Wolf Creek near the confluence with the East fork carson river

 

The Carson LCT Management Unit (CMU) encompasses several 8-digit United States Geological Survey (USGS) hydrologic units, including the: Upper Carson (hydrologic unit code (HUC) 16050201), Middle Carson (HUC 16050202), and Carson Desert (HUC 16050203). Currently, there are four potential LCT recovery populations in the CMU. All are in relatively small headwater stream fragments in the East Fork of the Carson River (Upper Carson hydraulic unit) that are unlikely to be resilient without increasing the amount of habitat available to each of them. The only realistic and effective conservation action is to reconnect these populations into one, large and interconnected population that would allow for the expression of migratory life-history characteristics and a large enough population size to maintain genetic health through time. Serendipitously, this is also the only shovel-ready, realistic way the 3rd CMU recovery objective. The Middle Carson and Carson Desert hydrologic units were historically occupied by LCT, but currently contain little suitable trout habitat due to mostly anthropogenic impacts (i.e., barriers, water diversions, reservoirs, higher water temperatures). The Upper Carson hydrologic unit contains ample additional, high-quality river and stream habitats within the most climate-resilient region of LCT’s range (Sierra Nevada Mountains).

The updated objectives for LCT in the Carson Management Unit are:

CMU 1) Remove threats (i.e., competition, predation, hybridization) associated with non-native trout species to allow for the formation and/or maintenance of CMU LCT populations identified in CMU objectives 3–4; and

CMU 2) Ensure all habitats required to meet CMU objectives 3–4 function ecologically. In some cases, this may require restoration and/or management changes; and

CMU 3) Provide enough stream and river habitat to allow for the expression of migratory life-history characteristics in at least 1 recovery population (i.e., interconnect population); and

CMU 4) Establish at least 2 additional recovery populations in the Upper Carson hydrologic unit, spatially separated from each other and the interconnected population required by CMU objective 3.