HOW THE CORAL WALLS OF A GHOST TOWN HOLD SE­CRETS OF THE SEA

The walls of Jazi­rat Al Hamra con­tain up to 12 mil­lion pieces of coral and each is a clue to the past, say NYUAD re­searchers

The National - News - - NEWS - ANNA ZACHARIAS

In the is­land vil­lage of Jazi­rat Al Hamra, peo­ple were so con­nected to the sea that even their homes were built of coral.

The aban­doned pearling town in Ras Al Khaimah has long been ad­mired as one of the best ex­am­ples of pre-oil ar­chi­tec­ture on the Ara­bian Gulf.

Its walls not only tell the story of the area’s peo­ple, but the his­tory of the sea it­self. Its homes, mosques and court­yard are built from al­most 12 mil­lion pieces of sun-baked coral and each is a clue to the Gulf’s ma­rine his­tory.

Bi­ol­o­gists at New York Univer­sity Abu Dhabi are now analysing these un­usual build­ing blocks to un­cover how the coast­line has changed in the past 400 years.

Jazi­rat Al Hamra has about 500 build­ings built from coral, sand brick and ce­ment. There are 53 kilo­me­tres of coral stone walls, av­er­ag­ing 2.85 me­tres in height and 50 cen­time­tres thick. Un­folded, they would reach al­most from the Abu Dhabi-Dubai border to Shar­jah.

The av­er­age coral piece is about 800 cu­bic cen­time­tres, slightly larger than a glass Vimto bot­tle.

“They would ba­si­cally fill a na­tional rugby pitch about a me­tre high, or a New York City block,” said John Burt, the ma­rine bi­ol­o­gist at NYUAD, who led the re­search.

“So they would have had to have mined about 10 hectares of reef sur­face.”

Pieces were re­cy­cled over the cen­turies. One piece dat­ing from 1551 was found in the wall of a mosque, sup­port­ing oral his­to­ries that trace the vil­lage’s ori­gins to the same pe­riod as the de­cline of the me­dieval port city of Jul­far.

A ques­tion re­mains: where did the coral come from?

Oral his­to­ries on coral min­ing are all but non-ex­is­tent. There is spec­u­la­tion that the Gulf did not have the reefs to sup­port this in­dus­try and that coral was mined in the Gulf of Oman or even off the coast of East Africa.

Dr Burt be­lieves oth­er­wise. Coastal maps de­vel­oped by the Bri­tish navy from the 1820s to the early 1900s show a sub­stan­tial reef once ex­tended al­most 10km along the shore­line be­tween Jazi­rat Al Hamra to the Umm Al Quwain la­goon.

“One ar­gu­ment has been that there was no coral reef near by and we’ve shown that that was not the case,” Dr Burt said. “It was very close to the coast and po­ten­tially could have been mined on foot dur­ing low tide.”

The com­po­si­tion of the reefs ap­pears to have changed lit­tle since the 1550s. To date, 11 dif­fer­ent gen­era of coral have been iden­ti­fied from the vil­lage walls, with a va­ri­ety and com­po­si­tion pro­por­tional to what ex­ists to­day.

“Brain coral was by far the most abun­dant on the build­ings in Jazi­rat Al Hamra and is still the most com­mon on reefs in Ras Al Khaimah,” Dr Burt said. “About 40 per cent of the corals in the walls were brain coral and that ba­si­cally re­flects what you’ll find in reefs.”

Size ranged from fist-size blocks to great chunks of brain coral used as foun­da­tion blocks. Once mined, they were sorted by size in fresh wa­ter to kill off the or­gan­isms and dried on the beach for a year.

The por­ous blocks were good in­su­la­tion and one of very few lo­cal build­ing ma­te­ri­als.

For this rea­son, many of the UAE’s historic build­ings used coral, such as the 15th-cen­tury Al Bidiya mosque in Fu­jairah and Qasr Al Hosn in Abu Dhabi, part of which is be­lieved to date from the late 18th cen­tury.

“Coral was the only hard ma­te­rial that peo­ple would have had,” Dr Burt said.

“You also have to recog­nise that this was an age long be­fore scuba, but we have here an in­dus­try that was based on div­ing.”

The fos­silised coral in Jazi­rat Al Hamra, dated by Dr Julie Retrum at the Univer­sity of Mis­sis­sippi, shows the town ex­pe­ri­enced a con­struc­tion boom in the 18th cen­tury.

Coral min­ing con­tin­ued into the 20th cen­tury. Sam­ples from the Ab­dul Ka­reem House, in the vil­lage souq, date from 1886 to 1921.

Soon, ce­ment would re­place coral stone and by the 1970s, the vil­lage was largely aban­doned. Seas­capes, too, were trans­form­ing. The reef that ex­tended to Umm Al Quwain has been lost to de­vel­op­ment.

“This area has been heav­ily de­vel­oped since the 1980s, first for port con­struc­tion and later for deep­en­ing of la­goons to make canals, as well as beach­front mod­i­fi­ca­tion and nearshore land recla­ma­tion,” Dr Burt said.

“While oc­ca­sional patch reefs still oc­cur in this area, the ex­ten­sive reefs that were once here no longer ex­ist.”

On Tues­day, Dr Burt pre­sented his find­ings to the Emi­rates Nat­u­ral His­tory Group, whose mem­bers helped with doc­u­men­ta­tion of 160 vil­lage walls and 2,000 pieces of coral.

Vol­un­teers have been es­sen­tial to the project. Dr Burt cred­its Noura Al Man­soori, a re­search as­sis­tant in his lab, for de­vel­op­ing it as a cit­i­zen science project. Their find­ings are now be­ing writ­ten up.

About 40 per cent of the corals in the walls were brain coral and that ba­si­cally re­flects what you’ll find in reefs DR JOHN BURT NYUAD ma­rine bi­ol­o­gist

Sarah Dea / The Na­tional

A mer­chant’s house in the pearling town of Jazi­rat Al Hamra, Ras Al Khaimah, which was built from 11.57 mil­lion pieces of coral

BP Ar­chive

Stacks of coral dry on the beach in Abu Dhabi in the mid-20th cen­tury. Coral stone was used in the con­struc­tion of many build­ings, in­clud­ing Qasr Al Hosn

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