Fast Somatic Growth May Cause Recruitment Overfishing in Vendace (coregonus Albula) Gillnet Fisheries

Vendace is commonly assumed at low risk to recruitment overfishing. This assumption has been confirmed for boreal stocks but might not apply at lower latitudes. We evaluated the risk of recruitment overfishing at the southernmost extent of vendace populations by comparing fecundity, natural mortality, and fishing mortality of two stocks differing in growth with those of a population not subject to fishing. Although in one study lake vendace grew faster owing to high lake productivity and low stock density, and had substantially higher age-specific fecundity, intense harvest before first spawning negatively affected the stock's recruitment potential by reducing spawner abundance. In contrast, in the slow-growing stock, vendace entered the fishery after first spawning, and egg production per recruit was similar to that of the population not subject to fishing. We conclude that vendace stocks characterized by fast somatic growth may be at higher risk of recruitment overfishing, which can be reduced by protecting first-time spawners.