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Since 2011, tropical beaches from Africa to Brazil, Central America, and the Caribbean have been inundated by tons of sargassum seaweed from a new equatorial source of pelagic sargassum in the Atlantic. In recent years the extraordinary accumulations of sargassum make this a nuisance algal bloom for tropical coasts. In 2018 satellite data indicated floating mats of sargassum that extended throughout the Caribbean to the northeast coast of Brazil with the highest percent coverage over the water yet recorded. A literature review suggests that Atlantic equatorial recirculation of seaweed mats combined with nutrients from several possible sources may be stimulating the growth and accumulations of sargassum. In the western equatorial recirculation area, new nutrient sources may include Amazon River floods and hurricanes; in the eastern equatorial recirculation area, nutrient sources that could sustain the sargassum blooms include coastal upwelling and Congo River freshwater and nutrients. • Tons of sargassum seaweed on Caribbean beaches • The Atlantic Equatorial Recirculation Area a new source of sargassum seaweed • Nutrients to support sargassum come from the Amazon River floods and hurricanes. • Nutrients to sustain sargassum originate in the Eastern Atlantic Equatorial. [ABSTRACT FROM AUTHOR]

The present state of knowledge regarding the input of anthropogenic pollutants into Narragansett Bay, Rhode Island was reviewed and benthic infaunal communities present at four depositional environments within the upper Bay were characterized. Inter-station differences in species composition and abundance of these assemblages were examined in relation to established pollution gradients. Using diversity curves and multivariate statistics, evidence of significant anthropogenic impact on the structure of benthic macrofaunal communities in Narragansett Bay was identified. The magnitude of this impact was greatest at stations closest to the Bay’s urban centers, where exposure to multiple stressors had resulted in communities of opportunistic taxa which persisted in a state of low faunal diversity characteristic of early stages of species succession. As was expected based on historic models of faunal succession; the apparent maturity of benthic assemblages in Narragansett Bay increased along the north-south gradient of decreasing anthropogenic stress. [Copyright &y& Elsevier]

Abstract: A variant of the Vertically Generalized Production Model (VGPM) was used to expand the spatial and temporal resolution of production estimates and better characterize the phytoplankton variability in Massachusetts and Cape Cod Bays. Satellite modeled production was used to supplement in situ 14C primary production measurements, which were spatially limited to two shipboard stations in the northern portion of Massachusetts Bay that were sampled up to 17 times per year. Modifications to the model included a regional parameterization of the euphotic depth (Zeu ) and an analysis of the maximum chlorophyll specific carbon fixation rate (), which failed to reveal a correlation between and temperature as suggested by previous studies. This primary production model successfully captured the seasonal and interannual variations of in situ production that were measured using the 14C uptake method and significantly enhanced the spatial and temporal resolution of primary production measurements in Massachusetts Bay. The use of satellite data better characterized event, seasonal and interannual variability of ecosystem primary production and revealed a three-fold decrease in production from the nearshore to offshore regions. Daily production ranged from less than 0.25gCm−2 d−1 in the offshore regions in January to greater than 2gCm−2 d−1 at various times throughout the year in Cape Cod Bay and along the coastline during the summer months. The mean annual production of Massachusetts Bay for the 8-year study period was 220gCm−2. The lowest production was estimated in 2004 (174gCm−2) and the greatest in 2000 (300gCm−2). Comparatively, mean production in Cape Cod Bay was 289gCm−2 and ranged from 231 in 1998 to 358gCm−2 in 2000. Unlike a number of other temperate continental shelf areas where the maximum production occurs during the summer months corresponding to the greatest PAR and temperature, the highest production and largest fraction of the annual production in Massachusetts Bay accompanied the high phytoplankton biomass during the spring (April–May) and fall blooms (September–October). [Copyright &y& Elsevier]

Abstract: Massachusetts Bay, a semi-enclosed embayment (50×100km) in the Northwest Atlantic, is the focus of a monitoring program designed to measure the effects of relocating the Boston Harbor sewage outfall to a site 15km offshore in Massachusetts Bay. The Massachusetts Water Resources Authority (MWRA) in situ monitoring program samples selected stations up to 17 times per year to observe seasonal changes in phytoplankton biomass and other water quality variables. We investigated the feasibility of augmenting the monitoring data with satellite ocean color data to increase the spatial and temporal resolution of quantitative phytoplankton measurements. In coastal regions such as Massachusetts Bay, ocean color remote sensing can be complicated by in-water constituents whose concentrations vary independently of phytoplankton and by inaccurate modeling of absorbing aerosols that tend to be concentrated near the coast. An evaluation of in situ and sea-viewing wide field-of-view sensor (SeaWiFS) measurements from 1998 to 2005 demonstrated that SeaWiFS overestimated chlorophyll a mainly due to atmospheric correction errors that were amplified by absorption from elevated concentrations of chlorophyll a and colored dissolved organic matter. Negative water-leaving radiances in the 412nm band, an obvious artifact of inadequate atmospheric correction, were recorded in approximately 60–80% of the cloud-free images along the coast, while the remaining portions of the Bay only experience negative radiances 35–55% of the time with a clear nearshore to offshore decrease in frequency. Seasonally, the greatest occurrences of negative 412nm radiances were in November and December and the lowest were recorded during the summer months. Concentrations of suspended solids in Massachusetts Bay were low compared with other coastal regions and did not have a significant impact on SeaWiFS chlorophyll a measurements. A regional empirical algorithm was developed to correct the SeaWiFS data to agree with in situ observations. Monthly SeaWiFS composites illustrated the spatial extent of a bimodal seasonal pattern, including prominent spring and fall phytoplankton blooms; and the approximate 115 cloud-free scenes per year revealed interannual variations in the timing, magnitude and duration of phytoplankton blooms. Despite known artifacts of SeaWiFS in coastal regions, this study provided a viable chlorophyll a product in Massachusetts Bay that significantly increased the spatial and temporal synoptic coverage of phytoplankton biomass, which can be used to gain a comprehensive ecosystem-wide understanding of phytoplankton dynamics at event, seasonal and interannual timescales. [Copyright &y& Elsevier]

Abstract: Previous work had indicated that the Virginian Province Index did not perform well in a smaller estuarine complex. While it was hoped that the existing Chesapeake Bay Benthic Index of Biotic Integrity, with its greater number of metrics and habitat separation would be more adaptable, this index also did not perform well outside of Chesapeake Bay. In this study we assembled additional metrics and applied different methods of index compilation to explore the indices relative strengths and weaknesses. Three different approaches were utilized – two multimetric indices (Chesapeake Bay IBI and the Mebane IBI) and a statistical logistic regression technique. The data were subdivided by habitat (salinity and grain size), and indices compiled using the same initial group of benthic metrics. Each approach was examined for its classification accuracy for both reference and impaired sites for the entire Virginian Province. The Chesapeake Bay IBI approach did not perform well in this study. In contrast, another multimetric approach, the Mebane IBI approach, performed well, as did the statistical logistic regression approach. Both techniques have promise for index development and could be useful in applying a biological condition gradient to estuaries. [Copyright &y& Elsevier]