PORTSMOUTH — Citing the risk of accidental and illicit discharge of sewage associated with the gathering of hundreds of boats off Prudence Island on Saturday, the R.I. Department of Environmental Management (RIDEM) will preemptively close 700 acres of shellfish grounds on the north end of the island. 

The closure is from sunrise on July 29 until sunrise on Aug. 5 and extends from the shoreline and all waters south and west of a line from Providence Point to the northwest extension of Warner Avenue on Prudence Island.

The so-called Aquapalooza gathering in Potters Cove — an unauthorized, social media-driven event whose organizers remain anonymous, and which is purposely scheduled on the summer’s busiest day on Narragansett Bay — is necessitating the precautionary closure, according to RIDEM.

Last year’s event drew more than 1,000 boats and personal watercraft. With so many boats concentrated in such a small area for hours, federal and state public health guidance requires that the shellfish harvest area, which includes all of Potters Cove, be closed to protect public health.

Although most recreational boaters follow Rhode Island’s “no discharge” law, a high concentration of vessels increases the chances of accidental or illicit discharge of sewage into shellfish waters. The week-long closure duration will provide a sufficient volume of water and time for the dilution of inadvertently discharged sewage before the area is reopened to shellfishing, RIDEM says. 

There are currently 15 pump-out boats and 59 facilities located across Narragansett Bay and coastal waters. However, these facilities are not routinely in operation along the undeveloped north shore of Prudence Island.  Around 40,000 boats are registered in Rhode Island, and the state welcomes many thousands more visiting boats each year. 

Last year, a total volume of over 600,000 gallons of sewage was pumped out at these facilities and diverted from directly entering Rhode Island’s surface waters. Visit RIDEM’s website for a map of marine pump-out facilities in Rhode Island.

Closing shellfishing areas when warranted protects public health by ensuring that only quality, safe shellfish is harvested and enters the food system, RIDEM says. RIDEM, the R.I. Department of Health, and the R.I. Coastal Resources Management Council, along with industry partners, collaborate to ensure that shellfish grown and harvested from Rhode Island waters continues to be a quality safe seafood product to be enjoyed by all consumers. This is achieved by diligent monitoring of shellfish harvesting waters. Such monitoring enables a quick response, including shellfish closures, when conditions indicate a change in water quality due to natural events such as algae blooms or unusual events.

For more information on the shellfish harvesting classifications, review the annual notice available at RIDEM-Shellfish. An interactive shellfishing map is also available.

For information on emergency and conditional area water quality-related shellfish closures, call RIDEM’s 24-hour shellfishing hotline at 401/222-2900, visit www.dem.ri.gov/shellfish, or sign up for the Office of Water Resources’ listserv here: RishellfishOWR-subscribe@listserve.ri.gov.