Harbor Wetland

Splashing Down in the Harbor

The National Aquarium Harbor Wetland presented by CFG Bank is a free, outdoor exhibit between Piers 3 and 4 of the National Aquarium campus on Baltimore's Inner Harbor. This latest exhibit allows visitors to the harbor to step onto floating docks and experience the diverse plant and animal life filling this innovative, re-created salt marsh.

Reintroducing Salt Marsh Habitat

The Aquarium's newest exhibit looks forward by looking back. Hundreds of years ago, Baltimore's Inner Harbor was a tidal salt marsh surrounded by forests. Back then, when rain fell or snow melted, it soaked into the soil. The soil held the water, filtered it and then slowly released it. This filtered water then seeped into the harbor—part of the Patapsco River—and its tributaries before flowing into the Chesapeake Bay and the Atlantic Ocean beyond. This natural process helped keep these waterways clean and healthy.

As the city grew, thanks to the natural resources provided by its streams and rivers, the harbor was dredged out, the soil was paved over with asphalt and concrete, and the forests were replaced by housing and industry.

Today, rain still falls and snow still melts, of course—but without much soil to seep into, the water instead rushes over sidewalks and roads, racing into storm drains or directly into the harbor and other waterways. All the pollutants, chemicals and trash it picks up along the way are carried with it.

By mimicking the natural salt marsh habitat that once existed in Baltimore City, Harbor Wetland is reintroducing an important ecosystem. In the process, it provides green infrastructure that promotes healthy water; attracts native species like blue crabs, American eels, Eastern oysters and night herons; and teaches students and guests about wetland ecosystems.

Baltimore's Inner Harbor is teeming with life, and it can be restored. Immerse yourself in Harbor Wetland and see how you can be part of the harbor's next chapter!

Spotlight on Cordgrass

Cordgrass is a workhorse of the salt marsh ecosystem. The roots help stabilize sandy soil and the plants absorb carbon. These grasses also provide essential habitat for a variety of species, both when it's submerged during high tides and exposed during low tides. Algae grow on the stems and are grazed upon by periwinkle snails during low tide; these snails, in turn, are eaten by fishes during high tide, when the grass is completely submerged. The plants also offer protection for small prey, like juvenile blue crabs. They hide among the thick stems, protected from larger predators that can't maneuver the tight spaces.

Excess nitrogen in the harbor—which comes from polluted stormwater runoff and Baltimore's aging sewage and stormwater systems—fuels algal and bacterial blooms that harm fishes, turtles, crabs, birds and other animals.

Beyond carefully recording all the wildlife seen on and around the floating wetlands, the National Aquarium team partners with researchers to analyze biofilm—structured mats of bacteria—from the harbor and conduct DNA barcoding. This allows us to identify species that aren't as easy to see and learn more about the Inner Harbor's biodiversity.

The Aquarium's Conservation team continued refining the floating wetland design to develop a model that best fit the specific needs of the Inner Harbor. Following much evaluation and research, the team installed the fourth prototype in 2017. This 400-square-foot wetland was very successful over the course of four years and became the model to replicate on a large scale for Harbor Wetland.

STEAM on the Harbor

Harbor Wetland is a blending of science, technology, engineering, art and mathematics—or STEAM skills. It could be viewed as a kind of environmental artwork, like a scaffold or canvas for nature to build or draw on. More traditional artists have lent their talents to this outdoor space, too; their work, both seen and heard, brings another dimension to the exhibit.

His mural opposite the dock entrance is no exception. It depicts iconic wetland species, people collecting and analyzing water quality samples, and oxygen-rich underwater bubbles. The components all highlight this habitat's biodiversity and emphasize how humans are connected to and responsible for this ecosystem.

As artists-in-residence ahead of their Voyages performance, Jess and Patrick were inspired by oyster reef development and water quality. Building off methods they'd used to create their original composition, "Will the Great Water Remember," the duo crafted three new movements, which are their auditory interpretations of past, present and future.