Learning Side Scan Sonar Techniques And Sharing Knowledge Across The South Atlantic Territories

A successful and exciting week of training in the use of side scan sonar (SSS) for habitat mapping has just ended in Ascension Island. Participating in the course were, Sam Cherrett from Saint Helena , who led the course, Andy Richardson, Emma Nolan and Kate Downes (the AIMS team) from Ascension, Debs Davidson and iLaria Marengo from the Falkland Islands.

SSS is a valuable technique for the investigation of the type seabed and for the detection of different submarine features. Acoustic pings (pulses) sent by the sonar are reflected differently by sand, mud, bedrocks and artificial objects, such as metal (e.g. pipelines and wrecks). The sea state can influence the quality of the images, however, good results depend as much on a careful survey design and a proper setting of the device used.

The goal for the Ascension team was to learn how to use side scan sonar and drop down cameras, the latter for ground truthing and features/seabed verification, in order to undertake a fine scale marine  habitat classification and mapping up to 1000 metres from the coast. To provide a complete and accurate picture of the underwater environment, a series of targeted dives are also planned. These will be a valuable addition to the data retrieved and processed from the side scan sonar.

Similarly, the Falklands team came all the way to Ascension to gain essential skills, not in how to survive the equatorial heat, but how to identify seabed types in order to better understand and map marine habitats in inshore waters. Acquiring this knowledge is going to be important in making decision for the development of inshore fisheries, marine spatial planning and to support Environmental Impact Assessments.

The course completely hooked all the participants as it was cleverly planned by Sam Cherrett to focus on the practical and operational aspects and techniques of  survey planning, deployment of the side scan sonar (Starfish device and Scanline software) and processing of the images (Triton Perspective software). The days were split on the boat collecting data and in the office processing the raw data to produce images.

The areas at sea where the side scan sonar was towed were identified by the Ascension team, so that the data collected could be used for one of the deliveries of the AIMS project (supported by Darwin Initiative funding). The tows took place at PanAm, Comfortless Cove, White Rock and the Georgetown moorings. A series of tests were carried out to understand the best setting of the weight to be applied to the Starfish. Then, the drop down camera was utilised to verify 27 points which were considered particularly interesting after the processing of the images.

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The seabed in the surveyed areas were found to be made by medium to coarse sand, maerl and bedrock. The green turtles, which are nesting in Ascension, were pleasant company and appeared as features in the images too.

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From the work carried out on boat and afterwards in the office, the participants could learn how the side scan sonar records the data, how significant ground truthing is, how influential the conditions of the sea are, how bottom tracking can be tedious in case of a bad scan, how important team working and communication is, how boat engines are “delicate” and sun cream might not be enough to avoid sunburn!

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A major success of the course was actually the capacity to work in synergy that was shown by the participants. The collaboration of everyone was the main factor that made the full week extremely productive and enjoyable. Everybody contributed positively to the course by exchanging marine biology knowledge, sharing interests in working with fisheries and spatial data, and comparing research and life experience in the three islands of the South Atlantic.

Special thanks to Ascension Island sea rescue team and Blaine Chester, skilful boatman of Swampdog.

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Falkland Islands Science Symposium: A Microbiologists Perspective

By Virginia Edgcomb, Woods Hole Oceanographic Institution, USA

Our Pan-American Science Delegation visit to the Falkland Islands is over now, but I leave with many incredible vistas imprinted on my mind, a new cohort of scientific colleagues and potential collaborators, and many ideas about scientific research opportunities in the area. The people we met in town, including business and local government officials were so friendly and welcoming, and were universally concerned about protecting and managing their resources and unique ecosystems in a sustainable fashion. It was refreshing to see a society that is forward thinking on this theme, especially given the relatively pristine condition of the environment there. Sadly, people the world over frequently only start to pay attention when they witness deterioration or experience personal impacts. Scientists at the South Atlantic Environmental Research Institute are already conducting excellent research on a wide variety of very important topics to the area. Yet there are many opportunities for collaborative research that can pull in complementary expertise to bear on new questions. Researchers at my home institution, the Woods Hole Oceanographic Institution include many who are engaged in studies of physical, chemical and biological oceanography, including fisheries, and of impacts of climate change on marine ecosystems worldwide. Climate change is significantly impacting our polar regions, and these changes have impacts that propagate to subpolar regions in the form of altered weather, ocean currents, temperature, etc. As a marine microbiologist I am particularly keen to collaborate with scientists at SAERI to collect data on impacts of these alterations to major biogeochemical cycles where microorganisms have center stage. Any major shifts in microbial communities and/or processes carried out by these communities can affect the many important fisheries in the region of the Falklands. We envision a very international collaborative study of atmospheric and marine processes involving SAERI, the British Antarctic Survey, and several US and South American institutions.

