|Budget Amount *help
¥4,810,000 (Direct Cost : ¥3,700,000、Indirect Cost : ¥1,110,000)
Fiscal Year 2011 : ¥1,430,000 (Direct Cost : ¥1,100,000、Indirect Cost : ¥330,000)
Fiscal Year 2010 : ¥1,430,000 (Direct Cost : ¥1,100,000、Indirect Cost : ¥330,000)
Fiscal Year 2009 : ¥1,950,000 (Direct Cost : ¥1,500,000、Indirect Cost : ¥450,000)
On-board survey of the fishing gear loss rate in the crab trap fishing ground in the Sea of Japan, interview surveys of fishing gear loss rates in 3 countries and under-water observation of the consequent changesin entry and death of crabs in deliberately-set derelict traps were conducted. The ghost-fishing mortality in a trap was represented with an experimental and theoretical equation as; f_g(t) = a(1-c^t)・(1-b)^t. Annual gear loss rates were 0.2 in Japanese crab-trap fisheryat the Sea of Japan, 0 in coastal fisheries in Thailand and Tanzania, while 0.08 to 0.23 in coastal fisheries in Southern Kyushu. Escape-ring as a countermeasure against ghost fishing was proved to have an additional function to increase large individuals in catch.