W. J. Overholtz
Northeast Fisheries Science Center, NOAA Fisheries Service
166 Water St, Woods Hole, Massachusetts 02543, USA
Publication (Upload) date: 4 Jan 2006
Overholtz, W. J. 2006. Estimates of consumption of Atlantic herring (Clupea harengus) by Bluefin tuna (Thunnus thynnus) during 1970–2002: an approach incorporating uncertainty. J. Northw. Atl. Fish. Sci., 36: 55–63. doi:10.2960/J.v36.m572
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Bluefin tuna (Thunnus thynnus) are a major apex predator in the Gulf of Maine-Georges Bank region and Atlantic herring are a keystone prey item in the diet of bluefin as well as the majority of other apex predators, seabirds and piscivorous fishes in this ecosystem. Key variables for the calculation of consumption of herring by bluefin tuna are uncertain, necessitating a modeling framework that can utilize scant and variable information. Input distributions for bluefin tuna biomass, percent of the Northwest Atlantic bluefin stock in the region, percent daily ration of bluefin, and percent of herring in the bluefin tuna diet were developed and used in a model that incorporates uncertainty. Consumption of Atlantic herring by bluefin tuna in the Gulf of Maine-Georges Bank region peaked at 58.0 kt in 1970, dropped to a series low of 2.2 kt in 1982, and increased steadily to 24.4 kt in 2002. Changes in abundance of bluefin tuna and herring, combined with substantial fishery removals on both species caused major fluctuations in herring consumption by tuna during 1970–2002. Sensitivity analysis indicates that tuna diet composition and daily ration are the most important variables affecting the estimates of herring consumed by bluefin tuna.
Key words: Atlantic herring, Bluefin tuna, consumption, uncertainty
: Overholtz, W. J. 2006. Estimates of consumption of Atlantic herring (
) during 1970–2002: an approach incorporating uncertainty.
: 55–63. doi:10.2960/J.v36.m572