Concrete jungle threatens mangroves on Pakistan's Bundle Island

Camels roam around on the Bundle Island. A short boat ride from the shores of Karachi, mangrove trees sprout along the quiet inlets of an uninhabited island that environmentalists say provides vital coastal protection to Pakistan's largest city.

But the calm of Bundle Island, home to a few camels, is at risk, with Prime Minister Imran Khan determined to turn it into an enormous real-estate project to ease pressure on the expanding megacity home to 20 million people.

The $50-billion housing development has pitted regional leaders against the central government, with local activists and lawmakers accusing the prime minister of reneging on pro-environment promises.

"Let nature restore itself and (do) not dream of these big, grand cities," said Mahera Omar (pictured), an environmental film-maker from Karachi who enjoys kayaking around Bundle and meandering through the island's mangroves. "We are all very tired of our concrete jungle. We all want to get away, out into the open," she added.

Coastal mangroves act as a natural barrier, soaking up wave energy and limiting the extent of flooding. "These islands form a barrier against storm surges and tsunamis. Their preservation is vital for the preservation of Karachi," Arif Belgaumi, an architect and town planner, told AFP.

Karachi is already prone to inundation and suffered catastrophic flooding during this year's record monsoon when filthy, chest-deep water filled the streets.

Bundle Island floods during particularly high tides, so any construction would also require environmentally damaging reclamation work that could have knock-on effects for Karachi, Belgaumi added.

But Khan's administration says the project would create thousands of local jobs and bring much-needed relief to chaotically expanding Karachi - not to mention new tax revenue for Pakistan's cash-strapped coffers.

A draft law - immediately challenged by the provincial government of Sindh, where Karachi is the capital city - would turn Bundle and neighbouring Buddo Island into federal territories.