SS1.02 Geochemical Tracers in Calcified Structures: Implications for Fisheries Research
Date: Tuesday, June 11, 2002
Time: 11:30:00 AM
Location: Carson A
 
MullineauxLS, Biology Department, Woods Hole Oceanographic Institution, Woods Hole, USA, lmullineaux@whoi.edu
Mills, S, W, Biology Department, Woods Hole Oceanpgraphic Institution, Woods Hole, USA, smills@whoi.edu
Blusztajn, J, , Geology and Geophysics Department, Woods Hole Oceanpgraphic Instution, Woods Hole, USA, jblusztajn@whoi.edu
Hart, S, , Geology and Geophysics Department, Woods Hole Oceanpgraphic Institution, Woods Hole, USA, shart@whoi.edu
 
DOES ELEMENTAL COMPOSITION OF LARVAL CLAM SHELLS REFLECT THEIR NATAL ENVIRONMENT?
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We are investigating the use of environmentally-occurring trace elements retained in the larval shells of bivalves as tags of their natal habitat. In previous laboratory studies, we demonstrated that newly fertilized larvae of the soft-shell clam, Mya arenaria, reared in Pb-spiked seawater incorporated Pb into their larval shells at higher levels than those in unspiked water. Our present studies focus on two other objectives: 1) to characterize geographic and interannual variation in elemental composition of juvenile Mya shells; and 2) to measure elemental composition of the initial larval shell (prodissoconch I) in new recruits. Our initial ICPMS analyses of clam juveniles from polluted (Neponset River) and clean (Barnstable Harbor) sites show a significant difference in Pb content of juvenile shells between these two locations. We also have developed a technique for handling and analyzing the initial larval shell of Mya juveniles in a large-format Cameca 1270 Ion microprobe. The biggest challenge in this project is the handling of the very small (~90 mm diameter) larval shells and the elemental analyses of the tiny amounts of material they provide.