147. Removal from water and handling are stressful to a fish, eliciting a maximal emergency physiological response, nevertheless it may be advantageous and necessary for good welfare. Where handling is necessary it should be carried out by the least stressful method available and sedation may be appropriate. Where hand-nets are used to handle fish they should present a smooth surface to the fish. Fish taken from water are out of their natural environment and adequate support must be given particularly when dealing with large, heavy fish; they should not be held up by the tail. Indications of poor handling include fin and skin injury and scale loss, to which salmon smolts are particularly susceptible.
148. Procedures and equipment should be designed to minimise injury. Personnel carrying out any handling procedures should have adequate training to avoid undue stress and injury to the fish. Handling frequently involves crowding but must be carried out so that there is adequate oxygenation of the water.
149. In general, the longer the period of stress the greater the injury and mortality, thus reducing the time taken in handling fish will encourage a more rapid recovery. The use of vacuum pumps to move fish around the site is common and some sectors of the industry have expressed a preference for this method because there is less injury to the fish.