The coral propagation programme consists of placing coral frames around the island to restore the reef and help the recruitment of fish.
Three different sizes of frames are available for sponsoring: small, medium and large; this picture depicts a small one.
My name is Louise, I am a French marine biology student from the IMBRSea Master. I am currently working on the island of Landaa Giraavaru in the Maldives, to work on my Master’s thesis with the Reefscapers team.
When arriving here, the first challenge is getting used to life on the island, and understanding how everything works, your new everyday routine and the functioning of the Marine Discovery Centre. Luckily, all this is made as easy as possible by the friendly and helpful staff. It took me two weeks to get used to things, train up in all the marine activities, and adopt a good-working routine. Then I could start working more specifically on my thesis.
The days at work begin at 9am at the MDC, with a flexible schedule that changes every day. We switch within our team of 10 people to lead the different snorkelling excursions, dolphin cruises, turtle safaris, taking care of the Olive Ridley turtles in our rehabilitation centre, breeding the clown fish in the lab, and communicating with the Four Seasons guests. It is very interesting to do all these activities, and each day is different. I really enjoy being in contact with the guests, as it is a great opportunity to meet people from different cultures, and to talk with them about our passion for the ocean and the conservation issues we are facing nowadays.
View of our “office”, the Marine Discovery Centre (right), Recreation (middle), and Dive Team (left). In this area of the lagoon the water visibility is truly amazing, and we can often see baby Black-tip sharks hunting small schooling fish.
For my project, I will be assessing the growth rate of the coral frames that are located around the island as part of the Reefscapers coral restoration programme. I will use the photographs from the coral frame database to assess the influence of two main parameters: sun exposure and depth. I will compare frames placed in the shade under the water-villas against frames in full sunlight, and frames placed at different depths along a gentle slope, from shallow (1.5m) to deep (10m).
The first stages of work were dedicated to the selection of the frames of interest, focusing on frames placed from 2017 onwards, to avoid any bias due to the 2016 global coral bleaching event. For the “Sun Exposure” condition, frames were selected due to their position around the water villas. The “Sun” frames are around 1.5m deep and completely exposed to sunlight throughout the day, whereas the “Shade” frames are at the same depth but under the water villa boardwalks, hence protected from direct sun exposure for the major part of the day. For the “Depth” condition, frames were selected in the Blu area, this time all completely exposed to sunlight, but distributed along the slope, with “Shallow” frames between 1.5m and 4m, and “Deep” frames between 7m and 9m.
After the frame selection, all the corresponding pictures were retrieved from the main database and compiled in dedicated folders to start the photo-analysis stage. Photo-analysis was conducted using the photoQuad software, a tool dedicated to the analysis of pictures from underwater surveys. Artificial quadrats were superimposed on the picture to delimit and standardise the area of study, before manually drawing the outlines of each coral colony visible. The software then extracts a variety of information, the most relevant for this project being the total coral coverage (in cm2 and as a percentage). Repeating this operation for each frame and each picture available through time (between 13 and 26 months of data for each frame), will enable the calculation of growth rates.
The photo-analysis began in February and took several weeks to perform. It was completed for all the conditions and all the frames during the month of March. I now have all the Excel worksheets organised, ready for the statistical analysis to assess if the tested conditions (sun/shade, shallow/deep) have a significant impact on the coral growth rate.
Stay tuned, as I will hopefully have the first results to share with you soon!
Louise ☺
Screenshot of the photoQuad interface. A red quadrat is superimposed on the picture to standardise the area of interest. Blue polygons are manually drawn around each visible coral colony. This example depicts one of the shallow frames.