Difference between revisions of "Dynamics, threats and management of biogenic reefs"
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====''Environmental Requirements ==== | ====''Environmental Requirements ==== | ||
| − | ''S.spinulosa'' is thought to require stable foundations on which to settle and establish a tube (Jackson, 1977; Wood, 1999; Chisholm and Kelley, 2001) and is thus likely to favour substrata which include bedrock; boulders, cobbles, mixed substrata; and mixed sediment (Connor et al., 1997). Although it is assumed that a firm substratum is required for colony establishment, it has been suggested that a reef can | + | ''S.spinulosa'' is thought to require stable foundations on which to settle and establish a tube (Jackson, 1977; Wood, 1999; Chisholm and Kelley, 2001) and is thus likely to favour substrata which include bedrock; boulders, cobbles, mixed substrata; and mixed sediment (Connor et al., 1997). Although it is assumed that a firm substratum is required for colony establishment, it has been suggested that a reef can increase in extent without the need for hard substratum (Holt ''et al.'', 1997). Many studies have reported extensive colonies in predominantly sandy areas (Warren & Sheldon 1967; Schäfer, 1972; Warren, 1973; Limpenny et al., 2010). Recent observations from The Wash, England show that ''S. spinulosa'' had ‘seeded’ on shell fragments predominantly from blue or horse mussels (Ian Reach, Natural England, pers. comm.). |
As ''S. spinulosa'' is a sedentary species, it relies on wave and current action to supply food and wash away waste products (Kirtley, 1992). Strong water movement is required for food provisions, but is perhaps more important to raise sediment into suspension for tube building (Jones, 1999). As a result, ''S. spinulosa'' colonies are typically located in areas of weak to moderately strong water flow (Jones ''et al.'', 2000). It also appears to favour locations around the edges of sand banks or areas with sand waves (Foster‐Smith, 2001a). S. spinulosa typically occurs subtidally in depths of a few meters to up to 40 m depth (Caspers, 1950; George & Warwick, 1985; Connor ''et al''., 1997; Jessop & Stoutt, 2006), but can occur in depths up to 600 m (Hartmann-Schröder, 1971). S. spinulosa occasionally occurs in the lower intertidal zone (Jessop & Stoutt, 2006). | As ''S. spinulosa'' is a sedentary species, it relies on wave and current action to supply food and wash away waste products (Kirtley, 1992). Strong water movement is required for food provisions, but is perhaps more important to raise sediment into suspension for tube building (Jones, 1999). As a result, ''S. spinulosa'' colonies are typically located in areas of weak to moderately strong water flow (Jones ''et al.'', 2000). It also appears to favour locations around the edges of sand banks or areas with sand waves (Foster‐Smith, 2001a). S. spinulosa typically occurs subtidally in depths of a few meters to up to 40 m depth (Caspers, 1950; George & Warwick, 1985; Connor ''et al''., 1997; Jessop & Stoutt, 2006), but can occur in depths up to 600 m (Hartmann-Schröder, 1971). S. spinulosa occasionally occurs in the lower intertidal zone (Jessop & Stoutt, 2006). | ||
Revision as of 15:29, 17 July 2012
UNDER CONSTRUCTION
Contents
- 1 PROCESSES AND MECHANISMS DRIVING NATURAL DYNAMICS & ECOSYSTEM DEVELOPMENT
- 2 VULNERABILITY & THREATS
- 3 SEE ALSO
- 4 REFERENCES
PROCESSES AND MECHANISMS DRIVING NATURAL DYNAMICS & ECOSYSTEM DEVELOPMENT
In this section, the processes and mechanisms driving natural dynamics and ecosystem development of biogenic reefs are discussed for each group in turn: Sabellaria spinulosa, Sabellaria alveolata, Mytilus spp. and Modiolus modiolus.
Sabellaria spinulosa
Environmental Requirements
S.spinulosa is thought to require stable foundations on which to settle and establish a tube (Jackson, 1977; Wood, 1999; Chisholm and Kelley, 2001) and is thus likely to favour substrata which include bedrock; boulders, cobbles, mixed substrata; and mixed sediment (Connor et al., 1997). Although it is assumed that a firm substratum is required for colony establishment, it has been suggested that a reef can increase in extent without the need for hard substratum (Holt et al., 1997). Many studies have reported extensive colonies in predominantly sandy areas (Warren & Sheldon 1967; Schäfer, 1972; Warren, 1973; Limpenny et al., 2010). Recent observations from The Wash, England show that S. spinulosa had ‘seeded’ on shell fragments predominantly from blue or horse mussels (Ian Reach, Natural England, pers. comm.).
As S. spinulosa is a sedentary species, it relies on wave and current action to supply food and wash away waste products (Kirtley, 1992). Strong water movement is required for food provisions, but is perhaps more important to raise sediment into suspension for tube building (Jones, 1999). As a result, S. spinulosa colonies are typically located in areas of weak to moderately strong water flow (Jones et al., 2000). It also appears to favour locations around the edges of sand banks or areas with sand waves (Foster‐Smith, 2001a). S. spinulosa typically occurs subtidally in depths of a few meters to up to 40 m depth (Caspers, 1950; George & Warwick, 1985; Connor et al., 1997; Jessop & Stoutt, 2006), but can occur in depths up to 600 m (Hartmann-Schröder, 1971). S. spinulosa occasionally occurs in the lower intertidal zone (Jessop & Stoutt, 2006).
Reproduction and Development
Sabellaria alveolata
Environmental Requirements
Reproduction and Development
Mytilus spp.
Environmental Requirements
Reproduction and Development
Modiolus modiolus
Environmental Requirements
Reproduction and Development
VULNERABILITY & THREATS
GENERAL SUMMARY
Sabellaria spinulosa
Sabellaria alveolata
Modiolus modiolus
Mytilus spp.
NATURAL AND ANTHROPOGENIC THREAT
Sabellaria spinulosa
Physical threats
Chemical threats
Biological threats
Sabellaria alveolata
Physical threats
Chemical threats
Biological threats
Mytilus spp.
Physical threats
Chemical threats
Biological threats
Modiolus modiolus
Physical threats
Chemical threats
Biological threats
KEY PROCESSES TO FOCUS ON FOR MAINTAINING ECOSYSTEMS INTEGRITY
CURRENT MANAGEMENT PRACTICES
Sabellaria spinulosa
Sabellaria alveolata
Mytilus spp.
Modiolus modiolus
SEE ALSO
REFERENCES
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