Date of Award

5-2009

Level of Access

Campus-Only Thesis

Degree Name

Master of Science (MS)

Department

Marine Biology

Advisor

Les Watling

Second Committee Member

James Wilson

Third Committee Member

James Acheson

Abstract

Fishing with mobile gear is the most common source of anthropogenic disturbance in marine systems, and can directly alter the biological structure of benthic communities, thereby changing functionality of the benthos. Consequently, the use of mobile fishing gear has the potential to cause ecosystem perturbation with a long-term impact on benthic communities. To address the question of how these communities change in the presence of different levels of anthropogenic disturbance as well as the extent of their recovery associated with the cessation of anthropogenic disturbance, we designed a four-year observational study (2001-2004) in the southern part of the Gulf of Maine. Infaunal communities associated with both fished and closed areas in the Stellwagen Bank National Marine Sanctuary (SBNMS) and Western Gulf of Maine Fishery Closure (WGoMFC) were sampled using a Smith-McIntyre grab. Epifaunal sampling was conducted using still-photographs and video imagery. Statistical analyses (Mann-Whitney U test; Kruskal-Wallace test) indicated a significant decrease in abundance of structure-forming organisms (tube builders: Maldanidae, Ampharetidae, and Terebellidae; Cucumaridae, Molgulidae, and Porifera) at fished sites. While sand infauna appeared to be more resilient to fishing disturbance than mud infauna, both mud and sand epifaunal community structure was statistically different between fished and unfished sites (MDS; ANOSIM analysis). Analysis of pulse disturbance associated with cable burial suggested a lack of observable long-term effects on epifaunal community structure.

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