Bight Redfish

•  Commonwealth Southern and Eastern Scalefish and Shark Fishery (Great Australian Bight Trawl Sector) (215t in 2021/22).

Bight redfish is an endemic benthic predatory fish found on rocky reef and muddy habitats in continental-shelf and upper-slope waters from South Australia to southern WA, in depths to 500m.

They are caught using bottom trawl fishing methods in the Commonwealth-managed Southern and Eastern Scalefish and Shark Fishery (SESSF) Great Australian Bight Trawl Sector, which is Australia’s largest source of locally caught finfish for the domestic market.

The biological structure of Bight redfish population/s in the SESSF fishery is unknown, but they are likely in a healthy and robust condition.

The fishery has made significant progress in reducing protected seabird bycatch, though fur seal bycatch is potentially increasing. Seal Excluder Devices (SEDs), which act as escape hatches for seals that enter trawl nets, are mandatory. All trawl boats must have a seabird management plan in place to guide how each boat aims to reduce interactions with seabirds while actively fishing. Many of the solutions to seabird interactions have been fishing industry-led innovations and are proving highly successful in reducing these impacts.

The SESSF operates around a global ocean heating hotspot, warming at almost four times the global average. While serious climate impacts have been attributed to declining SESSF fish stocks for around a decade, there is still no explicit consideration of climate impacts when setting future catch limits. Significant research is underway in this area, which is welcome but overdue.

Some of the area where fishing occurs has been well mapped in order to identify the distribution of sensitive bottom-dwelling species. Trawling sometimes takes place on areas of seafloor that support sponges, hard corals and bryozoans (small invertebrates that form colonies similar to coral reefs), but it is unclear how much trawling activity is resulting in damage to habitats and associated species. Some areas of marine habitat are protected in marine parks and through other spatial closures. It is likely the fishery has had a high impact on the marine environment in the past, and spatial closures and reductions in the amount of fishing over the past two decades has reduced that impact.

Independent monitoring of the part of the SESSF  that catches bight redfish has been insufficient to ensure robust information is collected on protected species bycatch and fish discarding, which can occur when fish are caught in trawl nets that the fisher holds no quota for, so cannot land without financial penalty. This creates significant risk as it impedes managers in reliably calculating the total impact (of all fishery mortality from retained plus the fish caught but thrown back) on fish stocks from the fishery.

There are concerns about the high volume of discarded, unwanted fish, though there is no evidence that this is causing declines of other species, it cannot be discounted. ‘Discards’ can account for 40-60% of the total catch weight, and are generally thrown overboard. There is some evidence that the catch composition of the fishery is changing, which may indicate that there is an ecosystem change in the fishery which may be in part caused by fishing imoacts.

The fishery is set to introduce video monitoring across the fleet in 2024 which is welcome and could substantially address this issue, but it is notable that improving this information collection was also a condition of a fishery reform process in 2006 that was not followed through.