A recent expedition to the BIOT Marine Protected Area (MPA) was undertaken with collaborators from Stanford University to retrieve acoustic tracking equipment from the seabed.
For the project, which was funded by the Bertarelli Programme in Marine Science, receivers that have been monitoring shark movements in the deep channels between islands were recovered from depths of more than 500m. These will provide a wealth of new data on ecological connectivity within the reserve, as ZSL's David jacoby explains.
The British Indian Ocean Territory (BIOT), otherwise known as the Chagos Archipelago, is one of the world’s largest no-take marine protected areas and it’s a difficult place to get to.
Having spent the last two years poring over the Admiralty Charts of the reserve trying to figure out how sharks move within the MPA, I jumped at the chance to get a first-hand perspective of this unique set of islands. And so via a commercial flight to Bahrain, followed by a heavily delayed military flight to Diego Garcia, myself and Dr Taylor Chapple (Stanford University) under the cover of darkness boarded the BPV Grampian Frontier at 02:30, ready to head out into this remote Indian Ocean archipelago.
Our mission was to retrieve 16 acoustic release (AR) receivers that had been sat on the seabed in the deep waters between islands and over seamounts, continuously listening out for over 400 fish carrying long-term acoustic pinger tags.
Deployed over 14 months prior to our expedition, these receivers took the total of acoustic monitoring receivers in the reserve to an impressive 93 devices. By communicating with the AR receivers via a surface modem dangled over the side of the boat, we sent a message to the device to unscrew from its mooring and in doing so allowing the attached buoys to bring the whole receiver to the surface.
An anxious wait ensued before the first receiver popped up over Sandes Seamount. Once back aboard the BPV we then downloaded the data gathered from each receiver which will ultimately help us shed some light on how far some of our tagged sharks actually venture.
During the 500 mile round trip we were able to retrieve 12 out of 16 devices in addition to switching the battery on two of our satellite-linkage receivers that transmit tag data in real-time. Of the four receivers not recovered, due to being in water much deeper than anticipated, one was found to contain no detections. These four receivers aside however, the total number of detections on the recovered devices was more than 500,000 detections, making this expedition a huge success.
My research focuses on how sharks connect habitats through their movements, which I like to think of as a network of linkages. These data from some of the deep water ‘blind spots’ around the reserve will be critical for informing this picture and it is hoped that with an improved knowledge of the structure of these networks, we can begin to predict where and when large reef predators are most vulnerable to illegal fishing in BIOT.
Select a blog
Get the latest on ZSL's conservation work in Asia.
Find out more about life in our B.U.G.S exhibit
Every month one of the pieces held in ZSL’s Library and at ZSL Whipsnade Zoo will feature here as Artefact of the month.
A new Open Access journal for research at the interface of remote sensing, ecology and conservation.
See the latest ranges, updates and special offers from our exciting new online shop.
Excerpts from ZSL's award winning members' magazine.
A blog for lovers of ZSL London Zoo. Bringing you amazing animal facts and exclusive access to the world's scientific oldest zoo.
Discover more about the UK's biggest zoo with our fun blog posts!
Join the ZSL Discovery and Learning team as they venture out of the zoo and in to the wild.
Catch up on our latest Conservation Blogs
Follow the latest news on ZSL’s Arts & Culture projects at ZSL London and Whipsnade Zoos, and ZSL’s conservation work through the lens of the Arts.
ZSL Whipsnade Zoo's elephant keepers give an insight into the daily goings on in the elephant barn.
Read about conservation of tigers in Asia.
One man is boldly going where no other ZSL videographer has gone before - the land of Mountain Chicken Frogs.
From the field, to the lab, catch up with the scientists on the cutting edge of conservation biology at ZSL’s Institute of Zoology.
The Wildlife Wood Project has been working in Cameroon since 2007 to encourage better wildlife management in logging concessions.
Updates from penguin conservation expeditions to Antarctica
Amur leopard conservation blog
Meet ZSL Whipsnade Zoo's latest (and leggiest) arrival, a baby giraffe!
Follow the ZSL Biodiversity and Palm Oil team, based in Bogor, Indonesia.
The Chagos marine reserve, designated in 2010 and currently the world’s largest no take marine reserve, is a sought-after spot for marine research.
Follow ZSL conservationists studying desert baboons in Namibia.