Slow to Recover

The slow, patient way sharks breed becomes a trap under industrial fishing. Many large shark species mature late and have just a few pups at a time, so a population stripped out by nets can take decades to climb back, if it ever does. Some apex species have fallen by the great majority of their former numbers.

Losing them sets off a trophic cascade, a chain reaction down the food web. One debated East Coast example: as big sharks thinned out, cownose rays may have surged and overgrazed shellfish beds — though scientists still argue over how much the missing sharks were really to blame.