next up previous
Next: Meyer - Interpreting life's Up: Special Symposium - From Previous: Lockwood - Extinction and

McMillan et al. - Elemental Fingerprinting to Determine Larval Dispersal - an example using mytilid mussels

Elemental Fingerprinting to Determine Larval Dispersal - an example using mytilid mussels

Pat A. McMillan1 , L. A. Levin1 , B. J. Becker,1,2 , F. J. Fodrie1 , L. Rasmussen1

1 Scripps Institution of Oceanography, UCSD, La Jolla, CA 92093-0218, USA; 2 Cabrillo National Monument (National Park Service), USA,pmcmillan@ucsd.edu

Due to the small size of a typical planktonic larvae, tracking larval movement has been a difficult, if not impossible, task. Questions about larval transport focus largely on where larvae go (dispersal) and where larvae come from (connectivity). To answer these questions, studies addressing dispersal have included direct observations, mark-recapture experiments with tags and dyes; while studies addressing connectivity have included physical modeling and elemental tags. Technological advances have facilitated the use of elemental fingerprinting analysis to evaluate origins and trajectories of some planktonic larvae. Spatial variability in trace elemental characteristics of different coastal water masses is recorded in the geochemistry of biogenic carbonates (e.g., otoliths, statoliths, shells). Since shells are deposited throughout planktonic larval growth, they effectively record the environmental characteristics of different water masses or habitats occupied by larvae during development. We are using trace element fingerprinting methods to evaluate the spatial scale and strength of connectivity among Mytilus galloprovincialis and M. californianus populations in southern California. Our approach involves laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to resolve variation in larval shell chemistry that reflects recruit origins and temporal patterns of larval transport. We are also testing realized population connectivity determined from trace elemental analysis of recruit origins against a priori predictions based on circulation and metapopulation models. The information obtained regarding source populations and connectivity will increase our understanding of larval transport and retention as well as marine metapopulation dynamics, ultimately aiding in the conservation of coastal resources and design of marine protected areas.


next up previous
Next: Meyer - Interpreting life's Up: Special Symposium - From Previous: Lockwood - Extinction and
Peter Roopnarine 2005-04-12