Health & Welfare
The use of larger and deeper tanks can reduce building, labor and other aquaculture production costs. However, the ability to grade and transfer large numbers of fish is more challenging when using large tanks. In a comparison of the effectiveness of a purse seine and a hinged clamshell to crowd fish in large tanks, the latter was easier to control and less stressful to salmonids. With a slotted bar rack in a side panel of the clamshell crowder, fish were simultaneously graded in size.