Groundfish tag data from Western Gulf of Maine Closure Area and surrounding areas

Note: This project was awarded funding in both 2000 and 2002. This summary encompasses both projects.

Two cod tagging projects have been funded, one that examines the effectiveness of the western Gulf of Maine rolling closures as a management tool (FY2000) and another that focuses on cod movements in and around the Western Gulf of Maine Area Closure (WGoMAC) (FY2002). Mark and recapture techniques were used for both.

During the first project, 91 tagging trips were conducted, making 555 tows in the 4 rolling closure areas. A total of 17,860 cod were tagged, as well as 1,138 haddock, 840 American plaice, 79 pollock, 41 wolf fish, 28 yellowtail flounder, 12 winter flounder, and 7 gray sole. A total of 1,086 cod (6.1%) were recaptured with enough information (exact location and date of recapture) to be usable in the study. All data have been entered, and the analyses have been completed. Results from the project formed the basis of a thesis prepared by Mike Morin, and a manuscript for publication is currently in review. Overall, movement of Atlantic cod in the western Gulf of Maine appears to be associated with spawning. In the spring, cod were observed to move from offshore areas and aggregate inshore (area 133) to spawn. Post-spawning movements began in June and were characterized as a general dispersion offshore away from the spawning grounds. Cod were again observed to move inshore for spawning in December-January, suggesting the possibility of two distinct spawning groups. These spawning events were each associated with movements in and out of area 133. To determine if these were to distinct groups or the same group spawning twice, average lengths of the three observed spawning groups (Spring 2001, Fall2001/Winter2002, and Spring 2002) were compared. Results showed that both the spring 2001 and 2002 groups had a significantly larger average size than the winter spawning group, suggesting that these are two different age groups of fish. Genetic analyses of these fish, conducted by Kovach et al. at UNH, indicate that the two spawning groups are genetically different. (abstract)

final report

codhad_tag.csv