Interspersed among the many intense and stimulating scientific discussions this past week were amazing field trips to see some of the local treasures; including Elephant Seals, nesting Shearwaters by the gazillions, and of course, penguins. I was enthralled by the penguins, particularly a small cluster of King Penguins who approached me on a beach as I sat still. It was clearly a mutual inspection, the outcome of which was universal agreement that clearly, they were better dressed. Another highlight for me was gazing through the microscope at interesting protozoa zipping around in a water sample I collected from an Elephant Seal wallow. The water was the color and consistency of soy sauce (probably a cocktail of peat, seawater and Elephant Seal feces). A microbiologist is easily amused.

Thank you to all the folks who made this past week possible. Now we all need to work hard to get funding for our research ideas!

Ginny and Penguins

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Falkland Islands Science Symposium: A Social Scientist in the Falkland Islands

By Kate Sherren, Dalhousie University, Halifax, Canada

Our Land Rovers lumbered slowly along the heathland like a convoy of awkward insects. We were heading to the penguin colony at Volunteer Point on the eve of the Falkland Islands Science Symposium. Recent rains had turned the track – rough at best – into a sodden mess. As one and then another of our eight vehicles ran into trouble, the others would fan out to avoid the same fate, resembling ants that have lost their pheromone track. All in all it was a six-hour round trip through rain and hail, and three vehicles had to be pulled out of precarious positions. The jarring drive made my ears ring well into the night. I remarked afterward that it was about the hardest place I’d ever tried to get to. This was greeted with surprise by my fellow delegates. “But I’m a social scientist, so you have to take that in context,” I said. My field destinations can usually be reached in a hatchback. Despite my discomfort, I was more than glad we had made the effort to reach the Point. Three species of penguin, each with its own personality, charmed us for hours.

Photo credit: Carlos Andrade

Photo credit: Carlos Andrade

Sheep wandered among the penguins at times, reminding us that Volunteer Point was part of a working farm. Several of the agricultural experts I met later in the week felt that the penguins played an important role in keeping farms viable. The ranching style of farming traditionally used in the Falkland Islands has resulted in substantial vegetation change. Most of the giant tussac grass that once fringed the islands is gone. Patches of it persist in ungrazed outer islands and fenced minefields left over from the Falklands War. In its place are coastal paddocks that are deemed to have the best grasses for grazing, and hence are used for lambing. The health of these fields is in large part thanks to penguin poop. Guano rich in fish remnants returns critical nutrients to the soil, and sheep help distribute it.

Photo credit: Steve Campana

Photo credit: Steve Campana

I have been one of the Pan-American delegates to this Symposium, representing the social sciences. My research often examines how people respond to local landscapes and how that affects resource decisions. My inspiration comes from talking to local people in places experiencing or facing change. This week I have spoken to leaders of legislation, policy and industry; cabbies and tour operators; long-time Islanders and members of a diverse network of contract workers with a cacophony of Commonwealth accents. These conversations have suggested many exciting research opportunities. Like Volunteer Point, it takes some effort to get to the Falkland Islands. But the destination – and its future – are worth it.

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Falkland Islands Science Symposium: South Atlantic Seduction

By Steve Campana, Bedford Institute of Oceanography, Dartmouth, Canada

I was seduced! And it wasn’t just me. The entire scientific delegation to the Falklands was seduced at one time or another while visiting. No – it wasn’t because of the open and charming people who lived here and welcomed us at every event. Nor was it because of the superb meals (and wine!) with which we were plied at every dinner. It wasn’t even because of the field trips to photograph penguins, or seals, or collect fossils, in wonderful outdoor settings. Rather, this was a totally non-subtle, full-on, in your face seduction that took advantage of a scientist’s greatest weakness. I’m talking of course about our unstoppable excitement when faced with new scientific challenges and possibilities. So the decision by SAERI, the Falkland Islands and the British government to fly us all down here to woo us with scientific seductions was a brilliant move. I suspect that all of the scientists in the delegation are already fully engaged in other projects back home and in other countries. So few of us expected to take on any new projects when we accepted the invitation to come to the Falklands; we just couldn’t resist the invitation to see a new part of the world. But once here, and once confronted with new scientific possibilities, we were hooked. Most of us are now committed to collaborate with SAERI on various projects. Scientists are so naïve!056IMG_3586

I do scientific research on fish and shark populations in Canada and Iceland, where the environmental conditions are very similar to those in the Falklands. So to a Canadian scientist, it is fascinating to see how life has evolved under Canadian temperatures in a location on the other side of the world. One thing that piqued my interest was the occasional capture of porbeagle sharks in the waters around the Falklands. Porbeagle sharks, which are a smaller relative of the great white shark, are a common fishing target in the waters off of eastern Canada, where the conditions are very similar to those here. So why aren’t there more porbeagles here? After asking around, I found out that none of the fishermen here use the pelagic longline gear and large hooks that would be suited for catching porbeagles. So it could be that porbeagles are actually quite common in Falkland waters. And if so, I wonder if they behave, live and grow in the same way that those in the North Atlantic do. How interesting! As I said earlier, I’ve been seduced!porbeagle thrashing in water_996

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