MPA regulations should incorporate adaptive management—The case of Gilbert Bay Labrador Atlantic cod (Gadus morhua)

Abstract

Although an important conservation tool, Marine Protected Areas sometimes fall short of intended goals; however, adaptive management can potentially improve their effectiveness. Efforts to develop an MPA in Gilbert Bay, Labrador, Canada, began in 1998 to protect the genetically distinct population of Atlantic cod (Gadus morhua) and its habitat. Population monitoring and research conducted in Gilbert Bay during 26 research trips over 14 years have documented significant population declines. The biomass declined by as much as 83% and research catch rates by 54% since Gilbert Bay became a MPA in 2005. Commercial fishing in adjacent waters was strongly correlated (Pearson correlation r=−0.87, p=0.002), with the declining trend in research catch rates. Tag recaptures from the commercial fishery (n=105) confirmed that fishing removed large adult Gilbert Bay cod that seasonally move outside the MPA. Evidence of the production of strong year classes even at low adult population levels indicate that the Gilbert Bay cod population has the potential to increase rapidly under appropriate adaptive management; thus improving MPA effectiveness. A relatively small change in the timing of commercial fishing in waters adjacent to the MPA would likely produce this result; however, inflexible MPA regulations, and poor co-ordination and agreement among differing fishery management processes and stakeholders has delayed the implementation of such a change.