MIT 2010/01 Development of Mitigation Strategies: Inshore Bottom - PowerPoint PPT Presentation

MIT 2010/01 Development of Mitigation Strategies: Inshore Bottom Longlining Dave Goad Vita Maris

Objectives Survey skippers of vessels fishing bottom longlines in FMA2 to discuss mitigation and fishing practices Investigate the sink rates of bottom longlines on vessels carrying government observers 2

Bottom lining in FMA2 Target species # Sets % Bluenose 1761 48.8 Ling 1336 37.0 439 12.2 Hapuku / Bass School shark 36 1.0 Changeable 27 0.7 Ribaldo Other 8 0.2 600 thousands of hooks ling 300 bluenose 0 J F M A M J J A S O N D J F M A M J J A S O N D 2010 2009 month

Autoline and ‘Clip on’ Gear 5 cm

Fishing Gear Both change set-up to suit different target species Video Bluenose / Hapuku Ling Float Weight

Mitigation Night setting Tori lines Offal management Not a lot of processing School shark, sometimes ling Separated from next set Old baits

Sink rates - Ling 0 5 depth (m) 10 15 0 60 120 180 time after TDR left vessel (s)

Sink rates - Bluenose 0 5 depth (m) 10 15 0 60 120 180 time after TDR left vessel (s)

Sink Time to 5m 400 Autoliner bluenose 300 time (s) 200 Clip on bluenose 100 Snapper Clip on ling 0 all SNA G BNS1 G BNS2 H BNS1 K BNS/ J HPB 1 J LIN1 F LIN1 F LIN2 n=191 n=56 n=22 n=77 HPB1 n=32 n=24 n=69 n=60 n=10

Distance behind vessel TDRs reached 5m 800 Autoliner bluenose 600 Distance (m) 400 Clip on bluenose Snapper 200 Clip on ling 0 all SNA G BNS1 G BNS2 H BNS1 K BNS/ J HPB 1 J LIN1 F LIN1 F LIN2 n=191 n=56 n=22 n=77 HPB1 n=32 n=24 n=69 n=60 n=10

Recommendations Weight spacing Speed Line Tension Float rope extensions? Investigate best practice line weighting Quantify tori line protection