Sewage-and fertilizer-derived nutrients alter the intensity, diversity, and toxicity of harmful cyanobacterial blooms in eutrophic lakes.

Cyanobacterial harmful algal blooms (CHABs) are promoted by excessive nutrient loading and, while fertilizers and sewage are the most prevalent external nutrient sources in most watersheds, the differential effects of these nutrient sources on CHABs are unknown. Here, we tracked CHABs and performed experiments in five distinct lakes across the Northern US including Lake Erie. Fertilizers with ammonium and orthophosphate, membrane (0.

Nitrogen Limitation of Intense and Toxic Cyanobacteria Blooms in Lakes within Two of the Most Visited Parks in the USA: The Lake in Central Park and Prospect Park Lake.

The Lake in Central Park (LCP) and Prospect Park Lake (PPL) in New York City (NYC), USA, are lakes within two of the most visited parks in the USA. Five years of nearshore sampling of these systems revealed extremely elevated levels of cyanobacteria and the toxin, microcystin, with microcystin levels averaging 920 µg L−1 and chlorophyll a from cyanobacterial (cyano-chla) populations averaging 1.0 × 105 µg cyano-chla L−1.

Transcriptomic and isotopic data reveal central role of ammonium in facilitating the growth of the mixotrophic dinoflagellate, Dinophysis acuminata.

Dinophysis spp. are mixotrophs that are dependent on specific prey, but are also potentially reliant on dissolved nutrients. The extent to which Dinophysis relies on exogenous N and the specific biochemical pathways important for supporting its autotrophic and heterotrophic growth are unknown.

Nitrogen limitation, toxin synthesis potential, and toxicity of cyanobacterial populations in Lake Okeechobee and the St. Lucie River Estuary, Florida, during the 2016 state of emergency event.

Lake Okeechobee, FL, USA, has been subjected to intensifying cyanobacterial blooms that can spread to the adjacent St. Lucie River and Estuary via natural and anthropogenically-induced flooding events. In July 2016, a large, toxic cyanobacterial bloom occurred in Lake Okeechobee and throughout the St.

Succession and toxicity of Microcystis and Anabaena (Dolichospermum) blooms are controlled by nutrient-dependent allelopathic interactions.

Microcystis and Anabaena (Dolichospermum) are among the most toxic cyanobacterial genera and often succeed each other during harmful algal blooms. The role allelopathy plays in the succession of these genera is not fully understood. The allelopathic interactions of six strains of Microcystis and Anabaena under different nutrient conditions in co-culture and in culture-filtrate experiments were investigated.

Nitrogenous nutrients promote the growth and toxicity of Dinophysis acuminata during estuarine bloom events.

Diarrhetic Shellfish Poisoning (DSP) is a globally significant human health syndrome most commonly caused by dinoflagellates within the genus Dinophysis. While blooms of harmful algae have frequently been linked to excessive nutrient loading, Dinophysis is a mixotrophic alga whose growth is typically associated with prey availability. Consequently, field studies of Dinophysis and nutrients have been rare.

Shifts in Cyanobacterial Strain Dominance during the Onset of Harmful Algal Blooms in Florida Bay, USA.

Cyanobacteria are fundamental components of aquatic phytoplankton communities and some taxa can cause harmful blooms in coastal ecosystems. Harmful cyanobacterial blooms are typically comprised of multiple strains of a single genus or species that cannot be resolved microscopically. Florida Bay, USA, has experienced harmful cyanobacterial blooms that have been associated with the loss of eelgrass, spiny lobsters, and general food web disruption for more than two decades.

The effects of elevated CO on the growth and toxicity of field populations and cultures of the saxitoxin-producing dinoflagellate, .

The effects of coastal acidification on the growth and toxicity of the saxitoxin-producing dinoflagellate were examined in culture and ecosystem studies. In culture experiments, strains isolated from Northport Bay NY, USA, and the Bay of Fundy, Canada, grew significantly faster (16 -190%; <0.05) when exposed to elevated levels of pCO (~ 800- 1900μatm) compared to lower levels (~390μatm).

Vitamin b(1) and b(12) uptake and cycling by plankton communities in coastal ecosystems.

While vitamin B(12) has recently been shown to co-limit the growth of coastal phytoplankton assemblages, the cycling of B-vitamins in coastal ecosystems is poorly understood as planktonic uptake rates of vitamins B(1) and B(12) have never been quantified in tandem in any aquatic ecosystem. The goal of this study was to establish the relationships between plankton community composition, carbon fixation, and B-vitamin assimilation in two contrasting estuarine systems. We show that, although B-vitamin concentrations were low (pM), vitamin concentrations and uptake rates were higher within a more eutrophic estuary and that vitamin B(12) uptake rates were significantly correlated with rates of primary production.