Size selection and release of juvenile monkfish Lophius vomerinus using rigid sorting grids

Selectivity experiments, testing various rigid sorting grids in the cod-end section of a commercial monkfish ( Lophius vomerinus) and sole ( Austroglossus microlepis) trawl to size select and release juvenile monkfish, were carried out off Namibia in February 2000. The experiment involved the testing of Sort-V rigid sorting grids with circular openings of 115, 120 and 130 mm diameter (∅) and an EX-it sorting grid with circular openings of 130 mm ∅. Results obtained from testing the Sort-V single grid with circular openings of 115 mm ∅ showed the greatest potential in terms of the length at 50% retention, the selection range, the percent monkfish ≤30 cm released and the percent monkfish >30 cm retained. Further work is, however, needed and considerations, including the survival of monkfish released by a rigid sorting grid, for future monkfish selectivity experiments are provided.