Addressing bycatch of depleted species through a marine conservation network in the Canadian Atlantic

Bycatch of depleted and vulnerable species is a pressing conservation issue that undermines the sustainability of fisheries worldwide. Here, we utilised spatiotemporal modelling of fisheries-independent survey data to evaluate the potential for existing and proposed Marine Conservation Areas (MCAs) in Atlantic Canada to reduce bycatch vulnerability for three severely depleted species—Atlantic cod ( Gadus morhua), American plaice ( Hippoglossoides platessoides), and white hake ( Urophycis tenuis)—commonly caught as bycatch in commercial trawl fisheries on the Scotian Shelf-Bay of Fundy. We overlaid predicted distributions of abundance for these depleted species with those of commercially targeted haddock ( Melanogrammus aeglefinus) and pollock ( Pollachius virens) to identify areas of high-vulnerability. Our analysis showed that a fully implemented MCA network would overlap with an average of 16% of high-vulnerability area for individual species and 20% when combined as a single group, an increase of 9% and 13%, respectively, from existing MCAs. This approach can be used more generally by employing readily available survey data to optimise both fisheries management and biodiversity objectives in marine conservation planning.