As seen in the given passage, the main issue is that of the misuse of government subsidies. Though such subsidies are intended to help struggling fisheries, it has also led to some unintended effect.
One such unintended effect is that these subsidies support overfishing. Overfishing is when more than the required or supported number of fishes are put in a single space or area. so, what the author presents is that government subsidies unintentionally help such overfishing that it has become a problem rather than helping it.
