INSTITUTE FOR MARINE AND ANTARCTIC STUDIES 2012 May/June BSCZSF Surveys IMAS - in collaboration with the Tasmanian State Government

234* sample tows conducted by 2 vessels in the BSCZSF in May/June Three main areas: 1 (Western Protected Area), 2 (2009 open area and viable area 10), 3 (Southern Protected Area), Area 4, Area 5* (not shown) and Area 6 (Lady Miriam – Edge of 2011 Area)

Area 1 (Western Protected Area): 48 shots (NS only) Average density 14 kg/1000 m 2 Ave New dead shell per shot 6%

Biomass Estimate (33% efficiency)

Area 1 (Western Protected Area)

Size Frequency (2385 scallops NS only)

November 2011 Size Frequency (965 scallops)

Area 2 (2009 Open Area and Viable Area 10): 40 shots (Anne B only) Average density 10 kg/1000 m 2 Ave new dead shell per shot 16%

Biomass Estimate (33% efficiency)

Size Frequency (1463 scallops AB only)

November 2011 Size Frequency (1053 scallops)

Area 3 (Southern Protected Area): 48 shots Average density 9 kg/1000 m 2 Ave New dead shell per shot 23%

Biomass Estimate (33% efficiency)

Size Frequency (761 scallops)

November 2011 Size Frequency (694 scallops)

Area 4: Size Frequency (386 scallops) Average density 5 kg/1000 m 2

Area 4: November 2011 Size Frequency (137 scallops) Average density 5.4 kg/1000 m 2

Summary Only Area 4 was below the discard rate, but had low densities. Area 1 scallops ranged from 69 to 123 mm and the discard rate was 25.1%. A large number of the undersized scallops were in the mm size classes. Area 1 had an average scallop density of 14 kg per 1000m 2. This equates to approximately 0.15 scallops per m 2 of the benthos. Area 3 appears to have declined since November 2011.