Glossary |
D |
| danish-seines IMAGE | |
| A type of seine net consisting of two wings, a body and a bag. Operated from a boat, they are generally used on the bottom, where they are hauled by two ropes, usually very long, set in the water so as to ensure that as many fish as possible are driven or herded towards the opening of the net | |
| discarded catch | |
| That portion of the catch which is brought upon board but not retained. Catch may be discarded for a number of reasons, such as the catch is not the target species; it is of a poor quality or too young (see high grading); or it is surplus to an operations quota. | |
| dredges IMAGE | |
| Fishing gear which is dragged along the sea bottom, usually to collect molluscs. The vessel drops a steel frame dredge to the sea floor and it is dragged across the sea bed. The catch is held in a sort of bag or sieve which allows the water, sand or mud to run out. | |
| driftnets IMAGE | |
| A driftnet is a type of gillnet, kept on the surface, or just below it, by numerous floats and kept vertical by a weighted foot rope. These nets drift freely with the currently, either separately or, more usually, with the boat to which they are attached. Until the 1950s the size of driftnets was necessarily limited by the weight of natural fibres (hemp or cotton) from which they were made. However, the introduction of synthetic fibres (mono- and multi-filament plastic) and other advances in technology allowed the use of much larger nets (up to 50 km). These nets caused considerable controversy, particularly because of concerns over the level of bycatch, and the UN General Assembly has called for a world-wide ban on the use of driftnets longer than 2.5 km on the high seas. | |
| dropouts | |
| The term 'dropout' refers to that part of the catch that falls out of the net as it is being hauled in. In some cases, such as in the large-driftnet fisheries, this may be a considerable factor as the nets take a long time to be hauled in. Fish can drop-out while the net is in the water and after it leaves the water. These fish are often killed or damaged in the nets. | |