Fisheries Terms

Question 1

Bycatch

Answer 1

Unintentional catch; catch that occurs incidentally in a fishery that intends to catch other fish

(e.g. different size, species); mortality caused by technical interactions in fisheries.

Question 2

Carry Capacity

Answer 2

The number of biomass of resources that can be supported by an ecosystem.

Question 3

Catch

Answer 3

The total number or weight of fish captured from an area over a period of time, including fish that car caught but are released or discarded. The catch may take place in an area different from where the fish are landed.

Question 4

Catchability coefficient

Answer 4

The average portion of a fish stock that a unit of gear (one crab pot) is capable of catching. Catchability is a measure of the catch efficient of the gear.

Question 5

CPUE

Answer 5

An indicator of stock abundance or stock density. THe number or weight (biomass) of fish caught by a given amount of effort. Effort is a combinator of gear type, size, and length of time a gear is used. The CPUR may be influenced by changes in abundance.

Question 6

Cohort

Answer 6

A group of fish spawned during a given period, usually within a year.

Question 7

Effort

Answer 7

The amount of time and fishing power used to harvest fish. Fishinger power includes gear size, boat size, and horsepower.

Question 8

Exploitation

Answer 8

The fraction of a population at a given time that is removed by fishing over the course of a year.

Also account for any concurrent natural mortality.

May also be expressed as a percentage of the population.

Question 9

fishery-dependent data

Answer 9

Data obtained from commercial or recreation harvest. Fishery-dependent data consist of catch reports, sea sampling, and other data concerning the resource and the fishery that are obtained from the fishery.

Question 10

fishery-independent data

Answer 10

Data is collected through independent research surveys rather than from commercial or recreational harvest, typically including abundance and recruitment information.

Question 11

fishing mortality rate

Answer 11

That part of the total mortality rate applies to a fish population caused by fishing. Fishing mortality is usually expressed as an instantaneous rate and can range to values exceeding unity, such as 2.0 or higher.

Question 12

Growth Overfishing

Answer 12

When total mortality on the stock causes many fish to be caught at a relatively small size (discarded or landed) such that the potential production of the stock due to individual fish growth (yield-per-recruit) is not realized.

Question 13

landings

Answer 13

The number of poundage of fish unloaded at a dock by commercial fisherman or brought to shore by recreational fishermen for personal use. Landing are reported at the places where fish are brought on shore.

Question 14

MSY

Answer 14

A management goal specifying the largest long -term average catch or yield (in terms of weight of fish) that can be taken continuously (sustainably) from a stock or stock complex under prevailing ecological environmental conditions without reducing the size of the population.

Question 15

Natural Mortality

Answer 15

The rate of removal of an organism from a population due to natural causes (disease, predation, old age). The fish dying during the year expressed as the fraction of the fish alive at the beginning of the year.

Question 16

Overfished

Answer 16

An overfished stock or stock complex is one “whose size is sufficiently small that a change in management practices is required in order to achieve an appropriate level and rate of rebuilding.”

A stock or stock complex is overfished when its size falls below the minimum stock sie threshold (MSST).

Overfished stocks require a rebuilding plan.

Question 17

Overfishing

Answer 17

Harvesting at a rate or level that jeopardizes the capacity of a stock or stock complex to produce maximum sustainable yield on a continuing basis.

Question 18

Recruitment

Answer 18

A measure of the weight or number of fish that enter a defined portion of the stock such as fishable stock (those fish above the minimum legal size) or spawning stock (those fish which are sexually mature).

Question 19

Recruitment Overfishing

Answer 19

When fishing mortality reaches a level at which removals from a stock are so high and its spawning capacity so diminished that fewer and fewer juveniles are produced.

Question 20

Stock

Answer 20

An interbreeding sub-population of a species reproductively isolated to some extent from other populations. Used as a unit for fishery management, however, “stock” refers to a specific population or group of populations of one or more species.

Question 21

Surplus Production

Answer 21

Total weight of fish that can be removed by fishing without changing the size of the population.

Calculated as the sum of growth (in weight of individuals) in a population, plus the biomass from new recruits, minus the biomass of animals lost to natural mortality during a defined period (usually one year).

Question 22

Total mortality

Answer 22

A measurement of the rate of removal of fish from a population by both fishing and natural causes (either annual or instantaneous).