Managing evolving fish stocks

Darwinian evolution is the driving process of innovation and adaptation across the world’s biota. Acting on top of natural selection, human-induced selection pressures can also cause rapid evolution. Sometimes such evolution has undesirable consequences, one example being the spreading resistance to antibiotics and pesticides, which causes suffering and billion-dollar losses annually (1). A comparable anthropogenic selection pressure originates from fishing, which has become the main source of mortality in many fish stocks, and may exceed natural mortality by more than 400% (2). This has, however, been largely ignored, even though studies based on fisheries data and controlled experiments have provided strong empirical evidence for fisheries-induced evolution over a range of species and regions (see table, page 1248). These evolutionary changes are unfolding on decadal time scales—much faster than previously thought.