Bioeconomics and Cacthability: Fish and Fishers Behaviour During Stock Collapse.

During periods of stock collapse, an increase in the catchability exhibited by many small pelagic fish is a consequence of two factors : their schooling habit and the remarkable efficiency of today's technology intensive fishing fleets. the net result is that a virtually constant catch per unit effort may be achieved regardless of stock size. We discuss the consequences of using a model where catchability is assumed constant for the management of fisheries on small schooling pelagic fish.