Regional Advisory Council. A stakeholder-led forum to give fishermen and other interested parties, including environmental organisations and consumer groups, a say in the way the Common Fisheries Policy is operated. RACs are the formal channel through which stakeholders can give suggestions and advice to the European Commission and the Council of Ministers.

The number of young produced by a given stock each year, or the numbers of new fish which are added to the exploitable portion of the stock resulting from growth or migration of smaller fish.

An assembly constructed from rubber discs or 'wheels' fitted through the ground rope, with a second wire passing through the discs off centre. This prevents the discs from rotating freely. When the ground rope snags on a seabed obstruction, the discs try to turn and the second wire winds around the ground rope and acts as an accumulator spring. Eventually, the tension becomes too much and as it is released, the trawl 'hops' free of the obstruction.