OCEANS AND ESTUARIES GLOSSARY

Biomass

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

Bycatch

A species that is: (a) incidentally taken in a fishery and returned to the sea; or (b) incidentally affected by interacting with fishing equipment in the fishery but not taken.

Coastal areas

Defined as a Statistical Local Area (SLA) that borders the coast, harbours, or estuarine rivers (with one exception of Unicorp Flinders Ranges). Note that many SLAs extend inland for large distances. This is based on 2009 Australian Standard Geographic Classification (ASGC) boundaries.

Fish stock

A fish stock refers to a specific population of fish, which may or may not be of the same species. Changes have occurred in the ways in which fish stocks are classified. For example, in 2008, orange roughy, previously assessed as a single stock, was divided into three separate stocks based on biological information - eastern, southern and western. The reclassification of this stock as three distinct stocks would influence fish stock status statistics.

Fish stock status

The Australian government classifies fish stocks according to their susceptibility to unsustainable fishing practices. The system used to classify stock status has undergone several modifications, the most recent in 2004, when the categories 'underfished' and 'fully fished' categories were replaced by a combined category of 'not overfished'. The number of fish stocks examined each year has generally increased over time although occasionally a stock may be removed from assessment. The reclassification of fish stocks would also influence fish stock status statistics for these species.

Fishery

The collective enterprise of taking fish, usually defined by a combination of the species caught (one or several), the gear and/or fishing methods used, and the area of operation.

Illegal fishing

Illegal, unreported and unregulated fishing

International Union for the Conservation of Nature (IUCN) protected area classification scheme

Category IA – Strict Nature Reserve: Protected area managed mainly for science.
Category IB – Wilderness Area: Protected area managed mainly for wilderness protection.
Category II – National Park: Protected area managed mainly for ecosystem protection and recreation.
Category III – Natural Monument: Protected area managed for conservation of specific natural features.
Category IV – Habitat/Species Management Area: Protected area managed mainly for conservation through management intervention.
Category V – Protected Landscape/Seascape: Protected area managed mainly for landscape/seascape conservation and recreation.
Category VI – Managed Resource Protected Areas: Protected area managed mainly for the sustainable use of natural ecosystems.

Longline

Fishing gear in which short lines carrying hooks are attached to a longer main line at regular intervals. The longlines can be as long as 100 km and have several thousand hooks attached. There are two types of longline: Pelagic longlines are suspended horizontally at a predetermined depth with the help of surface floats and demersal longlines are set at the seabed with weights.

Marine parks

A protected area managed mainly for ecosystem protection and recreation, such as the Great Barrier Reef Marine Park.

National plan

A national strategy for responding to marine spills and maritime chemical spills in Australian waters. It is aimed at providing a prompt and effective response to marine pollution incidents. The plan is designed to protect the community and the environment of Australia's marine and foreshore zones from the adverse effects of oil and other noxious or hazardous substances.

Overfished

A fish stock with a biomass below the biomass limit reference point. 'Not overfished' implies that the stock is not below the threshold.

Overfishing

Overfishing can occur when the catch rate exceeds the capacity of the natural population to renew itself through reproduction.

Protected areas

An area of land and/or sea especially dedicated to the protection and maintenance of biological diversity and of natural and associated cultural resources, and managed through legal or other effective means. It is classified as protected under the International Union for the Conservation of Nature (IUCN) protected area classification scheme.