A number of houses including tourists' hotels near seashore in Zanzibar Islands are now under threat due to sea erosion attributed to climate change and expanding careless human activity. The erosion is also attributed cutting down of mangroves trees, and destruction of coral-reefs. The soil and shoreline erosion are putting near by houses at risk of demolition.

Zanzibar is an archipelago made up of Unguja and Pemba Islands , and several islets. It is located in the Indian Ocean , about 25 miles from the Tanzanian coast, and 6° south of the equator. Zanzibar Island (known locally as Unguja, but as Zanzibar internationally) is 60 miles long and 20 miles wide, occupying a total area of approximately 650 square miles. It is characterised by beautiful sandy beaches with fringing coral reefs and the magic of historic Stone Town - said to be the only functioning ancient town in East Africa.

About 20 years ago when the block or wall was built, Jambian beach has been was being affected by strong waves, but now with the collapse of the wall, some tourists' hotels and villages close to the seashore are under high threat due to sea erosion.

According to Mr Hamza Rijali, Environmentalist from the 'Zanzibar Ministry of agriculture, livestock, and environment', said that even water in the wells and boreholes used by people for domestic use have been affected by salty water from the sea.

‘Seashore erosion and rising sea levels are threatening; causing threats to Zanzibar villages which also face damage on rice farms and other crops, an occupation of a cross-section of Zanzibar citizens’, said Hamza.

It was not immediately known how many hectares of land and farms have been affected so far by serious soil erosion and salty water, but Mr Rijali cites a few different causes of this excessive erosion.

‘Sea waves which causes shoreline erosion, destroying crops and coconuts trees. Uncontrolled falling of trees especially mangroves trees at coastal areas and destruction of coral-reefs by reckless diving and fishing,’ he said.

Mr Hassan Sineni, a local farmer and fishermen at the Jambiani- Kibigija, about 37 ‘there is little fish catch compared in the past. Unfortunately human being is not taking any quick efforts to control the phenomenon.’

He observed further that their traditional fishing method was environmentally unfriendly to the increasing fishing, which, if properly developed, could increase job opportunities and alleviate unemployment, particularly in coastal areas.

Fishers and small farmers including seaweed farmers in the sector endure vulnerable social and economic conditions owed to loss of income and the dwindling of resources, with the harshness of nature and the impacts of climate changes.

These challenges are faced by many fishing villages in Zanzibar coasts; yet, the local population continues to rely on unacceptable methods of fishing. ‘Climate change affects fishermen activities by limiting fishing days and influencing the quantity and quality of fish harvested,’ said Sineni. Other factors of impact include the tourism development in the islands and which generates solid and liquid waste polluting the coast in some parts of Zanzibar .

Wastes from hotels close to the sea, sludge from septic pits and latrines also seep into the sea from the mangrove stands where it is dumped. Contamination has already been noted in Nungwi, north of Zanzibar , and Maruhubi area, north of Zanzibar City , according to a government report prepared for the WIO-LaB project, coordinated by the UN Environment Programme and the Global Environment Facility.