A Ray of Light

By Sophia Read

For The Bali Times

SEMINYAK ~ In Bali, off the island of Nusa Penida, April to May is manta season. While you can see manta rays in our waters all year, April and May bring large numbers of them to the cleaning stations on the south coast of Nusa Penida known as Manta Point.

Manta rays are one of the most admired creatures in the ocean, and a prized sight for divers and snorkellers, for one reason: manta, unlike most other ocean creatures, seem to be inordinately curious about humans, almost as much so as we are about them.

Curious as we may be about these amazing creatures, we know very little about them. Manta rays are elasmobrachii, along with skates and sharks – cartilaginous (i.e. non bony) fish, without swim bladders. There are currently three recognized species of manta, though investigations as to whether two are simply isolated populations of the same species are currently underway. They are found throughout the tropical waters of the world, generally seasonally, and we have little idea where they go when they are not giving divers and snorkellers a show.

They are plankton feeders, and harmless to humans. Contrary to popular belief, they do have teeth, but these are for use only in mating, and are not used for feeding. They have suffered a bad reputation in years gone by – fishermen called them the “devil ray” (because of the distinctive horns on each side of the head), and made some gruesome claims: that manta deliberately leapt from the water and landed on boats in order to kill the crew; that manta would deliberately entangle themselves in fishermen’s nets and drag them out to sea. These stories are certainly apocryphal.

Manta do jump out of the water, most likely in an attempt to rid themselves of irksome parasites, but why an essentially soft-bodied creature would choose to land on a fishing boat cannot be explained. The other tale is perhaps easier to explain. Manta cannot swim backwards and, if tangled in a net, they will go forwards, generally as fast as they can, due to panic. As manta are large, powerful creatures, and fishing boats 100 years ago generally were rather flimsy, a scenario where a boat was dragged for some time by a trapped manta is not that difficult to envision.

The biggest manta reported was 25 feet across, though those normally reported by divers about half that size! Manta give birth to live young; it’s thought one to two pups per litter. Scientists also think that the length of pregnancy is somewhere between nine to 12 months, but as no one has tracked a manta from mating until birth, this is somewhat difficult to ascertain. Manta are listed as “near threatened” due to their apparently healthy local populations. They have very few natural predators – large sharks, and the occasional orca – but, as always, the main threat is man.

In parts of the world their meat has a high value, and in the past, fisheries have depleted stocks almost past the point of no return. Many end up as by catch in fishing nets. Even well-meaning diver interactions can seriously harm manta. It has only been realized recently that touching one of these creatures removes the protective mucus from its skin, leaving it liable to nasty infections.

But at the moment, things are still looking good for the manta of Nusa Penida, and for the divers who throng to see them. As always, do take the opportunity to see these giants of the deep in their natural habitat, but go with a reputable operator. Don’t crowd the manta, show consideration to other divers and snorkellers and – don’t touch.

The writer is sales manager of AquaMarine Diving – Bali.

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