From 2001 to 2005, the populations of smallmouth bass in the Chesapeake Bay decreased 80%, reported The Washington Post.

Researchers point to a combination of factors as the reason behind this massive decline in the population of that which was once so abundant species in the Chesapeake Bay.
Pollution, parasites, disease, and endocrine disruptors that are altering the sex of males are among the causes scientists pointed.

“More often than not, we catch fish that is sick and undersized, not even worth a snapshot as proof of capture,” said an amateur fisherman.

Fishermen around the area reminisce with nostalgia the days when they could catch and release hundreds in one night.

“It’s all gone now,” said James Newton, an old fisherman. “All gone.”

The Susquehanna River is the most affected by this dramatic shrinking on the population of smallmouth bass.

According to “The Washington Post,” the Pennsylvania Fish and Boat Commission's has called on the Environmental Protection Agency to declare a 98 mile stretch of the river as "impaired" under the Clean Water Act, which could happen in the next days.

That coming to pass, EPA would ask farmers and cities to regulate their nitrogen and phosphorus runoff into the river more aggressively than current standards. Opponents of the move state that this would only help one cause of the declining fish population, and that fish are dying of mysterious diseases even in the cleanest water in the state.

"We don't make impairment designations based on the health of a species of fish. We make them based on water quality..,” said Kevin Sunday, a spokesman for the Environmental Protection Agency.

Smallmouth bass is known for acting like a barometer for the overall fish population's health, as they are particularly sensitive to disease and pollution.

Usually, if something is effecting the smallmouth bass population, then it will soon start to affect other fish in the ecosystem.