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Soil Investigations for Data Collection in the Delta Initial Study/Proposed Mitigated Negative Declaration 82 approximately 5 miles from any of the Impact Sites. Implementation of Mitigation Measures MM BIO-1 and MM BIO-12 would avoid and minimize adverse impacts to suitable habitat and would reduce potential impacts to molestan blister beetle to: Less than Significant with Mitigation Incorporated. Green Sturgeon (Acipenser medirostris) There are two DPSs of North American green sturgeon: the Northern DPS, which includes fish spawned in the Eel River and northward; and the Southern DPS, which includes all fish spawned south of the Eel River. The Northern DPS currently spawns in the Klamath River in California and the Rogue River in Oregon, and is listed as a Species of Concern (NMFS 2004). Only the Southern DPS, which is listed as a threatened species under FESA, is found in the Delta and the Sacramento River and its tributaries. In its final rule to list the Southern DPS as threatened (NMFS 2006a), NMFS cited threats as concentration of the only known spawning population into a single river (Sacramento River), loss of historical spawning habitat, mounting threats with regard to maintenance of habitat quality and quantity in the Delta and Sacramento River, and an indication of declining abundance based upon salvage data at the State and Federal salvage facilities. Included in the listing are green sturgeon originating from the Sacramento River basin, including the spawning population in the Sacramento River and green sturgeon living in the Sacramento River, the Delta, and the San Francisco Estuary. Adult North American green sturgeon are believed to spawn every 3 to 5 years, but can spawn as frequently as every 2 years (NMFS 2005a) and reach sexual maturity at an age of 15 to 20 years, with males maturing earlier than females. Adult Green Sturgeon enter San Francisco Bay in late winter through early spring and migrate to spawning areas in the Sacramento River primarily from late February through April. Spawning primarily occurs April through late July although late summer and early fall spawning may also occur based on the presence of larvae in the fall (Heublein et al. 2017). Historical and recent information confirms that both green and white sturgeons occasionally range into the Feather, Yuba, and Bear rivers but numbers are low (Beamesderfer et al. 2004). It is unknown whether green sturgeon historically spawned in the Feather River either downstream or upstream of Oroville Dam or the Thermalito Afterbay outlet. Spawning is suspected to have occurred in the past due to the continued presence of adult green sturgeon in the river below Fish Barrier Dam. This continued presence of adults below the dam suggests that fish are trying to migrate to upstream spawning areas now blocked by the dam, which was constructed in 1968. Little is known about rearing, migratory behavior, and general emigration patterns of juvenile Southern DPS Green Sturgeon. Based on captures of juveniles in the Sacramento River near Red Bluff, it is likely that juveniles rear near spawning habitat for a few months or more before migrating to the Delta (Heublein et al. 2017). Juvenile green sturgeon continue to exhibit nocturnal behavior beyond the