S., Gómez-Jakobsen, F., Yebra, L., Ferrera, I., Moreno-Ostos, E., Dolores Belando, M., Ruiz, J.M. and Mercado, J.M. 2023. Phytoplankton dynamics in the Mar Menor, a Mediterranean coastal lagoon strongly impacted by eutrophication. Marine Pollution Bulletin 192, 115074</ref>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Phytoplankton species require inorganic [[Nutrient|nutrients]] such as nitrates, phosphates, and sulfur which they convert into proteins, fats and carbohydrates. When '''too many''' of these '''nutrients''' (by natural or [[Anthropogenic|anthropogenic]] cause) are available in the water, phytoplankton may grow and multiply very fast forming algal blooms (see [[Algal bloom dynamics]]). Algal blooms may occur in freshwater as well as marine environments. Only one or a small number of phytoplankton species are involved and some blooms discolor (green, yellow-brown or red) the water due to their high density of pigmented cells. Blooms in the ocean may cover a large area and are easily visible in satellite images (Fig. 1) – see the article [[<ins class="diffchange diffchange-inline">Plankton remote sensing</ins>]]. Enclosed and semi-enclosed water bodies (e.g., coastal lagoons) are particularly sensitive to increased nutrient loads (especially nitrogen input from agricultural effluents), potentially leading to ecosystem collapse<ref>Ouaissa, S., Gómez-Jakobsen, F., Yebra, L., Ferrera, I., Moreno-Ostos, E., Dolores Belando, M., Ruiz, J.M. and Mercado, J.M. 2023. Phytoplankton dynamics in the Mar Menor, a Mediterranean coastal lagoon strongly impacted by eutrophication. Marine Pollution Bulletin 192, 115074</ref>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Toxic or inedible phytoplankton species ([[harmful algal blooms]])===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Toxic or inedible phytoplankton species ([[harmful algal blooms]])===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Harmful algal blooms (HAB)''' are bloom events involving '''toxic or harmful phytoplankton'''. These cause harm through the production of toxins or by their accumulated biomass, which can effect co-occurring organisms and alter food web dynamics. Impacts include:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Harmful algal blooms (HAB)''' are bloom events involving '''toxic or harmful phytoplankton'''. These cause harm through the production of toxins or by their accumulated biomass, which can effect co-occurring organisms and alter food web dynamics. Impacts include:</div></td></tr>
</table>Dronkers Jhttps://www.coastalwiki.org/w/index.php?title=Possible_consequences_of_eutrophication&diff=80387&oldid=prevDronkers J at 08:34, 13 August 20232023-08-13T08:34:59Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 08:34, 13 August 2023</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l27" >Line 27:</td>
<td colspan="2" class="diff-lineno">Line 27:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>There is some evidence that hypoxic conditions promote the growth of cyanobacteria as a consequence of enhanced phosphorus release<ref>Funkey, C.P., Conley, D.J., Reuss, N.S., Humborg, C, Jilbert, T. and Slomp, C.P. 2014. Hypoxia Sustains Cyanobacteria Blooms in the Baltic Sea. Environ. Sci. Technol. 48: 2598−2602</ref>. Many cyanobacteria species produce toxins that are lethal to birds and animals.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>There is some evidence that hypoxic conditions promote the growth of cyanobacteria as a consequence of enhanced phosphorus release<ref>Funkey, C.P., Conley, D.J., Reuss, N.S., Humborg, C, Jilbert, T. and Slomp, C.P. 2014. Hypoxia Sustains Cyanobacteria Blooms in the Baltic Sea. Environ. Sci. Technol. 48: 2598−2602</ref>. Many cyanobacteria species produce toxins that are lethal to birds and animals.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Eutrophication-driven acidification===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Eutrophication-driven acidification===</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The respiration of bacteria that decompose dead algae not only causes hypoxia due to oxygen consumption, but also produces CO<sub>2</sub> and thus causes an increase in the carbonic acid content of the water. A sharp increase in acidity (pH even below 7) has been observed in highly eutrophic estuaries and lagoons along the east coast of the US, coinciding with hypoxia<ref>Wallace, R.B., Baumann, H., Grear, J.S., Aller, R.C. and Gobler, C.J. 2014. Coastal ocean acidification: The other eutrophication problem. Estuarine, Coastal and Shelf Science 148: 1-13</ref>. Acidification is an annual feature of these estuaries during summer when algae decay and oxygen depletes. Lowest pH levels (undersaturated with respect to aragonite) occur near the bottom, especially in poorly flushed stratified systems. This poses a serious threat to calcifying benthic organisms, for example scallops and other bivalves that spawn in mid-to-late summer.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The respiration of bacteria that decompose dead algae not only causes hypoxia due to oxygen consumption, but also produces CO<sub>2</sub> and thus causes an increase in the carbonic acid content of the water. A sharp increase in acidity (pH even below 7) has been observed in highly eutrophic estuaries and lagoons along the east coast of the US, coinciding with hypoxia<ref>Wallace, R.B., Baumann, H., Grear, J.S., Aller, R.C. and Gobler, C.J. 2014. Coastal ocean acidification: The other eutrophication problem. Estuarine, Coastal and Shelf Science 148: 1-13</ref>. Acidification is an annual feature of these estuaries during summer when algae decay and oxygen depletes. Lowest pH levels (undersaturated with respect to aragonite) occur near the bottom, especially in poorly flushed stratified systems. This poses a serious threat to calcifying benthic organisms, for example scallops and other bivalves that spawn in mid-to-late summer<ins class="diffchange diffchange-inline">. Eutrophication-driven acidification exacerbates [[ocean acidification]] due to uptake of atmospheric CO<sub>2</sub></ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dead zones===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dead zones===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Zones with extreme hypoxia are called [https://en.wikipedia.org/wiki/Dead_zone_(ecology) dead zones]. Upwelling of nutrient-rich waters may produce 'natural' dead zones in some ocean regions where water mass circulation is weak. These so-called 'oxygen minimum zones' occur below the photic zone, between about 200 - 1500 m depth, and are related to microbial mineralization of sinking organic material<ref name=BG>Breitburg, D., Gregoire, M. Isensee, K. (eds.) 2018. The ocean is losing its breath: Declining oxygen in the world’s ocean and coastal waters. IOC-UNESCO, IOC Technical Series, No. 137 40pp. (IOC/2018/TS/137)</ref>. However, most severe dead zones occur as a result of anthropogenic eutrophication of stratified water masses. Stratification is mainly caused by temperature-induced density differences between surface waters and deeper waters in the ocean; stratification in estuaries and coastal waters is mainly due to the salinity-induced density difference between seawater and river water. When an algal bloom in the surface layer decays, the deeper water layers become laden with sinking dead algae that are decomposed by oxygen consuming bacteria. Stratification inhibits turbulent mixing of the oxygen-rich surface layer into the underlying water layer that therefore becomes depleted from oxygen.  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Zones with extreme hypoxia are called [https://en.wikipedia.org/wiki/Dead_zone_(ecology) dead zones]. Upwelling of nutrient-rich waters may produce 'natural' dead zones in some ocean regions where water mass circulation is weak. These so-called 'oxygen minimum zones' occur below the photic zone, between about 200 - 1500 m depth, and are related to microbial mineralization of sinking organic material<ref name=BG>Breitburg, D., Gregoire, M. Isensee, K. (eds.) 2018. The ocean is losing its breath: Declining oxygen in the world’s ocean and coastal waters. IOC-UNESCO, IOC Technical Series, No. 137 40pp. (IOC/2018/TS/137)</ref>. However, most severe dead zones occur as a result of anthropogenic eutrophication of stratified water masses. Stratification is mainly caused by temperature-induced density differences between surface waters and deeper waters in the ocean; stratification in estuaries and coastal waters is mainly due to the salinity-induced density difference between seawater and river water. When an algal bloom in the surface layer decays, the deeper water layers become laden with sinking dead algae that are decomposed by oxygen consuming bacteria. Stratification inhibits turbulent mixing of the oxygen-rich surface layer into the underlying water layer that therefore becomes depleted from oxygen.  </div></td></tr>
