Flat, glistening, tranquil. Not the desert of Arabia, but the

Gulf of Oman, rich in nutrients, a bounty of natural resources.

Among them, the Sultanate’s cetaceans, a well-kept secret of scientific,

cultural and aesthetic appeal. Robert Baldwin is an accomplished

diver and marine biologist who has co-authored a guide to skin-diving

in Oman. He has taken a particular interest in Arabia’s rich cetacean

fauna, of which the spinner dolphin is one of the most spectacular,

at least in terms of their antics.

There is a relative lack of knowledge of whales and dolphins found

around the Arabian peninsula, a myriad of unanswered questions

surrounding each of the 15 species so far identified. And yet,

if revealed, the few facts known would surely generate a tidal

wave of interest and attention. The story of the spinner dolphin

(Stenella longirostris), an agile acrobat, abundant and commonly

seen in the calm waters of the Gulf of Oman, hints at the substance

of Arabia’s cetacean secret.

THE NATURAL ARENA

The spinner dolphin is justly named for its spectacular spinning

behaviour, unique to, and diagnostic of, the species. Leaping

three metres or more into the air and spinning like a barrel,

before slapping back down into the water may be a form of communication

or an attempt to dislodge irritating parasites. Or perhaps it

is just a playful spirit that drives the behaviour. Three or four

kilometres off the rocky coast of Muscat, spinner dolphins often

put on dazzling displays of grace, agility and speed, including

double backward flips, somersaults, leaps and spins, to contest

any aquarium show.

Groups of up to 1,000 spinner dolphins have been observed along

the Gulf of Oman coast, and smaller groups of three or four hundred

are regularly encountered. Only a handful of private boat owners

venture out to watch, as streamlined shapes dart to the bow-waves

of their boats, sometimes remaining with a chosen craft for several

hours.

Underwater, patient snorkellers are ap-proached with caution and

curiosity, and regaled with the staccato music of resonant clicks,

pulses, squeaks and whistles that forms their characteristic call-sign.

Before long, normal behaviour resumes, with much nudging and caressing,

and frequent coupling. Very young dolphins swim shielded by an

ever-present mother or “baby-sitter” whom they will stay alongside

for two or more years before they venture out to make their own

way in the school.

MIXED RELATIVES AND FISHY FRIENDS

It is not uncommon to find spinner dolphins in mixed schools with

the more robust common dolphin (Delphis delphis), the latter usually

towards the outside of the group. Such schools are often observed

feeding in relatively deep water, several kilometres offshore.

In one instance a school of sardines surrounded divers, forming

a tight, writhing ball of fish. They were apparently using the

two divers as cover since they watched in awe as spinner dolphins

carved through the fish, taking mouthfuls as they swam. It seemed

as if the dolphins had organised themselves into a co-ordinated

hunting group. Feeding packs of three or four individuals powered

their way through the ball of sardines in sequential droves before

circling to join the other members of the school, herding the

fish together, and waiting for their turn to feed.

Seen for the first time in Oman’s waters in May 1993, pan tropical

spotted dolphins (Stenella attenuata) are now also known to school

with spinner and common dolphins, making a threesome of related

species, about which little is known. It is possible that mixed

schools of this type are more common further offshore. However,

it is the spinner dolphins association with another kind of animal

that has earned it a place in Oman’s rich culture.

Local, traditional fishermen respect and revere “hout”, “the dolphin

that spins”. Some even talk of the dolphins as if they were deceased

relatives. Without them, locating and keeping track of tuna, a

fish fetching one of the highest prices at the local ‘suq’, would

be virtually impossible. Standing at the bows of their boats,

fishermen can scan the horizon for a tell-tale splash or the arch

of a glinting back in the dawn light. Then, racing ahead of a

dolphin school, fishermen sink their baited hooks, wrapped around

and weighted by a stone attached by means of a slip-knot. Long

ago, trial and error taught them that the tuna are to be found

feeding below the dolphins. The bait falls through the water,

glistening and glinting enticingly as the line unravels, until,

with a sharp tug, the stone is released, leaving the baited hook

free. Tuna invariably succumb to the fisherman’s tactic, which

the dolphins seem able to foresee. However, nets, once traditionally

woven, now bought with government subsidy, are also set to catch

tuna. It is a sad and well rehearsed irony that the “hout”, which

by its high spins and graceful leaps signals to the fishermen

the presence of their livelihood, also, all too often, becomes

entangled in the monofilament, virtually invisible, netting. The

death of spinner dolphins, and indeed of all cetaceans, largely

passes unnoticed, except perhaps for the fisherman’s family, who

may decide to utilise the carcasses as fertiliser for their date

palms.

SANCTUARY TO A NEW SPECIES

As Arabia’s only member of the International Whaling Committee,

the Sultanate of Oman has played an evocative role in the plight

of cetaceans world-wide, particularly in connection with the Indian

Ocean Whale Sanctuary. Nevertheless, to date, no specific legal

protection has been granted for any of the cetaceans of Oman,

despite the continued death-toll. The importance of conservation

of the spinner dolphin, and indeed of all cetaceans in Oman, became

all the more acute when, during the course of a seven year coastal

zone management project conducted by IUCN, small groups of dolphins

of uncertain identity were sighted. Very similar in appearance

to the spinner dolphin, the small, stocky, pink-bellied dolphins

that are still occasionally seen, were at first assumed to be

juvenile spinner dolphins. On closer inspection, the dolphins

seemed to have more striking facial markings with shorter, dark

tipped snouts and to have somewhat different behaviour. Until

such time as a detailed taxonomic study is carried out, the true

identity of the dolphins must remain an enigma, but could well

be a race or species new to science.

A SPINNING WHEEL OF TALES

The story of the spectacular spinner dolphin in the Gulf of Oman

is just one of many to be told about Oman’s cetaceans; from humpback

whales (Megaptera novaeangliae) which may be the world’s only

non-migrating population of this species; to the humpback dolphin

(Sousa chinensis), whose populations are curiously split by a

stretch of over 500 kilometres of coastline where they have not

been recorded. And yet, without sufficient legal protection, all

of Arabia’s cetaceans are at risk. There is still time to ensure

their survival. It is a task well worth the effort.