Apex Predators Program
28 Tarzwell Drive
Narragansett RI 02882-1152 USA
NEFSC Apex Predators Program
Rewards Offered for Tagged Spiny Dogfish
In January 2011, NOAA Fisheries Service's Northeast Fisheries Science Center launched a cooperative initiative to tag spiny dogfish (Squalus acanthias) in the Gulf of Maine, Southern New England, and Georges Bank. This project is an effort to answer long-standing questions about stock structure, movement patterns, and life history of the species in order to update and improve dogfish stock assessments.
Over a two-year period, a minimum of 33,000 dogfish will be tagged during the winter and summer months from three commercial vessels. Some of these fish will be double tagged for a tag retention study. Some also will be injected with oxytetracycline (OTC) for an age validation study.
Fish age is often measured by counting the growth rings on certain calcified structures in the fish. To verify that these rings develop every year, OTC, a common antibiotic, is used to leave a permanent mark on structures such as the vertebrae or spines. When a tagged fish is recaptured, these structures can be examined to see how many layers are added each year, which provides a verified ageing method.
Standard fin tags called rototags will be used during the project and will include a toll-free number for reporting required recapture information -- tag number, fork length, date, and location. Anyone who captures a tagged fish and returns complete information can earn either a $20 cash reward for one of the 27,000 white tags or a $100 cash reward for one of the 3,000 "high reward" orange tags.
Recaptures of fish injected with OTC and fish with two tag types -- a rototag and a dart tag -- will require return of the whole fish for a $100 cash reward (3,000 green tags). This will ensure that the OTC-marked vertebrae and spines are received and allow the condition of the tag in the fish to be examined. Whole fish to be returned should be iced or frozen. Shipping instructions will be provided upon contact.