Dogfish Age and Growth
Spiny dogfish (also called Cape Shark in the United States or Rock Salmon in England) are small sharks that migrate along the eastern seaboard of the United States. They have become an increasingly important fishery here on Cape Cod, where fishermen land them throughout the summer. When a dogfish is landed, none of it goes to waste. The meat is used around the world for fish and chips, fish burgers, and fish tenders. The fins are sold for shark fin soup both domestically and internationally, and any leftovers pieces are sold to fertilizer companies. NOAA calls wild-caught, Atlantic spiny dogfish a smart seafood choice because it is sustainably harvested.
Here at the Fishermen's Alliance, we will be working with researchers at the University of Maine and the University of Connecticut during 2018 to help managers better understand dogfish growth rates by collecting spines from dogfish landed in Chatham. The spines can be cut into thin slices on a jeweler’s saw and put under a microscope where scientists count growth rings to estimate the fish’s age (like counting rings on a tree, but much, much smaller). The thickness of the rings helps scientists understand how quickly the fish grew at different times of its life.