The turtles of Martinique and Guadeloupe
|Caitlyn diving down to survey seagrass|
In the morning we tested the settings of the DJI Phantom 3 quadcopter/drone over land before releasing it to the elements over an open body of water. France requires fashionable parameters for flight!
|Grand Anse in Martinique. Beth Whitman (with drone), Dr. Jeremy Kiszka, and Caitlyn Webster are dressed in the required safety gear and the landing pad is roped off!|
We launched the drone over Grand Anse for a test flight in hopes of using the aerial vantage point to survey turtle densities and map seagrass cover within the bay. Although the drone took impressive aerial footage, the glare, rippling of the water's surface, and water depth made it difficult to detect turtles while flying high enough to avoid collision with the many boat masts scattered throughout the bay. Admitting this is a fantastic technology, but more applicable to shallow, mast-free environments, we opted for plan B: in-water snorkel surveys of turtle abundance. Over the course of the next week in Martinique we conducted 60 of these surveys along 300-600m long transects, and then 30 more in Guadeloupe! During our snorkel surveys we found that most of the moorings in Grand Anse were broken, and unusable for the many pleasure yachts that inevitably anchored in the seagrass and/or sand throughout the bay. These anchors leave large scars and leaving open areas for the invasive seagrass Halophila stipulacea and dispurse fragments of the seagrass contributing to it’s spread. During our snorkel transects we dodged boats (usually successfully) while recording turtle locations, behaviors and food availability. Some nights we asked ourselves, “Is 7PM too early for bed”? However, our hard work paid off! Surveying until the very morning of our departure, we completed 60 transects throughout Grande Anse.
|Green turtle grazing in a mixed bed of native and invasive seagrass|
Our local collaborator, Emilie, agreed to continue focal follows and seagrass collection (for nutrient analysis at FIU) in our absence after showing us a site she has great interest in, Sainte-Anne. The invasion of H. stipulacea in Sainte Anne is not as as great as in Grand Anse, so it will be interesting to see if our pilot surveys detect a significant difference. Also, keep an eye out for Beth and I in the local Martinique newspaper. After catching enough eyes with our bright orange buoys, clipboards, and zinc-oxide caked faces, Emilie coordinated an interview with a journalist about the research that we were conducting. After twelve days 11, we said “Au revoir!” to Martinique and hopped over to our next field site, Malendure, Guadeloupe.
|Beth, Emilie and Caitlyn collecting seagrass samples|
|View from the summit (1,467m) of La Grande Soufriere.|