Otolith chemistry to describe movements and life -history parameters of fishes: hypotheses, assumptions, limitations and inferences

Abstract

E-mail: travis.elsdon@adelaide.edu.au, bronwyn.gillanders@adelaide.edu.au 2Southwest Fisheries Science Center, Fisheries Ecology Division, Santa Cruz, CA 95060, USA E-mail: Brian.Wells@noaa.gov 3University of California Santa Cruz, Long Marine Laboratory, Santa Cruz, CA 95060, USA 4Population Ecology Division, Bedford Institute of Oceanography, Dartmouth, Nova Scotia B2Y 4A2, Canada E-mail: campanas@mar.dfo-mpo.gc.ca 5Center for Quantitative Fisheries Ecology, Old Dominion University, Norfolk, VA 23529, USA E-mail: cjones@odu.edu 6State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA E-mail: KLimburg@esf.edu 7Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, Solomons, MD 20688, USA E-mail: secor@cbl.umces.edu 8Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA E-mail: sthorrold@whoi.edu, benjwalther@gmail.com Abstract In ever-increasing numbers, researchers wish to extract information based on chemical analyses from otoliths to determine movements and life-history patterns of sh. Such analyses make assumptions about chemical incorporation and interpretation that are beyond those that are important for stock discrimination studies, another common application. The authors aim to clarify the methods of determining sh movement based on natural and articial otolith chemical tags and review current trends in determining movement using otolith chemistry, otolith sampling methods, and what inuences otolith chemistry. Both spatial and temporal variability in water and otolith chemistries, which underpin the assumptions of several methods, are discussed. Five methods for determining movement and migration of sh are outlined: (1) estimates of movement and life-history traits of a single sh group, (2) assessing connectivity among groups using natural chemical tags in otoliths, (3) transgenerational marks to determine parentage and natal origins, (4) prole analysis to dene life-history variation within a population and (5) prole analysis to describe movements through different environments. Within each of these methods, background information, specic hypotheses being tested and assumptions and limitations of each technique are provided. Finally, research directions required to ll current knowledge gaps and enhance the usefulness of otolith chemistry to determine sh movement are identied.