PORTSMOUTH/TIVERTON — A shellfish harvesting closure is in effect for lower Sakonnet River, Harvester Tagging Area 5C, until further notice, the R.I. Department of Environmental Management (RIDEM) announced Thursday.

The closure is due to a preliminary toxic shellfish finding associated with the harmful algae bloom being monitored in Rhode Island waters. The closure includes carnivorous snails, such as whelk and moon snails.

On Oct. 7, DEM and the R.I. Department of Health (RIDOH) announced a precautionary shellfishing closure for Rhode Island waters due to a confirmed bloom of toxic phytoplankton, Pseudo-nitzschia spp. 

During the week-long closure, water and shellfish samples were analyzed for the presence of the toxin domoic acid which is responsible for amnesic shellfish poisoning in humans. All shellfish samples collected tested negative. The closure was lifted on Oct. 15 as a result. However, DEM and RIDOH continued to collect and analyze samples given the bloom’s continued presence in local and regional waters. 

On Oct. 19, domoic acid was detected in a preliminary screening of shellfish collected from lower Sakonnet River. Additional samples are being collected from the area for analysis to determine if the toxin is present at levels of concern. Shellfish samples from throughout Rhode Island waters will continue to be collected and analyzed until the bloom subsides. 

Impacted waters extend north of a line from Sachuest Point to Sakonnet Point Light and south of an east/west line across the Sakonnet River, lying one-quarter mile south of the pipeline just south of Black Point and east of a north/south line running from Flint Point to Taggert’s Ferry in Middletown.

For updates on shellfish closure areas, contact the DEM 24-hour shellfishing hotline at 401/222-2900. To join the DEM Marine Fisheries e-mail list, subscribe at rimarinefisheries-subscribe@listserve.ri.gov.