This spring’s drastic reduction to groundfish fishing limits signaled that several key Gulf of Maine fisheries are in crisis and dealt a significant blow to an already struggling industry.
“During this time of uncertainty, the power of GMRI’s integrated approach comes into sharp focus,” said Jonathan Labaree, GMRI Director of Community Initiatives. “The species in the Gulf of Maine and the people who depend on them for their livelihood have never been in such dire need of improved science and industry innovation.”
Assessments in 2011 revealed that the health of key groundfish stocks, especially cod, had been greatly overestimated, requiring a massive correction to fishing quotas to get back on track.This unexpected news has highlighted the need to reexamine the underlying assumptions used to manage Gulf of Maine fisheries. GMRI scientists are using genetics, movement, growth, and spawning data to study how well biologically distinct subpopulations match up with the geographic regions used to manage groundfish. The team is also examining the effectiveness of strategic areas that are closed to commercial fishermen as a means of bolstering the groundfish populations, particularly cod, as a whole.
“Cod is a poster child for complex stock structure,” said Lisa Kerr, GMRI Fisheries Ecologist. “The lessons we learn from it have important implications for many other fisheries around the world.”
Further complicating successful fisheries management is a warming trend that is challenging scientists’ traditional understanding of the Gulf of Maine ecosystem. Temperature has a strong influence on fish throughout their life, and 2012 was the warmest year on record, with surface temperatures in the northwest Atlantic 2–5 °F above the 30-year average. GMRI scientists are conducting a number of research projects into the effects of ecosystem conditions on body size, larval distribution, reproduction, migration, and survival rates of young fish.
“Understanding how fish populations respond to changes in water conditions and in the food web is critical to managing the ecosystem in the face of climate change,” said Andrew Pershing, Ecosystem Modeler at GMRI and the University of Maine.
While increased temperatures have made the Gulf of Maine less hospitable for cod and other subarctic species, they have also brought an influx of more southerly species, such as black sea bass and squid. Scientists at GMRI are studying these shifts in environmental conditions and species abundance to understand if the ecosystem has crossed a tipping point where the changes permanently alter the norm for the region.
“Fisheries management is based on the historical populations in the Gulf of Maine,” said John Annala, GMRI Chief Scientific Officer. “As the region is undergoing rapid and significant environmental changes, our research may help to redefine the targets used to measure management success in the future.”