Glossary

Anadromous: Anadromous fish live most of their lives in saltwater and return to freshwater to spawn. These fish are highly specialized to endure the changes in salinity. Other common anadromous species occurring in the Chesapeake Bay include American shad, hickory shad, blueback herring, alewife herring, striped bass and Atlantic sturgeon. Pacific salmon are also anadromous. The American eel is known as a catadromous species. It lives most of its life in freshwater and returns to the marine environment of the Sargasso Sea to spawn.

Aquaculture: Aquaculture means the commercial rearing of the species of fish or aquatic plants listed in Regulation .07, or as otherwise permitted by these regulations. It includes one or more activities that are related to the production of fish or aquatic plants.

Aquaculture activities: Activities that may include the purchase, sale, possession, capture, production, breeding, transportation, and processing of fish or aquatic plants.

Code Wire Tags or CWT: Manufactured by Northwest Marine Technologies (Bellvue, Washington), these one-millimeter long metal tags are etched with a numerical code. CWT are implanted into the gill cover or musculature of juvenile fish. A specialized tag reader detects tags. The codes can be used to identify a recaptured fish as hatchery origin. Codes are applied to batches of fish so the biologist can also identify the stocking date and location. This data is important to assess the impact of the stocking program.

Culture methods:

• Extensive culture is a subjective term that refers to raising fish in a method whereby the culturist has minimal control over the factors that affect the fish. The cultured population is generally at a low density. Pond culture is representative of extensive fish culture. This is generally a more "natural" system.
• Intensive culture is a subjective term that refers to raising fish in a method whereby the culturist has direct control over habitat, water quality and food supply. The cultured population can be at a very high density. Tank or raceway culture is representative of extensive fish culture.
• Integrated culture is a combination of extensive and intensive culture. For example, fish may be intensively cultured as larvae or juveniles but grown out to adulthood extensively.

Extirpated: Extirpated describes a population that has been depressed to the point that it is barely reproducing. Only a remnant population exists, but it is so low that the stock will probably never fully recover on its own.

Fish: Defined as finfish, crustaceans, mollusks, and amphibians and reptiles which spend the majority of their life cycle in water, and any part, egg, offspring, or dead body of any of these species.

Grading: Grading is the process of sorting fish by size, usually with some sort of screen or cage. This is necessary to prevent cannibalism in dense populations. It also allows the fish culturist to apply feed at the appropriate rates since all the fish in a given tank will be roughly the same weight after grading.

Recruitment: According to Everhart and Youngs (1981), recruitment is "defined as the addition of new members to the aggregate under consideration". Essentially, recruitment is a description of how many fish are entering a given population. In our restoration work, it is usually used to describe the number of fish that exist in the non-migratory juvenile population or the number of young fish that will eventually enter the migratory population and return to successfully spawn.

Inquiries for matters relating to Hatcheries and Finfish Restoration can be directed to Brian Richardson at (410) 643-6788 or E-mail Customer Service.