In what way does overfishing practically alter marine food webs?

Overfishing significantly alters marine food webs by disrupting food chains and leading to the depletion of fish populations. When certain fish species are overfished—often those that are key predators or prey—the balance of the ecosystem is thrown off. Predator fish may decline in number due to the lack of sufficient prey, while prey species may experience population booms, as their natural predators are removed. This can lead to an overpopulation of certain species and a subsequent imbalance in the ecosystem.

For example, if a particular species of fish is heavily targeted by fishing practices, it can reduce their population to unsustainable levels. This not only affects that specific species but also the various organisms that rely on it as a food source, thereby influencing multiple layers of the food web. Such disruptions can result in cascading effects, ultimately altering species composition, ecosystem stability, and the health of marine environments.

The other options suggest either a neutral or beneficial outcome from overfishing, which overlooks the significant ecological consequences observed in many marine habitats as a direct result of unsustainable fishing practices. Thus, understanding that overfishing leads to disruption and depletion is crucial in recognizing the need for sustainable management of marine resources.