Sediment from these natural features is also responsible for periods of unseasonal turbidity in these streams. Stream temperatures are warmer than optimum for fish in many of the streams in this analysis area. Salmon and trout play an important role in the ecology, economy, politics, history and culture of natural and human systems in and near the watershed. The mainstem Rogue River between Marial and Agness is a major migration corridor for anadromous fish. It is a link between the coast range, inland valleys and southern Cascade Mountains.
Few adults spawn in the mainstem, and redd success here is naturally very low.
Powerful winter flows turn the gravels and destroy fish eggs. Shasta Costa and Foster Creeks are the only tributaries in the watershed with extensive low-gradient reaches capable of producing salmon and steelhead in abundance. Stair Creek is unique in that it provides extensive resident trout habitat. The numerous small, steep face tributaries to the Rogue River generally produce a small number of steelhead and cutthroat in their lowest reaches. They can be important slack-water refuges from high winter storm flows in the mainstem.