Bulletin 2 - June 1977: Masirah Island



Masirah Island

by D.M. Corfield

Masirah is an island approximately 40 miles long by 10 miles wide at its maximum point. On plan it is shaped like an hourglass, being five miles wide at its narrowest point. It lies approximately 15 miles off the Oman coast, to which it belongs politically. It is about 225 miles due south of Muscat and 400 miles southeast of Salalah.

The island is very interesting both geologically and for the study of natural history. The main backbone of the island is of basalt rock interspersed with flat limestone ridges, the highest point being about 900 feet above sea level.

Rainfall is very spasmodic, though in the year I was there (January 1972 to January 1973) it was very wet and well above the average which is only three inches per year.

The main vegetation is scrub type, with one area known locally as the Palm Wadi, containing nearly all Masirah's palm.

The principal natural history interest is turtles, although bird watching ran a close second. Over 300 species have been observed on the island (ref. An Interim List of Birds of Masirah Island, Oman, by C.I. Griffiths and T.D. Rogers).

Masirah has long been important for its strategic position i.e. at the entrance to the "Gulf". The earliest remains I came across were four Portuguese forts dating from the 16th Century. Life must have been very difficult for these settlers, as there is very little natural water on the island.

The RAF had a base on the island until March of this year when it was closed down. During the last year there were facilities for a sea plane base in a bay south of the present base. At one time it was also used as a "staging post" by the old Imperial Airways (forerunner of BA of today) and was one of their stops between England and the Far East. The old buildings are still standing and were used by a local trader for one of only two shops on the island -- the other being the NAAFI.

There is a short account of the island in a book by Hammon Innes (Harvest of Journeys).

Of all the sights I saw on Masirah, the most memorable is of the turtles. To see the females come out of the sea at dusk and proceed to lay their eggs is something I will never forget. The following points are from a lecture given on the island by a man from UNESCO. His main theme was that if harvested properly turtles could produce a better return than beef for some of the poorer countries of the world. There are four types sill found on Masirah -- these being Hawksbill, Green Turtle, Leatherback and Loggerhead. The largest type is the Leatherback, which has been known to grow to eight feet long and can weigh up to 1500lb. The Green Turtle by comparison grows to about 3.5ft and weighs up to 400lb.

Once a male leaves the 'sand' where it was born it never returns to land and spends its whole life at sea.

Females only return to land to lay their eggs. During one year they can mate at sea three to five times and therefore are capable of laying 300 to 500 eggs. The eggs are slightly larger than a table tennis ball and are soft and rubbery to the touch. Of an average clutch of 100 eggs, only one or two turtles reach adulthood. The following summary shows what happens to the eggs laid:

  • 10 percent do not hatch because they get too hot
  • 70 percent hatch but only one or two percent of these reach adulthood
  • 10 percent hatch but do not reach the surface and suffocate
  • 10 percent do not hatch because they got too cold

When the young turtles hatch most head for sea but occasionally some will turn inland and soon die. Most of the other turtles are caught by such things as land crabs, sea birds, and fish lying offshore.

For the first year of their lives the young are totally carnivorous living on decaying fish etc. After that they become mainly herbivorous although it's now thought that some fish and mollusks are eaten.

From my observations the eggs are laid at night. The females can be seen just before sunset, swimming just off shore, occasionally stopping with heads extended looking towards the mainland. When the female lands she hauls herself up the beach for 50 to 100 yards prior to scooping out a hollow which takes her body just below the ground (sand) level, then with her hind flippers she excavates a cylindrical hole approximately 18 inches deep by 12 inches diameter, all the time scattering the excavated sand forwards over her back and head. When egg laying is finished she fills the hole in, spreads sand all over the site and returns to the sea to either mate again or to swim away. The eggs are left to the mercy of nature. Once a female starts laying her eggs nothing will disturb her single-minded attitude to complete this reproduction of her species. When a turtle reaches adulthood its only real enemy is man, although a shark may occasionally try to take a flipper.


 


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