Publication Date

Fall 2017

Degree Type

Thesis

Degree Name

Master of Science (MS)

Department

Moss Landing Marine Laboratories

Advisor

Stacy Kim

Keywords

Antarctica, Benthic ecology, Community structure, Invertebrates, ROV, Seafloor

Subject Areas

Biology

Abstract

The Ross Sea, Antarctica is a deep bay of the Southern Ocean that exhibits seasonal sea ice and is adjacent to a permanent ice shelf overlying seawater. In 2008 and 2009, imagery of the seafloor under the McMurdo Ice Shelf and under the seasonal ice in the Ross Sea was collected via remotely operated vehicle (ROV) at depths to 300 m. Distinct differences in Antarctic benthic communities were observed over multiple environmental gradients. Species abundance typically exhibited a unimodal distribution with depth with mid-depth peaks, reflecting a food limitation at the deep end and potentially ice disturbance on the shallow end. Diversity and depth had a unimodal relationship at two of three sites encompassing a depth gradient. In terms of functional groups, the proportion of suspension feeders decreased with depth at one site, and no pattern was found at other sites. The group of sessile predators, comprised of several species of anemones, increased with depth proportionally, suggesting that they use a range of feeding strategies to adapt to life at depth. Benthic communities under seasonal ice were different than those under permanent ice shelves, with higher overall species diversity, a greater proportion of suspension feeders, and a degree of magnitude higher abundance.

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