Feeding preferences of Celtic Sea fishes were investigated using a database of stomach content records, collected between 1977 and 1994. The diet of cod Gadus morhua, hake Merluccius merluccius, megrim Lepidorhombus whiffiagonis, whiting Merlangius merlangus and saithe Pollachius virens changed markedly as the animals grew larger, and although large predators generally chose larger bodied prey, the variability of prey sizes consumed also increased. Large predators continued to select small, low value, benthic prey (e.g. Callionymus spp. and Trisopterus spp.) which were easier to catch, rather than larger, more energy lucrative pelagic prey (e.g. mackerel Scomber scombrus), even though these pelagic prey-fishes were nearly always available and were often very abundant. Stock estimates of the International Council for the Exploration of the Sea and U.K. groundfish survey catches were used as indices of prey abundance. Blue-whiting Micromesistius poutassou and other small pelagic fishes (Argentina spp. and clupeoids) were identified as being particularly important, and were consumed by some predators more often than would be expected given the abundance of these prey in the environment. There was no evidence for density-dependent feeding by predators on mackerel and only hake exhibited density-dependent feeding on horse-mackerel. Hake, cod and megrim consumed more blue-whiting when this prey was at higher abundance in the environment. In choosing what prey to consume, predators must balance costs and benefits, considering the quality of prey and the energy expended during search, capture and handling.

Item Type:	Refereed Article
Keywords:	availability, Celtic Sea, diet, preference, stomach contents
Research Division:	Agricultural, Veterinary and Food Sciences
Research Group:	Fisheries sciences
Research Field:	Fisheries management
Objective Division:	Environmental Management
Objective Group:	Terrestrial systems and management
Objective Field:	Assessment and management of terrestrial ecosystems
UTAS Author:	Tidd, AN (Dr Alexander Tidd)
ID Code:	116259
Year Published:	2003
Web of Science® Times Cited:	83
Deposited By:	Fisheries and Aquaculture
Deposited On:	2017-05-04
Last Modified:	2017-12-01
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