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Benjamin Walther
Assistant Professor
The University of Texas at Austin
Marine Science Institute
Ph.D., Woods Hole Oceanographic Institution/Massachusetts Institute of Technology Joint Program (2007)
B.S., Biology, University of Texas at Austin (2000)
B.A., Plan II, University of Texas at Austin (2000)
[Walther Lab Website]
Fish Migration Ecology, Nursery Habitat Ecology, Population Connectivity
Coastal fish migration dynamics, otolith chemistry & natural geochemical tags to quantify population connectivity,
nursery habitat requirements, diadromy, and environmental proxies in biogenic carbonates including corals and bivalves.
Research Interests
Dr. Walther is interested in the patterns and mechanisms driving fish migration, population dynamics, and habitat use in coastal regions.
He is particularly driven to understand the importance of individual movement and habitat requirements for commercially and recreationally
important fish and to provide biological information vital for the effective management of heavily exploited species. He has conducted research
in diverse regions worldwide, including the western North Atlantic, southern Australia, the Great Barrier Reef, and the Gulf of Mexico.
One of the primary tools that Dr. Walther uses to investigate migration dynamics is fish ear bones, or otoliths. Otoliths grow throughout the
lifetime of each fish, and record chemical variation in the water they swim through. In this way, they act like natural “tags” that record movement
through chemically different environments. By analyzing otolith chemistry, Dr. Walther can help reconstruct where each fish was born or where it lived
at specific life history stages. This information is generally unknown for the vast majority of fish species, and unraveling these mysteries is crucial
for a comprehensive understanding of fish population dynamics.
Current lab research involves species and habitats in the Gulf of Mexico, the North Atlantic, and the Great Barrier Reef. Specific topics of interest include
1) ontogenetic shifts in coastal distributions and population mixing of migratory fishes (e.g. American shad in the North Atlantic); 2) variation in habitat use
patterns among discrete populations of diadromous species (e.g. southern flounder in Texas, barramundi in northern Australia); 3) influence of energetic status
on population connectivity patterns (e.g. black bream in southern Australia); 4) flood and upwelling events recorded in Porites coral skeletons and damselfish
otoliths (Great Barrier Reef).
Selected Publications:
Walther, B.D. and S. R. Thorrold. 2009. Inter-annual variability in isotope and elemental ratios recorded in otoliths of an anadromous fish. Journal of Geochemical
Exploration. 102:181-186.
Clarke, L.M., Walther, B.D., Munch, S.B., Thorrold, S.R., and D.O. Conover. 2009. Chemical signatures in the otoliths of a coastal marine fish, Menidia menidia, from
the northeastern United States: spatial and temporal differences. Marine Ecology Progress Series. 384:261-271.
Walther, B.D. and S. R. Thorrold. 2008. Continental-scale variation in otolith geochemistry of juvenile American shad. Canadian Journal of Fisheries and Aquatic Sciences. 65:2623-2635.
Elsdon, T.S., Wells, B.K., Campana, S.E., Gillanders, B.M., Jones, C.M., Limburg, K.E., Secor, D.H., Thorrold, S.R., and Walther, B.D. 2008. Otolith chemistry to describe
movements and life-history parameters of fishes: hypotheses, assumptions, limitations, and inferences. Oceanography and Marine Biology: An Annual Review. 46: 297-330.
Walther, B.D., Thorrold, S.R., and Olney, J.E. 2008. Geochemical signatures in otoliths record natal origins of American shad. Transactions of the American Fisheries Society. 137: 57-69.
Walther, B. D., and S. R. Thorrold. 2006 Water, not food, contributes the majority of strontium and barium deposited in the otoliths of a marine fish. Marine Ecology Progress Series. 311:125-130.
More information:
Research Areas:
Fisheries & Ecology
Publications
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