<!-- diff cache key wiki:diff::1.12:old-80344:rev-80387 -->
</table>Dronkers Jhttps://www.coastalwiki.org/w/index.php?title=Possible_consequences_of_eutrophication&diff=80344&oldid=prevDronkers J at 10:58, 3 August 20232023-08-03T10:58:27Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 10:58, 3 August 2023</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l11" >Line 11:</td>
<td colspan="2" class="diff-lineno">Line 11:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Phytoplankton]] or microalgae are [[photosynthesizing]] microscopic organisms. They contain chlorophyll and require sunlight in order to live and grow. Most phytoplankton are buoyant and float in the upper part of the ocean where sunlight penetrates the water. In a balanced ecosystem they provide food for a wide range of organisms such as whales, shrimp, snails and jellyfish.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Phytoplankton]] or microalgae are [[photosynthesizing]] microscopic organisms. They contain chlorophyll and require sunlight in order to live and grow. Most phytoplankton are buoyant and float in the upper part of the ocean where sunlight penetrates the water. In a balanced ecosystem they provide food for a wide range of organisms such as whales, shrimp, snails and jellyfish.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Among the more important groups are the diatoms, cyanobacteria, dinoflagellates and coccolithophores (see: [[Marine Plankton]]).  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Among the more important groups are the diatoms, cyanobacteria, dinoflagellates and coccolithophores (see: [[Marine Plankton]]).  </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Phytoplankton species require inorganic [[Nutrient|nutrients]] such as nitrates, phosphates, and sulfur which they convert into proteins, fats and carbohydrates. When '''too many''' of these '''nutrients''' (by natural or [[Anthropogenic|anthropogenic]] cause) are available in the water, phytoplankton may grow and multiply very fast forming algal blooms (see [[Algal bloom dynamics]]). Algal blooms may occur in freshwater as well as marine environments. Only one or a small number of phytoplankton species are involved and some blooms discolor (green, yellow-brown or red) the water due to their high density of pigmented cells. Blooms in the ocean may cover a large area and are easily visible in satellite images (Fig. 1) – see the article [[Determining coastal water constituents from space]].</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Phytoplankton species require inorganic [[Nutrient|nutrients]] such as nitrates, phosphates, and sulfur which they convert into proteins, fats and carbohydrates. When '''too many''' of these '''nutrients''' (by natural or [[Anthropogenic|anthropogenic]] cause) are available in the water, phytoplankton may grow and multiply very fast forming algal blooms (see [[Algal bloom dynamics]]). Algal blooms may occur in freshwater as well as marine environments. Only one or a small number of phytoplankton species are involved and some blooms discolor (green, yellow-brown or red) the water due to their high density of pigmented cells. Blooms in the ocean may cover a large area and are easily visible in satellite images (Fig. 1) – see the article [[Determining coastal water constituents from space]]<ins class="diffchange diffchange-inline">. Enclosed and semi-enclosed water bodies (e.g., coastal lagoons) are particularly sensitive to increased nutrient loads (especially nitrogen input from agricultural effluents), potentially leading to ecosystem collapse<ref>Ouaissa, S., Gómez-Jakobsen, F., Yebra, L., Ferrera, I., Moreno-Ostos, E., Dolores Belando, M., Ruiz, J.M. and Mercado, J.M. 2023. Phytoplankton dynamics in the Mar Menor, a Mediterranean coastal lagoon strongly impacted by eutrophication. Marine Pollution Bulletin 192, 115074</ref></ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Toxic or inedible phytoplankton species ([[harmful algal blooms]])===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Toxic or inedible phytoplankton species ([[harmful algal blooms]])===</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Harmful algal blooms (HAB)''' are bloom events involving '''toxic or harmful phytoplankton'''. These cause harm through the production of toxins or by their accumulated biomass, which can effect co-occurring organisms and alter food web dynamics. Impacts include:</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>'''Harmful algal blooms (HAB)''' are bloom events involving '''toxic or harmful phytoplankton'''. These cause harm through the production of toxins or by their accumulated biomass, which can effect co-occurring organisms and alter food web dynamics. Impacts include:</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l32" >Line 32:</td>
<td colspan="2" class="diff-lineno">Line 32:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Although many species have adaptations to low oxygen conditions<ref>Altieri, A.H., Johnson, M.D., Swaminathan, S.D., Nelson, H.R. and Gedan, K.B. 2021. Resilience of Tropical Ecosystems to</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Although many species have adaptations to low oxygen conditions<ref>Altieri, A.H., Johnson, M.D., Swaminathan, S.D., Nelson, H.R. and Gedan, K.B. 2021. Resilience of Tropical Ecosystems to</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Ocean Deoxygenation. Trends in Ecology and Evolution 36: 227-238</ref>, fish and crustaceans suffer significant mortality already at 2 mg/l O<sub>2</sub> <ref>Vaquer-Sunyer, R. and Duarte, C.M. 2008. Thresholds of hypoxia for marine biodiversity. PNAS 105: 15452–15457</ref>. The die-off of [[seagrass meadows]] under low oxygen levels is enhanced by positive feedback from oxygen consuming mineralization, but recolonization by germinating seedlings can be quite rapid<ref>Greve, T.M., Krause-Jensen, D., Rasmussen, M.B. and Christense, P.B. 2005. Means of rapid eelgrass (Zostera marina L.) recolonisation in former dieback areas. Aquatic Botany 82: 143-156</ref>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Ocean Deoxygenation. Trends in Ecology and Evolution 36: 227-238</ref>, fish and crustaceans suffer significant mortality already at 2 mg/l O<sub>2</sub> <ref>Vaquer-Sunyer, R. and Duarte, C.M. 2008. Thresholds of hypoxia for marine biodiversity. PNAS 105: 15452–15457</ref>. The die-off of [[seagrass meadows]] under low oxygen levels is enhanced by positive feedback from oxygen consuming mineralization, but recolonization by germinating seedlings can be quite rapid <ref>Greve, T.M., Krause-Jensen, D., Rasmussen, M.B. and Christense, P.B. 2005. Means of rapid eelgrass (Zostera marina L.) recolonisation in former dieback areas. Aquatic Botany 82: 143-156</ref>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:OceanHypoxia.jpg|thumb|500px|left|<small>Fig. 3. Areas with hypoxia in coastal seas (red) and in the oceans (blue). From IOC-UNESCO 2018<ref name=BG/> Creative Commons Licence.</small>]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:OceanHypoxia.jpg|thumb|500px|left|<small>Fig. 3. Areas with hypoxia in coastal seas (red) and in the oceans (blue). From IOC-UNESCO 2018<ref name=BG/> Creative Commons Licence.</small>]]</div></td></tr>
<!-- diff cache key wiki:diff::1.12:old-79887:rev-80344 -->
</table>Dronkers Jhttps://www.coastalwiki.org/w/index.php?title=Possible_consequences_of_eutrophication&diff=79887&oldid=prevDronkers J at 14:36, 2 October 20222022-10-02T14:36:52Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 14:36, 2 October 2022</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l31" >Line 31:</td>
