Recreational dive guides can help researchers to keep track of changes in shark populations, according to a new study by researchers at The University of Western Australia and the Australian Institute of Marine Science.
The study compared counts of sharks reported by professional dive guides with automated counts generated by sharks tagged with acoustic tags at popular dive sites in Palau, Micronesia. The data from the dive guides, who monitored sharks over five years in more than 1000 dives, closely mirrored results from the tags, showing that the guides were accurate and reliable observers - and in some cases even better than the high-tech tags.
Excitingly, data from the dive guides showed clear preferences by reef sharks for particular water temperatures and current regimes on the reef - information that wasn't revealed by the tags.
The study's authors said the study supported the use of citizen science - an increasingly popular strategy that aims to engage regular citizens in the data collection for shark research.
Lead author Gabriel Vianna said that while earlier studies had used citizen science to investigate trends in shark populations, this was the first independent, long-term assessment of the quality of such data.
"Citizen science projects are becoming increasingly popular for the scientific community and general public. However, there is still some controversy about the reliability of the results they produce," Mr Vianna said.
"Our study shows that with a little bit of training, experienced recreational divers can collect very useful data that can be used to monitor shark populations over broad areas and long periods of time at minimal cost."
Study co-author Mark Meekan, of the Australian Institute of Marine Science - who has been involved in a citizen science project on whale sharks at Ningaloo Reef - said the findings were important.
"They show that partnerships between scientists and the diving industry could allow the establishment of low-cost research projects that can assist the conservation of sharks at popular diving destinations," he said.
"This is particularly important for many developing countries and island nations that rely on marine tourism. Reef sharks are being heavily overfished and at the same time the lack of financial resources for monitoring shark populations hampers efforts for conservation."
The project was part of a collaboration between researchers from UWA, AIMS and the Micronesian Shark Foundation. It was supported by the Save Our Seas Foundation and the Micronesian Shark Foundation.
An article on the study, Acoustic telemetry validates a citizen science approach for monitoring sharks on coral reefs, has been published today in the scientific journal PLoS ONE .
Gabriel Vianna (UWA School of Animal Biology and Oceans Institute; Australian Institute of Marine Science) (+61 4) 31 559 147
Mark Meekan (Australian Institute of Marine Science) (+61 4) 29 101 812
Guiomar Duarte (UWA Oceans Institute) (+61 8) 6495 9545