Suriname aims to reverse coastal erosion with mangroves

by Marvin Hokstam | Thomson Reuters Foundation
Thursday, 23 December 2010 01:24 GMT
Researchers are rebuilding Suriname's devastated coastal mangroves to cope with climate pressures

CORONIE, Suriname (AlertNet) – Sieuwnath Naipal sheds his work clothes and in little more than his underwear wades waist deep out into the sludge of Suriname’s muddy coastline to inspect his red mangrove seedlings.

“This is definitely a challenge, but it’s important,” he says. Without efforts to restore Suriname’s coastal mangroves “this area here can disappear in 30 years,” he said.

Suriname’s muddy coastline, fed by the silt washed from the mouth of the Amazon River, has lost many of its mangroves in recent decades, a growing concern since the groves are seen as a bulwark against erosion and worsening climate change-related sea level rise along Suriname’s coast.

But Naipal and others are working to build Suriname’s coastal mangrove forests, planting seedlings they hope will survive both growing climate pressures and engineering changes that over the last half century have killed many of the country’s mangroves.

A former colony of the Netherlands, sparsely populated Suriname lies north of Brazil on the northeastern shoulder of South America. Much of the republic’s hinterland is covered in thick Amazon rainforest and its densely populated coastline is home to some 90 percent of its approximately 500,000 inhabitants.

 Coronie, where Naipal’s mangrove project is located, is a two-hour drive west from the capital, Paramaribo, on the East West Link, a road constructed in the 1960s to connect the capital with picturesque Albina on the east, near the French Guiana border, and bustling Nickerie on the west, at the Guyana border.

Perched between Paramaribo and Nickerie, Coronie is a district of old coconut plantations. Its coastline for years has been tormented by heavy sea swells, and the problem is worsening.

HOLDING COASTAL SILT

Suriname’s coastline is continuously replenished by sludge dumped in front of the country by currents from the mighty Amazon river; Coronie in particularly takes on a lot of silt.

“The Amazon river spits out about one billion tons of mud every year into the sea. Twenty percent of that passes right in front of our coast and about one percent stays with us. That’s why we don’t have those nice sandy beaches out here,” said Naipal, a Russian-trained hydrology professor at the Anton de Kom University of Suriname (ADEKUS).

The red mangrove - also called parwa - should flourish in this environment. Amazon river sediment carried in by the waves gets caught between the parwa roots and eventually becomes mud, which then spurs both the parwa and the coastline to expand.

“Our coast should be growing. It has always been like that. Our coastal area is relatively young and very fertile,” Naipal explained.

But when engineers plotted the construction of the East West Link, they didn’t take into account that the road would cut straight through wetlands where freshwater and sea water mix.

“There’s millions and millions of liters of sweet water that makes its way from the hinterland to the sea, and by building the East West Link the engineers disturbed the natural flow of things,” Naipail said.

Red mangroves, it turns out, flourish in water that has a specific intermediate salinity, created when sweet water and salt water mix. With the free flow of sweet water blocked in many places, the parwa forests have been dying since the 1960s.

EROSION LOSSES

That has given free reign to sea swells and reversed the normal cycle of land building: Fewer parwa roots to lock in sediments mean an eroding and retreating coastline, and more and more mangrove trees dying.

“That is why we have been having this problem with erosion in this area all the time,” Naipal explained. Sea level rise is also contributing to the problem, he said.

 “Climate change is having its toll now. We’re seeing totally different rain patterns now than 30 years ago,” Naipal said. He has registered months with no rain, when up to 30 mm used to fall. That means less fresh water finding its way to the coastline.

He points to erosion as proof of the growing problems.

He drives to a government-built dike -made out of mud and 12 kilometers (7.5 miles) long - that is nearing completion, to show where 10 years ago there used to be a forest of mangrove protecting the coast line. Now all that’s left after the onslaught of the waves is mud and the occasional heap of dried-up mangrove branches scattered on the seaward side of the dike.

“They spent 60 million euros to build the dike, but they gave up that stretch of land (beyond the dike), because they figured it couldn’t be saved,” Naipal says wearily.

REBUILDING THE GROVES

His mangrove reintroduction project aims to stop such losses. Funded through the Suriname Conservation Foundation – an organization funded by the governments of Suriname and the Netherlands, Conservation International and the Global Environmental Facility - Naipal and university students have studied the density of the coastal mud and what salinity levels mangroves can tolerate.

Based on their work, Vitotech, a local research company, was contracted to clone surviving red mangroves and deliver 500,000 seedlings. As part of a pilot effort, Napal’s team has already planted a few hundred of the seedlings in the mud, with splints placed to reinforce them against the crashing waves.

The plants, put in spots where the salinity levels are most favorable, are now being monitored carefully. Naipal drives out from the university to the mosquito-ridden base camp several times a week, and a young local has been hired to keep an eye on things.

“They’re doing great,” an enthusiastic Naipal says, pointing at how well the splinted plants are doing in comparison to a few others that have sprouted on their own in the mud.

If in a few months he is satisfied with the development of the pilot effort, he plans to rally local residents to plant all 500,000 seedlings in long rows along parts of the coastline the dike does not reach. Then he plans to bring the replanting effort to another area closer to Paramaribo, where mangroves have been lost to man-made coastal developments. The total replanting effort is expected to cost $1.8 million.

“If we’re able to establish ‘islands’ of mangrove vegetation along several kilometers of the coastline, then nature should take over” and allow the mangroves to expand, Naipal predicted.

Better yet,  “if we are able to pull this off … not only will government no longer have to spend millions in the short term on rebuilding dikes (but) we will also maintain the mangrove forests as habitat for wildlife for birdwatchers and other tourists, and as a source of income for the fishermen of this area,” he said.

“And we’ll be able to show the world that reintroducing mangroves is a good defense against sea level rise. It would be a thing to be proud of,” he said.

Marvin Hokstam is a freelance writer who focuses on the Netherlands Antilles and Suriname.

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