<td colspan="2" class="diff-lineno">Line 31:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Zones with extreme hypoxia are called [https://en.wikipedia.org/wiki/Dead_zone_(ecology) dead zones]. Upwelling of nutrient-rich waters may produce 'natural' dead zones in some ocean regions where water mass circulation is weak. These so-called 'oxygen minimum zones' occur below the photic zone, between about 200 - 1500 m depth, and are related to microbial mineralization of sinking organic material<ref name=BG>Breitburg, D., Gregoire, M. Isensee, K. (eds.) 2018. The ocean is losing its breath: Declining oxygen in the world’s ocean and coastal waters. IOC-UNESCO, IOC Technical Series, No. 137 40pp. (IOC/2018/TS/137)</ref>. However, most severe dead zones occur as a result of anthropogenic eutrophication of stratified water masses. Stratification is mainly caused by temperature-induced density differences between surface waters and deeper waters in the ocean; stratification in estuaries and coastal waters is mainly due to the salinity-induced density difference between seawater and river water. When an algal bloom in the surface layer decays, the deeper water layers become laden with sinking dead algae that are decomposed by oxygen consuming bacteria. Stratification inhibits turbulent mixing of the oxygen-rich surface layer into the underlying water layer that therefore becomes depleted from oxygen.  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Zones with extreme hypoxia are called [https://en.wikipedia.org/wiki/Dead_zone_(ecology) dead zones]. Upwelling of nutrient-rich waters may produce 'natural' dead zones in some ocean regions where water mass circulation is weak. These so-called 'oxygen minimum zones' occur below the photic zone, between about 200 - 1500 m depth, and are related to microbial mineralization of sinking organic material<ref name=BG>Breitburg, D., Gregoire, M. Isensee, K. (eds.) 2018. The ocean is losing its breath: Declining oxygen in the world’s ocean and coastal waters. IOC-UNESCO, IOC Technical Series, No. 137 40pp. (IOC/2018/TS/137)</ref>. However, most severe dead zones occur as a result of anthropogenic eutrophication of stratified water masses. Stratification is mainly caused by temperature-induced density differences between surface waters and deeper waters in the ocean; stratification in estuaries and coastal waters is mainly due to the salinity-induced density difference between seawater and river water. When an algal bloom in the surface layer decays, the deeper water layers become laden with sinking dead algae that are decomposed by oxygen consuming bacteria. Stratification inhibits turbulent mixing of the oxygen-rich surface layer into the underlying water layer that therefore becomes depleted from oxygen.  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Although many species have adaptations to low oxygen conditions<ref>Altieri, A.H., Johnson, M.D., Swaminathan, S.D., Nelson, H.R. and Gedan, K.B. 2021. Resilience of Tropical Ecosystems to</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">Ocean Deoxygenation. Trends in Ecology and Evolution 36: 227-238</ref>, fish and crustaceans suffer significant mortality already at 2 mg/l O<sub>2</sub> <ref>Vaquer-Sunyer, R. and Duarte, C.M. 2008. Thresholds of hypoxia for marine biodiversity. PNAS 105: 15452–15457</ref>. The die-off of [[seagrass meadows]] under low oxygen levels is enhanced by positive feedback from oxygen consuming mineralization, but recolonization by germinating seedlings can be quite rapid<ref>Greve, T.M., Krause-Jensen, D., Rasmussen, M.B. and Christense, P.B. 2005. Means of rapid eelgrass (Zostera marina L.) recolonisation in former dieback areas. Aquatic Botany 82: 143-156</ref>.</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:OceanHypoxia.jpg|thumb|500px|left|<small>Fig. 3. Areas with hypoxia in coastal seas (red) and in the oceans (blue). From IOC-UNESCO 2018<ref name=BG/> Creative Commons Licence.</small>]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:OceanHypoxia.jpg|thumb|500px|left|<small>Fig. 3. Areas with hypoxia in coastal seas (red) and in the oceans (blue). From IOC-UNESCO 2018<ref name=BG/> Creative Commons Licence.</small>]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del style="font-weight: bold; text-decoration: none;"></del></div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Fig. 3 shows a map of coastal and ocean regions with frequently occurring hypoxia. The largest and most persistent dead zones are situated in the Baltic Sea, the Black Sea, the Arabian Sea and the Gulf of Mexico. The size of dead zones decreases during severe storms when strong wind-driven turbulent water motion partially neutralizes stratification.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Fig. 3 shows a map of coastal and ocean regions with frequently occurring hypoxia. The largest and most persistent dead zones are situated in the Baltic Sea, the Black Sea, the Arabian Sea and the Gulf of Mexico. The size of dead zones decreases during severe storms when strong wind-driven turbulent water motion partially neutralizes stratification.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">Climate change is </del>expected to <del class="diffchange diffchange-inline">worsen oxygen </del>depletion in the ocean and coastal waters <del class="diffchange diffchange-inline">by </del>increasing <del class="diffchange diffchange-inline">nutrient supply</del><ref>Baroni, I.R., Palastanga, V. and Slomp, C. P. 2020. Enhanced Organic</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">Demographic growth and economic development are </ins>expected to <ins class="diffchange diffchange-inline">increase the supply of nutrients<ref>Beusen, A.H.W., Doelman, J.C., Van Beek, L.P.H., Van Puijenbroek, P.J.T.M., M. Mogollon, J., Van Grinsven, H.J.M., Stehfest, E., Van Vuuren, D.P. and Bouwman A.F. 2022. Exploring river nitrogen and phosphorus loading and export to global coastal waters in the Shared Socio-economic pathways. Global Environmental Change 72: 102426</ref>. Oxygen </ins>depletion in the ocean and coastal waters <ins class="diffchange diffchange-inline">and climate change will be further exacerbated through </ins>increasing <ins class="diffchange diffchange-inline">ocean surface temperature and stratification</ins><ref>Baroni, I.R., Palastanga, V. and Slomp, C. P. 2020. Enhanced Organic Carbon Burial in Sediments of Oxygen Minimum Zones Upon Ocean Deoxygenation. Front. Mar. Sci. 6: 839</ref><ref>Li, G., Cheng, L., Zhu, J., Trenberth, K.E., Mann, M.E. and Abraham, J.P. 2020. Increasing ocean stratification over the past half-century. Nature Climate Change https://doi.org/10.1038/s41558-020-00918-2</ref>. In turn, ocean oxygen depletion can <ins class="diffchange diffchange-inline">generate a positive feedback </ins>to climate change <ins class="diffchange diffchange-inline">through </ins>increased production of the greenhouse gas NO<sub>2</sub> <ins class="diffchange diffchange-inline">by microbial denitrification</ins><ref name=BG/>.</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Carbon Burial in Sediments of Oxygen Minimum Zones Upon Ocean Deoxygenation. Front. Mar. Sci. 6: 839</ref> <del class="diffchange diffchange-inline">and increasing ocean surface temperature and stratification</del><ref>Li, G., Cheng, L., Zhu, J., Trenberth, K.E., Mann, M.E. and Abraham, J.P. 2020. Increasing ocean stratification over the past half-century. Nature Climate Change https://doi.org/10.1038/s41558-020-00918-2</ref>. In turn, ocean oxygen depletion can <del class="diffchange diffchange-inline">contribute </del>to climate change <del class="diffchange diffchange-inline">by </del>increased <del class="diffchange diffchange-inline">microbial denitrification with </del>production of the greenhouse gas NO<sub>2</sub><ref name=BG/>.</div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br clear=all></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br clear=all></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Species biodiversity decreases and the dominant biota changes===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Species biodiversity decreases and the dominant biota changes===</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l44" >Line 44:</td>
<td colspan="2" class="diff-lineno">Line 44:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Eutrophication leads to changes in the availability of light and certain nutrients to an ecosystem. This causes shifts in the species composition so that only the more tolerant species survive and new competitive species invade and out-compete original inhabitants. Examples are macroalgae and their massive biomass which inhibits the growth of other aquatic plants and algal blooms that consists of one type of phytoplankton species because other species are outcompeted.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Eutrophication leads to changes in the availability of light and certain nutrients to an ecosystem. This causes shifts in the species composition so that only the more tolerant species survive and new competitive species invade and out-compete original inhabitants. Examples are macroalgae and their massive biomass which inhibits the growth of other aquatic plants and algal blooms that consists of one type of phytoplankton species because other species are outcompeted.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Green tides===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Green tides===</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Many observations and experiments provide evidence that the occurrence of so-called 'green tides', consisting of '''marine seaweeds''' or '''macroalgae''', is increased in eutrophicated coastal waters<ref name=SZ>Smetacek, V. and Zingone, A. 2013. Green and golden seaweed tides on the rise. Nature 504, doi:10.1038/nature12860</ref>. These blooms are recognizable by large blades of algae that may wash up onto the shoreline (Fig. 4). Green tides can asphyxiate aquacultures or disrupt traditional artisanal fisheries. Macroalgae can also be valorized as a raw material; harvesting could therefore be an effective solution<ref name=SZ/>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Many observations and experiments provide evidence that the occurrence of so-called 'green tides', consisting of '''marine seaweeds''' or '''macroalgae''', is increased in eutrophicated coastal waters<ref name=SZ>Smetacek, V. and Zingone, A. 2013. Green and golden seaweed tides on the rise. Nature 504, doi:10.1038/nature12860</ref>. These blooms are recognizable by large blades of algae that may wash up onto the shoreline (Fig. 4). Green tides can asphyxiate aquacultures or disrupt traditional artisanal fisheries. Macroalgae can also be valorized as a raw material; harvesting could therefore be an effective solution<ref name=SZ/> <ins class="diffchange diffchange-inline">(see also [[Seaweed (macro-algae) ecosystem services]])</ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br clear=all></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br clear=all></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l105" >Line 105:</td>
<td colspan="2" class="diff-lineno">Line 105:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Related articles==</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>==Related articles==</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Harmful algal bloom]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Harmful algal bloom]]</div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">:[[Nutrient conversion in the marine environment]]</ins></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Algal bloom dynamics]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Algal bloom dynamics]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">:[[Nutrient conversion in the marine environment]]</del></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:[[ What causes eutrophication?]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:[[What causes eutrophication?]]</div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Threats to the coastal zone]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Threats to the coastal zone]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Estuarine turbidity maximum]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Estuarine turbidity maximum]]</div></td></tr>
<!-- diff cache key wiki:diff::1.12:old-78689:rev-79887 -->
</table>Dronkers Jhttps://www.coastalwiki.org/w/index.php?title=Possible_consequences_of_eutrophication&diff=78689&oldid=prevDronkers J at 11:47, 22 February 20212021-02-22T11:47:04Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 11:47, 22 February 2021</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l106" >Line 106:</td>
<td colspan="2" class="diff-lineno">Line 106:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Harmful algal bloom]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Harmful algal bloom]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Algal bloom dynamics]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Algal bloom dynamics]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:[[ What causes eutrophication?]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:[[Nutrient conversion in the marine environment]]</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:[[What causes eutrophication?]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Threats to the coastal zone]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Threats to the coastal zone]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Estuarine turbidity maximum]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Estuarine turbidity maximum]]</div></td></tr>
<!-- diff cache key wiki:diff::1.12:old-78688:rev-78689 -->
</table>Dronkers Jhttps://www.coastalwiki.org/w/index.php?title=Possible_consequences_of_eutrophication&diff=78688&oldid=prevDronkers J at 11:43, 22 February 20212021-02-22T11:43:27Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 11:43, 22 February 2021</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l29" >Line 29:</td>
<td colspan="2" class="diff-lineno">Line 29:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The respiration of bacteria that decompose dead algae not only causes hypoxia due to oxygen consumption, but also produces CO<sub>2</sub> and thus causes an increase in the carbonic acid content of the water. A sharp increase in acidity (pH even below 7) has been observed in highly eutrophic estuaries and lagoons along the east coast of the US, coinciding with hypoxia<ref>Wallace, R.B., Baumann, H., Grear, J.S., Aller, R.C. and Gobler, C.J. 2014. Coastal ocean acidification: The other eutrophication problem. Estuarine, Coastal and Shelf Science 148: 1-13</ref>. Acidification is an annual feature of these estuaries during summer when algae decay and oxygen depletes. Lowest pH levels (undersaturated with respect to aragonite) occur near the bottom, especially in poorly flushed stratified systems. This poses a serious threat to calcifying benthic organisms, for example scallops and other bivalves that spawn in mid-to-late summer.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>The respiration of bacteria that decompose dead algae not only causes hypoxia due to oxygen consumption, but also produces CO<sub>2</sub> and thus causes an increase in the carbonic acid content of the water. A sharp increase in acidity (pH even below 7) has been observed in highly eutrophic estuaries and lagoons along the east coast of the US, coinciding with hypoxia<ref>Wallace, R.B., Baumann, H., Grear, J.S., Aller, R.C. and Gobler, C.J. 2014. Coastal ocean acidification: The other eutrophication problem. Estuarine, Coastal and Shelf Science 148: 1-13</ref>. Acidification is an annual feature of these estuaries during summer when algae decay and oxygen depletes. Lowest pH levels (undersaturated with respect to aragonite) occur near the bottom, especially in poorly flushed stratified systems. This poses a serious threat to calcifying benthic organisms, for example scallops and other bivalves that spawn in mid-to-late summer.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dead zones===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dead zones===</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Zones with extreme hypoxia are called [https://en.wikipedia.org/wiki/Dead_zone_(ecology) dead zones]. Upwelling of nutrient-rich waters may produce 'natural' dead zones in some ocean regions where water mass circulation is <del class="diffchange diffchange-inline">minimal</del>. However, most severe dead zones occur as a result of anthropogenic eutrophication of stratified water masses. Stratification is mainly caused by temperature-induced density differences between surface waters and deeper waters in the ocean; stratification in estuaries and coastal waters is mainly due to the salinity-induced density difference between seawater and river water. When an algal bloom in the surface layer decays, the deeper water layers become laden with sinking dead algae that <del class="diffchange diffchange-inline">consume </del>oxygen <del class="diffchange diffchange-inline">while decomposing</del>. Stratification inhibits turbulent mixing of the oxygen-rich surface layer into the underlying water layer that therefore becomes depleted from oxygen.  </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Zones with extreme hypoxia are called [https://en.wikipedia.org/wiki/Dead_zone_(ecology) dead zones]. Upwelling of nutrient-rich waters may produce 'natural' dead zones in some ocean regions where water mass circulation is <ins class="diffchange diffchange-inline">weak. These so-called 'oxygen minimum zones' occur below the photic zone, between about 200 - 1500 m depth, and are related to microbial mineralization of sinking organic material<ref name=BG>Breitburg, D., Gregoire, M. Isensee, K. (eds.) 2018. The ocean is losing its breath: Declining oxygen in the world’s ocean and coastal waters. IOC-UNESCO, IOC Technical Series, No. 137 40pp. (IOC/2018/TS/137)</ref></ins>. However, most severe dead zones occur as a result of anthropogenic eutrophication of stratified water masses. Stratification is mainly caused by temperature-induced density differences between surface waters and deeper waters in the ocean; stratification in estuaries and coastal waters is mainly due to the salinity-induced density difference between seawater and river water. When an algal bloom in the surface layer decays, the deeper water layers become laden with sinking dead algae that <ins class="diffchange diffchange-inline">are decomposed by </ins>oxygen <ins class="diffchange diffchange-inline">consuming bacteria</ins>. Stratification inhibits turbulent mixing of the oxygen-rich surface layer into the underlying water layer that therefore becomes depleted from oxygen.  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[File:OceanHypoxia.jpg|thumb|500px|left|<small>Fig. 3. Areas with hypoxia in coastal seas (red) and in the oceans (blue). From IOC-UNESCO 2018<ref name=BG<del class="diffchange diffchange-inline">>Breitburg, D., Gregoire, M. Isensee, K. (eds.) 2018. The ocean is losing its breath: Declining oxygen in the world’s ocean and coastal waters. IOC-UNESCO, IOC Technical Series, No. 137 40pp. (IOC</del>/<del class="diffchange diffchange-inline">2018/TS/137)</ref</del>> Creative Commons Licence.</small>]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[File:OceanHypoxia.jpg|thumb|500px|left|<small>Fig. 3. Areas with hypoxia in coastal seas (red) and in the oceans (blue). From IOC-UNESCO 2018<ref name=BG/> Creative Commons Licence.</small>]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Fig. 3 shows a map of coastal and ocean regions with frequently occurring hypoxia. The largest and most persistent dead zones are situated in the Baltic Sea, the Black Sea, the Arabian Sea and the Gulf of Mexico. The size of dead zones decreases during severe storms when strong wind-driven turbulent water motion partially neutralizes stratification.</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>Fig. 3 shows a map of coastal and ocean regions with frequently occurring hypoxia. The largest and most persistent dead zones are situated in the Baltic Sea, the Black Sea, the Arabian Sea and the Gulf of Mexico. The size of dead zones decreases during severe storms when strong wind-driven turbulent water motion partially neutralizes stratification.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Climate change is expected to worsen oxygen depletion in the ocean and coastal waters by increasing surface <del class="diffchange diffchange-inline">temperatures </del>and stratification<ref> Li, G., Cheng, L., Zhu, J., Trenberth, K.E., Mann, M.E. and Abraham, J.P. 2020. Increasing ocean stratification over the past half-century. Nature Climate Change https://doi.org/10.1038/s41558-020-00918-2</ref><del class="diffchange diffchange-inline">; in </del>turn, ocean oxygen depletion can contribute to climate change by increased microbial denitrification with production of the greenhouse gas NO<sub>2</sub><ref name=BG/>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Climate change is expected to worsen oxygen depletion in the ocean and coastal waters by increasing <ins class="diffchange diffchange-inline">nutrient supply<ref>Baroni, I.R., Palastanga, V. and Slomp, C. P. 2020. Enhanced Organic</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">Carbon Burial in Sediments of Oxygen Minimum Zones Upon Ocean Deoxygenation. Front. Mar. Sci. 6: 839</ref> and increasing ocean </ins>surface <ins class="diffchange diffchange-inline">temperature </ins>and stratification<ref>Li, G., Cheng, L., Zhu, J., Trenberth, K.E., Mann, M.E. and Abraham, J.P. 2020. Increasing ocean stratification over the past half-century. Nature Climate Change https://doi.org/10.1038/s41558-020-00918-2</ref><ins class="diffchange diffchange-inline">. In </ins>turn, ocean oxygen depletion can contribute to climate change by increased microbial denitrification with production of the greenhouse gas NO<sub>2</sub><ref name=BG/>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br clear=all></div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div><br clear=all></div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Species biodiversity decreases and the dominant biota changes===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Species biodiversity decreases and the dominant biota changes===</div></td></tr>
<tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l105" >Line 105:</td>
<td colspan="2" class="diff-lineno">Line 106:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Harmful algal bloom]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Harmful algal bloom]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Algal bloom dynamics]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Algal bloom dynamics]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:[[What causes eutrophication?<del class="diffchange diffchange-inline">]]</del></div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:[[ What causes eutrophication?]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div><del class="diffchange diffchange-inline">:[[Nutrient conversion in the marine environment</del>]]</div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Threats to the coastal zone]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Threats to the coastal zone]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Estuarine turbidity maximum]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Estuarine turbidity maximum]]</div></td></tr>
<!-- diff cache key wiki:diff::1.12:old-78638:rev-78688 -->
</table>Dronkers Jhttps://www.coastalwiki.org/w/index.php?title=Possible_consequences_of_eutrophication&diff=78638&oldid=prevDronkers J at 12:31, 4 February 20212021-02-04T12:31:24Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 12:31, 4 February 2021</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l105" >Line 105:</td>
<td colspan="2" class="diff-lineno">Line 105:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Harmful algal bloom]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Harmful algal bloom]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Algal bloom dynamics]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Algal bloom dynamics]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>:[[ What causes eutrophication?]]</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>:[[What causes eutrophication?<ins class="diffchange diffchange-inline">]]</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">:[[Nutrient conversion in the marine environment</ins>]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Threats to the coastal zone]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Threats to the coastal zone]]</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Estuarine turbidity maximum]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>:[[Estuarine turbidity maximum]]</div></td></tr>
<!-- diff cache key wiki:diff::1.12:old-78617:rev-78638 -->
</table>Dronkers Jhttps://www.coastalwiki.org/w/index.php?title=Possible_consequences_of_eutrophication&diff=78617&oldid=prevDronkers J at 14:21, 31 January 20212021-01-31T14:21:49Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 14:21, 31 January 2021</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l19" >Line 19:</td>
