EFFECTS OF LATE-SEASON CATCH AND RELEASE ANGLING ON ANAEROBIC METABOLISM, ACID-BASE STATUS, SURVIVAL, AND GAMETE VIABILITY IN WILD ATLANTICSALMON (SALMO-SALAR)

The effects of catch and release angling on muscle physiology, surviva l and gamete viability were examined in wild Atlantic salmon (Salmo sa lar), just prior to spawning. Lactate in the white muscle increased to 37.4 mu mol . g(-1) after angling and recovered within 4 h. Muscle pH decreased from 7.46 at rest to 6.80 following angling, but returned t o resting levels within 2 h. White muscle concentrations of PCr, ATP, and glycogen were depleted by 74, 46, and 73%, respectively, following angling. ATP and PCr returned to resting levels within 2 h, but glyco gen did not recover until 12 h. The absence of significant changes in blood glucose indicated that the stress response was minimal in salmon angled under these conditions (6 degrees C). There were also no morta lities among 20 salmon that were angled and transported to the hatcher y. Multi-sea-winter (MSW) salmon (> 63 cm) required a longer period to angle to exhaustion than grilse (< 63 cm), but the physiological dist urbance was less in MSW salmon. The survival of eggs from angled and n onangled salmon was 98 and 97%, respectively. Together, these results support the strategy of a late-season catch and release fishery for At lantic salmon.