Professor Jessica Meeuwig writes about the final day of BRUVing at Sandes Seamount:We left the island of Egmont overnight for what the charts suggest is a field of shallow seamounts, rising from 1,000m to less than 100m from the surface, to the northwest of Diego Garcia.
Tom Bech Letessier takes on the story of the remarkably good quality deep (and shallow) stereo film being taken of the reef and pelagic fish:We are now reaching the end of our expedition, and from a BRUVing perspective, it has been a resounding success.
As well as being a collection of scientists from around the world, we also have a young trainee member of our team. Pascaline Cotte is 19 years old and is of Chagossian descent, her grandfather being born on Ile du Coin, Peros Banhos atoll.
The strong winds are starting to take a toll on the divers. So far it hasn’t stopped any work yet but heavy sea conditions have made what is normally a fairly effortless task into hard work, and one data logger located in a storm corner of reef was left because the sea was too rough for safety.
The Three Brothers islands on the Great Chagos Bank is a magical place filled with more birds than you would think could fit on the tiny islands. On Middle Brother, a beautiful island with its own large lagoon, over thirty thousand sooty terns were nesting, as well as noddy terns and red-footed boobies.On North Brother, a more challenging island to land on, thousands of wedge-tailed shearwaters had nesting burrows in every suitable space on the ground that they could - except for that occupied by the ground-nesting brown boobies.These illustrate how important unspoilt islands are for these birds, as, being ground nesters, they would be completely vulnerable to rats, cats, dogs and of course man in inhabited areas.
On our way to the Three Brothers (the islands on the Great Chagos Bank where we will be working next) we returned and spent the day on Victory Bank, a dish-shaped atoll submerged to at least 5 metres depth at its shallowest, where the BRUVers needed to do some more sampling.
This was our last day at Peros Banhos before we move onto the islands of the Great Chagos Bank.A typical day: divers set off in the morning at 8am. Two teams went to the seaward reefs, a trip of about forty minutes in choppy seas, to continue various fish behaviour studies in undisturbed locations, and shark abundance counts.
Expedition Diving Officer David Tickler takes on the story from here:You never know what to expect when you’re asked to act as dive supervisor on an expedition to one of the more isolated reef systems in the world, and it was with a degree of trepidation that I agreed to take on the role for the Chagos 2012 Scientific Expedition.As it was, any fears I may have had were quickly allayed on meeting the team.
Wind and moderately heavy seas the past couple of days have made heavy work of the diving and video deployment, but this morning we woke to a calm Peros Banhos lagoon, where working underwater this morning was a real pleasure.
We awoke around 4:30 this morning to the clanking of the anchor being raised. Those of us who were lucky were able to get back to sleep for another couple of hours.
A very busy work schedule this morning as we try to make sure that we finish off all that needs to be done on Salomons atoll before moving on this evening.
We arrived at Salomons Atoll while it was still dark and waited for first light to enter the lagoon. The captain of the Pacific Marlin, Neil Sandes, has obviously done this many times and the GPS waypoints are well known, but it is still a good precaution to be able to see where you are going.We started work immediately -- Pete Carr visited the islands to do vegetation mapping and bird counts while the rest of us went diving.
Distances around Diego Garcia atoll are much greater than in the northern atolls as the only exit from the lagoon is the pass at the north. The other atolls have several passes through which we can get to seaward sites.
Today, we worked on the reefs on the northeast and north sectors of Diego Garcia, the largest island of the Chagos archipelago, at depths ranging from 25 meters up to 5 meters.
This morning, we did a ‘shakedown’ dive to check the dive equipment and see how some of the specialised equipment performed. In the afternoon, we did the first of the ‘work’ dives, recording cryptic fauna, coral cover, recovering temperature data loggers and some pretty complicated stuff to do with the Baited Remote Underwater Video Cameras, or BRUV, work, which involves a set of stereo underwater HD video systems for collecting fish data in deeper water.Only some members of our team have dived in Chagos before.
Vast coral reefs, hundreds of fish species, hundreds of thousands of pairs of breeding seabirds, a refuge and breeding ground for large, critically important marine species such as sharks, dolphins, and green and hawksbill turtles: I am describing the Chagos Archipelago, one of the most remote and unspoiled marine areas on the planet.