Sharks equipped with cameras help make an unprecedented find
An investigation led by the American NGO Beneath the Waves finds the largest seagrass meadow in the world covering a surface area the size of Maine.
Research by the US NGO Beneath the Waves, which put geolocation sensors and a 360-degree camera on a series of previously selected tiger sharks, has found the largest seagrass meadow in the world. It is located in the Bahamas, at a depth of between 30 to 50 feet and has an area of over 35,500 square miles, an area similar to that of Maine. The discovery opens the possibility of using other marine animals to further explore the oceans.
Seagrass meadows are a great ally in combating climate change by capturing carbon, the main greenhouse gas behind global warming. They are also essential for the habitats of marine species and act as coastline defenses against erosion from storms and tsunamis. According to El País, the greatest threat the meadows are the anchors of the yachts that gather above them. Seagrass is one of the most threatened marine enviroments in Florida due to propellers and anchors scarring which can take upwards of ten years to naturally heal.
“This work provides evidence of major knowledge gaps in the ocean ecosystem, the benefits in partnering with marine animals to address these gaps, and underscores support for rapid protection of oceanic carbon sinks,” says the study, published in the journal Nature Communications.
Why did they use sharks?
The researchers chose sharks for a variety of reasons. First, the tiger shark helps maintain the grasslands by preying on herbivorous species which, if too many, could reduce the extent of ocean plants. On the other hand, when looking for green turtles (their favorite food), sharks spend 72% of their time patrolling the seabed and swim around 44 miles a day.
Without the sharks the investigation would have been impossible. Says Carlos M. Duarte, Professor of Marine Sciences at the King Abdullah University of Science and Technology (Saudi Arabia): The underwater dives previously carried out, 2,400 of them, “only covered 5% of the area, so the data provided by the sharks proved essential.”
But capturing the sharks and installing a camera on them is not an easy thing. “[They] can measure up to 18 feet in length and weigh more than 1,250 pounds,” says Duarte. “They are dangerous animals, which cause deaths, and more so if they are in danger or stressed.” The researchers discovered that tiger sharks traversed these meadows, so they decided to place 15 devices, of which 8 were for position, temperature and other parameters; and the other 7 were cameras.
The discovery “is a clear sign of the poor knowledge that exists of the ocean” according to Duarte. He feels that it is time to reflect on the reasons why this meadow, with its extension, “being only 30 to 50 feet deep.” Austin Gallagher, principal scientist and CEO of Beneath the Waves said that “this discovery proves how everything is connected.” It was thanks to shark protection in the Bahamas which guided the researchers to the seagrass ecosystem, “which could be the most important blue carbon sink on the planet.”