Kit‐Based Sampling by Trained Fishers Yields Successful DNA Identification of Depredating Shark Species in the Marianas

Abstract

Shark depredation is a worldwide yet not well understood problem that is responsible for economic losses in both commercial and recreational fisheries. We collaborated with fishers from the Mariana Islands in the western Pacific to identify depredating shark species via mitochondrial DNA (mtDNA) barcoding of partially consumed fish from real-world depredation events. Trained fishers collected swabs from 29 shark depredation events in a line fishery targeting snappers, emperors, and jacks. Results showed that an assemblage of coral reef-and shelf-associated shark species was responsible for catch depredation in this fishery. The successful collection of transfer DNA from depredated fish by trained fishers and a 90% success rate in identifying the depredating shark species via mtDNA barcoding confirm that this approach is a practical tool for improving our understanding of depredation in a wide variety of fisheries. Although identifying the depredating shark species does not solve the problem of shark depredation in fisheries, it is a critical step in better understanding the phenomenon so that potential solutions can be identified.

Shark depredation: future directions in research and management

“…The application has now been trialled on commercial line (e.g. Webb et al 2022) and net fisheries, as well as in charter and recreational fisheries, but considerable scope for broadening and enhancing the application of genetic approaches in depredation research exist.…”