Surface Mapping

Surface chlorophyll data were collected on July 15, 2026, while the R/V Data Stream was underway collecting bacteria samples in the Providence and Seekonk River Estuaries. The chlorophyll concentrations were categorized as fair overall with all areas sampled having average chlorophyll concentrations between 5 µg/L and 20 µg/L. Overall, chlorophyll ranged from 0.92 µg/L to 145.69 µg/L with an average of 12.05 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

Surface chlorophyll data were collected on July 8, 2026, while the R/V Data Stream was underway collecting nutrient samples in the Providence and Seekonk River Estuaries. The chlorophyll concentrations were categorized as fair overall. The North Providence River Channel, Southern Providence River and Pawtuxet River Area exhibited good water quality with average chlorophyll concentrations <5 µg/L. The Seekonk River and Edgewood Shoal had fair water quality with average chlorophyll concentrations that ranged between 5 µg/L and 20 µg/L. None of the sampled areas exhibited poor water quality with average chlorophyll concentration > 20 µg/L. Overall, chlorophyll ranged from 1.11 µg/L to 78.74 µg/L with an average of 7.31 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

Surface chlorophyll data were collected on June 24, 2026, while the R/V Data Stream was underway collecting nutrient samples in the Providence and Seekonk River Estuaries. The chlorophyll concentrations were categorized as good overall. No areas exhibited fair or poor water quality (>10 µg/L and >20 µg/L, respectively). Overall, chlorophyll ranged from 1.08 µg/L to 12.65 µg/L with an average 3.98 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

Surface chlorophyll data were collected on June 10, 2026, while the R/V Data Stream was underway collecting nutrient samples in the Providence and Seekonk River Estuaries. The chlorophyll concentrations were categorized as fair overall. Only the Seekonk River exhibited poor water quality (>20 µg/L) while the remaining areas sampled exhibited fair water quality (>10 µg/L). Overall, chlorophyll ranged from 2.56 µg/L to 45.25 µg/L with an average 14.57 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

Surface chlorophyll data were collected on May 20, 2026, while the R/V Data Stream was underway collecting bacteria samples in the Providence and Seekonk River Estuaries. The average chlorophyll concentrations were categorized as fair in all areas. The average chlorophyll concentrations were also categorized as fair over all areas surveyed. Overall, chlorophyll ranged from 0.97 µg/L to 120.89 µg/L with an average of 6.97 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

Surface chlorophyll data were collected on May 7, 2026, while the R/V Data Stream was underway collecting bacteria samples in the Providence and Seekonk River Estuaries. The average chlorophyll concentrations were categorized as good in all areas. The average chlorophyll concentrations were categorized as good to fair over all areas surveyed. Overall, chlorophyll ranged from 1.60 µg/L to 13.44 µg/L with an average of 4.63 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

Surface chlorophyll data were collected on April 29, 2026, while the R/V Data Stream was underway collecting nutrient samples in the Providence and Seekonk River Estuaries. The average chlorophyll concentrations were categorized as good in all areas. The average chlorophyll concentrations were categorized as good to fair over all areas surveyed. Overall, chlorophyll ranged from 1.50 µg/L to 14.60 µg/L with an average of 4.50 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

Surface chlorophyll data were collected on April 29, 2026, while the R/V Data Stream was underway collecting bacteria samples in the Providence and Seekonk River Estuaries. The average chlorophyll concentrations were categorized as good in all areas. The average chlorophyll concentrations were also categorized as good over all areas surveyed. Overall, chlorophyll ranged from 1.09 µg/L to 3.94 µg/L with an average of 1.96 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

Surface chlorophyll data were collected on April 15, 2026, while the R/V Data Stream was underway collecting nutrient samples in the Providence and Seekonk River Estuaries. The average chlorophyll concentrations were categorized as fair in all areas. The average chlorophyll concentrations were also categorized as fair over all areas surveyed. Overall, chlorophyll ranged from 1.67 µg/L to 44.92 µg/L with an average of 13.52 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.

Surface chlorophyll data were collected on October 15, 2025, while the R/V Monitor was underway collecting nutrient samples in the Providence and Seekonk River estuary. The average chlorophyll concentrations were categorized as good in all areas. The average chlorophyll concentrations were also categorized as good over all areas surveyed. Overall, chlorophyll ranged from 0.64 µg/L to 3.60 µg/L with an average of 1.57 µg/L. The chlorophyll concentrations from this date are presented in the map below using Inverse Distance Weighting (IDW) interpolation.