<td colspan="2" class="diff-lineno">Line 19:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>For more details on toxic algal blooms, see the article [[Harmful algal bloom]].</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>For more details on toxic algal blooms, see the article [[Harmful algal bloom]].</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Increased blooms of gelatinous zooplankton===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Increased blooms of gelatinous zooplankton===</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[Phytoplankton]] are the food source for numerous other organisms, especially the zooplankton. [[Zooplankton]] are heterotrophic plankton. They are primarily transported by ambient water currents but many can swim. Through their consumption and processing of phytoplankton and other food sources they play a role in aquatic food webs as a resource for higher trophic levels including fish. Zooplankton can be divided in two important groups: crustacean (copepods and krill) and <del class="diffchange diffchange-inline">[https://en.wikipedia.org/wiki/Gelatinous_zooplankton </del>gelatinous zooplankton<del class="diffchange diffchange-inline">]</del>. Gelatinous zooplankton have relatively fragile, plastic gelatinous bodies that contain at least 95% water and which lack rigid skeletal parts. The most well-known are the jellyfish. There is some evidence that gelatinous zooplankton organisms increase in relative importance versus crustacean zooplankton in areas where the natural species diversity has been affected by pollution, over-fishing and climate change<ref> Condon, R.H., Duarte, C.M., Pitt, K.A., Robinson, K.L., Lucas, C.H., Sutherland, K.R., Mianzan, H.W., Bogeberg, M., Purcell, J.E., Decker, M.B., Uye, S.-I., Madin, L.P., Brodeur, R.D., Haddock, S.H.D., Malej, A., Parry, G.D., Eriksen, E., Quiñones, J., Acha, M., Harvey, M., Arthur, J.M. and Graham W.M. 2013. Recurrent jellyfish blooms are a consequence of global oscillations. PNAS 110: 1000-1005</ref>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[Phytoplankton]] are the food source for numerous other organisms, especially the zooplankton. [[Zooplankton]] are heterotrophic plankton. They are primarily transported by ambient water currents but many can swim. Through their consumption and processing of phytoplankton and other food sources they play a role in aquatic food webs as a resource for higher trophic levels including fish. Zooplankton can be divided in two important groups: crustacean (copepods and krill) and <ins class="diffchange diffchange-inline">'''</ins>gelatinous zooplankton<ins class="diffchange diffchange-inline">'''</ins>. Gelatinous zooplankton have relatively fragile, plastic gelatinous bodies that contain at least 95% water and which lack rigid skeletal parts. The most well-known are the jellyfish. There is some evidence that gelatinous zooplankton organisms increase in relative importance versus crustacean zooplankton in areas where the natural species diversity has been affected by pollution, over-fishing and climate change<ref> Condon, R.H., Duarte, C.M., Pitt, K.A., Robinson, K.L., Lucas, C.H., Sutherland, K.R., Mianzan, H.W., Bogeberg, M., Purcell, J.E., Decker, M.B., Uye, S.-I., Madin, L.P., Brodeur, R.D., Haddock, S.H.D., Malej, A., Parry, G.D., Eriksen, E., Quiñones, J., Acha, M., Harvey, M., Arthur, J.M. and Graham W.M. 2013. Recurrent jellyfish blooms are a consequence of global oscillations. PNAS 110: 1000-1005</ref>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Decreases in water transparency (increased turbidity)===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Decreases in water transparency (increased turbidity)===</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The growth of phytoplankton causes increased [[Turbidity|turbidity]] or decreased penetration of light into the lower depths of the water column. In lakes and rivers this can inhibit growth of submerged aquatic plants and affect species which are dependent on them (fish, shellfish)<del class="diffchange diffchange-inline"><ref>Chislock, M. F., Doster, E., Zitomer, R. A. and Wilson, A. E. 2013. Eutrophication: Causes, Consequences, and Controls in Aquatic Ecosystems. Nature Education Knowledge 4(4):10</ref></del>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The growth of phytoplankton causes increased [[Turbidity|turbidity]] or decreased penetration of light into the lower depths of the water column. In lakes and rivers this can inhibit growth of submerged aquatic plants and affect species which are dependent on them (fish, shellfish).</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dissolved oxygen depletion or hypoxia===  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dissolved oxygen depletion or hypoxia===  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:FishKill.jpg|250px|thumb|right|<small>Fig. 2. Fish kill (menhaden) due to severe hypoxia (Photo credit: Chris Deacutis, IAN Image library )</small>]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:FishKill.jpg|250px|thumb|right|<small>Fig. 2. Fish kill (menhaden) due to severe hypoxia (Photo credit: Chris Deacutis, IAN Image library )</small>]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Oxygen is required for all life forms on the planet. Oxygen is produced by plants during [[photosynthesis]]. At night animals and plants, as well as aerobic micro-organisms respire and so consume oxygen which results in a decrease in dissolved oxygen levels. [[Algal bloom]]s may cause strong fluctuations in dissolved oxygen levels<del class="diffchange diffchange-inline"><ref>Odum, H.T. 1956. Primary production in flowing waters. Limnol Oceanogr 1: 102–117</ref></del>. When the algae population is growing at a fast rate, it may block sunlight from reaching other organisms and cause a decrease of dissolved oxygen levels. When algae die, they are decomposed by bacteria which in this process consume oxygen so that the water can become temporarily hypoxic. Oxygen depletion, or [[Hypoxia|hypoxia]]<del class="diffchange diffchange-inline">, which often co-occurs with other stressors such as hydrogen sulfide and elevated temperature</del>, is a common consequence of eutrophication, both in fresh water and seawater<del class="diffchange diffchange-inline">. Hypoxia primarily affects the benthic fauna and bottom-dwelling fishes, which as are consequently more severely impacted than species inhabiting the upper water column</del>. The <del class="diffchange diffchange-inline">effect </del>of hypoxia <del class="diffchange diffchange-inline">on sessile benthic organisms is often lethal</del>, <del class="diffchange diffchange-inline">but also for </del>fish that need high levels of dissolved oxygen<del class="diffchange diffchange-inline"><ref>Vaquer-Sunyer, R., Duarte, C.M. 2008. Thresholds of hypoxia for marine biodiversity. Proc. Natl. Acad. Sci. U. S. A. 105: 15452–15457</ref> </del>(Fig. 2). <del class="diffchange diffchange-inline">For other organisms, effects are often sub-lethal and include a reduction in growth and reproduction, physiological stress and a forced migration to more suitable habitats. When the oxygen level is restored, recovery of the impacted benthic area can occur, either through migration or larval settlement, with the recolonization time depending on the frequency and intensity of hypoxia events<ref name=L9>Levin, L.A., Ekau, W., Gooday, A.J., Jorissen, F., Middelburg, J.J., Naqvi, S.W.A., Neira, C., Rabalais, N.N., Zhang, J. 2009. Effects of natural and human-induced hypoxia on coastal benthos. Biogeosciences 6: 2063–2098</ref>. </del>There is some evidence that hypoxic conditions promote the growth of cyanobacteria as a consequence of enhanced phosphorus release<ref>Funkey, C.P., Conley, D.J., Reuss, N.S., Humborg, C, Jilbert, T. and Slomp, C.P. 2014. Hypoxia Sustains Cyanobacteria Blooms in the Baltic Sea. Environ. Sci. Technol. 48: 2598−2602</ref>. Many cyanobacteria species produce toxins that are lethal to birds and animals.  </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Oxygen is required for all life forms on the planet. Oxygen is produced by plants during [[photosynthesis]]. At night animals and plants, as well as aerobic micro-organisms respire and so consume oxygen which results in a decrease in dissolved oxygen levels. [[Algal bloom]]s may cause strong fluctuations in dissolved oxygen levels. When the algae population is growing at a fast rate, it may block sunlight from reaching other organisms and cause a decrease of dissolved oxygen levels. When algae die, they are decomposed by bacteria which in this process consume oxygen so that the water can become temporarily hypoxic. Oxygen depletion, or [[Hypoxia|hypoxia]], is a common consequence of eutrophication, both in fresh water and seawater. The <ins class="diffchange diffchange-inline">'''direct effects''' </ins>of hypoxia <ins class="diffchange diffchange-inline">include '''fish kills'''</ins>, <ins class="diffchange diffchange-inline">especially the death of </ins>fish that need high levels of dissolved oxygen (Fig. 2).  </div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>There is some evidence that hypoxic conditions promote the growth of cyanobacteria as a consequence of enhanced phosphorus release<ref>Funkey, C.P., Conley, D.J., Reuss, N.S., Humborg, C, Jilbert, T. and Slomp, C.P. 2014. Hypoxia Sustains Cyanobacteria Blooms in the Baltic Sea. Environ. Sci. Technol. 48: 2598−2602</ref>. Many cyanobacteria species produce toxins that are lethal to birds and animals<ins class="diffchange diffchange-inline">.</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">===Eutrophication-driven acidification===</ins></div></td></tr>
