Zanzibar's tourist high season hit by blackout

* Power supply disconnected since Dec 10

* Zanzibar tourism profits eroded by diesel spend

* Power might be back before Christmas

By Katrina Manson

STONE TOWN, Zanzibar, Dec 22 (Reuters) - Zanzibar's tourism sector faces heavy losses after a power outage caused by a broken connector plunged the islands into darkness at the height of the holiday season.

The Indian Ocean archipelago relies on tourism for more than 25 percent of its gross domestic product and 70 percent of its foreign exchange. The outage occurred on Dec. 10, authorities said.

Zanzibar was already facing reduced income due to the global downturn, which has cut arrivals by 12 percent this year.

"It's costing us dearly. It couldn't have come at a worse time ... in a year where takings are down because of the world crisis," said Julia Bishop, director of the Zanzibar Association of Tourism Investors.

"It looks like this year's profit is going to go on diesel."

Some resorts have been forced to spend more than $3,500 per day on diesel to fuel generators. Humidity soars during peak holiday season, prompting hoteliers to turn on air-conditioning.

"All the profits for this year have gone on the last 10 days," said Agnes Viellard, manager of Monsoon, a Swahili restaurant that has lost 20 million shillings ($14,980) as a result of the outage.

In Forodhani Gardens, where chefs grill fresh octopus, prawns and meat kebabs beside the sea, some visitors expressed their concern.

"I arrived yesterday and I was surprised that the electricity is not working," said Alan Jansky, a Czech tourist who visited four hotels before he found one with water.

"I don't care about the electricity but the water -- it's bad because the pump is not working."

Prices for black market fuel almost tripled as some pumps ran dry and hotels reported guests cancelling trips. Managers without back-up generators threw out the contents of freezers.

"How much has been lost hasn't been calculated yet," said Ali Khalil Mirza, head of the Zanzibar Commission of Tourism.

Authorities said power might return before Christmas after they ordered a spare part for the broken connector for the link which transmits the 45MW of electricity, supplied from the Tanzanian mainland. (Editing by Jeremy Clarke and Robin Pomeroy)