What effect does overfishing have on marine biodiversity?

Overfishing has a profound effect on marine biodiversity, primarily by disrupting marine ecosystems and leading to the depletion of fish populations. When fishing exceeds the natural reproductive capacity of fish species, it not only reduces the populations of targeted species but also impacts the entire food web. This disruption can lead to overpopulation of smaller fish or invertebrate species that may outcompete other important species, further altering the balance of the ecosystem.

Additionally, by removing large fish, which often play crucial roles as predators, the dynamics of the ecosystem are altered. This can result in a cascade of effects known as trophic cascades, where changes at the top of the food chain affect populations and health at lower levels. The decline in fish populations can also reduce genetic diversity, limiting the resilience of these species to adapt to changing environmental conditions. Thus, overfishing not only threatens individual species but also the ecological structures and functions of marine environments as a whole.