Artificial Reefs Installed Along Providence Waterfront

Shellfish reefs have been installed along the shoreline of India Point Park. The nine reefs are only visible at low tide. (RISD photos)

Shellfish reefs have been installed along the shoreline of India Point Park. The nine reefs are only visible at low tide. (RISD photos)

By KEVIN PROFT/ecoRI News staff

PROVIDENCE — On the morning of Saturday, June 18, visitors to India Point Park witnessed something unusual. This tranquil park, at the confluence of the Providence and Seekonk rivers, normally attracts walkers, joggers, sunbathers, fishermen, and yoga and tai chi practitioners. But, on this day, there were also people splashing in the river.

With the tide low, the water didn’t reach much higher than their knees. They placed sculptural forms, about 3 feet in diameter and made of metal frames and concrete plates, among the wooden pilings just beyond the seawall. Parkgoers curious enough to ask, learned they were watching the deployment of nine artificial shellfish reefs — the culmination of nearly four years of collaborative research and planning among many of the state’s public and private universities.

The installation couldn’t have gone smoother, according to Emily Vogler, a landscape architecture professor at the Rhode Island School of Design and one of the project’s leaders. Timed for the four-hour window surrounding low tide, the team finished securing the reefs just before the water got too deep to work in.

Now all they can do is wait and see if oysters and other shellfish actually settle on the structures. Because upper Narragansett Bay is closed to shellfishing, the plates couldn't be seeded with larvae prior to deployment. Instead, shellfish larvae will need to find their way to the reefs naturally.

The city's waterfront supported millions of oysters at the turn of the 20th century, with 5,000 acres of leased oyster beds in the Providence River and upper bay in 1905. In the decades that followed, pollution, bacteria and sedimentation caused a sharp decline in the oyster population. The Hurricane of 1938 put an end to the already-declining local oyster industry, and shellfishing was later banned in the upper bay because of polluted sediment and bacteria in the water.

Today, the oyster population along Providence's shoreline is counted in the thousands, not millions. In 2008, when the first phase of the Narragansett Bay Commission’s combined sewer overflow project was completed and began reducing pollutants and untreated sewage entering the upper bay, the oyster population began to rebound in the Providence and Seekonk rivers.

Despite cleaner water, sedimentation still limits the oyster population’s recovery; oyster larvae latch onto rocky substrate, which has been coated or buried by sediment resulting from ecologically unsound land management and erosion upstream. It's this issue that the artificial reef project — dubbed SHELL-ter — hopes to address.

Vogler is fairly confident that shellfish larvae will settle and grow on the reefs' concrete plates. Much of the research leading up to the reef deployment concentrated on creating plates that maximize settlement. Prototypes, varying in texture and concrete composition, were tested in tanks and open water at Roger Williams University in Bristol. Some plates were also tested at Bold Point Park, just across the river from India Point Park.

The ecological benefits of oysters are numerous. A single adult oyster can filter up to 50 gallons of water daily, removing nutrients and improving water quality. Oyster reefs, which develop as new oysters grow on older or dead oysters, act as coastal buffers, reducing wave action and erosion during storms and creating conditions that allow marsh habitat to expand.

Three distinct reef types were deployed and depth was varied to experiment with which combinations are most successful.

Three distinct reef types were deployed and depth was varied to experiment with which combinations are most successful.

As sea levels rise and more frequent storms hammer the coast, oyster reefs offer a natural infrastructure solution to help keep the coastline intact. Additionally, reefs act as prime habitat for other marine life such as crabs and juvenile finfish.

Health concerns about people harvesting and eating oysters off the artificial reefs have been raised, according to Scheri Fultineer, department head of Landscape Architecture at RISD.

“Siting the reefs so people can see, but not get to them is important,” she said. The goal of the project is environmental restoration, not growing culinary oysters, she added.

Friends of India Point Park (FIPP), initially concerned by the scale and location of the project, is now enthusiastic about hosting the reefs. A main objective of FIPP is to limit the impact of the built environment on the park. FIPP and the project's leaders were able to come to a compromise that shifted the location of the deployment and scaled back the number of forms that would be placed in the water.

Marjorie Powning, co-chair of FIPP, said she hopes the reefs draw more attention to the historic seawall and wooden pilings along the shore of the park; the seawall is “in trouble,” she said, and in need of restoration.

The reefs are permitted to remain in the water for three years. Vogler is currently working on a long-term monitoring plan with Marta Gomez-Chiarri, department chair of fisheries, animal and veterinary sciences at the University of Rhode Island. Three distinct reef types were deployed, all at different depths, so data will be collected on which types and depths provide the best results.

Middle-school and high-school science classes will be involved in the monitoring effort, according to Vogler.

Monitoring days will be opportunities to educate the public about the reefs, Vogler said. While FIPP doesn't permit signage in the park due to the high volume of requests it receives, information about the reefs will be made available at the community bulletin board near the playground, and possibly in the parking areas and at entrances to the park, according to Powning. Vogler also is interested in having examples of each reef type installed at Kennedy Plaza as a sculptural art installation that would attract more attention to the project.

After three years, the reefs will be removed from the water and studied so improvements and modifications can be made to future reefs. Vogler said she would like a future deployment to study the coastal services the reefs can offer, such as marsh restoration. The current location, abutting the seawall, will not offer such insight.