当前位置： SCI文献检索 > ECOLOGY期刊下所有文献 > Trophic structure of coastal Antarctic food webs associated with changes in sea ice and food supply.

Trophic structure of coastal Antarctic food webs associated with changes in sea ice and food supply.

Abstract：

:Predicting the dynamics of ecosystems requires an understanding of how trophic interactions respond to environmental change. In Antarctic marine ecosystems, food web dynamics are inextricably linked to sea ice conditions that affect the nature and magnitude of primary food sources available to higher trophic levels. Recent attention on the changing sea ice conditions in polar seas highlights the need to better understand how marine food webs respond to changes in such broad-scale environmental drivers. This study investigated the importance of sea ice and advected primary food sources to the structure of benthic food webs in coastal Antarctica. We compared the isotopic composition of several seafloor taxa (including primary producers and invertebrates with a variety of feeding modes) that are widely distributed in the Antarctic. We assessed shifts in the trophic role of numerically dominant benthic omnivores at five coastal Ross Sea locations. These locations vary in primary productivity and food availability, due to their different levels of sea ice cover, and proximity to polynyas and advected primary production. The delta15N signatures and isotope mixing model results for the bivalves Laternula elliptica and Adamussium colbecki and the urchin Sterechinus neumeyeri indicate a shift from consumption of a higher proportion of detritus at locations with more permanent sea ice in the south to more freshly produced algal material associated with proximity to ice-free water in the north and east. The detrital pathways utilized by many benthic species may act to dampen the impacts of large seasonal fluctuations in the availability of primary production. The limiting relationship between sea ice distribution and in situ primary productivity emphasizes the role of connectivity and spatial subsidies of organic matter in fueling the food web. Our results begin to provide a basis for predicting how benthic ecosystems will respond to changes in sea ice persistence and extent along environmental gradients in the high Antarctic.

journal_name

Ecology

journal_title

Ecology

authors

Norkko A,Thrush SF,Cummings VJ,Gibbs MM,Andrew NL,Norkko J,Schwarz AM

doi

10.1890/06-1396.1

subject

Has Abstract

pub_date

2007-11-01 00:00:00

pages

2810-20

issue

eissn

0012-9658

issn

1939-9170

journal_volume

pub_type

杂志文章

在线工具

Trophic structure of coastal Antarctic food webs associated with changes in sea ice and food supply.