Mozambique Mission 2016

FinPrint Spotlight

                                                                      Anna FlamAlexandra Watts

In August, the Global FinPrint team headed to Mozambique to assess the marine life found on the reefs around Vilanculos and Bazarut Archipelago National Park. Anna Flam (left) and Alexandra Watts (right) from the locally based Marine Megafauna Foundation joined the team to deploy baited underwater videos (BRUVs). Alexandra Watts reports from the field.

The Marine Megafauna Foundation (MMF) has been researching large fish such as sharks and rays in southern Mozambique for over 10 years. So we were really excited when the Global FinPrint research team invited us to help them with the reef assessment in this beautiful and biodiverse part of Mozambique. The goal of this collaboration was to complete half the BRUV drops inside the Bazaruto Archipelago National Park and half outside, to look at the differences inside and outside the protected area. After the equipment arrived from Australia, we began setting up the BRUVs by securing frames, legs, GoPro housings, ropes, buoys and floats, batteries – these had to stay dry until ready for use.

central-mozambique-aug-2016

The first day, we waddled down to the beach; each laden with various bits of the BRUV kits, and loaded them onto the boat with the help of Zito, our local skipper. We were aiming for the northern end of the archipelago and dropped around ‘Spaghettis’ and ‘Three trees’ – reefs on the northeast side of Bazaruto Island. Luckily, the weather was on our side and we were able to drop here for several days. By day 3 and 4, the weather had closed in a little and so we stayed closer to Vilanculos, on our second site at Two Mile reef.

Photo: Alexandra Watts

Photo: Alexandra Watts

After the first few days, we eagerly waited as the experienced BRUVers Conrad Speed and Jordan Goetze downloaded all the footage and replayed it. The footage was fantastic. Moon wrasse, yellow snapper, red fanged trigger fish, sailfin tangs and a giant guitarfish were just part of a kaleidoscope of species of all shapes and colour. Within the first day the guys had noticed something they had never seen before; schooling Moorish idols. They saw this species in Australia and other locations but never in such huge numbers before. Moray eels took a particular interest in the bait bags, grabbing them and death rolling to get access to the fish, while an octopus and a blotched fantail ray just sat on top of the entire bag, preventing anything else from getting access.

moorish-idols

Moorish idols surround bait bag

BRUVs are a useful tool to collect data on marine species composition and information such as this can be communicated to local government. Sampling is often done using underwater surveys. However, BRUVs are especially useful for avoiding biases with these techniques such as behaviour changes by species in response to a diver carrying out video surveys. This is important when carrying out species counts – fish which actively avoid divers may cause a species to be completely omitted from a study, resulting in an inaccurate account of species within an area. It is also an efficient census technique – they don’t require skilled divers in the water and all the associated risks and technical equipment. They can be left on the seafloor without an operator, simply with a marker nearby to make it easy to find them, whilst further work can be continued elsewhere.

Technically, this is an advantage. But, after reviewing some of the footage, we wish we had been there to see it with our own eyes – not only did we have visits from both reef and giant manta rays but also smalleye stingrays, round ribbontail (aka blotched fantail) rays, pink whiprays, Jenkins’ whipray, spotted eagle ray, bull sharks, blacktip sharks, blacktip reef sharks, grey reef sharks, and whitetip reef sharks.

We were also specifically looking out for dugongs, which are one of the only herbivorous marine mammals in the world and rare inhabitants off the coast of Africa. This animal is extremely sensitive to anthropogenic threats such as gill netting, hunting, pollution, habitat loss, and coastal development. Population numbers have been drastically reduced in East Africa. The Bazaruto Archipelago population is now possibly the only viable population in Africa, and the second largest in the Western Indian Ocean. And, although we didn’t manage to see one face to face, we did get a couple of glimpses of these curious animals on BRUVs!

A dugong casually swims past one of the BRUVs.

Analysis of the footage is (understandably) time-consuming and will take a little longer until we can begin to summarise the findings. It was an absolute pleasure for Anna and myself to be involved in this study and we hope it paves the way for further collaborations of this nature. The more marine scientists can connect and work together on both international and regional projects, the more efficient research becomes. Human pressures have exerted such a huge threat to so many forms of marine life that the oceans are reaching a breaking point. Targeted conservation initiatives – informed by projects such as this – are the only way we are going to begin to make a difference.

Conrad carefully drops the BRUV. Photo: Alexandra Watts

Conrad carefully drops the BRUV. Photo: Alexandra Watts

Global FinPrint

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