Sacramento suckers (Catostomus occidentalis occidentalis), Tule perch (Hysterocarpus traskii), Hitches (Lavinia exilicauda), Hardheads (Mylopharodon conocephalus), Sacramento blackfish, and Sacramento pikeminnow (Ptychocheilus grandis). Many of these fishes still occupy the creek, although the number of introduced exotic fishes continues to increase. Exotic fish species such as the largemouth and Smallmouth basses (Micropterus salmoides and Micropterus dolomieui) respectively, were introduced to Alameda Creek (and the Napa River) by Livingston Stone in 1874. There is historical evidence of beaver in the Alameda Creek watershed. In 1828 fur trapper Michel La Framboise travelled to "the missions of San José, San Francisco Solano and San Rafael Arcángel. La Framboise stated that "the Bay of San Francisco abounds in beaver", and that he "made his best hunt in the vicinity of the missions". Alexander Roderick McLeod reported on the progress of the first Hudson's Bay Company fur brigade sent to California in 1829, "Beaver is become an article of traffic on the Coast as at the Mission of St. Joseph alone upwards of Fifteen hundred Beaver Skins were collected from the natives at a trifling value and sold to Ships at 3 Dollars". In the 1840s Kit Carson was granted rights to trap beaver on Alameda Creek in the East Bay where they "abounded...from the mouth of its canyon to the broad delta on the bay". Physical evidence of beaver include faunal remains in the Arroyo de la Laguna tributary recovered in an archaeological site west of Interstate 680. Beaver may be beneficial to efforts to restore salmonids in Alameda Creek as beaver ponds benefit oversummering salmonid smolts by raising the water table which then recharges streams in the dry summer season and also by providing perennial deep pools when streams are only seasonal. Conservation In January, 2011, the San Francisco Public Utilities Commission won approvals to construct a replacement dam just downstream from the existing earthen Calaveras Dam, which has been maintained at 40% of capacity because of seismic concerns. However, construction of a fish ladder to provide steelhead (Oncorhynchus mykiss) access to the waters above the dam were deemed not feasible because at , it would be the tallest fish ladder in the country, and would cost $40 million. Steelhead have not had access to spawning streams above Calaveras Dam since it was built in 1925. However, environmentalists won concessions from the SFPUC to assure adequate water releases from the new dam to improve