DNA-based identification of larval cod in stomach contents of predatory fishes

• Published in: Journal of experimental marine biology and ecology 2002-01, Vol.267 (1), p.75-88
• Main Authors: Rosel, P.E, Kocher, T.D
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; DNA assay; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Fundamental and applied biological sciences. Psychology; Gadus morhua; General aspects. Techniques; Methods and techniques (sampling, tagging, trapping, modelling...); Mitochondrial DNA; PCR; Predator–prey relationships; Stomach contents
• ISSN: 0022-0981; 1879-1697
• DOI: 10.1016/S0022-0981(01)00359-8

Predator–prey interactions play an influential role in determining the demographics of a population or species. In the Northwest Atlantic, Atlantic cod, Gadus morhua, once the basis of a lucrative commercial fishery, have not recovered despite regulations imposed on the fishery to reduce harvest rates. One possible reason for the lack of recovery is that high predation pressure on juvenile and larval stages, particularly from species such as herring and mackerel, may regulate the abundance of cod. However, traditional methods used to identify larval cod and haddock often fail when applied to partially digested remains. Here, we described a DNA-based assay to identify the presence of digested cod remains from the stomachs of predatory fish species. After development, the assay was tested on two sets of field samples. Larval and juvenile cod were successfully detected in both tests.