title: The effects of salinity exposure on multiple life stages of a common freshwater mussel, Elliptio complanata.
abstract: There is growing concern over the effects of increased salinization on freshwater organisms, which are largely unknown for unionid mussels. Adult and larval Elliptio complanata were exposed to low-level salt concentrations to determine the effects on mussel survival, physiology, and reproduction. Adults were exposed to salt concentrations of 0 parts per thousand (ppt), 2 ppt, 4 ppt, and 6 ppt NaCl and monitored over 7 d for mortality. Treatment groups exposed to 6 ppt and 4 ppt experienced 50% mortality at day 3 and day 4, respectively, with complete mortality by day 7. No mortality was observed in the other treatments. Adults were also exposed to sublethal salinity levels of 1 ppt and 2 ppt NaCl for 4 wk to determine physiological consequences of prolonged salinity exposure. Mussels exposed to 1 ppt and 2 ppt experienced reduced metabolic rates within the first 24 h of exposure that recovered to control levels in the 1-ppt treatment within 7 d. Metabolic recovery did not occur in the 2-ppt treatment by the end of 28 d. Glochidia exposed to 3-ppt NaCl during attachment to their host fish suffered a reduction in attachment success and metamorphosis, resulting in a 10-fold reduction in the number of juveniles produced per host fish. The present study demonstrates that low levels of salt can have a dramatic effect on the reproduction, physiology, and survival of freshwater mussels.
authors.affiliation: US Geological Survey Leetown Science Center, Northern Appalachian Research Laboratory, Wellsboro, Pennsylvania, USA.
authors.forename: Carrie J
authors.initials: CJ
authors.lastname: Blakeslee
authors.forename: Heather S
authors.initials: HS
authors.lastname: Galbraith
authors.forename: Laura S
authors.initials: LS
authors.lastname: Robertson
authors.forename: Barbara
authors.initials: B
authors.lastname: St John White
mesh_terms: D000811:Anguilla; D000818:Animals; D005618:Fresh Water; D007814:Larva / Q000187:drug effects / Q000378:metabolism; D008675:Metamorphosis, Biological / Q000187:drug effects; D012098:Reproduction / Q000187:drug effects; D054712:Salinity; D012965:Sodium Chloride / Q000633:toxicity*; D049876:Unionidae / Q000187:drug effects* / Q000378:metabolism
chemical_list: D012965:Sodium Chloride
keywords: Glochidia; Host fish; Salinization; Survival; Unionid