A Fishery collapse can be defined as the condition in which the composition of different species of fishes forming a food chain or a food web and located in a marine or aquatic community undergoes a drastic alteration.
The alternation can be caused due to environmental or anthropological factors.
A fishery collapse usually affects the larger fish population like sharks and tuna as their commercial and economic demand is higher.
Excessive fishing cause the population of the large fishes to decline without affecting the small fish population.
This is because the small fishes do not have high economic or commercial demand, hence they have very less probability of being angled or captured.
Natural selection is when the organisms that have the better adaptation so they survive. In this case, the green was the better adaptation so they lived.
