Data from: All is fish that comes to the net: metabarcoding for rapid fisheries catch assessment

AbstractMonitoring marine resource exploitation is a key activity in
fisheries science and biodiversity conservation. Since research surveys
are time-consuming and costly, fishery-dependent data (i.e. derived
directly from fishing vessels) are increasingly credited with a key role
in expanding the reach of ocean monitoring. Fishing vessels may be seen as
widely ranging data-collecting platforms, which could act as a fleet of
sentinels for monitoring marine life, in particular exploited stocks.
Here, we investigate the possibility of assessing catch composition of
single hauls carried out by trawlers by applying DNA metabarcoding to the
“slush” collected from fishing nets just after the end of hauling
operations. We assess the performance of this approach in portraying
β-diversity and examining the quantitative relationship between species
abundances in the catch and DNA amount in the slush (reads counts
generated by amplicon sequencing). We demonstrate that the assemblages
identified using DNA in the slush mirror those returned by visual
inspection of net content and detect a strong relationship between read
counts and species abundances in the catch. We therefore argue that this
approach could be upscaled to serve as a powerful source of information on
the structure of demersal assemblages and the impact of fisheries.