<tr><td colspan="2"> </td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins class="diffchange diffchange-inline">The respiration of bacteria that decompose dead algae not only causes hypoxia due to oxygen consumption, but also produces CO<sub>2</sub> and thus causes an increase in the carbonic acid content of the water. A sharp increase in acidity (pH even below 7) has been observed in highly eutrophic estuaries and lagoons along the east coast of the US, coinciding with hypoxia<ref>Wallace, R.B., Baumann, H., Grear, J.S., Aller, R.C. and Gobler, C.J. 2014. Coastal ocean acidification: The other eutrophication problem. Estuarine, Coastal and Shelf Science 148: 1-13</ref>. Acidification is an annual feature of these estuaries during summer when algae decay and oxygen depletes. Lowest pH levels (undersaturated with respect to aragonite) occur near the bottom, especially in poorly flushed stratified systems. This poses a serious threat to calcifying benthic organisms, for example scallops and other bivalves that spawn in mid-to-late summer</ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dead zones===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dead zones===</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Zones with extreme hypoxia are called [https://en.wikipedia.org/wiki/Dead_zone_(ecology) dead zones]. Upwelling of nutrient-rich waters may produce 'natural' dead zones in some ocean regions where water mass circulation is minimal. However, most severe dead zones occur as a result of anthropogenic eutrophication of stratified water masses. Stratification is mainly caused by temperature-induced density differences between surface waters and deeper waters in the ocean; stratification in estuaries and coastal waters is mainly due to the salinity-induced density difference between seawater and river water <del class="diffchange diffchange-inline">(see the article [[Seawater density]])</del>. When an algal bloom in the surface layer decays, the deeper water layers become laden with sinking dead algae that consume oxygen while decomposing. Stratification inhibits turbulent mixing of the oxygen-rich surface layer into the underlying water layer that therefore becomes depleted from oxygen.  </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Zones with extreme hypoxia are called [https://en.wikipedia.org/wiki/Dead_zone_(ecology) dead zones]. Upwelling of nutrient-rich waters may produce 'natural' dead zones in some ocean regions where water mass circulation is minimal. However, most severe dead zones occur as a result of anthropogenic eutrophication of stratified water masses. Stratification is mainly caused by temperature-induced density differences between surface waters and deeper waters in the ocean; stratification in estuaries and coastal waters is mainly due to the salinity-induced density difference between seawater and river water. When an algal bloom in the surface layer decays, the deeper water layers become laden with sinking dead algae that consume oxygen while decomposing. Stratification inhibits turbulent mixing of the oxygen-rich surface layer into the underlying water layer that therefore becomes depleted from oxygen.  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<!-- diff cache key wiki:diff::1.12:old-78550:rev-78617 -->
</table>Dronkers Jhttps://www.coastalwiki.org/w/index.php?title=Possible_consequences_of_eutrophication&diff=78550&oldid=prevDronkers J at 15:18, 2 January 20212021-01-02T15:18:03Z<p></p>
<table class="diff diff-contentalign-left" data-mw="interface">
<col class="diff-marker" />
<col class="diff-content" />
<col class="diff-marker" />
<col class="diff-content" />
<tr class="diff-title" lang="en">
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">← Older revision</td>
<td colspan="2" style="background-color: #fff; color: #222; text-align: center;">Revision as of 15:18, 2 January 2021</td>
</tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l19" >Line 19:</td>
<td colspan="2" class="diff-lineno">Line 19:</td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>For more details on toxic algal blooms, see the article [[Harmful algal bloom]].</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>For more details on toxic algal blooms, see the article [[Harmful algal bloom]].</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Increased blooms of gelatinous zooplankton===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Increased blooms of gelatinous zooplankton===</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>[[Phytoplankton]] are the food source for numerous other organisms, especially the zooplankton. [[Zooplankton]] are heterotrophic plankton. They are primarily transported by ambient water currents but many can swim. Through their consumption and processing of phytoplankton and other food sources they play a role in aquatic food webs as a resource for higher trophic levels including fish. Zooplankton can be divided in two important groups: crustacean (copepods and krill) and <del class="diffchange diffchange-inline">'''</del>gelatinous zooplankton<del class="diffchange diffchange-inline">'''</del>. Gelatinous zooplankton have relatively fragile, plastic gelatinous bodies that contain at least 95% water and which lack rigid skeletal parts. The most well-known are the jellyfish. There is some evidence that gelatinous zooplankton organisms increase in relative importance versus crustacean zooplankton in areas where the natural species diversity has been affected by pollution, over-fishing and climate change<ref> Condon, R.H., Duarte, C.M., Pitt, K.A., Robinson, K.L., Lucas, C.H., Sutherland, K.R., Mianzan, H.W., Bogeberg, M., Purcell, J.E., Decker, M.B., Uye, S.-I., Madin, L.P., Brodeur, R.D., Haddock, S.H.D., Malej, A., Parry, G.D., Eriksen, E., Quiñones, J., Acha, M., Harvey, M., Arthur, J.M. and Graham W.M. 2013. Recurrent jellyfish blooms are a consequence of global oscillations. PNAS 110: 1000-1005</ref>.</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>[[Phytoplankton]] are the food source for numerous other organisms, especially the zooplankton. [[Zooplankton]] are heterotrophic plankton. They are primarily transported by ambient water currents but many can swim. Through their consumption and processing of phytoplankton and other food sources they play a role in aquatic food webs as a resource for higher trophic levels including fish. Zooplankton can be divided in two important groups: crustacean (copepods and krill) and <ins class="diffchange diffchange-inline">[https://en.wikipedia.org/wiki/Gelatinous_zooplankton </ins>gelatinous zooplankton<ins class="diffchange diffchange-inline">]</ins>. Gelatinous zooplankton have relatively fragile, plastic gelatinous bodies that contain at least 95% water and which lack rigid skeletal parts. The most well-known are the jellyfish. There is some evidence that gelatinous zooplankton organisms increase in relative importance versus crustacean zooplankton in areas where the natural species diversity has been affected by pollution, over-fishing and climate change<ref> Condon, R.H., Duarte, C.M., Pitt, K.A., Robinson, K.L., Lucas, C.H., Sutherland, K.R., Mianzan, H.W., Bogeberg, M., Purcell, J.E., Decker, M.B., Uye, S.-I., Madin, L.P., Brodeur, R.D., Haddock, S.H.D., Malej, A., Parry, G.D., Eriksen, E., Quiñones, J., Acha, M., Harvey, M., Arthur, J.M. and Graham W.M. 2013. Recurrent jellyfish blooms are a consequence of global oscillations. PNAS 110: 1000-1005</ref>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Decreases in water transparency (increased turbidity)===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Decreases in water transparency (increased turbidity)===</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>The growth of phytoplankton causes increased [[Turbidity|turbidity]] or decreased penetration of light into the lower depths of the water column. In lakes and rivers this can inhibit growth of submerged aquatic plants and affect species which are dependent on them (fish, shellfish).