SS1.02 Geochemical Tracers in Calcified Structures: Implications for Fisheries Research
Date: Tuesday, June 11, 2002
Time: 10:00:00 AM
Location: Carson A
 
LevinLA, Scripps Inst. Oceanography, La Jolla, USA, llevin@ucsd.edu
Becker, B, J, Cabrillo (NPS)/SIO, La Jolla, USA, bjbecker@ucsd.edu
McMillan, P, A, SIO, La Jolla, USA, pmcmillan@ucsd.edu
Fodrie, F, J, SIO, La Jolla, USA, ffodrie@ucsd.edu
Largier, J, , SIO, La Jolla, USA, jll@coast.ucsd.edu
DiBacco, C, , WHOI, Woods Hole, USA, cdibacco@whoi.edu
Walther, S, , SIO, La Jolla, USA, shellywalther@hotmail.com
 
CONSTRUCTION OF LARVAL TRAJECTORIES USING TRACE ELEMENT CONCENTRATIONS IN MYTILID LARVAL SHELLS
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Using elemental fingerprinting, we are evaluating the sites of origin and larval trajectories of mytilid mussel recruits in southern California. Analysis of trace metal composition of larval shells offers an opportunity to reconstruct the environmental conditions and therefore the approximate trajectory the mussels experienced during planktonic development. Key steps involve (1) defining the relationship of seawater T, S and metal concentration to shell composition, (2) determining location-specific differences in shells of larvae and new recruits, and (3) documenting temporal, ontogenetic and other vital effects on shell composition. Based on ICP-MS analyses, differences in seawater chemistry have been detected among bay and coastal sites in southern California. Mytilid shell elemental fingerprints derived from solution-based (ICP-OES) analyses yield differences by site of collection, species and shell size. Ongoing, high resolution, fine scale (8-20 micron) analysis of shells (LA-ICP-MS) of outplanted larvae and new recruits will allow reconstruction of larval dispersal trajectories and comparisons with predictions based on a physical connectivity model created for the southern California bays and coastal zone. Ultimate goals are to assess the extent of self-seeding and exchange between populations.