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Glossary of Terms |
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Glossary of Terms |
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Terms: |
Definition: |
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(coded wire tag) |
"Coded wire tags are small pieces of wire which are imbedded with a small applicator or by hand... into the snouts [or dorsal surface] of fish... These tags allow recognition of groups, either with color-coded markings or with notches... Tags are detected with a sensitive metal detector" (AFS Fisheries Techniques, 1983) Most often, CWT are used in large scale hatchery tagging efforts. These tags may only be read post-mortem, so often it is the location of insertion in the body of the fish that provides some information as to the fish's origin and year class.
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The use of electricity to catch fish. A positive current is applied to water and fish within the electrical field experience varied responses. Generally, fish are drawn to the positive lead and are stunned, at which time the researcher captures the fish and places in a holding container for later examination. When used properly, electrofishing results in no permanent damage to the fish, only a temporary stunned effect.
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A widely used statistical method for wildlife population estimation and analysis. Individuals of a population are captured, marked, and released in the hopes that if recaptured, that individual will be identifiable and distinguished from others by it's "mark". Statistical methods are used and in short, inferences are made as to the size of a population based on the numbers of marked and unmarked individuals captured. Even within fisheries studies, marking techniques vary considerably. Marks may be external (fin clips, external tags, branding) or internal (PIT tag, CWT) depending on the species and survey needs.
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Native and non-native (a.k.a. introduced) are terms used to indicate whether a species evolved in a specific locality in which they are found. Non-native fishes may be found in a location with native fishes, but the non-natives arrived there by artificial means (intentionally stocked or accidentally released). See the species of interest page for more information on Arizona's Native Fish.
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(passive integrated transponder)
Link to video of PIT implantation: |
"A small externally mounted or implanted RFID (Radio Frequency Identification) product used to positively identify animals and other objects (rocks, golf balls, driftwood, etc.) for a lifetime. Each tag is a read-only tag that is programmed to transmit a unique code only when activated. Implantable tags are "integrated" circuits with an antenna that are encapsulated in glass. The term "passive" means there is no battery on the tag. The tag is powered through the activation of a handheld or stationary transceiver/reader that generates an electromagnetic signal used to momentarily activate the tag. The tag then transmits a unique digital code back to the transceiver/reader where the code is displayed and/or stored. The tag only transmits its unique code when the tag is present in the transceiver's electromagnetic activation field. With no battery to fail, PIT tags are expected to last 100 years or more. The tag detection and display is almost instantaneous." (Excerpt from www.biomark.com)
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A term used to differentiate a wild-born-and-raised fish from one that has been bred, hatched, raised, or cultivated in some manner in an artificial setting (such as a hatchery or stock pond) and subsequently returned to the wild. Repatriated fish would also include those that are artificially raised from wild-spawned larvae, as is practiced in razorback recovery on the lower Colorado River.
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This term is used to differentiate a fish species as one which is often legally pursued by recreational angling (hook and line). Most often this term is used as the antithesis to "native fish," but this is not necessarily the case. A native fish may also be a sport-fish if that fish has no protected status (threatened or endangered) and is legally captured by approved recreational methods.
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