4 things we’ve discovered from tagging Indonesia’s mantas


Manta rays are amongst dive vacationers’ most beloved swimming companions. However regardless of frequent interactions between people and mantas, we didn’t know a lot about them — till now.

Since 2014, Conservation Worldwide (CI) and its companions (together with the Indonesian Ministry of Marine Affairs and Fisheries, the Indonesian Institute of Sciences, S.E.A. Aquarium and Manta Belief) have been becoming mantas in Indonesia with satellite tv for pc tags to study extra about their habits and the way we will finest defend them.

Thanks to those tags, listed below are 4 things we’ve discovered thus far.

  1. Wayag Lagoon is Southeast Asia’s first documented manta ray nursery.

Dwelling to essentially the most marine species on Earth, the waters of the Raja Ampat archipelago beam with life at each angle. But the area stored a secret that was solely not too long ago uncovered by our tagging examine.

Wayag Lagoon, probably the most picturesque and finest protected lagoon programs in Indonesia, is the primary documented manta ray nursery in Southeast Asia.

When the group adopted a tagged pregnant feminine into Wayag, they discovered teams of new child and juvenile reef manta rays swimming above the colourful coral. Seizing the prospect, the group tagged a number of juveniles within the following days. With the information that adopted,
they recognized the lagoon as a main nursery and pupping floor.

  1. Child and juvenile mantas use their house in numerous methods.

As juveniles, manta rays typically enterprise out into the deep blue. Nevertheless, they all the time return to the protected shallows of the Wayag Lagoon, their childhood house.

As infants, the mantas are much less adventurous, preferring to drift close to the floor inside the lagoon. This places them prone to being hit by passing speedboats.

This discovery has led to swift motion from the Raja Ampat authorities. We count on new rules curbing speedboat utilization inside the lagoon to be applied inside the subsequent six to 12 months.

This can be a main win — not only for conservation, however for folks as effectively. Defending child manta rays is vital to make sure the continued survival of the species, which bolsters the dive tourism business that gives jobs and revenue for hundreds
of locals.

Additional studying

  1. Reef mantas can dive actually deep.

At the least 624 meters (2,047 toes) deep, to be actual. Whereas earlier tagging research have revealed common deep-diving habits in reef manta rays — together with one particular person which reached 432 m (1,417 ft) within the Pink Sea off Saudi Arabia — one
of our mantas tagged off the coast of Borneo has now smashed the world report. Furthermore, nearly all of our tagged mantas recorded most depths of a minimum of 200 m (656 ft), with 5 of them frequently diving under 400 m (1,312 ft).

Why are they diving so deep? And why do some appear to persistently dive deeper than others? Are they feeding on deep planktonic meals sources? Diving to flee predators? Or maybe in search of mates? Our group in Indonesia is presently analyzing information for
clues about whether or not this habits correlates with the dimensions or intercourse of people, or could also be associated to the lunar cycle.

  1. Mantas transfer throughout recognized searching grounds in southern Indonesia.

Photographic identification work by native environmental organizations Aquatic Alliance and Manta Watch has proven that mantas a minimum of sometimes swim between the tourism hotspots of Nusa Penida (Bali) and Komodo Nationwide Park. Our satellite tv for pc tagging
program has now revealed the small print of those actions, confirming that the mantas are passing by recognized searching grounds off the southern coasts of Lombok and Sumbawa islands.

In current a long time, mantas have been hunted in some areas of southern Indonesia to produce the now-illegal commerce in manta gill rakers to conventional medication markets in southern China. Whereas fishers can earn as much as US$ 500 from promoting the gill rakers off a single massive manta, a “mantanomics” evaluation we introduced to the Indonesian minister of marine affairs and fisheries confirmed conclusively that killing mantas is dangerous enterprise for Indonesia; the identical manta can simply be value greater than $1 million in tourism revenue over the course of its lifetime — offered that the tourism is environmentally accountable.

This financial argument was sufficient to influence the minister to declare Indonesia because the world’s largest manta ray sanctuary in February 2014.

Implementing this sanctuary is a (*4*)precedence of the ministry. Indonesia has quite a lot of
ocean to patrol, nonetheless, and a elementary query remained about whether or not to unfold safety efforts over the 4 most important manta tourism areas in Indonesia, or to pinpoint enforcement efforts inside the searching grounds. This new information on manta motion
has satisfied the ministry that it should do the latter to make sure the top to unlawful searching.

The extra we see, the extra we all know

Analysis is futile until it’s shared with the suitable folks. CI’s quite a few instructional initiatives in Raja Ampat’s villages have helped shift native attitudes concerning the worth of manta rays. As well as, our accomplice S.E.A. Aquarium in Singapore bridges the hole between the rays and people who find themselves unable to see them within the wild. By enabling guests to see mantas up shut and instructing them concerning the threats these animals face, the aquarium can
encourage folks to advocate for his or her safety.

There are different methods non-scientists can become involved, too — significantly scuba divers.

Whereas our satellite tv for pc tags give us an in depth glimpse into the diving and actions of the mantas, these glimpses are fairly temporary; tags usually stay on the animals between one and 4 months.

To enhance the tagging, manta researchers additionally compile long-term databases of manta sightings by divers — an train made simpler by the truth that particular person manta rays are recognizable by the distinctive spot patterns on their bellies (very similar to
a human fingerprint).

By amassing “ID photos” of manta bellies in a given space, researchers can observe manta actions, progress and copy over intervals of years to a long time. One such database, targeted on the mantas of Raja Ampat and compiled by our companions at Manta Belief, was not too long ago opened for public participation. It already comprises images of greater than 300 particular person mantas and is rising every day.

As extra citizen scientists share their images and researchers delve into this worthwhile database, who is aware of what new insights we’ll achieve subsequent?

Nicole Han is a communications guide for CI Singapore. Wish to learn extra tales like this? Join e-mail updates. Donate to Conservation Worldwide.


Please enter your comment!
Please enter your name here

Share post:




More like this