Black bream is targeted by both recreational and commercial fishers in Western Australia and we manage both fishing sectors together to ensure black bream stocks remain sustainable.
We manage commercial fishing through entry limits, gear restrictions, seasonal and time closures, area closures and size limits. We manage recreational fishing through bag and size limits. A Recreational Fishing from Boat Licence is also required when fishing from a powered boat.
Black bream are restricted to estuaries and each estuary hosts a distinct stock of black bream. Growth rates between populations vary greatly. In all estuaries, the legal minimum length is set above the length at maturity, which helps protect each breeding stock.
Monitoring, assessment and research
WA’s coastal area is divided into four bioregions and the fish in each have been placed into groups (or ‘suites’). We use indicator species from each suite in each bioregion to help assess the status of breeding stocks for finfish.
They are monitored and assessed, then their status is used to indicate the status of all species in the same suite. Indicator species are chosen based on their vulnerability to fishing plus other factors, including whether they are targeted by major fisheries.
Black bream is an indicator species for the estuarine finfish suite in the West Coast and South Coast bioregions.
Monitoring and assessment of fisheries and fish stocks is based on commercial catch and effort statistics (catch related to the amount of fishing effort made) from compulsory monthly returns. In addition, recreational fishing catch and effort data comes from voluntary Recreational Angler Program (RAP) log books. The results of a Statewide recreational boat fishing survey will also be available in 2013.
Most of the commercial black bream catch is taken in the South Coast Estuarine Fishery in four main estuaries – Stokes Inlet, Beaufort Inlet, Wilson Inlet and Oyster Harbour. In this fishery breeding stocks have been assessed as adequate and fishing effort as acceptable.
Only a small percentage of WA’s commercial black bream catch is taken in the West Coast Bioregion - seven per cent of the State's commercial catch is taken in the West Coast Estuarine Fishery.
Catch rates from volunteers’ recreational fishing log books suggest a slight decline in availability of black bream in the Swan-Canning Estuary from 2005 to 2011. However, breeding stock levels have been assessed as acceptable. Black bream in other West Coast Bioregion estuaries are not assessed. Fishing effort has been assessed as acceptable.
Black bream status 2011
| South Coast Estuarine Fishery |
Adequate
(Walpole-Nornalup Inlet
is closed to commercial fishing and not assessed) |
Acceptable |
|---|
| West Coast Estuarine Fishery |
Adequate
(Swan-Canning Estuary
only – other estuaries not assessed) |
Acceptable |
|---|
Black bream landings vary in response to environmental factors in individual estuaries. Simultaneous increases in catch rates in South Coast Bioregion estuaries from 1995 to 2005 suggest a widespread factor, such as rainfall, has influenced black bream availability.
Research has been done on the migration habits of black bream. Scientists believe many adults migrate upstream in drier parts of the year when salinity levels are higher (more like the ocean) in the upper estuary. They then migrate back downstream in winter when the estuary’s upper areas are fresher.
Using acoustic transmitters, University of Western Australia researchers tracked the movement of black bream in the Wellstead Estuary at Bremer Bay. The 2010 study showed they were highly mobile and capable of withstanding very high salinity. Some moved up to six kilometres upstream and downstream every few days for periods of several months.