BENTHIC AMPHIPOD COMMUNITY IN THE NORTHERN BERING SEA - ANALYSIS OF POTENTIAL STRUCTURING MECHANISMS

Citation
Ko. Coyle et Rc. Highsmith, BENTHIC AMPHIPOD COMMUNITY IN THE NORTHERN BERING SEA - ANALYSIS OF POTENTIAL STRUCTURING MECHANISMS, Marine ecology. Progress series, 107(3), 1994, pp. 233-244
Citations number
36
Categorie Soggetti
Marine & Freshwater Biology",Ecology
ISSN journal
01718630
Volume
107
Issue
3
Year of publication
1994
Pages
233 - 244
Database
ISI
SICI code
0171-8630(1994)107:3<233:BACITN>2.0.ZU;2-1
Abstract
The age class structure of ampeliscid populations is determined largel y by competition for space. Population densities of the various ampeli scid species are regulated by a balance between required carbon flux r ates to the seafloor, predation rates, competition for space and repro ductive potential. The largest taxa require high organic matter input and low predation rates to mature and reproduce. Reductions in organic matter flux favor smaller taxa. Low predation rates favor larger taxa , which can out-compete the smaller taxa for available space. High pre dation rates favor smaller taxa, which have a higher reproductive rate and are therefore more effective colonizers. The above factors can ex plain the relative concentrations of Ampelisca macrocephala, Ampelisca birulai and Byblis spp., the most abundant ampeliscids in the norther n Bering Sea. Elevated predation losses to gray whales will depress th e density of the large-sized A. macrocephala populations and increase the density of the smallest species, A. birulai. Global warming should elevate ampeliscid food requirements, and may also lead to elevated p redation rates, both selecting for smaller species.