Why boosting Chesapeake Bay seaweed is good news for crab lovers
Grasses provide cover for young crabs, allowing them to avoid predators. This is good news for the life cycle of blue crabs, and for people who like to consume them.
Weeds in Chesapeake Bay waters play a large role in blue crab survival strategies, and a recent study showed that the number of acres of bay weeds increased by 12%.
This is good news for the life cycle of blue crabs, and for people who like to eat them. Grasses provide cover for young crabs, allowing them to avoid predators.
But as Doug Myers, chief scientist in Maryland at the Chesapeake Bay Foundation, explains, grasses in the lower bay — eelgrass, in particular — are critical to crab mating, too.
In order to mate, Myers said the female crab molts so that its shell becomes smooth. Just as eelgrass provides hiding places for young crabs, it provides additional protection for adult crabs during the mating process.
Bay grasses are also essential to the waterfowl populations that feed on them in areas such as the Susquehanna Flats near Havre de Grace.
According to the latest survey by the Virginia Marine Science Institute, 76,400 acres of bay kelp were recorded in 2022, compared to 69,600 acres the previous year.
The goal is to cover a total of 185,000 acres, Myers said. However, he said the increase in bay grasses is good news.
In 1972, when Hurricane Agnes hit the region with massive amounts of rain and runoff, bay grass coverage was already declining, Myers said. It led Agnes to the “Mother of the Dead Zones,” after which “the weeds disappeared for 30 years.”
Efforts to clean the Chesapeake River have since helped with water clarity, which is necessary to allow light to filter into the water so weeds can grow.
The key to continuing progress on grass restoration is a push for things like modernizing wastewater treatment plants and improving agricultural practices to cut pollution, Myers said.
Myers said he realizes that decades-long restoration efforts can be “stressful,” and that some people find the bay weeds “a nuisance…they wrap around the boat’s propeller.”
But he said the grasses are essential to the health of the bay.
He asked the audience: “Be patient.” “Weeds are very important to the Bay’s ecology.”
“Our cleanup efforts are really working to restore those grasses and all the living resources that depend on them,” he said.