EAR BONES HOLD THE KEY TO FISHY SECRETS

9 July 2004

An Otolith, or fish ear bone. Photo by CRC Reef

Fish may not keep diaries, but they do record information about their lives – including how old they are, where they have been and what they eat – in their ear bones. Scientists from around the world are converging on Townsville next week to discuss the latest developments in the cutting-edge science of fish ear bone, or ‘otolith’, research at the Third International Symposium on Fish Otolith Research and Application.

“Fish otoliths are natural data loggers – they grow throughout the fish’s lifetime, and their structure and chemistry can reveal an amazing amount of information,” according to CRC Reef scientist Dr Gavin Begg, from James Cook University, who is chairing the Symposium. “Otoliths can tell us about age and growth patterns, even about the environments in which the fish have lived.”

As technology improves, scientists are able to get more and more information from these tiny bones, which fish use for balance. One recent development is the ability to use otoliths as highly sensitive environmental indicators.

Otoliths are ground using specialised equipment to reveal their secrets. Photo by CRC Reef

“Looking at the chemistry of otoliths can help us detect environmental problems such as heavy metal pollution, which is very hard to measure at low levels in water, but accumulates in fish and can be seen in their ear bones,” Dr Begg said. “The Symposium will allow specialists in otolith research from around the world to share their expertise, and hopefully enable us to unlock even more secrets from these bones.”

The information encoded in the otoliths can also be vital for fisheries management.

“In the last ten years we’ve been able to age reef fish and discovered that some of the smaller fish live much longer than anyone realised – up to 50 years in some cods, for instance,” said Dr Begg. “Knowing what age the fish mature and spawn helps managers to set appropriate minimum size and catch limits, so that we can ensure our fisheries are sustainable.”

Up to 300 scientists from as far afield as Europe, China, and the USA are expected to attend the week-long Symposium to discuss the latest techniques and applications of otolith research. Workshops will also be held at the CRC Reef and School of Biological Sciences Laboratories at James Cook University, where scientists will demonstrate state-of-the-art technologies.

The Third International Symposium on Fish Otolith Research and Application, hosted by CRC Reef and James Cook University, will be held from 11-16 July at Jupiter’s Hotel and Casino in Townsville.

For more information:
Dr Gavin Begg, CRC Reef and James Cook University, 07 4781 5287 or 0407 966 786, gavin.begg@jcu.edu.au
Ms Chloe Lucas, CRC Reef Media Liaison, 07 4729 8450 or 0408 884 521, chloe.lucas@crcreef.com