Favored habitat is well-oxygenated and clear water, such as over gravel riffles in mountain streams, springs, and along rocky lake shores.
[4] The favored habitat of a mottled sculpin is one rich in macroinvertebrate prey, which usually occurs in fast riffle areas[5] with clear substrates and moderate velocities between 0.20 m/s to 0.38 m/s.
[6] Spawning season for the mottled sculpin starts in April or May [7] with the males taking up residency in benthic rocks.
Climate change does not seem to be a threat to this species since they inhabit a wide range of temperature gradients throughout the United States.
However, one human activity that affects them is runoff from mining, which particularly is harmful to the newly hatched larvae and developing eggs.
[9] The mottled sculpin, Cottus bairdii, is known to inhabit a large geographical range in North America.
For the most part, the geographical range of the mottled sculpin has not changed throughout the years due to it is being a resilient fish and because it has a large temperature gradient in which it can reside.
Mottled sculpins are known for living in fast moving current areas where they feed primarily on bottom dwelling aquatic insects.
[4] The remaining 0.3% was made up of snails, fingernail clams, water mites, sculpin eggs and fish.
[4] Thus the mottled sculpin is not a major threat to game fish though it has been found to eat trout eggs.
[6] Female and immature mottled sculpins are commonly found in clean water rock substrates.
[7] At the beginning of the season the males will take refuge under flat-bottomed rocks, waterlogged wood or other rubble found in stream beds.
The reason for the species receiving no current management plan is due to its high abundance all over North America.
[10] 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.
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.