- Say No
VIC, TAS, Commonwealth waters
- Assessing the stock status of commercial scallops is complicated by significant annual natural variability in population numbers.
- High numbers of scallops caught in the 2017 fishing season in the Commonwealth-managed fishery shows that recovery of the previously overfished stock has occurred, however it is not clear what impact the high catches of scallop will have on future scallop numbers.
- In TAS, neither of the two areas explored were considered to have high enough numbers of scallops to support fishing activity, which indicates that fishing in 2015 had once again depleted the stock.
- The VIC fishery was previously overfished and closed to support scallop recovery. Scientists and fishery managers have not been able to determine if there had been any stock recovery.
- Dredging for scallops is an inherently high-impact fishing method. Reports suggest that the nature of the trawled habitat in Commonwealth waters is low risk as it is predominantly soft sediments, but uncertainty over the habitat type of new areas being explored is of concern.
- There is a high degree of uncertainty regarding impact of dredging on habitat in TAS and VIC state waters, as little of the fished area has been mapped.
Note: Dive caught commercial scallops from Port Philip Bay in VIC and queen scallops SA would receive a green, ‘Better Choice’ rating. Scallops in both VIC and SA are collected by hand, a method of fishing that has no significant effect on other marine species or the habitat. There are minimal concerns over the health of scallop populations in these regions.
- Commonwealth Bass Strait Central Zone Scallop Fishery (2,697t in 2017)
- TAS Scallop Fishery (781t in 2015)
- VIC Ocean Scallop Fishery (7.6t in 2015-16)
The Commonwealth scallop fishery operates in Bass Strait, adjacent to scallop fisheries in VIC and TAS state waters. The TAS fishery operates in various regions around the island, dependent on where scallops can be found at the beginning of a fishing season. Some areas are closed to all scallop dredging activity. The VIC scallop fishery was closed due to stock status concerns 2010-2013 and has more recently reopened to conduct exploratory fishing to assess if the scallop stock has recovered.
It is fairly complex for fisheries scientists to assess the stock status of scallops, as their populations naturally fluctuate significantly from year to year, and are usually described as ‘boom and bust’. Stock status information comes from annual dredge surveys at the beginning of each fishing season, which is then used to set the quota for the permitted catch.
Commercial scallop stocks caught in the Commonwealth-managed fishery were previously defined as ‘overfished’ in fishery reports. Fishery managers initially closed extensive areas of fishing ground, and the whole fishery was closed between 2006-08 to allow for stock recovery. High numbers of scallops have been caught in recent fishing seasons, suggesting some recovery has taken place. It is not clear what impact the high catches of scallop will have on future scallop numbers.
Historically overfished areas of TAS state waters have also been permanently closed to scallop fishing. The fishery is currently managed on a rotational basis, with surveys identifying which areas have healthy enough stocks to support fishing activity. 2016 surveys only assessed two scallop beds on the east coast, with no understanding of scallop numbers in the rest of state waters. Neither of the two areas explored were considered to have high enough numbers of scallops to support fishing activity, suggesting fishing in 2015 had once again depleted the stock.
There is limited information on the nature of seabed historically and currently dredged in Tasmanian waters. There have been issues with poor quality scallops and low catch rates in some areas during the 2013 fishing season, although the reasons for this are not clear.
Although the VIC fishery was reopened to allow exploratory fishing and assess if recovery of the scallop stock had taken place, scientists and fishery managers were not able to determine if there had been any stock recovery.
Scallops live on the seafloor, and are caught using dredges that scrape along the bottom. Scallop dredging is inherently a high impact fishing method. The extent of impact of scallop dredging on bottom-dwelling species depends on where the dredgers operate – they generally dredge over soft sediments in Commonwealth waters and the risk to other species is considered low. However, continued exploration for new scallop beds, lack of knowledge about the seabed habitats and potential impacts on associated species is a concern. There is limited information regarding the nature of seabed that has been and is currently dredged in TAS and VIC state waters.