Estimated food consumption of minke whales &lt;i&gt;Balaenoptera acutorostrata&lt;/i&gt; in Northeast Atlantic waters in 1992-1995

Lars P Folkow,Tore Haug,Kjell T Nilssen,Erling S Nordøy

doi:10.7557/3.2972

Abstract

Data on energy requirements, diet composition, and stock size were combined to estimate the consumption of various prey species by minke whales (Balaenoptera acutorostrata) in Northeast Atlantic waters. In the period 1992-1995, the stock of 85,000 minke whales appeared to have consumed more than 1.8 million tonnes of prey per year in coastal waters off northern Norway, in the Barents Sea and around Spitsbergen during an assumed 6 month stay between mid-April and mid-October.Uncertainties in stock estimates suggest a 95% confidence range of 1.4 - 2.1 million tonnes. The point estimate was composed of 602,000 tonnes of krill Thysanoessa spp., 633,000 tonnes of herring Clupea harengus, 142,000 tonnes of capelin Mallotus villosus, 256,000 tonnes of cod Gadus morhua, 128,000 tonnes of haddock Melanogrammus aeglefinus and 54,500 tonnes of other fish species, including saithe Pollaehius virens and sand eel Ammodytes sp. Consumption of various prey items by minke whales may represent an important mortality factor for some of the species. For example, the estimated annual consumption of herring corresponds to about 70% of the herring fisheries in the Northeast Atlantic in 1995. Minke whale diets are subject to year-to-year variations due to changes in the resource base in different feeding areas. Thus, the regional distribution of consumption of different prey items is highly dynamic.

Highlights

Attempts to develop multispecies models for the spring, and southwards to breeding areas ·of management of marine resources have led to unknown location in the autumn (Jonsgard increased interest in the quantitative analysis of 1966)
During spring > 90% of metabolizabl e energy (ME) was expended for these purposes in all groups
Minke whales of the Northeast Atlantic represent one of the most euryphagous stocks of baleen whales (Haug et al 1995a, Haug et al 1996a), but the bulk of their diet is comprised of relatively few species

Summary

Introduction

Attempts to develop multispecies models for the spring, and southwards to breeding areas ·of management of marine resources have led to unknown location in the autumn (Jonsgard increased interest in the quantitative analysis of 1966). These animals are reported to feed on varthe feeding ecology of top predators. Part of the Northeast Atlantic stock of minke whales migrates northwards to feeding A sampling programme was carried out in 1988areas in the Norwegian and Barents Seas 111 1990, in which 51 minke whales were taken.

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Conclusion