- Date: July 13, 2020
Sharks and rays are crucial for the health of our planet, but they are some of the most enigmatic and misunderstood creatures in the ocean. Here are five ways in which sharks and rays help the world, from fighting climate change to digging through sand for their neighbors to feeding phytoplankton.
1) Climate action advocates
Did you know that tiger sharks help to make oceans more resilient to climate change? How? Swimming around the shallow seagrass meadows, these sharks serve as crowd-controllers and prevent overgrazing by marine creatures such as turtles or dugongs. Less continuous grazing in the same spot means more abundant, denser seagrass. And you know what captures carbon from the atmosphere 35 times faster than tropical rainforests? Yes, that’s right – seagrass!
2) Good-hearted architects
Thanks to their unique way of feeding, large bottom-dwelling rays – such as stingrays, cownose rays, or whiptail rays – act as “habitat engineers”. Hovering over sandy areas, they excavate the sand in search of food while simultaneously creating micro-habitats for various tiny invertebrates. For these “architects”, sharing is caring! As they uncover tasty snacks for themselves, they also help many other marine species to feed, from small reef fishes, to bigger predatory jacks, all the way to seabirds such as cormorants.
3) Underwater gardeners
Large, deep-diving sharks and rays help phytoplankton (microscopic marine plants) to grow, simply by cruising between ocean depths and the shallows. One species of open-ocean mobula ray was found to dive to around 6,560 feet – nearly 2.5 times more than the height of the tallest building in the world! These creatures dive down to feed and as they return to the surface, they defecate, bringing back crucial nutrients. Without those essential elements, phytoplankton – which forms the foundation of many oceanic food chains – couldn’t grow! And you know what is responsible for every breath you take? Phytoplankton, as it produces half of Earth’s oxygen supply! So yes, some sharks and rays really are deep-diving gardeners that help us breathe…
4) Marine ecotourism stars
Just as nature-loving tourists all around the world dream of seeing elephants, lions, or gorillas in the wild, many cannot imagine their lives without swimming with sharks and rays underwater! Every year around 600,000 shark divers travel the world to witness these magnificent creatures in their natural surroundings. In 2014 in Australia alone, shark tourism brought at least $32.5 million to the economy. The economy of Maldives – a small island nation in South Asia – is driven by tourism, with diving and snorkeling as the country’s most popular tourist activity. Shark divers brought over $65 million to their local economy in 2016, contributing directly to the diving industry and many other business sectors. A tourism survey revealed that 74% of travelers came to Maldives because of diving and devoted shark divers said that they would not return if there were no live sharks to be seen!
5) Blue circle of life
Even after they die of natural causes, sharks and rays contribute so much to the marine ecosystems! Scientists analyzing video footage from the seafloor off Angola’s coast discovered that carcasses of a dead whale shark and large rays resting peacefully at 3,937 feet supported entire communities of deep-sea scavengers. A real blue circle of life!
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