Oregon marsh
(Photo credit: Rick Obst / Flickr)

Where the land meets the sea, you’ll often find coastal wetlands called salt marshes. During high tide, salt water floods the low-lying part of the marsh, the tidal flats. The high marsh, a drier sandy area, floods less frequently.

When there’s a storm, the high marsh provides an important buffer – helping protect inland areas from waves and flooding.

But as the climate changes, rising seas could put high marshes in jeopardy.

“What we’ve been doing is trying to figure out how will salt marshes respond to sea-level rise,” says Martin Lafrenz, a geographer at Portland State University.

He and his colleagues have been studying salt marshes along the Oregon coast. He says by 2050, the high marsh will begin to shrink.

And then by 2100, he expects a very large decrease in the amount of high marsh and very large extension of the tide flats.

He says roads and dikes prevent the high marsh from expanding inland.

“So the marsh can’t migrate anywhere,” he says. “It’s sort of stuck in place. And so what that means is as we lose that high marsh, all the coastal communities will be losing that protection from stormwater and from storm surges.”

So he says in many cases, they need to consider moving vulnerable resources inland.

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Reporting credit: ChavoBart Digital Media.

Topics: Oceans