Marine and Freshwater Fishes

Abstract

The current list of freshwater fishes known from Virginia stands at 206 species, including 10 that are diadromous and 4 other ranked as freshwater-estuarine. Of the 197 native freshwater species, 3 are considered as endangered, 6 threatened, and 25 are so restricted in distribution and/or so rare in Virginia that they are listed as of special concern. Additionally one of the 197 species is completely extinct, another is extirpated from the state, and a third has one of its subspecies extirpated from the state. Five other species are of undetermined status, and at least one of these probably is extirpated. The freshwater ichthyofauna as a whole is affected by a number of factors adverse to survival. Major factors include excessive turbidity and silt loads, domestic and chemical pollution, channel modification, disruption of natural temperature regimen, reduction of instream flow, impoundment, and competitive species interactions (in one case following introduction of a non-native fish species). Virginia's marine and estuarine fish fauna is characterized by its dynamic nature. Most elements of the fauna are migratory. All are highly mobile. Only 3 species of marine or estuarine habitats are recognized for inclusion in the list of Virginia threatened and endangered biota. These are 2 anadromous fishes, the shortnose sturgeon (endangered), Atlantic sturgeon (threatened) and an estuarine fish, the marsh killifish (special concern). Some of the marine and estuarine problems are dredging, thermal pollution, chemical pollution including oil spills and spraying for insects, alteration of marshes to drier habitats, and overfishing of commercially important species.

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