Fisheries-induced life-history changes recover in experimentally harvested fish populations.

Abstract

Overfishing is one of the greatest threats to fish populations. Size-selective harvesting favours faster juvenile growth, younger maturation, small adult body size and low reproductive output. Such changes might be slow to recover and ultimately threaten population fitness and survival. To study the recovery potential of exploited experimental populations, we compared life-history traits in three differently size-selected experimental lines (large-selected, small-selected and random-selected) after five generations of harvesting and 10 subsequent generations of recovery (i.e. cessation of harvesting). We show that after a recovery period twice as long as the harvesting period, the differences in adult body size among the selection lines have eroded. While there was still a significant body size difference among the selection lines, this did not translate to differences in reproductive success. Although size-selective harvesting causes phenotypic changes in exploited fish populations, we show that such changes are reversible if the recovery period is long enough.