Surveillance de la zone de protection marine du Gully : Poissons et ressources halieutiques

Abstract

Of four Indicators proposed in 2010 for monitoring the fish of the Gully MPA, only one that utilizes data from on-going halibut surveys has been implemented. Those data suggest that the ecosystems have been broadly stable since 1998, though subject to regional trends in some species – Atlantic Halibut itself perhaps increasing by about 5% per year. It is recommended that routine sampling continue on the one fixed station of the Halibut survey that falls within the MPA, while more attention be paid to setting the gear at a constant depth. Since 2015, regular Snow Crab trawl surveys have included ten fixed stations around the shallow margins of The Gully. To date, the resulting time series are too short for any conclusions to be drawn but emerging trends suggest that the data may have future value in MPA monitoring, if the surveys continue to work the ten stations. Closer control of the seasonal timing of the sampling there would be an advantage. In contrast, the existing data from stratified-random groundfish-trawl surveys, which have been on-going since 1970, have no value in MPA monitoring. Artifacts arising from the broad variety of depths sampled in different years obscure any temporal trends. Those data are nevertheless summarized here for their contribution to understanding of the biodiversity of The Gully. Lastly, midwater-trawl surveys during 2007–10 have generated data that could provide a quantitative baseline for future monitoring of the micronekton in the MPA but no further sampling has been attempted during the past decade.