Print PageThis presentation synthesizes data from fish ecology, archaeological ichthyofaunal remains, ethnographic sources, and traditional knowledge to reconstruct the landscape of the lower Cosumnes River watershed prior to Euro-American settlement. The Cosumnes River is located in the northeastern portion of the Sacramento-San Joaquin Delta of Central California. Prior to European settlement, this area was Plains Miwok territory, possibly supporting a population density of 57 individuals per square mile along riparian areas. Our hypothesis is that floodplain biodiversity and native fish productivity benefited from burning and other traditional management practices utilized by the Plains Miwok and other Native Californians. Ethnographic and archaeological data were used to reconstruct pre-European settlement traditional management practices. Ethnographic data was gathered from historical literature and local Miwok informants. Archaeological data from four Cosumnes River sites dating to the Late Period (1200 to 100 B.P.) were analyzed and compared to records of modern fish abundance and floodplain habitat modifications.
Results/Conclusions
The results indicate that traditional management practices, such as burning and harvesting plant materials in the floodplain, may have increased the productivity of floodplain rearing habitat, thereby increasing fish growth and reducing fish mortality. Loss of traditional tending practices compounded by widespread degradation of habitat, alteration of flows, and introduction of exotic species has resulted in the catastrophic decline of most California native fish species. Minnows and other native fishes that were originally abundant in lowland lakes, tule marshes, sloughs and slow moving sections of the river have diminished significantly or disappeared from pre-European settlement numbers. Just over 50% of the fish species present within the archaeological record for the study area are now either on watch status, threatened, of special concern, or extinct. The Sacramento perch (Archoplites interruptus), which composed 42% of the entire archaeological icthyofaunal record presented here, is no longer present within the study area. The thicktail chub (Gila crassicauda), which composed 32% of all the assemblages, is now extinct. Chinook salmon (Oncorhynchus tshawytscha) which are referred to in the ethnographic record are listed as species of special concern. Based on this synthesis of multiple sources of information, it is likely that traditional tending practices optimized habitat productivity and fecundity for California native fish species, contributing to their resiliency to fluctuating environmental conditions. In conclusion, information provided here may provide valuable cultural and ecological data for habitat restoration and conservation of native California fish species.