</div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>The growth of phytoplankton causes increased [[Turbidity|turbidity]] or decreased penetration of light into the lower depths of the water column. In lakes and rivers this can inhibit growth of submerged aquatic plants and affect species which are dependent on them (fish, shellfish)<ins class="diffchange diffchange-inline"><ref>Chislock, M. F., Doster, E., Zitomer, R. A. and Wilson, A. E. 2013. Eutrophication: Causes, Consequences, and Controls in Aquatic Ecosystems. Nature Education Knowledge 4(4):10</ref></ins>.</div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dissolved oxygen depletion or hypoxia===  </div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dissolved oxygen depletion or hypoxia===  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:FishKill.jpg|250px|thumb|right|<small>Fig. 2. Fish kill (menhaden) due to severe hypoxia (Photo credit: Chris Deacutis, IAN Image library )</small>]]</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[File:FishKill.jpg|250px|thumb|right|<small>Fig. 2. Fish kill (menhaden) due to severe hypoxia (Photo credit: Chris Deacutis, IAN Image library )</small>]]</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Oxygen is required for all life forms on the planet. Oxygen is produced by plants during [[photosynthesis]]. At night animals and plants, as well as aerobic micro-organisms respire and so consume oxygen which results in a decrease in dissolved oxygen levels. [[Algal bloom]]s may cause strong fluctuations in dissolved oxygen levels. When the algae population is growing at a fast rate, it may block sunlight from reaching other organisms and cause a decrease of dissolved oxygen levels. When algae die, they are decomposed by bacteria which in this process consume oxygen so that the water can become temporarily hypoxic. Oxygen depletion, or [[Hypoxia|hypoxia]], is a common consequence of eutrophication, both in fresh water and seawater. The <del class="diffchange diffchange-inline">'''direct effects''' </del>of hypoxia <del class="diffchange diffchange-inline">include '''fish kills'''</del>, <del class="diffchange diffchange-inline">especially the death of </del>fish that need high levels of dissolved oxygen (Fig. 2).  </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Oxygen is required for all life forms on the planet. Oxygen is produced by plants during [[photosynthesis]]. At night animals and plants, as well as aerobic micro-organisms respire and so consume oxygen which results in a decrease in dissolved oxygen levels. [[Algal bloom]]s may cause strong fluctuations in dissolved oxygen levels<ins class="diffchange diffchange-inline"><ref>Odum, H.T. 1956. Primary production in flowing waters. Limnol Oceanogr 1: 102–117</ref></ins>. When the algae population is growing at a fast rate, it may block sunlight from reaching other organisms and cause a decrease of dissolved oxygen levels. When algae die, they are decomposed by bacteria which in this process consume oxygen so that the water can become temporarily hypoxic. Oxygen depletion, or [[Hypoxia|hypoxia]]<ins class="diffchange diffchange-inline">, which often co-occurs with other stressors such as hydrogen sulfide and elevated temperature</ins>, is a common consequence of eutrophication, both in fresh water and seawater<ins class="diffchange diffchange-inline">. Hypoxia primarily affects the benthic fauna and bottom-dwelling fishes, which as are consequently more severely impacted than species inhabiting the upper water column</ins>. The <ins class="diffchange diffchange-inline">effect </ins>of hypoxia <ins class="diffchange diffchange-inline">on sessile benthic organisms is often lethal</ins>, <ins class="diffchange diffchange-inline">but also for </ins>fish that need high levels of dissolved oxygen<ins class="diffchange diffchange-inline"><ref>Vaquer-Sunyer, R., Duarte, C.M. 2008. Thresholds of hypoxia for marine biodiversity. Proc. Natl. Acad. Sci. U. S. A. 105: 15452–15457</ref> </ins>(Fig. 2). <ins class="diffchange diffchange-inline">For other organisms, effects are often sub-lethal and include a reduction in growth and reproduction, physiological stress and a forced migration to more suitable habitats. When the oxygen level is restored, recovery of the impacted benthic area can occur, either through migration or larval settlement, with the recolonization time depending on the frequency and intensity of hypoxia events<ref name=L9>Levin, L.A., Ekau, W., Gooday, A.J., Jorissen, F., Middelburg, J.J., Naqvi, S.W.A., Neira, C., Rabalais, N.N., Zhang, J. 2009. Effects of natural and human-induced hypoxia on coastal benthos. Biogeosciences 6: 2063–2098</ref>. </ins>There is some evidence that hypoxic conditions promote the growth of cyanobacteria as a consequence of enhanced phosphorus release<ref>Funkey, C.P., Conley, D.J., Reuss, N.S., Humborg, C, Jilbert, T. and Slomp, C.P. 2014. Hypoxia Sustains Cyanobacteria Blooms in the Baltic Sea. Environ. Sci. Technol. 48: 2598−2602</ref>. Many cyanobacteria species produce toxins that are lethal to birds and animals.  </div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>There is some evidence that hypoxic conditions promote the growth of cyanobacteria as a consequence of enhanced phosphorus release<ref>Funkey, C.P., Conley, D.J., Reuss, N.S., Humborg, C, Jilbert, T. and Slomp, C.P. 2014. Hypoxia Sustains Cyanobacteria Blooms in the Baltic Sea. Environ. Sci. Technol. 48: 2598−2602</ref>. Many cyanobacteria species produce toxins that are lethal to birds and animals.</div></td><td colspan="2"> </td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dead zones===</div></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>===Dead zones===</div></td></tr>
<tr><td class='diff-marker'>−</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;"><div>Zones with extreme hypoxia are called [https://en.wikipedia.org/wiki/Dead_zone_(ecology) dead zones]. Upwelling of nutrient-rich waters may produce 'natural' dead zones in some ocean regions where water mass circulation is minimal. However, most severe dead zones occur as a result of anthropogenic eutrophication of stratified water masses. Stratification is mainly caused by temperature-induced density differences between surface waters and deeper waters in the ocean; stratification in estuaries and coastal waters is mainly due to the salinity-induced density difference between seawater and river water. When an algal bloom in the surface layer decays, the deeper water layers become laden with sinking dead algae that consume oxygen while decomposing. Stratification inhibits turbulent mixing of the oxygen-rich surface layer into the underlying water layer that therefore becomes depleted from oxygen.  </div></td><td class='diff-marker'>+</td><td style="color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div>Zones with extreme hypoxia are called [https://en.wikipedia.org/wiki/Dead_zone_(ecology) dead zones]. Upwelling of nutrient-rich waters may produce 'natural' dead zones in some ocean regions where water mass circulation is minimal. However, most severe dead zones occur as a result of anthropogenic eutrophication of stratified water masses. Stratification is mainly caused by temperature-induced density differences between surface waters and deeper waters in the ocean; stratification in estuaries and coastal waters is mainly due to the salinity-induced density difference between seawater and river water <ins class="diffchange diffchange-inline">(see the article [[Seawater density]])</ins>. When an algal bloom in the surface layer decays, the deeper water layers become laden with sinking dead algae that consume oxygen while decomposing. Stratification inhibits turbulent mixing of the oxygen-rich surface layer into the underlying water layer that therefore becomes depleted from oxygen.  </div></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<tr><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td><td class='diff-marker'> </td><td style="background-color: #f8f9fa; color: #222; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"></td></tr>
<!-- diff cache key wiki:diff::1.12:old-78352:rev-78550 -->
</table>Dronkers J