| one publication added to basket [79565] | Does recruitment limitation structure populations and communities of macro-invertebrates in marine soft sediments: the relative significance of pre- and post-settlement processes
Ólafsson, E.B.; Peterson, C.H.; Ambrose Jr., W.G. (1994). Does recruitment limitation structure populations and communities of macro-invertebrates in marine soft sediments: the relative significance of pre- and post-settlement processes, in: Ansell, A.D. et al. Oceanogr. Mar. Biol. Ann. Rev. 32. Oceanography and Marine Biology: An Annual Review, 32: pp. 65-109 In: Ansell, A.D.; Gibson, R.N.; Barnes, M. (Ed.) (1994). Oceanogr. Mar. Biol. Ann. Rev. 32. Oceanography and Marine Biology: An Annual Review, 32. UCL Press: London. ISBN 1-85728-236-1. vi, 617 pp., more In: Oceanography and Marine Biology: An Annual Review. Aberdeen University Press/Allen & Unwin: London. ISSN 0078-3218; e-ISSN 2154-9125, more |  |
| Keywords | Biological settlement
Composition > Community composition
Population dynamics
Population functions > Recruitment
Marine/Coastal |
| Authors | | Top | - Ólafsson, E.B.
- Peterson, C.H.
- Ambrose Jr., W.G.
| | |
| Abstract | Debate over the relative importance of larval availability (recruitment limitation) compared with post-settlement processes, such as competition for limited resources, predation, and physical disturbance, in structuring populations and communities has characterized the literature on rocky intertidal organisms and coral reef fishes for the past decade. Here we apply this same question to marine soft-sediment systems in a synthetic review of all the major processes that may regulate population density and structure communities in this environment. A paradigm established by Gunnar Thorson over 40 years ago still appears to control the views of most soft-sediment ecologists on the importance of recruitment limitation. Thorson maintained that spatial and temporal variability in adult populations of soft-sediment invertebrates is created by the variability of successful completion of the risky planktonic life stage. He argued that the longer duration of planktonic life for planktotrophic species induces greater intrinsic variability in zygote survival, settlement rate, and adult population than is exhibited by lecithotrophic species and direct developers.A review of the literature relating population variability to reproductive mode in softsediment marine invertebrates does not provide compelling support for the hypothesis that planktotrophic species have more variable adult population sizes. Furthermore, abundant evidence exists to show that post-settlement mortality can operate to regulate density of invertebrates in soft sediments. Predation by large epibenthic consumers often appears to control infaunal abundances in shallow-water, unvegetated habitats, although hydrodynamic cage artefacts taint that conclusion. Density-dependent inhibition of recruitment by adult deposit-feeders and infaunal predators also has been commonly documented, in most cases operating after settlement. Even where inhibitory adult-juvenile interactions regulate settlement, the existence of this process is inconsistent with recruitment limitation in its strongest form because larval availability is not limiting. Physical disturbance of the sea floor has been shown to erode and kill small infaunal invertebrates, although the full implications of postsettlement sedimentary dynamics to pattern generation in soft sediments have not been determined. Finally, although food supply typically regulates benthic secondary production by affecting individual growth and fecundity of adult invertebrates, some evidence also implies density-dependent starvation of recent settlers. Consequently, sufficient information is available to show that post-settlement processes play a significant role in population regulation and community organization of soft-sediment benthos to conclude that recruitment limitation is not the dominant determinant of spatial and temporal pattern in this system. |
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