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

The effects of catch and release angling on muscle physiology, survival and gamete viability were examined in wild Atlantic salmon (Salmo salar), 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 to 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 glycogen 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 mortalities among 20 salmon that were angled and transported to the hatchery. Multi-sea-winter (MSW) salmon (> 63 cm) required a longer period to angle to exhaustion than grilse (< 63 cm), but the physiological disturbance was less in MSW salmon. The survival of eggs from angled and nonangled salmon was 98 and 97%, respectively. Together, these results support the strategy of a late-season catch and release fishery for Atlantic salmon.