sculpin is currently not federal or state listed for being threatened or endangered. In New Mexico the species is given limited protection. The reason for the species receiving no current management plan is due to its high abundance all over North America. Its high prevalence is due to the species tolerance' for all types of environment. Although the species is not threatened anywhere in North America, it has received attention in recent areas in the Western United States due to its absence in some streams that are highly populated with trout species but not sculpins. This was odd since the two species usually coexist in similar habitats. The problem was that the streams absent of sculpin had high concentrations of zinc. One study showed that mottled sculpin are the third most sensitive species to high levels of zinc. The reason this occurring is because the U.S. Environmental Protection Agency (EPA) uses trout species to determine the water quality criteria (WQC) for zinc. Therefore, the WQC standards are not good enough to protect all species of fish. In southeast Minnesota there are plans to rebuild the sculpin population in streams where the water quality was once unfavorable for the species but has since been improved. The next step is to introduce 200 mottled sculpin a year until the population is showing signs of a comeback in the local streams. However zinc is not the only metal threatening mottled sculpin populations. One study found mottled sculpins were also more sensitive to levels of copper and cadmium than other species of fish. The leading causes of increase of these three metals into aquatic environments are from mining, the burning of coal, steel production, and smelting metals. References Cottus (fish) Fauna of the United States Fish of the Great Lakes Fish described in 1850