Conservation Focus – the successful story of the Manta Birostris

Mantas were extensively hunted for their gills for use in Traditional Chinese Medicine applications, with most of the killings made in the area of the Indonesian archipelago. Today, in one of the few miraculous conservation stories, the Indonesian government has done well to reverse the trend of declining manta sightings. A policy of establishing marine conversation zones and paying former fishermen as “marine park rangers” has done much to bring Mantas back to the waters of Indonesia in numbers not seen in the last decade. As the Indonesians authorities and local islanders start to recognise that mantas are worth more alive economically in tourist dollars than for its worth in weight as meat, we will perhaps start to see a new zenith in species sightings.

The Manta Birostris, or more commonly known as the Giant Oceanic Manta Ray is the largest Ray in the world. Growing up to a staggering 9m from wingtip to wingtip, it resembles in size something more like a whale than a ray or fish. It is a migratory creature that spends its time mostly in the dark depths of the ocean, with almost all of its interaction with human divers coming from their shallow trips to ocean pinnacles and rocky outcrops to get themselves cleaned by cleaner fish. Its diet consists mostly of plankton, which influences its movement and migratory habits as it “chases” the plankton booms in the ocean.

There are two known types (or subspecies) of Manta Rays in existence, the Manta Alfredi and its bigger cousin the Manta Birostris. Though Mantas are classified as rays, they share very little in common with the more famous string rays. Sting rays are often bottom feeders, they lie on the bottom of the sea in shallow reefs, moving little and feeding from the ground. This rather sedentary lifestyle is supplemented with a stinging barb at the end of its body that delivers toxins and venom to approaching predators. The Mantas on the other hand, need to continuously be moving and swimming in order to pass oxygen rich ocean water through its gills for respiration, a characteristic that these awesome creatures share with sharks. They are considered a species under the eagle ray genus and glide and fly through the ocean like its namesake through the sky.Despite its relative proximity to humans in the wild, very little is known about the Giant Mantas because of a lack of dedicated research and the difficulty in lengthy observations of these massive creatures. For all its regular sightings at the same few spots in South East Asia, it is inconceivable to imagine that just a decade ago, these magnificent creatures were being culled in the thousands every year, lined up along the shore lines of far flung fishing communities in the Indonesian archipelago, displayed and revered as prized catches. For many decades, targeted fishing of mantas, overfishing of manta eco systems and extensive encroachment of its habitat in the Coral Triangle has contributed to the exponential decline of species sightings especially in Indonesia.

In January of 2014 in a dive trip to Ko Lanta, Thailand, I came face to face with this creature in the depths of the Andaman Sea. It was heartening to see packs of mantas in healthy numbers during many of my dives. The beauty and awe of these creatures needs to be seen to be believed. In some of my dives they came no further than a meter away from me, playfully checking me out and swimming curiously around my bubbles. I also saw for myself how these giant creatures contribute to their eco-systems by providing the food for the many species of cleaner fishes that live on the pinnacle. These giants would swim up to the rocks and stay stationary giving human divers an incredible opportunity to come close to observe them. It is heartening to know that these creatures are well taken care off and can continue to thrive in the oceans. We should continue to be diligent in our conservation efforts to preserve this gift of nature.Many threatened oceanic species suffers from the same threat of fishing and human encroachment into its habitat, it is with great hope that the success story of the conversation of the Giant Oceanic Mantas in South East Asia will continue to yield results, and also be an example for the sustainable eco-tourism model of oceanic species. With perhaps the same kind of care, attention to indigenous community needs and dedicated conservation programs, the fate of many more endangered oceanic creatures can be reversed.











Photos from Stefanie Wagner

About the Author:
Zhimin is a second year Mechanical Engineering student who finds reason to be curious about other disciplines. He is an amateur triathlete, divemaster and a paratrooper. An avid adventure-seeker, he never backs down from a challenge and enjoys pushing the boundaries of the human condition.