KARACHI, Pakistan — Saleh Mohammad trudged through knee-high mud, clutching onto the skyward facing roots of the mangrove that surrounded him.

“Now look at these ones,” he said as he vigorously shook the roots. “These are healthy. See how strong they are, and how dense the growth. If the island had this type of growth on that side too, it could be saved.”

He points to the west where, only a few hundred meters away a veritable mangrove graveyard is spread across an entirely different, sandy landscape.

Buddo and Bundal are twin islands just off the coast of Karachi at the southern edge of Pakistan, a city that rubs shoulders with the Arabian Sea. Islands born out of silt deposits from the Indus River, they were once, possibly only a hundred years ago — inhabited by the city’s chief fishing community.

Today, thanks to a variety of climate change and man-made disasters, the islands are gradually eroding — creating a potentially grave threat to Karachi, Pakistan’s financial center. The erosion of the islands, coupled with rising sea levels, could lead to massive flooding in the city, which resides below sea level.

The effects of climate change, in fact, are a growing threat for Pakistan as a whole, analysts say. Unchecked development and a lack of government oversight with regard to the environment has led Maplecroft, a risk analysis group based in the United Kingdom, to list Pakistan among the 16 countries at the greatest risk from climate change.

On first sight, it is difficult to see why the islands are worth a fight. Stray dogs that are sometimes rabid are the chief inhabitants. One side of the island’s beaches is strewn with garbage that washes up from Defence, the posh Karachi neighborhood. But a closer look around the mudflats reveals a healthy, if shrinking, ecosystem.

But development in Karachi, and a lack of government regulation to protect the islands, is slowly but surely destroying them.

“The islands are eroding at an alarming rate,” said Shahid Amjad, a marine biologist, who until recently, headed up the National Institute of Oceanography. He added that the islands and their mangroves protect coastal communities from sea disturbances, like the southwest monsoon, which rips into the Sindh coastline almost every year.

In addition to frenetic shipping around Karachi, unrestrained effluent pouring into the surrounding sea from the city’s main industrial area, Korangi, is also threatening the islands — not to mention the area’s fishermen.

“If they want to save the islands,” Saleh said, “they have to start dredging. But the authorities rarely think about the longterm, even if they want to develop the islands.”

The docks at Ibrahim Hyderi, the mainland fishing village in west Karachi, are a veritable force of life. Groups of men sit drinking tea and repairing fishing nets. Ice is hauled onto the boats to preserve the catch. Builders are working on new projects, either carving small fishing boats for shore side fishing, or larger trawlers, or large boats for deep sea fishing that are reminiscent of picture-book images of Noah’s Ark.

Here, the fishing community has remained poor and lives on the fringes of society. Illiteracy figures are high and many children tend to drop out after the fourth or fifth grade if they go to school at all, opting for an unpredictable life at sea.

In 2006, however, the community managed to defeat plans for a $43 billion luxury living complex that was to be built by EMAAR, a company based in the United Arab Emirates.

Diamond Bar, as the project was titled, was part of a larger 8,000-kilometer luxury development project called Sugarland City. EMAAR planned to build a bridge connecting Defence, one of Karachi’s poshest locals, to the islands by way of a 10-minute drive. Although an Environment Impact Assessment was passed, little thought appears to have been given to either the island’s ecosystem or the impact of the project on the area’s impoverished and struggling fishing community.

“This project would have had immense environmental and social issues because you’d have these luxury flats, and you’d have the slums of Karachi just looking at this huge development,” said Rab Nawaz, director of the Natural Resource Management Program at the World Wildlife Fund’s Karachi office. “I think it would have been war, having all this money next to a city that is just dying — water problems, social problems.”

The local fishing community understood that a project of this sort would essentially evict them from the waters — their livelihood. They bandied around Zubaida Birwani, an activist who has worked over several years to stand up for the people of Ibrahim Hyderi and Rehri.

Her organization, Pakistan Mahigiri Tehrik, launched a massive campaign against the development. They demanded that Pakistanis pay attention to the more urgent needs of their community’s survival and the area’s once-rich mangrove eco-system.

By 2007, EMAAR quietly bowed out of the agreement, and Buddo and Bundal returned to their previous state of anonymity.

On one trawler that works around Buddo and Bundal, Mohammad Ishaq brought his nephew, Abid, along to help. At 17, he quit school a few years ago and his uncle was livid.

“I beat him up to try and knock some sense into his head,” he said. “This is not the sort of life we imagine for our children.”

Abid, however, seems unfazed. His face is still unaffected by a short career out on sea. He gazes out into the distance, his concentration centered on a wad of tobacco in his mouth, a constant fixture that has stained his teeth and makes any conversation difficult.

“It’s fine,” he mumbles. “I’m happier here on the water than in the classroom.”

He’s blithely ignorant of the woes that Birwani and her team are trying to avoid. If a development project does go through on the islands, this community’s access to the waters — and to their livelihood — will be cut off. Moreover, the island holds religious significance.

Fishermen and their families regularly visit the shrine of Yusuf Shah, a Sufi saint who is buried on the island and is a sort of a patron saint for the fishing community. Once every year, families from across Ibrahim Hyderi and Rehri, as well as other parts of Pakistan, flock to the island for a special pilgrimage.

“We had another Sufi saint buried on the mainland,” Birwani said. “But the Pakistan Air Force built a base and took over the land where the shrine was, so we could not visit the shrine any more. Yusuf Shah’s shrine is our last remaining spiritual place.”

Saleh Mohammad knows that they are the weaker force in this fight against overdevelopment and climate change. Still, he says they are up for another battle, and several more if necessary.

“Their eyes are still on these islands. They will return again for sure. And when they come we will be ready for them,” he said.