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Current Research

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My research generally focuses on using the “natural tag” properties of carbonate hard parts in marine and diadromous fishes to examine dynamics of migration, dispersal, and life history

dynamics of species with mobile phases.  This field has grown exponentially in the past couple of decades, yet significant unknowns remain about highly migratory or dispersive species, particularly in the marine environment.  Otolith chemistry has the potential to reveal key information about identity and movement patterns that is essential for the effective management of exploited species and ecosystems. 

My research currently lies in two main areas.

1. Carbonate biomonitors of environmental variability

Fish otoliths and coral skeletons can record temporal variability in environmental parameters such as temperature, salinity, and nutrient availability via chemical proxies recorded in biogenic carbonate.  My research uses chemical time series of Ba/Ca in otoliths and corals to investigate variation in upwelling strength and river plumes at various locations on the Great Barrier Reef.  These time series will help construct a baseline of environmental variability to determine both high frequency events (such as wind-driven upwelling) and longer term climatic shifts (such as ENSO).  Establishing this baseline is necessary to explore ecological responses to pulse and press events at a variety of temporal and spatial scales.

2. Otolith chemistry, migration, and mixed stock analyses

My Ph.D. research was on the migratory dynamics of American shad (Alosa sapidissima), a large anadromous clupeid.  I characterized river-specific isotopic and elemental signatures from 20 source rivers and used those to estimate natal homing rates of returning spawners and conduct mixed stock analyses on immature migrants in the ocean.  I will continue work on life history variability in diadromous fishes such as barramundi, and in particular will use otolith chemistry to ask questions including 1) are there ontogenetic shifts in oceanic distributions and the degree of mixing among populations and 2) are patterns in habitat use (e.g. movements among fresh and marine habitats) constant or variable among geographically discrete populations.