“Trapping Zone” In Maldives Is Buffet For Sharks

The bubbles slowly rose to the surface as the Omega Seamaster II submersible sunk lower in the water column. Above, the sun trickled through the water and left some warmth on the faces of the scientists before they turned their attention to the inky depths below. Having come all the way from the University of Oxford, the researchers were eager to see what the depths around the Maldives held.

The Maldives – comprised of 1,192 islands – are located in the Indian Ocean, spanning across the equator and covering an area of approximately 90,000 square kilometers. Sounds like a lot, and the number is mind-boggling when you realize only 298 square kilometers of that is dry land. Instead, the beauty lies beneath the tiny jewel-like islands rimmed with white sand that sparkles like diamonds. Home to about five percent of the planet’s reefs, the explosion of colorful structures is home to thousands of fish species, including large pelagic fishes such as manta rays and whale sharks.

While the clear, shallow waters around the Maldives are famous and well-known, the deep is still a mystery. Enter the Nekton Maldives Mission, which is undertaking the first systematic survey and sampling of the Maldives from the surface to 1,000 metre (3,280 feet) depths. The submersibles were equipped with multiple cameras to record their descent into the darkness, as well as other scientific tool to collect biological samples and map the previously un-explored area extensively using sonar. The video evidence, coupled with the other data, uncovered an undiscovered ecosystem that is already being praised as highly significant by the Maldives Government.

At around 500 meters (1,640 feet) deep swarms of small organisms known as micro-nekton flourished. Micro-nekton is the name for an intermediate group between zooplankton and nekton, both small aquatic organisms that can swim independently of the current.Distributed between the surface and 1,000 m deep, it is a highly diverse group. Known as one of the animals that link the primary producers and consumers with the top of the food web, the data collected by the Nekton Maldives Mission were trapped by those at the top of the food web, including schools of tuna and sharks.

Thus the nickname, “The Trapping Zone,” was decided on for this new discovery. “The discovery of ‘The Trapping Zone’ and the oasis of life in the depths surrounding the Maldives provides us with critical new knowledge that further supports our conservation commitments and sustainable ocean management, and almost certainly support fisheries and tourism,” said President of the Maldives H.E Ibrahim Mohamed Solih. Lucy Woodall, Associate Professor of Marine Biology and Nekton Principal Scientist, agreed with the significance of the latest discovery, and says the whole team is interested in understanding exactly what happens here: “Is this something that’s specific at 500 meters, does this life go even deeper, what is this transition, what is there and why? Why are we seeing the patterns that we have observed on this expedition? This will enable us to understand the deep ocean in much better terms.”

But why are sharks here? Part of the answer might lie in the fact that the territorial water around the country has been turned into Maldives shark sanctuary. One of less than twenty shark sanctuaries in the world, it provides a safe haven for more than thirty species of shark, many of which are globally threatened or endangered. The waters here have a high level of visibility, also making it easier to have a clearer view of these charismatic animals – something tourists take advantage of! People from all over the world enjoy shark diving and snorkeling tours to swim side-by-side with these fearsome predators.

While sharks are commonly observed swimming in the crystal-clear shallow waters of the Maldives, the diversity seen here in the dark deep was outstanding. Tiger sharks (Galeocerdo cuvier), six-gill sharks (Hexanchus griseus), sand tiger sharks (Carcharias taurus), gulper sharks (Centrophorus granulosus), scalloped hammerhead sharks (Sphyrna lewini), silky sharks (Carcharhinus falciformis) and bramble shark (Echinorhinus brucus) were just some of the many species documented by the mission. “We’ve observed sharks in shallower waters quite extensively in the Maldives before, but for the first time we’ve have been able to document an immense diversity of sharks in the deep sea,” commented Shafiya Naeem, Director General of the Maldives Marine Research Institute. From the video footage, the scientists could see that the swarms of plankton were attracting large, deep-water fish that were, in turn, attracting the sharks to the area. Many of the above species are shallow-water animals that may be diving into these depths to take advantage of the activity.

Lots of food in one area? Count them in!

Marine ecosystems are defined not only by what ocean life is in a region but also the area’s topography (the landscape). “This has all the hallmarks of a distinct new ecosystem,” explained Professor Alex Rogers of the University of Oxford; Rogers was one of the researchers who spent over 30 hours underwater in the submarines observing the unique Trapping Zone during the expedition. “The Trapping Zone is creating an oasis of life in the Maldives and it is highly likely to exist in other oceanic islands and also on the slopes of continents.”

The analysis of the data collected in the mission is ongoing, but it is believe this discovery could have important implications for not only sustainable fisheries management, but the burial and storage of carbon and climate change mitigation. What the Trapping Zone means for the Maldives is yet to be fully understood.