Connectivity Among Coastal Spawning Sites of Atlantic Cod

The Gulf of Maine stock of Atlantic cod is rebuilding after decades of overfishing. Relatively low abundance and concomitant reductions in spawning diversity have negatively influenced recruitment and productivity. Acoustic telemetry suggests fine-scale, multi-year fidelity to a coastal spawning site. Residence times of individual cod on their spawning site ranged from approximately three to seven weeks, with infrequent off-site movements. Spawning site fidelity suggests spatial segregation of spawning. However, fishery tag recaptures have indicated a connection between spawning sites up to 45km apart, which is corroborated by recent genetic findings. A high degree of connectivity suggests an inter-connected network of spawning sites, which is expected to increase resilience and sustainability when compared to a more closed, isolated system. Connectivity is expected to also promote the recolonization of inactive spawning sites through a spillover effect. The prevalence of spawning site fidelity, movements while on the spawning site, and degree of connectivity among spawning sites will help to determine the appropriate management scales for cod in the Gulf of Maine.