Rising Sea Levels And Disappearing Mangrove Forests Spell Trouble For Vietnam

In the late 1960s, as a reporter working for an international news agency during the Vietnam War, I had traveled to every province in South Vietnam except for one.

That province was Ca Mau, the country’s southernmost province, located where the Mekong Delta meets the South China Sea.

Much of Ca Mau had long been virtually written off as lost to the Viet Cong. And it was home to the most formidable Viet Cong sanctuary—the U Minh Forest.

“The U Minh Forest is perhaps the last place we’ll ever pacify in Vietnam,” an American official told me back in 1969.

Legend has it that during the French Indo-China War from late 1946 until mid-July of 1954, an entire French paratroop battalion was swallowed up, never to be seen again, in the mangrove swamps of the U Minh Forest.

Ca Mau ranked as the “worst” province in South Vietnam in terms of government control. But following an aborted Viet Cong attack on the province capital in 1968, the South Vietnamese government went on the offensive and opened several villages and canals previously held for years by the Viet Cong.

The Communists and South Vietnamese government had separately announced that they would respect a two-day cease-fire starting Jan. 30, 1968 in order to permit a celebration of Tet, the Vietnamese Lunar New Year. But the Communists broke the cease-fire with surprise attacks on provincial capitals throughout Vietnam. This became known as the Tet Offensive.

In Ca Mau, as in most other provinces in South Vietnam, the attacks turned out to be a disaster for the Viet Cong. With support from American air power, the South Vietnamese quickly reclaimed most of the cities that the Viet Cong had occupied.

The Viet Cong then had to lie low, making it safer to move around the country. So I decided that it was time to visit Ca Mau and to take a look at those impenetrable mangrove swamps.

I went out on an operation with a South Vietnamese Army battalion. The soldiers encountered no resistance, so I didn’t have much of a story. But I did get a look at mangrove swamps, which might be best described as forests growing in swampy ground.

Now, decades later, as part of my research on the impact of climate change in Southeast Asia, I find myself studying why Vietnam has, for years, been losing those formidable mangrove forests, which, as I’ve now learned, play an important role in protecting their surrounding environment.

The Impact of Agent Orange

I should mention early on that in an effort to deny cover to the Viet Cong in Ca Mau and other parts of Vietnam, U.S. planes sprayed a defoliant called Agent Orange.

On a postwar trip into the Mekong Delta in 2005, I met a number of Vietnamese who told me that Agent Orange had damaged their health and that of their children.

I visited the home of a 10-year-old child whose arms were shortened and deformed. A local school official told me that she was born with birth defects caused by Agent Orange. She nonetheless turned out to be an excellent student, the official said. And she proudly showed me one of her school notebooks.

Thousands of American and South Vietnamese soldiers also suffered from Agent Orange-related illnesses. In many cases their children developed disabilities. But while American veterans have been eligible for disability compensation, their Vietnamese counterparts have not.

In a New York Times article published on April 18, 2017, authors Nguyen Thanh Nguyen and Richard Hughes wrote that the U.S. government's "one concession to responsibility for the ravages of Agent Orange has been environmental remediation."

More than $100 million was allocated by the U.S. government to clean up the Da Nang airport, one of 28 “hot spots” for defoliant contamination. But only $20 million was allocated for victims of Agent Orange.

Disappearing mangrove forests

Agent Orange alone has not been responsible for the loss of these forests, though.

Mangrove forests consist of small trees that thrive in saline water.

In Vietnam, the mangroves guard against dangerous salt water intrusions into farm land in the southernmost part of the Mekong Delta and also provide protection for a variety of wildlife.

As Delta ecologist Nguyen Huu Thien explains, the Delta is the main food basket of Vietnam. It produces more than 50 percent of the country’s food, 90 percent of its rice exports, 65 percent of its fruit, and 75 percent of its fish, which are a major source of protein.

The Delta still suffers from the impact of an ill-advised attempt by the Communist authorities after they took power in South Vietnam in the spring of 1975 to increase rice production there.

In order to expand the space for rice production, the new rulers encouraged the destruction of the mangrove forests which had acted as a buffer to protect farm land from sea-driven salt intrusions.

Add to this loss of mangrove forests the impacts of climate change and the upstream hydropower dams in China and Laos which have blocked much of the sediment that once reached the Delta and replenished it with nutrients, and you have a disaster in the making.

On June 19 of this year, Brian Eyler and the Washington, D.C.-based Stimson Center explained in a paper co-authored with Jake Brenner of the Swiss-based International Union for Conservation of Nature (IUCN) how this could come about.

“Without sufficient sediment to replenish the land,” they said, “the delta will sink beneath the East Sea—a problem compounded by unsustainable groundwater pumping and a rising sea level.”

The loss of sediment as well as rising sea levels have, along with the destruction of the mangrove forests, resulted in salt water reaching as far as 40 miles into the southern tip of the Delta.

On the positive side, some farmers have coped with the loss of the mangrove trees by raising shrimp in the briny water created by salt coming in from the South China Sea, or East Sea, as the Vietnamese call it.

But a reduction in rice exports has meant a drop in income for many, with a number of young men and women leaving the Delta to seek work in urban areas.

When I first reported from Ca Mau five decades ago, I could never have imagined the damage now being done to the province both by storms and rising sea levels.

Take for example, the heavy damage caused in early August of this year to villages in Ca Mau located next to an embankment meant to hold back the sea. The embankment was designed to protect two districts, U Minh and Tran Van Thoi, from saline intrusions that could affect thousands of families tending rice paddies in the area.

VnExpress, a Vietnamese online newspaper, said that the embankment was eroded by heavy rains, strong winds, waves, and high tides.

The collapse of a 350-meter-long (1,148-foot-long) section of the embankment caused the province to issue an emergency warning over coastal erosion, according to VnExpress.

Vietnam’s Ministry of Construction has now proposed building concrete barriers to protect more than 44,000 families in the area from rising sea levels.

Dan Southerland is RFA’s founding executive editor.