Saudi Arabia is blessed by being bordered with two unique tropical
seas, the Red Sea and the Arabian Gulf. Although the Red Sea is
known worldwide as a diving paradise, fewer people know, or believe,
that the Arabian Gulf has its own rich coral reefs. The fact is
that parallel to the east coast of Saudi Arabia there is a string
of offshore islands that present exciting diving opportunities,
even to well-travelled divers. Of these islands, Jana is the most
accessible and frequently dived.
Jana island is situated about 20 kilometres north-east of Al Jubail
Industrial City. A low coral cay with long stretches of sandy
beaches, the island is surrounded with a fringing reef which,
in places, lies more than 1.5 kms out from the shore. A shallow
lagoon, enclosed and protected by the fringing reef, has many
bottom-dwelling creatures and scattered coral blocks. Moving seaward
from the reef crest, the coral reef has a gentle slope down to
a depth of 10m. In most locations this slope continues until the
coral growth thins out to a sandy bottom, 15-20 m below the surface.
In other places, the transition from the 10 m depth to the sandy
bottom takes the form of a steep coral drop-off.
Strictly speaking, the diving conditions near Jana are by no means
ideal. Surface water temperatures drop lower than 15°C in winter
and may rise over 33°C in summer. This limits the recreational
diving season to the period from April to October. In addition,
the underwater visibility ranges from a low of 5 m to a high of
20 m, with 10 m as the norm. The visibility is affected by the
daily tidal changes and the seasonal plankton blooming can give
a diver an eerie feeling of diving in a soup of marine organisms.
The salinity, temperature fluctuation, and turbidity in the Gulf
limits the number of species that can survive in these adverse
conditions. but this is outweighed by the fact that the species
that live here benefit from abundant food sources resulting in
faster growth rates and larger single species assemblages, compared
to other locations.
Most diving trips to Jana depart from Al-Jubail. The boats cruise
through Berri oil field and past the eastern tip of Abu Ali Island,
reaching Jana in about two hours. Due to the predominant northerly
winds, diving usually takes place on the south-side of the fringing
reef. Most divers prefer to spend their time in the shallows where
the highest concentration of marine life is found. Extending for
long distances are flat coral gardens that teem with colourful
reef fishes, including several species of butterflyfish and parrot
fish. Three different butterflyfish species are common, the Arabian
butterflyfish (Chaetodon melapterus), the blackspotted butterflyfish
(C. nigropunctatus) and the banner fish (Heniochus acuminatus).
Large parrotfishes, some with remoras attached to them, swim idly
by, scraping the coral with their fused teeth. They are usually
followed by the strange-looking broomtail wrasse or a school of
tiny moon wrasse. Meanwhile, the brightly-coloured Picasso triggerfish
can be seen feeding on molluscs and burrowing invertebrates in
the sand, blowing out the unwanted debris through its gills.
But the most conspicuous reef resident is definitely the Arabian
angelfish (Pomacanthus maculosus) with its distinctive yellow
spot. Unlike in the Red Sea, this species is so abundant here
that it is not surprising to see dozens of them in a single dive.
On one occasion, I encountered a school of more than 50 sub-adults
cruising in a group, stopping every few metres to feed.
In the 10 m range, the reef is dominated by Acropora table corals
that may grow to a size of 3 m. These intricately laced table
corals provide a home for many juvenile buttlerflyfishes and damselfishes.
In the shade of these living tables live other fish such as menacing-looking
moray eels and the common half-spotted coral grouper (Cephalopholis
hemistiktos). Not far away, are families of clownfish darting
in and out of the tentacles of their anemone hosts.
Toward the eastern part of the fringing reef, one can swim around
big coral pinnacles that rise from the bottom to near the surface.
Their sides are usually well-lit and hence are full of marine
life. Schools of blue sailfin tang, fusiliers and the ever-present
sergeant-majors circle the outcrops. Other reef residents come
to be manicured by the cleaner wrasse. A close examination of
the burrows in the walls reveal tiny colourful blennies and juvenile
lobsters.
Divers who descend to the bottom of the reef at 15-20 m are rewarded
with sightings of different fish species. In these depths, the
light level can be low and the pace is not as fast as in the shallows,
but interesting species are abundant. On the bottom, small coral
blocks and rubble provide a suitable habitat for several species
of lionfish and the venomous scorpionfish. Facing the current,
groups of spotted sweetlips hover near the sea-floor, seemingly
oblivious to approaching divers. On patrol are emperorfish no
doubt searching for exposed or injured sea urchins. Among the
commonly observed fish seen here are smalltooth -, long-faced
-, and blue-scaled emperorfish.
Even the sandy bottom has some special surprises for the observant
diver. Benefiting from an almost perfect camouflage, the bizarre-looking
Moses sole is difficult to distinguish from the sand. If forced
to move, it swims by undulating its flat body. Another master
of camouflage is the marbled electric ray (Torpedo sinuspersici)
which is capable of jolting its prey with more than 200 volts
of electric shock. Another resident of these depths is the spiny
porcupine fish. If threatened, this species will inflate its body
into a spherical shape with erect spines, rendering it impossible
for a predator to swallow.
For pelagics and other big fish, divers usually focus their attention
on the blue water out beyond the cosy protection of the reef-face.
There, it is possible to see passing schools of jacks, barracudas,
or a rare formation of devilrays. Solitary eagle rays may also
be encountered, but they usually flee quickly. However, the ultimate
reward has to be a face-to-face encounter with a whale shark.
This rare creature, the largest fish on our planet, grows to more
than 12 m and is seen surprisingly frequently near Jana. During
the summer of 1994, I was lucky to see a whale shark on three
different days. Nothing in my diving career comes even close to
an adrenaline-pumping five-minute dive with one of these graceful
giants.
The importance of Jana as a valuable and unique ecosystem is not
limited to its coral reefs. The island is a primary breeding site
for several bird species, and a nesting ground for the endangered
hawksbill and green turtles. As a result, plans have been prepared
by the National Commission for Wildlife Conservation and Development
(NCWCD) to include Jana, and other offshore islands in the Jubail
Marine Wildlife Sanctuary. Once implemented, restrictions on spearfishing
and anchor-use will ensure the preservation of the fragile marine
and terrestrial habitats of this fascinating and beautiful Gulf
island.