title: The control of an invasive bivalve, Corbicula fluminea, using gas impermeable benthic barriers in a large natural lake.
abstract: Anoxia can restrict species establishment in aquatic systems and the artificial promotion of these conditions can provide an effective control strategy for invasive molluscs. Low abundances (2-20 m(-2)) of the nonnative bivalve, Asian clam (Corbicula fluminea), were first recorded in Lake Tahoe, CA-NV in 2002 and by 2010 nuisance-level population densities (>10,000 m(-2)) were observed. A non-chemical control method using gas impermeable benthic barriers to reduce dissolved oxygen (DO) concentrations available to C. fluminea was tested in this ultra-oligotrophic natural lake. In 2009, the impact of ethylene propylene diene monomer (EPDM) sheets (9 m(2), n = 6) on C. fluminea beds was tested on 1-7 day intervals over a 56 day period (August-September). At an average water temperature of 18 °C, DO concentrations under these small barriers were reduced to zero after 72 h resulting in 100 % C. fluminea mortality after 28 days. In 2010, a large EPDM barrier (1,950 m(2)) was applied to C. fluminea populations for 120 days (July-November). C. fluminea abundances were reduced over 98 % after barrier removal, and remained significantly reduced (>90 %) 1 year later. Non-target benthic macroinvertebrate abundances were also reduced, with variable taxon-specific recolonization rates. High C. fluminea abundance under anoxic conditions increased the release of ammonium and soluble reactive phosphorus from the sediment substrate; but levels of unionized ammonia were low at 0.004-0.005 mg L(-1). Prolonged exposure to anoxia using benthic barriers can provide an effective short term control strategy for C. fluminea.
authors.affiliation: Tahoe Environmental Research Center, University of California Davis, Incline Village, NV 89451, USA. Marion.E.Wittmann.3@nd.edu
authors.forename: Marion E
authors.initials: ME
authors.lastname: Wittmann
authors.forename: Sudeep
authors.initials: S
authors.lastname: Chandra
authors.forename: John E
authors.initials: JE
authors.lastname: Reuter
authors.forename: S Geoffrey
authors.initials: SG
authors.lastname: Schladow
authors.forename: Brant C
authors.initials: BC
authors.lastname: Allen
authors.forename: Katie J
authors.initials: KJ
authors.lastname: Webb
mesh_terms: D000818:Animals; D057919:Biological Oxygen Demand Analysis; D003247:Conservation of Natural Resources / Q000379:methods*; D049874:Corbicula / Q000254:growth & development* / Q000378:metabolism; D020724:Elastomers / Q000737:chemistry*; D004784:Environmental Monitoring; D005030:Ethylenes / Q000737:chemistry; D000860:Hypoxia / Q000378:metabolism / Q000503:physiopathology; D060106:Lakes / Q000737:chemistry*; D010100:Oxygen / Q000032:analysis*; D010539:Permeability; D011156:Population Density; D012621:Seasons; D013499:Surface Properties; D014481:United States
chemical_list: D020724:Elastomers; D005030:Ethylenes; C505585:ethylene-propylene-diene-monomer; D010100:Oxygen