David Kacev

Who I am

Born in South Africa, I was fortunate enough to experience wild open spaces and amazing wildlife from an early age. When I moved to Southern California, I soon realised that the local open space and wildlife were all found in the Pacific Ocean. I became obsessed with the water, spending all my free time surfing and free diving, all the while learning about our amazing sea life.

I first started working with elasmobranchs as an undergraduate studying in Australia, where I was able to see firsthand the effects of human impacts on shark populations. Learning about how grey nurse sharks migrate across state and management boundaries helped me to realise how understanding population connectivity is vital for managing highly migratory species. Movement patterns of transient fish are difficult to study, so I became interested in both telemetry and population genetics. Telemetry enables scientists to look directly at animal movement by means of electronic tags. Genetics, on the other hand, tests for functional connectivity, as interbreeding leads to similar allele frequencies.

My PhD dissertation at San Diego State University focuses on understanding the population structure of shortfin mako sharks. Due to their reputation as good fighters that produce high-quality meat and their distribution around the world, makos are highly susceptible to fishing pressure. Through the use of both genetics and tagging, I aim to better inform management of this globally important species.

Where I work

I am a student in a joint programme in ecology between San Diego State University and the University of California, Davis, so I work in both Southern California and Northern California. As a collaborator with the Fisheries Genetics group at the Southwest Fisheries Science Center, I spend much of my time at a state-of-the-art research facility set on a hill overlooking La Jolla Shores Beach. Not only blessed with beautiful panoramic views and world-class sunsets, this location is convenient due to its proximity to amazing scientists at both the National Marine Fisheries Service and Scripps Institution of Oceanography.

The majority of my field work is conducted in the Southern California Bight. Every summer I participate in a survey for juvenile pelagic sharks. During this survey we spend two weeks offshore of Southern California, where we are away from the crazy city life and surrounded by ocean breezes and salty sea air. I am also fortunate enough to carry out field studies surveying fishing camps in Baja California, Mexico. During week-long voyages south of the border we spend time in isolated fishing communities on remote beaches. Despite being just a day’s drive south of San Diego, Baja is certainly a world apart from the hustle and bustle of Southern California.

What I do

The life-history traits of many elasmobranch species make them vulnerable to human impacts such as fishing pressure and habitat degradation. At the same time, their marine way of life and often migratory nature can make them difficult to study. Molecular research has recently become more common, as technological and analytical advances have made it both less expensive to apply and more accessible to wildlife applications.

Population genetics is a powerful tool for understanding the ecology and dynamics of wild populations. If applied correctly, molecular techniques can inform management and conservation policy. In order for these tools to be most effective for elasmobranch populations, it is vital that researchers have a good understanding of what techniques are available and how to properly interpret their results.

Our workshop on molecular genetics (held in Chattanooga, Tennessee, immediately before the annual American Elasmobranch Society meeting) was conducted by current leaders in the field and helped to train students and interested ecologists in the correct use of molecular tools, as well as the best way to both interpret and communicate research results. We learned about current trends in population genetics as well as future directions. By engaging in an active dialogue, all workshop participants learned not only how to stay at the cutting edge of a rapidly expanding discipline, but also how to communicate their results clearly to a wide audience. The skills honed during this workshop are now being applied in labs around the country, furthering our understanding of shark and ray population ecology.