Recovery on the Sea Floor

Posted on Thursday, October 8th, 2020 | Posted in News

Story Map Shows 30 Years of Change at the Bottom of Narragansett Bay

“There is a secret underwater world at the bottom of Narragansett Bay,” starts a new online resource from the Narragansett Bay Estuary Program.

That secret underwater world is helping scientists understand the ecological impact of water quality improvements in the estuary.

In September, the NBEP released a “StoryMap“—an interactive, Esri GIS-based tool—to share research on the Narragansett Bay’s sea floor in an accessible and engaging way.

Julia Twichell is the watershed and GIS specialist for the NBEP. She used her expertise in GIS programs, as well as her graphic design skills, to create the story map.

A screenshot from the new NBEP story map. Julia Twichell, environmental analyst at the NBEP, designed this graphic to show the kinds of species that live at the bottom of Narragansett Bay.

Using Twichell’s story map, readers can scroll through text, photos, cartoons, and maps, gradually unfolding the 30 years of science and history at the bottom of Narragansett Bay.

A Walk along the Sea Floor

Water quality in the Narragansett estuary has greatly improved over the last three decades. One sign is the habitat restoration and recovery happening on the bay floor.

Twichell explained how researchers analyzed the sediments on the bay floor in 1988, 2008, and 2018.

The story map walks through the species succession scientists saw happening as water quality improved—starting with a pioneer species, then an intermediate tube-building species, which today appears to be giving way to a mature and diverse community.

A screenshot of the NBEP story map, showing species succession at the bottom of Narragansett Bay.

In 1988, the Narragansett Bay was heavily polluted. “The sea floor becomes uninhabitable,” reads the story map, next to a murky photo of the bottom of the Seekonk River. “It might remind you a bit of the surface of the Earth’s Moon.”

But over the last thirty years, through upgrades to wastewater treatment plants and other changes, nutrient pollution has declined in the watershed.

In 2008, researchers found thriving beds of Ampelisca, a tube-building animal they considered a “promising” sign of intermediate recovery. “As these organisms grow into the sea floor, they begin to pump oxygen in and filter out decaying matter,” the story map reads.

“When scientists redid surveys in 2018, they saw that a lot of Ampelisca had been replaced by more diverse communities, kind of confirming what they thought would happen,” said Twichell.

Getting the Word Out

For Twichell, knowing how the Narragansett estuary is changing isn’t enough; she wants to make sure the community-at-large in the Narragansett Bay can understand what’s happening.

“For science applications, we don’t yet appreciate how important it is to make the info we produce visual and easy to understand.”

“I wanted to create something that could span a lot of interest and experience levels. The story map is written mostly for someone not familiar with the topic, but with the ability for someone to dig into the science a little more if they want to.”

She said she hopes teachers will use this resource to educate students about the watershed they live in. She’s looking at working with local teachers to create lesson plans to send out to schools, libraries, and other environmental nonprofits in the area.

“In normal circumstances, resources like this StoryMap would be good to have. Now with more remote learning, we have to make more stuff like this available.”

The NBEP is a program partner of NEIWPCC.