TAC is Total Allowable Catch. This is the upper limit in the amount of fish, either by weight or number, that a fishery is allocated in a given season or year. TACs can apply to the targeted fish and/or bycatch, where once the limit is reached the fishery is closed for the remainder of the applicable … [Read more…]
A trap or pound net is a type of fishing gear with a complex organization of nets anchored to the substrate that “lead” or funnel fish into a final compartment (i.e., trap or pound) from which they cannot escape. In the Laurentian Great Lakes, this type of fishing gear is called a trap net and … [Read more…]
Tubercles are skin nodules made of keratin, the same materials as hair, hooves, and fingernails. They are present on species representing at least 15 families of fishes, including even pet goldfish. In many species, tubercles are found only on males during the breeding season and are shed shortly there after. They are often called breeding … [Read more…]
Trophic levels are a defined by the position of organisms in a food chain or food web. The different levels help define the flow of energy within an ecosystem. The lowest trophic level is primary producers, such as algae and phytoplankton, which generate their own energy from the sun via photosynthesis. Primary consumers, such as … [Read more…]
T & E is an acronym for threatened and endangered. These are both status metrics for risk of extinction. Endangered species are considered on the “brink of extinction” throughout their range and threatened species are likely to become endangered in the near future. The species that are on this list in the United States receive … [Read more…]
Thermoregulation is the process by which an organism controls its internal temperature. Fish have many different mechanisms for regulating their temperature. Most fish are ectothermic, using their environmental temperature to manage their body temperature, but some fish are endothermic, having the metabolic ability to internally manage temperature. Poikilothermic fish are ectotherms which have no control over … [Read more…]
Teleosts are the most diverse group of fishes (over 26,500 extant species). Over half of all living vertebrate species are teleosts. Teleosts are characterized by a protrusible jaw (musculature gives them the ability to move their maxilla and premaxilla) and a symmetrical tail (their spine that ends at the caudal peduncle unlike, for example, sharks). Teleosts … [Read more…]
Turtle Excluder Devices (TEDs) are a specific type of bycatch reduction device (BRD) that are a modification to a trawl net to keep turtles, which are not targets of the fishery, from being caught in the net. TEDs are generally composed of a set of bars over the trawl net. While small target animals, such … [Read more…]