Difference between revisions of "Disturbances of nematodes"

From Coastal Wiki
Jump to: navigation, search
Line 48: Line 48:
[[Category:Coastal and marine ecosystems]]
[[Category:Coastal and marine ecosystems]]
[[Category:MarBEF Booklet]]
[[Category:MarBEF Booklet]]
[[Category: Marine biodiversity and ecosystem functioning]]

Latest revision as of 15:12, 3 August 2019

Nematode disturbances

Sediment movement, erosion and deposition are natural processes, and benthic organisms have adapted to such disturbances. Man-made physical disturbances (e.g., beam trawling, dredged material disposal, coastal development) occur at a much larger scale, rate and magnitude and may exceed the adaptive capacity of sediment-inhabiting organisms.

MarBEF researchers on the MANUELA project compiled and analysed an extensive database of experimental and observational studies to investigate the effects of physical disturbances in sediments on nematodes. [1]

Different disturbances in the same region

Some measures of diversity decreased with increasing level of disturbance regardless of the disturbance type. Others, however, were more variable and depended on the nature and origin of the disturbance. Hence, there is no consistent effect of physical disturbances on nematode assemblages. [1]

Similar disturbances in different regions

It was shown that man-induced changes are intrinsically different from those of natural origin. Nematode assemblages were more similar after being subjected to high-intensity disturbances, even if they originated from geographically distinct areas.

However, it is largely unknown whether nematodes respond in a similar way to the same disturbance, independently from the geographical location. MANUELA researchers mimicked the effect of an increased amount and frequency of rainfall (as predicted by climate change models) on sandy beaches from four different locations in Europe. Experimental beaches were located in Poland (Baltic Sea), Belgium (North Sea), Portugal (North East Atlantic Ocean) and Crete (Mediterranean Sea). Beaches covered a range of tidal regimes, salinity and temperature environments.

The frequent addition of freshwater to the Baltic beach did not affect salinity in the sand, due to the low natural salinity. All other beaches showed modified salinity profiles. All nematode assemblages changed significantly as a consequence of the experimental treatment but the underlying mechanisms were different. This shows that there is no universal response of nematode assemblages to disturbances and that changes occurring at a global scale will have different impacts in different localities.[1]

Further reading

Marbef booklet Marine Biodiversity Ecosystem Functioning