UWA Scientists lead in shark research

Shark repellents may work best if they target specific species rather than try to deter all types of sharks, say scientists from the Oceans Institute at The University of Western Australia.

Their findings are among six papers published by Oceans Institute scientists in the April edition of the prestigious Journal of Fish Biology, reflecting the big impact UWA research is having worldwide.

Three of the papers (see list below) contain latest research on how sharks see (Collin, Hart), their unique electroreception sense (Kempster, Collin), and how sharks' brains use sensory signals to detect prey (Yopak).

Winthrop Professor Shaun Collin, a WA Premier's Research Fellow at UWA's School of Animal Biology, said understanding the basic neurobiology and neural basis of shark behaviour might help the development of effective shark repellent devices.

"We cannot begin to understand how to develop deterrents under different conditions without a basic understanding of these senses and the thresholds to detect objects and weak electric fields in the shark's natural environment," Professor Collin said.

"Three of these papers emphasise the fact that each species of shark is different, and their senses are refined for different purposes under different environmental conditions."

The results might indicate the need to target a variety of senses at a range of thresholds rather than aim for a "blanket" repellent that might focus solely on one sensory system to repel all sharks in the same manner, Professor Collin said.

The other papers focus on using body scarring to identify and tag whale sharks in Mexico for better management programs; the mating and reproduction habits of sharks and rays; and a study of Spain's blue shark catch and policy implications for enforcing a European Union ban on shark finning.

The Oceans Institute papers are:
• Phylogenetic and ecological factors influencing the number and distribution ofelectroreceptors in elasmobranchs, (Ryan Kempster, Winthrop Professor Shaun Collin)
• Vision in elasmobranchs and their relatives: 21st century advances, (Winthrop Professor Shaun Collin, Associate Professor Nathan Hart)
• Neuroecology of cartilaginous fishes: the functional implications of brain scaling, (Dr Kara Yopak)
• Assessing the potential for post-copulatory sexual selection in elasmobranchs, (Dr John Ftizpatrick, Ryan Kempster, Winthrop Professor Shaun Collin, Associate Professor Jon Evans)
• Patterns in composition, abundance and scarring of whale sharks Rhincodon typus near Holbox Island, Mexico, (Dr Mark Meekan)
• Blue shark Prionace glauca fin-to-carcass-mass ratios in Spain and implications for finning ban enforcement, (Dr Julia Santana Garcon)