June 23, 2012 – The troubled future of Atlantic cod is murkier than ever as science reveals a myriad of behaviors in this iconic fish, making it more daunting to say when and where it should be caught. “We’re almost overwhelmed with complexity,” said Tom Nies, groundfish analyst for the New England Fishery Management Council. “We still have vast areas that have not been sampled, vast areas where we don’t know what’s happening.”
The complexity was clarified last week at a scientific conference convened by the council and the Gulf of Maine Research Institute. The conference was held in the wake of the discovery earlier this year that cod were not recovering as hoped for in the Gulf of Maine under a 10-year-plan to reestablish stocks by 2014. Fishermen are currently operating under a 22-percent cut in their allowable catch, and likely face a far more dramatic cut next year from the National Oceanic and Atmospheric Administration.
Scientists say the emerging problem in assessing future catches is not only the raw numbers of cod being caught. It is also that cod have more genetic substocks than once thought, meaning that decimation of any one substock could dramatically alter the reproductive ability of the whole stock. Also, studies of tagged cod show that a fair amount of fish move back and forth between the Bay of Fundy and Georges Bank and between inshore Gulf of Maine waters and Cape Cod waters. Tagging researcher Shelly Tallack said, “This connectivity really makes it difficult to interpret what you’re seeing at any one time.”
Other research of tagged cod suggests that some subpopulations have an amazing homing instinct for spawning sites, given the vastness of the ocean. UMass Dartmouth researcher Douglas Zemeckis is documenting multi-year fidelity of cod to their spawning sites and finding that they can return to within 100 meters of the site.
Read the full story at the Boston Globe.