Sensitivity of early life stages of freshwater mussels (Bivalvia: Unionidae) to copper

Four life stages of freshwater mussels were tested for their sensitivity to copper and a metal-containing effluent. This permitted an assessment of the variability in sensitivity among the life stages in order to identify those stages most threatened in the wild from copper exposure. Glochidia, while held within the marsupia of the adult, the released or isolated glochidia, the encysted glochidia, and the gravid mussel were tested. Little effect on glochidia was detected following 30- day artificial stream exposures of gravid adults to 19.1 ug Cu/L and an effluent containing an average of 23.9 ug Cu/L. Isolated glochidia were killed by copper concentrations ranging from 20-80 ug/L in 24-hour exposures, with sensitivity increasing with hardness and temperature. Encysted glochidia were resistant to exposures up to 400 ug Cu/L. No significant effect on metamorphosis to the stage was detected. This is likely due to the encapsulation of the glochidium by the host fish. Juvenile mussels reduced their activity during 24-hour exposures to copper concentrations as low as 17 to 24 ug/L and concentrations of 30 to 42 ug/L caused mortality. Juvenile mussels and glochidia within the marsupia are probably the two most sensitive stages in the life cycle of the freshwater mussel. Copper pollution will have its greatest impact in the summer, during periods of high water temperature and low flow.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Biology

Department dc:contributor.department

Biology

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1990

Author dc:creator

• Jacobson, Peter James

Chairs dc:contributor.committeechair

• Cherry, Donald S.
• Neves, Richard J.

Committee members dc:contributor.committeemember

• Benfield, Ernest F.
• Heath, Alan G.
• Farris, Jerry L.

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-12172008-063755

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/46313