A fishery collapse is when: A. a commercially important species goes extinct B. a commercially important species cannot sustain itself. C. the annual catch declines to less than 10% of its historic catch. D. a larger than normal catch in one year reduces the population to 10% of its historic abundance.

C. the annual catch declines to less than 10% of its historic catch.

Explanation:

Fishery collapse can be defined as the situation whereby the annual catch of fish reduces by 10% of its historic catch.

This can be due to :

a. Advancement in fishing technology

b. Over fishing

c. Destructive fishing practices

d. Natural conditions.

We can prevent fishery collapse by

a. Substituting our consistent consumption of fishes with other sea foods like scallops, crabs, shrimps, octopus, mussels e.t.c. This would help to reduce the rate of over fishing which can lead to fishery collapse.

b. Regulations should be put in place to monitoring the rate and ways in which fishing is carried out. This can help to prevent fishery collapse.

Fishing licenses should also be given out to fishermen as this would help to monitor and regulate who carries out the fishing as well as prevent over fishing.