Lisa Sorg

(States Newsroom) Roughly 670,000 acres of salt marshes and swamps — greater than the land area of Rhode Island — disappeared between 2009 and 2019 in the contiguous 48 states, a congressional report released last week shows, threatening key flood controls, wildlife habitats and access to clean water.

Mandated by Congress, the recent Wetlands Status and Trends report is the sixth such document since 1954. It is published by the U.S. Fish and Wildlife Service.

“Wetland loss leads to the reduced health, safety and prosperity of all Americans,” wrote U.S. Department of Interior Secretary Deb Haaland, in the report’s preface. “When wetlands are lost, society loses services such as clean water; slowing of coastal erosion; protection against flooding, drought and fire; resilience to climate change and sea level rise.” There are also losses in fish, wildlife and plant habitats.

Not only is the U.S. losing sheer acreage of wetlands, but also the rate of loss has increased by 50% since the turn of the century, or about 21,000 acres per year. The remaining wetlands are being transformed into ponds, mudflats and sand bars; these are known as non-vegetated wetlands — a change that alters “wetland function and lead to the reduction of wetland benefits, like the mitigation of severe storms and sea level rise, and water quality improvement,” the report reads.

It’s likely that the loss of wetlands will accelerate over the next decade. Fish and Wildlife’s recent study period ran from 2009 through 2019 — before the U.S. Supreme Court’s controversial decision that stripped environmental protections from tens of millions of acres of wetlands nationwide.

The report says that studies show that over the long term, wetlands may disappear from some regions within several decades.

“For example, under high sea level rise scenarios, all salt marsh is predicted to be lost in California and Oregon by 2100,” the report says.

“Globally, between 20 – 90% of coastal wetlands are predicted to be lost before 2100.”

Even though the U.S. has set a “no net loss” policy about wetlands, the nation has hit that mark only once in 70 years. That occurred in the early 2000s.

Most of the wetland losses in the mid-20th century occurred because of agricultural practices, like draining and filling. But later, from 1986 to 1997, urban and rural development were associated with over half of the net wetland loss. Agricultural and timber practices — clearcutting — made up about a quarter of wetland losses each.

Here are several more key numbers from the report:

116.4 million acres — amount of wetlands in the contiguous U.S.

110.4 million — of the total, the amount that are freshwater wetlands

6.1 million — that are saltwater

426,000 — net decrease in freshwater forested wetlands

70,000 — net decrease acreage of salt marshes, or about 2% of their total

7% — increase in pond area nationwide, the result of more agricultural, as well as urban and industrial stormwater ponds.

50% — of North American bird species depend on wetlands

80% — of protected birds that depend on wetlands

61% — of amphibian species are declining in the U.S. Many amphibians, like frogs and salamanders, depend on wetlands for their habitats.

50% — of crayfish species, also found in wetlands, are declining in the U.S.

Two-thirds — of freshwater mollusk species are at risk of extinction

10% — of mollusk species are already extinct