PT08 Chronic and Sublethal Sediment Toxicity
Exhibit Hall
8:00 AM - Tuesday
(PT131) Biomarker responses and growth in Macoma spec. outplanted at field sites in California marshes.
Werner, I.1, Judah, L. 1, Brooks, A.2, Grosholz, E.1, Higashi, R.1, Datta, S.1, Kuivila, K.3, 1 UC Davis, Davis, CA, USA2 UC Santa Barbara, Santa Barbara, CA, USA3 US Geological Survey, Sacramento, CA, USA
ABSTRACT- Clams of the genus Macoma are surface deposit feeders living in mud or silt in marshes and estuaries along the coast of California. As part of an effort to identify and characterize indicators of environmental stress in estuarine ecosystems (Pacific Estuarine Ecosystem Indicator Research Consortium, PEEIR), field experiments were conducted to determine whether growth in Macoma petalum and Macoma nasuta was linked to biomarkers of cellular stress (stress proteins, lysosome membrane damage). To measure growth during field exposures, clams were stained for 24 h in a 100mg/L calcein solution prior to outplanting experiments. Clams were then transported to field locations in San Francisco Bay, Tomales Bay and Carpinteria Marsh (Santa Barbara) and outplanted in leached cages (3-4 clams per cage) in three blocks consisting of eight cages. Two rows of 4 cages were aligned parallel to the channel, and cages were spaced 0.5 m apart. Blocks were spaced 1m apart. Cages were constructed of 3-in diameter PVC, 20 1-cm holes were drilled to aid water circulation and the top end was covered with 0.5-cm plastic mesh. Samples were retrieved from each block after 2, 4 and 11 weeks, and snap-frozen. Clams were analyzed for growth, stress proteins and lysosomal membrane damage. Preliminary data indicates that growth was reduced, and stress protein levels were significantly elevated at several field sites. Data is related to dominant contaminants present in sediments and clams.
Key words: Macoma spec, sediment toxicity, wetlands, sublethal effects