2019/20 Scallop Status (Released Dec 21)
|Stock||Tasmanian Scallop Fishery|
|Indicator(s)||Size structure, catch, effort and CPUE trends|
The Tasmanian Scallop Fishery (TSF) is managed with a harvest strategy where surveys are undertaken to estimate abundance and decision rules are used to open areas to fishing with total allowable catches (TACs) based on the estimated abundance.
Biomass in the Tasmanian Scallop Fishery (TSF) is historically overfished (Caton and McLoughlin, 2004), with recruitment and production levels now affected. In 2013, 2014 and 2015, surveys generally found low scallop densities and limited evidence of successful recent recruitment but did identify two beds (one on the north-west coast and the other on the east coast) containing commercial quantities (Ewing et al., 2016). Surveys in 2016 and again in 2017 generally only found very low levels of scallop abundance and limited evidence of successful recruitment, with no area considered to contain commercially viable quantities in either year (Ewing et al., 2017; Semmens et al., 2018). This includes the east and north-west coast beds fished in 2013-2015, which appeared to have been fished down to a commercially unviable density, with no subsequent recruitment evident. Given the results of the 2016 and 2017 surveys, there was a low expectation that conducting pre-season surveys in 2018 and 2019 would yield the presence of commercially viable scallop beds, and as such, pre-season surveys were not conducted.
In 2020, a pre-season survey was conducted, consisting of 635 survey dredge tows and around 1300 commercial tows across all areas of the fishery. Although the survey results were dominated by low to moderate densities of legal sized scallops, several areas demonstrated signs of recruitment that suggest the possibility of supporting a tightly managed commercial fishery in the near- to medium-term.
Fishing mortality is managed with the aim of restricting catches to beds of mature scallops near the end of their lifespan. The combination of the harvest strategy and depleted biomass has led to a history of closures due to low abundance. In recent times, the fishery was closed between 2000-2002 and again between 2009 and 2010. Areas with commercial density of scallops towards the end of their lifespan were opened to fishing each year between 2013 and 2015. The fishery was closed between 2016 and 2020.
On the basis that biomass is depleted, and large-scale recruitment is impaired, but that current restrictions are effectively limiting fishing mortality, and there is evidence of recovery of recruitment, the TSF is classified as recovering.
Learn more about what each stock status classification means on our Stock Status Classifications Information Page: