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

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.

Automated summary

Shark depredation is a global problem that causes economic losses in commercial and recreational fisheries. Through the use of mitochondrial DNA barcoding, researchers were able to identify the shark species responsible for depredation in a line fishery targeting snappers, emperors, and jacks. This approach proved to be a practical tool for improving our understanding of depredation in different types of fisheries.