Feeding ecology of sea trout in the Irish Sea

Research output: Chapter in Book/Report/Conference proceedingChapter

  • William Roche
    Inland Fisheries Ireland
  • Nigel Milner
    Bangor University
  • Carys Davies
  • Sam Shepherd
    Inland Fisheries Ireland
  • Jonathan King
  • John Coyne
    Inland Fisheries Ireland
  • Paddy Gargan
    Inland Fisheries Ireland
  • Roger Hughes
The marine feeding ecology of sea trout (Salmo trutta) and information on the prey species they consume is fundamental to understanding the factors likely to influence their distribution, migration and growth in the marine environment. This paper presents stomach content analysis from 991 marine-caught sea trout, sampled from around the Irish Sea, in littoral and offshore pelagic habitat. Frequency of occurrence and percentage composition by weight were used to compute an index of prey importance. Fish, which was the major dietary component, was dominated by two components, sand eels (Ammodytes spp.) and sprat (Sprattus sprattus L.). Sand eels were the most prevalent with percentage occurrence and percentage abundance by weight of 56% and 62% respectively, followed by sprat at 28% and 18% respectively. Spatial and ontogenic variation was observed and pelagic feeding fish, which were almost exclusively feeding on sprat, demonstrated significantly higher feeding intensity compared to inshore feeding fish. Identifying the keystone prey species contributes to identification and understanding of the distribution of important sea trout habitats and, in the longer term, to development of enhanced management and conservation strategies for sea trout and its marine habitat, their prey and associated habitat types.

Keywords

  • Salmo trutta, Irish Sea, marine feeding, diet, pelagic
Original languageEnglish
Title of host publicationSea Trout: Science and Management
Subtitle of host publicationProceedings of the 2nd International Sea Trout Symposium
EditorsGraeme Harris
Place of PublicationKibworth Beauchamp
PublisherMatador
Pages371-395
Number of pages25
ISBN (Print)978 1788035 354
Publication statusPublished - 1 Nov 2017
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