The Historical Abundance of Cod on the Nova Scotian Shelf
Only a generation ago marine scientists, fishery managers, and maritime historians shared the popular assumption that diminished fish stocks and damaged marine ecosystems were lamentable artifacts of the late twentieth century, of synthetic filaments, fis
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The Historical Abundance of Cod on the Nova Scotian Shelf W. Jeffrey Bolster, Karen E. Alexander, and William B. Leavenworth
Only a generation ago marine scientists, fishery managers, and maritime historians shared the popular assumption that diminished fish stocks and damaged marine ecosystems were lamentable artifacts of the late twentieth century, of synthetic filaments, fish finding sonar, and electronic navigational systems. It seemed highly unlikely that historic sailing fleets could have depleted naturally abundant fish populations with simple hooks, hemp line, and handmade nets. Times have changed. Recently scientists, historians, journalists, and fishery managers have come to the realization that, while destructive anthropogenic impacts on the ocean have accelerated dramatically since World War II, this phenomenon has deep roots, and deeper implications. As governments and NGOs grapple with the extent of the fisheries crisis and attempt to implement policies that promote restoration of degraded marine ecosystems, questions arise about the extent of the damage and about appropriate targets for rebuilding fish stocks. Just what constitutes a healthy marine ecosystem or a healthy population of a desirable species like cod? What sort of baseline populations existed at certain points in the past? What is the magnitude of current problems? Questions like these can only be answered by incorporating historical perspective.
J.B.C. Jackson (eds.), Shifting Baselines: The Past and the Future of Ocean Fisheries, DOI 10.5822/978-1-61091-029-3_6, © Island Press 2011
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This chapter presents the results of collaboration by maritime historians and marine ecologists assessing one part of the nineteenth-century Northwest Atlantic cod fishery. It expands upon a paper previously published by our interdisciplinary group. Our subjects are New England fishermen in the age of sail and the cod they caught with hand lines on the Nova Scotian Shelf. Our group discovered that data recorded with quill pens in stained logbooks during the 1850s proved suitable for computerized stock assessment models and distribution analysis using GIS. The analysis relies on historians’ assessment and contextualization of archival documents pertinent to the fishery, notably thousands of historical fishermen’s logbooks that can be linked to other customs house records to provide fleet size, landings in weight and numbers, fishing effort, and geographic location. Our results are noteworthy in several ways. We have calculated the earliest biomass estimate for a fished cod stock anywhere in the world using data from the 1850s for the Scotian Shelf. We have reconstructed the history of localized overfishing by the Scotian Shelf fleet during the 1850s, a pivotal decade during which New Englanders reluctantly adopted a new longline technology—dory tub trawling—in response to declining catch and overpowering competition by large French factory brigs. And we have developed an interdisciplinary methodology that may inform future collaborations. In
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