A comparison between the FlowCam 8100, microscopy, and sandwich hybridization assay for quantifying abundances of the saxitoxin-producing dinoflagellate, Alexandrium catenella.

Light microscopy, FlowCam, and sandwich hybridization assay (SHA) are three approaches that facilitate the monitoring of harmful algal bloom (HAB) forming phytoplankton. Yet, cross-comparisons among these techniques have not been conducted. This study addressed that gap using the saxitoxin-producing 'red tide' dinoflagellate Alexandrium catenella, a species responsible for blooms and paralytic shellfish poisoning worldwide.

Transitions in nitrogen and organic matter form and concentration correspond to bacterial population dynamics in a hypoxic urban estuary.

Unlabelled: Nitrogen (N) inputs to developed coastlines are linked with multiple ecosystem and socio-economic impacts worldwide such as algal blooms, habitat/resource deterioration, and hypoxia. This study investigated the microbial and biogeochemical processes associated with recurrent, seasonal bottom-water hypoxia in an urban estuary, western Long Island Sound (WLIS), that receives high N inputs. A 2-year (2020-2021) field study spanned two hypoxia events and entailed surface and bottom depth water sampling for dissolved nutrients as inorganic N (DIN; ammonia-N and nitrite + nitrate (N + N)), organic N, orthophosphate, organic carbon (DOC), as well as chlorophyll and bacterial abundances.