SS1.10 Marine Protected Areas: Critical tools for Marine Biodiversity Conservation
Date: Monday, June 10, 2002
Time: 2:30:00 PM
Location: Esquimalt
 
DupliseaDE, Fisheries and Oceans Canada, Institut Maurice-Lamontagne, Mont-Joli, QC, Canada, duplisead@dfo-mpo.gc.ca
 
THE INFLUENCE OF HETEROGENEITY IN TRAWLING ACTIVITIES FOR BENTHIC COMMUNITY PERSISTENCE AND IMPLICATIONS FOR ESTABLISHING MPAS
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Experiments indicate that mortality of benthic organisms can be up to 80% for a single pass over the bottom of some mobile fishing gears. Analysis of fishing effort in some shelf areas such as the North Sea and Eastern Canada, indicates that on average the bottom can be dragged by mobile gears by up to ten times per year; however, benthic communities consisting of large, long-lived, yet sensitive (to mobile gear) organisms persist in these regions. This apparent paradox is reconciled when we consider the local spatial heterogeneity in fishing activities which leaves some areas of the bottom untouched. Small scale heterogeneity in fishing activity is probably an important mortality refuge for benthic communities affected by trawling activities. Management actions which lead to increasing homogeneity in fishing activity without concomitant decreases in fishing effort could lead to a more disturbed benthic community. Heterogeneity in and the amount of fishing effort should be considered when establishing marine protected areas for protection of benthic habitats from mobile fishing gear.