Sherman, K. NOAA-NMFS, 401-782-3201
EMERGING PATTERNS OF FORCES DRIVING CHANGES IN LARGE MARINE ECOSYSTEMS : A GLOBAL PERSPECTIVE
On a global scale, principal driving forces of changing abundance and species dominance levels have been examined in case studies encompassing multidecadal changes in fish and fisheries, from the geographic construct of large marine ecosystems (LMEs). Results indicate that the principal driving force in biomass yields in the US Northeast shelf, East China Sea, Yellow Sea, and Gulf of Thailand (LMEs) has been excessive fishing induced mortality. In contrast, the evidence points to natural environmentally induced changes as a primary cause of fluctuation in yields of small sized but high biomass levels of pelagic fish yields in the Benguela Current, California Current, Oyashio Current, Kuroshio Current, Humboldt Current, Guinea Current, and Sea of Japan LMEs. The effects of fisheries in depressing the small pelagic fish stocks in these LMEs appears to be a secondary force driving change in population levels. In contrast, in the Baltic Sea and the Black Sea, declines in fisheries are attributed to habitat loss and coastal eutrophication as the principal driving forces in changing abundance levels followed by overexploitation and climatological variability as secondary and tertiary causes. Other LMEs where fish and fisheries appear to be under the principal influence of naturally occurring environmentally induced perturbations include the Barents Sea, Norwegian Sea, Icelandic Shelf, West Greenland Sea, and East Bering Sea. Based on these results, a systems approach for LME assessment and management is proposed and described.
Day: Friday, Feb. 5
Time: 03:45 - 04:00pm
Location: Eldorado Hotel