Biological stock

Individuals of a given fish species which are part of the same breeding population.


Total weight of a stock or a specified component of a biological stock.

Biomass proxy

A relative biomass level used in place of a quantitatively estimated biological reference point when this is not available.


A species taken incidentally in a fishery during fishing for another species. The species is retained for sale because it has some commercial value.

Catch and effort reporting

Official record of the location, time, gear and method of fishing and amounts of fish landed or produced under each commercial licence. Catch and effort records are mandatory for most fisheries and must be submitted on a monthly basis, with the exception of Abalone fishers who are required to submit an "abalone docket" within two business days after the time of landing. Aquaculture licence holders are required to submit a return every six months.

Carrying capacity

The maximum number of individuals of a particular species that can 
be supported indefinitely in a given environment.

Catch disposal records

Official record of who caught the fish, when it was caught, details of who the product was sold or consigned to and how much was sold or consigned. Catch disposal records are mandatory for quota-based fisheries (i.e. abalone, rock lobster, giant crab and scallop fisheries) (in the case of abalone these are referred to as 'transfer certificates').

Catch per unit of effort (CPUE)

The number or weight of fish caught by a unit of fishing effort. Often used as a measure (proxy) of fish abundance.

Customary fishing permits

This catch estimate includes fishing that is authorised under (i) a Traditional Owner Recognition Permit issued under s69 of the Fisheries Regulations 2009; or (ii) a general permit to take fish for a specified indigenous cultural ceremony or event under s49(h) of the Fisheries Act 1995.

Fisheries-dependent data

Data collected directly on a fish or fishery from commercial fishers, processors and retailers. Common methods include catch and effort records.

Fisheries-independent data

Data collected by systematic scientific surveys (e.g. juvenile abundance surveys, population sampling). These surveys gather information independently of commercial fishing operations.

Fishing mortality

The rate of fish deaths due to fishing a component of the fish stock.

Growth overfished

When fish are harvested at an average size that is smaller than the size that would produce the maximum yield per recruit. When a fish stock is growth overfished, increases in fishing effort and fishing mortality produce decreasing yields, even though more individuals are harvested, because of the reduced average size of harvested fish.


To catch, take, or remove for personal or commercial purposes.

Harvest strategy

Strategy outlining how the catch in a fishery will be adjusted over time depending on measures such as the size or biomass of the stock, economic or social conditions of the fishery, conditions of other interdependent stocks or species and/or uncertainty of biological knowledge.

Natural mortality

Deaths of fish from all natural causes except fishing. Usually expressed as an rate or a percentage of fish dying in a year.


Fish that have not yet entered a fishery (i.e. not able to be caught or retained).


The number of fish surviving to enter the fishery or to some specified life history stage such as settlement or maturity.

Recruitment overfished

The point at which a stock is considered to be recruitment overfished is the point where the spawning stock biomass has been reduced through catch, so that average recruitment levels are significantly reduced.

Stock assessment model

Statistical models that estimate aspects of stock status such as biomass, growth, recruitment and fishing mortality using time series data on measures such as catch and effort, age and length composition of the catch or other relevant indicators.  These models can be used to inform fisheries management decisions.

Sustainable fishing

Fishing is sustainable when it can be conducted over the long-term at an acceptable level of biological and economic productivity, without leading to ecological changes that foreclose options for future generations.

Total allowable catch

Catch limit set on a fishery that includes harvest from commercial, recreational and indigenous fishers.

Total allowable commercial catch

Catch limit set on commercial fishers.

Transitional–depleting stock

A deteriorating stock—biomass is not yet recruitment overfished, but fishing pressure is too high and moving the stock in the direction of becoming recruitment overfished.