This seagrass is taking over the Chesapeake Bay. That’s good and bad news

On the U.S. mid-Atlantic seaboard, efforts to restore the health of the Chesapeake Bay over the last 10 years have faced a mysterious challenge — massive booms and busts of the seagrass meadows that provide crucial habitats for juvenile blue crabs, black sea bass and scores of other creatures. Now researchers have uncovered the surprising reasons for these dramatic swings.

A weedy plant that used to lurk only at low levels in the Bay is becoming dominant, dethroning the Bay’s historically predominant eelgrass, says ecologist Chris Patrick of the Virginia Institute of Marine Sciences in Gloucester Point. Widgeongrass’s ability to grow like, well, a weed has caused the Bay’s seagrass meadow to nearly triple in extent, Patrick and colleagues report May 30 in the Proceedings of the National Academy of Sciences. That was a “big shock…