HISTORICAL ANALYSIS OF FISH IN COASTAL ECOSYSTEMS

Abstract

Fisheries have contributed to human well-being for centuries. Coastal ecosystems function as fish nurseries, thus adding to fisheries productivity. This thesis examines historical change of commercially important fish in coastal ecosystems. Firstly, I examine the impacts of extreme overfishing on coastal ecosystems by comparing coastal fish communities before and after the dramatic collapse of Atlantic cod. I found an overall shift in the community likely due to decreased predation by adult cod and fewer juveniles in coastal regions. Secondly, I have quantitatively compared historical abundances of juvenile commercially harvested fish in coastal vegetated habitats using various case studies. This second chapter addresses fish habitat management in Canada with a uniquely historical lens, specifically examining potential shortcomings with respect to recovery prospects. In light of these results, I discuss the connection of coastal ecosystems with commercial fisheries.