Qatar Sea Snakes

Sea Snakes: the Myths and the Facts

by Fran Gillespie

Copyright © Ibrahim Fouad Ahmed

Of the fifty-three species of sea snake worldwide, nine occur in the waters of the Arabian Gulf and of these five have been identified in the coastal waters of Qatar.

Relatives of cobras, sea snakes are thought to have descended from snakes which live on land. Like their terrestrial cousins, they are all extremely venomous. In fact the venom of some species of sea snake is even more deadly than that of cobras. They inject their venom into the small fish and crustaceans on which they prey, and because a fish's circulation is slow the venom has to be highly toxic to work quickly.

How Dangerous are Sea Snakes?

In the waters off Malaysia, fishermen sometimes get bitten when sea snakes get entangled in their nets. There is no pain at first after the bite, then about half an hour later stiffness and muscle ache is followed by increasing pain in the bitten limb. This is followed by blurred vision, drowsiness and finally respiratory paralysis.

This sort of information sounds like bad news, and in Qatar some people are understandably a little nervous about encountering a snake while swimming. However, the good news is that, although in other parts of the world there are species of sea snake which can be aggressive to humans, none of them inhabit the waters off Qatar. Most species of sea-snake are not aggressive and would never attack a swimmer or diver unless molested.

My own experience of sea snakes, having encountered quite a number during twenty years of diving and snorkelling, is that they take no notice of humans at all. Unlike land snakes, they exhibit no fear, nor do they demonstrate any curiosity, simply continuing to go about their business.

However, during the breeding season there have been occasions both in Qatar and elsewhere when snakes have mistaken the air hoses connected to dive tanks for rivals, or possibly female sea snakes! A few years ago a sports diver surfacing near the beach at Messai'eed was found to have a sea snake entangled in his air hoses. There followed some tense moments for him and his buddy, but the snake was successfully dislodged without incident.

A marine biologist working in Qatar since 1978 says that he has never heard of a single instance of a sea snake attack. This does not mean, however, that you can swim around showing off to your friends by pulling the tails of sea snakes and otherwise behaving with reckless abandon in their vicinity. They are potentially very dangerous, and should be treated with caution. But there is no need to feel nervous should you come across one. Just carry on swimming, and the snake will do the same.

In and Out of the Water

If you see a sea snake approaching you from below, there is no need to worry. It is simply coming to the surface to breathe. The snake spends only a couple of seconds at the surface before descending again. They are said to be capable of staying submerged for up to two hours, and can reach depths of 100 metres.

All sea snakes have a paddle-shaped tail to help them with swimming, but on shore they are helpless because they lack the ventral scales that all land snakes have to give them purchase on the ground as they slither along. It sometimes happens that sea snakes are cast up on the beach and have to wait for the next tide to take them off. You may sometimes come across apparently lifeless snakes on the beach, but the chances are that they are not dead, they are just waiting to be re-floated.

Copyright © David Gillespie

Breeding

Sea snakes cannot breed in water where the temperature is less than 18C, so they reproduce during the warmer months. The species which inhabit the Gulf are all viviparous, giving birth to between two and eighteen young. Here in Qatar sea snakes are commonly seen along the coast south of Dukhan, where there are rocky reefs in around 6 metres of water. One reef is even known as 'Snake Alley' by sports divers because of the numbers of snakes which congregate there in a narrow corridor between two rocky walls. They swim up and down, poking their small heads into crevices in search of prey: crabs, shrimps and small fish.

Snakes are also encountered on the artificial diving reefs at Messaieed, and around Saffliyah Island. Up north, they can be seen in numbers along the east coast off Fuwairat and Maranwah where there are shallow reefs.

Biting

A myth about sea snakes I've often heard repeated is that their mouths are too small to effectively bite a human. This is not true: although the snakes have small heads, to enable them to catch prey that is hiding in crevices or under rocks, like all snakes they can unhinge their lower jaw to extend the reach of their 'bite'. They are able to swallow a fish more than twice the diameter of their neck. A sea snake is quite capable of biting a human leg or arm, but that does not mean that it is likely to do so.

Unlike land snakes, sea snakes can control the amount of venom they release, and are capable of biting without releasing any venom at all. A few years ago a British commercial diver and his Filipino buddy were working on a pipe line near an offshore oil rig when they disturbed a large sea snake which bit both of them on their legs, the fangs puncturing the skin through their wet suits. They surfaced and a doctor from Hamad Hospital arrived at the rig by helicopter, but decided to wait for a while until administering the antivenin, as the side-effects of this can be almost as devastating to the system as the bite itself. Eventually, it became clear that all that was needed was treatment for shock.

Inshore and Offshore Sea Snakes

Inshore, the sea snakes most likely to be encountered are the Arabian Gulf Sea Snake [Hydrophis lapemoides] and the Annulated or Blue Sea Snake [Hydrophis cyanocinctus]: only an expert can tell them apart. They measure about 95 cm in length, and are a pale yellowy/green, with clearly defined dark bands along the whole length of the body. Another snake I have sometimes encountered just off the coast is the Common or Beaked Sea Snake [Enhydrina schistosa]. This is rather shorter and thinner and has darker, charcoal-grey bands extending further around the body. Its venom is said to be extremely toxic and it is also reputed to be aggressive, but the snakes of this species which I have encountered off the coast at Fuwairat simply carried on with what they were doing, so I did the same.

Snakes encountered far out at sea are likely to be the Yellow-bellied Sea Snake [Pelamis Platurus] which feeds on pelagic fish, drifting along in the currents on or near the surface. Unlike other sea snakes, the entire length of the body is flattened from side to side. It is a dark brown with a pale underside, and the tail has a yellow diamond-shaped pattern. This snake is a surface feeder, and sometimes dozens of snakes will coil together in a floating mass, tempting fish to shelter beneath it and so providing an easy meal.

A Beautiful Creature

In my own view - and I know that it is not shared by everyone - sea snakes are among the most beautiful and interesting inhabitants of Qatar's shallow coastal waters. They swim with an elegant rippling movement, like a length of ribbon blowing in the breeze, perfectly adapted to their environment. In a world where almost all wildlife has learned to fear man, there is something strangely appealing about a creature which ignores the presence of humans, apparently accepting us as a natural part of its world.

Frances Gillespie has contributed to several publications related to Qatar, is the author of Discovering Qatar and also writes regular feature articles for a national newspaper on the cultural heritage and natural history of the country. She is a former chairperson of the Qatar Natural History Group, and is still active on the committee.

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