Quick questions on Fisheries and marine resource management (QCE Marine Science Unit 4)

Overfishing is harvesting faster than a population can replace itself, so the stock declines. If it continues, the population can collapse and may not recover even when fishing stops, because too few breeding adults remain. Slow-growing, late-maturing species (such as many sharks and the orange roughy fished in southern Australian waters, which lives for over a century) are especially vulnerable because they replace themselves slowly.

Bycatch is the non-target species caught and usually killed alongside the target catch, such as turtles, dugongs, dolphins and juvenile fish caught in trawl nets. Bycatch can drive declines in species that are not even being fished, which is why turtle excluder devices and bycatch reduction devices are required in Queensland prawn trawl fisheries.