Research mission to St Brandon’s Rock, a paradise coral reef atoll in the Indian Ocean

Johan Van Zyl -- Tue, 04/26/2016 - 14:51

Research mission to St Brandon’s Rock

Prof Henk Bouwman, a zoologist of the School of Biological Sciences at the North-West University (NWU) just returned from St Brandon’s Rock (450 km north of Mauritius) where a group of scientists investigated the feasibility of this island for sustainable development of eco-tourism and low-impact fishing. This is his experience in his own words…

I have returned from a fact-finding mission to St Brandon’s Rock, located 450 km north of Mauritius. This wonderful and uninhabited (except for some rotating fishermen and government officials) coral reef system has been the focus of research on the effects of marine plastic debris by my team, in collaboration with the University of Mauritius. This was my third visit to this ecosystem and two papers have appeared, with more coming. This mission was by a team of six stakeholders to investigate the feasibility of this island for eco-tourism in addition to low-impact fishing. The team was led by Mr Sybrand van der Spuy, CEO of the Raphael Fishing Co. Ltd. of Mauritius. Other members included scientists from Mauritius, the UK, and the owners of the fishing company. We travelled in relative luxury in the MV Gryphon, with four two-person cabins, a mess with a chef, and air-conditioning. The last was the best feature of the whole trip (perhaps, apart from the well-stocked fridge..)…

We spent ten days travelling and on site. The atoll is about 56 km long and 22 km wide with 30+ prominent sandbars and vegetated islands in a stunning lagoon. Some of the island names reminds me of Star Wars (Courson, Chaloupe, Avocaire, Sirene). There is no fresh water. It was summer and the temperatures and sun was quite intense; sunburn management and rehydration (with the help of the aforementioned fridge) was a premium health maintenance activity. We visited 19 of the islands on a tight schedule. At most, we spent an hour or so per island, as the traveling between islands was by small boats in the shallow lagoon. We also investigated the site of a recent fishing vessel wreck. St Brandon’s was the site where the racing yacht of Team Vestas participating in the Volvo Ocean Race stranded in October 2014. On our previous visit, we left two weeks before this happened. The atoll is very low and is difficult to detect with radar, and very small in a large ocean. We also looked out for debris from MH 370. There was some excitement when we found remains of a dingy, but it was not from an aircraft.

We knew from our previous visits that the birdlife is fantastic. With over a million birds crammed on five square kilometres, it is something to be believed. Wave conditions during our previous visits prevented us from landing on some islands (not all island are located in the lagoon). This time, however, we managed to swim in and out from two of them. (If you ask me privately, I can tell some stories about the swimming, preferably close to a fridge.) North Island was a revelation (I’m getting goose bumps as I write this). One species of marine bird (the Wedge-tailed Shearwater) has not been seen or recorded breeding on St Brandon’s since the 1960’s. Its last possible holdout was on North Island. And we found it! Breeding as well. Also, recorded for the first time ever, was the breeding of the Masked Booby.

And then we visited Fregate Island - again having to swim in and out (again, ask me). After completing some measurements on the beach (temperatures of beached plastics for instance), I broke through the fringe vegetation to the central meadow, a characteristic of most of the islands. While bundu bashing, I saw a beautiful red dragonfly. I almost slipped out of my plakkies. Dragonflies need freshwater! Now the background story. Fregate Island had large deposits of guano. Most was removed many decades ago to fertilise sugarcane on Mauritius. The digging was difficult, and only small irregular pits and scrapes could be dug between the fossil coral that formed the bedrock of the island. Hundreds of these pits dot the central meadow. With much anticipation, I started skipping between the pits, looking for puddles of freshwater left by the frequent tropical rains. And I found it! Testing for freshwater is easy – taste it. Eventually I found two, possibly three species of dragonfly, and two species of damselflies. Each pit is different, some forming ponds. We only had an hour, but this, to me, was a wonderful experience. A seemingly stable freshwater ecology on an island that is no wider than 500 metres in any direction, 450 km from the closest other freshwater on Mauritius. Where this all came from I don’t know. I-don’t-know’s of this kind (and there are more of these mysteries than what I described here) is a challenge that I would dearly like to investigate (with or without a fridge).

On our return to Mauritius we held a press conference where we reported our findings. Apart from the obvious need for planning and consultation, the team reported that this system should be conserved, and that low-impact eco-tourism and fishing is feasible. Issues such as climate change, sea level rise, and ocean acidification are additional issues that I think can be addressed with research. I will not forget this trip!

Prof Henk Bouwman at one of the many fresh water pools found on Fregate Island where dragonflies and damselflies were seen.