Long-Term Surveys Show Invasive Overbite Clams (Potamocorbula amurensis) are Spatially Limitedin Suisun Marsh, California

San Francisco Estuary and Watershed Science

Robert E. Schroeter¹  Teejay O'Rear¹  Peter B. Moyle¹  Jason Baumsteiger²  Jonathan D. Cook³ 

[1] Center for Watershed Sciences and Dept. of Wildlife, Fish and Conservation Biology,University of California, Davis;Center for Watershed Sciences, University of California, Davis;Dept. of Wildlife, Fish and Conservation Biology, University of California, Davis;

关键词: Bivalve, salinity, otter trawls, GAM models, wetlands, restoration;   

DOI  :  

来源: DOAJ

【 摘 要 】

https://doi.org/10.15447/sfews.2017v15iss2art6

The overbite clam (Potamocorbula amurensis) is a major invasive species in the San Francisco Estuary, California, and has been implicated in the decline of pelagic productivity and native fish species. Little is known of its impact on Suisun Marsh, a large brackish tidal region of the estuary. We looked at the abundance and spatial distribution of clams in the marsh, including examining the influence of water quality, using long-term (1988–2015) otter trawl surveys. Temporal trends indicated that overbite clam abundance has been increasing, but adult clams were spatially restricted to a single large slough (Suisun). Clams were absent from most interior channels, limiting their overall effect on the marsh aquatic ecosystem. Abiotic variables, particularly salinity, proved important predictors of overbite clam abundance, although the variables examined alone could not explain overbite clam distributions. We propose that connectivity, detritus loads, and/or predation pressure may work in conjunction with abiotic variables to cause poor survival rates for recruits in interior marsh sites, keeping the distribution limited. Overall results are encouraging for restoration projects in brackish tidal marshes that need to deal with overbite clams.

【 授权许可】

Unknown