Surface Mapping

Surface chlorophyll data were collected on September 22, 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 the Northern Providence River Channel and the Pawtuxet River Area, and as fair in all other areas. The average chlorophyll concentrations were categorized as fair over all areas surveyed. Overall, chlorophyll ranged from 2.10 µg/L to 15.02 µg/L with an average of 6.57 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 September 16, 2026, while the R/V Data Stream was underway collecting nutrients samples in the Providence and Seekonk River Estuaries. The average 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 3.77 µg/L to 20.37 µg/L with an average of 8.27 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 September 9, 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 overall with all areas sampled having average chlorophyll concentrations between 5 µg/L and 20 µg/L. Overall, chlorophyll ranged from 2.56 µg/L to 21.64 µg/L with an average of 6.88 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 August 26, 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 overall with all areas sampled having average chlorophyll concentrations between 5 µg/L and 20 µg/L. Overall, chlorophyll ranged from 2.23 µg/L to 172.72 µg/L with an average of 11.20 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 August 19, 2026, while the R/V Data Stream was underway collecting nutrients samples in the Providence and Seekonk River Estuaries. The chlorophyll concentrations were categorized as fair overall with most areas sampled having average chlorophyll concentrations between 5 µg/L and 20 µg/L, with the exception of the Seekonk River, which had average chlorophyll concentrations above 20 µg/L (categorized as poor), and the Northern Providence River Channel, which had average chlorophyll concentrations below 5 µg/L (categorized as good). Overall, chlorophyll ranged from 1.93 µg/L to 557.34 µg/L with an average of 17.05 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 30, 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 most areas sampled having average chlorophyll concentrations between 5 µg/L and 20 µg/L, with the exception of the Seekonk River, which had average chlorophyll concentrations above 20 µg/L (categorized as poor). Overall, chlorophyll ranged from 3.63 µg/L to 128.48 µg/L with an average of 15.46 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 23, 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 most areas sampled having average chlorophyll concentrations between 5 µg/L and 20 µg/L, with the exception of the Seekonk River, which had average chlorophyll concentrations above 20 µg/L (categorized as poor). Overall, chlorophyll ranged from 4.51 µg/L to 77.03 µg/L with an average of 15.49 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 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.