Palau dive guides provide shark conservation data0
From: Science Network Western Australia
by Rebecca Graham
RECREATIONAL dive guides collecting data on grey reef sharks (Carcharhinus amblyrhynchos) have uncovered more information than traditional acoustic telemetry tags—signifying a win for citizen science.
The research partnership between UWA, the Australian Institute of Marine Science and the Micronesian Shark Foundation in Palau presented a unique opportunity to test the reliability of shark counts collected by recreational dive guides at popular diving sites in Palau.
Lead researcher from UWA’s School of Animal Biology and Oceans Institute, Gabriel Vianna, says citizen science projects—data collected by the general public—are becoming increasingly popular as they generate large datasets at much lower costs when compared with traditional sampling methods.
“The problem is that there’s been a lot of controversy about the reliability of the data collected by these programs,” he says.
“Our partnership with Micronesian Shark Foundation allowed us to have recreational dive guides reporting shark sightings at the same sites where we have been monitoring sharks tagged with acoustic transmitters over the years.”
Sixty-two dive guides from a dive operator in Palau participated in the study between 2007 and 2012.
The divers completed a questionnaire after each dive about the dive site, shark species and counts and dive depth and current strength across a total of 2,360 dives.
Diver datasets were compared with those collected by acoustic telemetry from tagged grey reef sharks from 2008 to 2012.
Data on daily and monthly shark abundance collected by the dive guides correlated significantly with data collected using acoustic telemetry.
However, the divers were also able to provide additional information on environmental drivers influencing the number of sharks at the sites, such as estimates of water temperature and current strength.
“The data actually allowed us to understand the reasons for the patterns [displayed in the telemetry data] of numbers of sharks at the dive sites,” Mr Vianna says.
“Interestingly, when we combined this extra information with the shark counts, we were able to predict the conditions when the divers were likely to see more sharks at the dive sites.” Mr Vianna says these findings support the efficacy of well-designed citizen science projects in assisting conservation programs.
“This is particularly important in places where the diving industry is well developed but money for monitoring programs is limited, such as many developing countries,” he says.
Also, it supports the idea that the tourism industry can get directly involved with shark conservation and generate reliable data to assist shark research.”
The guides were instructed to observe identification markers on individual sharks, such as pigments and scars, to ensure repeated counts were minimized.
Published in Fisheries & Water