Sponsored Research Archives - Page 2 of 37 - NCCOS - National Centers for Coastal Ocean Science

Mitigating the Expansion of Harmful Algal Blooms Across the Freshwater-to-Marine Continuum

Anthropogenic nutrient overenrichment, coupled with rising temperatures, and an increasing frequency of extreme hydrologic events (storms and droughts) are accelerating eutrophication and promoting the expansion of harmful algal blooms (HABs) across the freshwater-to-marine continuum. All HABs—with a focus here on cyanobacterial blooms—pose serious consequences for water supplies, fisheries, recreational uses, tourism, and property values. As … Read more

Effects of growth phase, diel cycle and macronutrient stress on the quantification of Heterosigma akashiwo using qPCR and SHA

The development of molecular probe technologies over the last several decades has enabled more rapid and specific identification and enumeration of phytoplankton species compared to traditional technologies, such as light microscopy. Direct comparisons of these methods with respect to physiological status, however, are sparse. Here we directly compare quantitative real-time PCR (qPCR) and sandwich hybridization … Read more

The contribution of inorganic and organic nutrients to the growth of a North American isolate of the mixotrophic dinoflagellate, Dinophysis acuminata

Diarrhetic Shellfish Poisoning (DSP) is a globally significant human health syndrome most commonly caused by dinoflagellates of the genus Dinophysis. While ecosystem studies suggest that blooms of this mixotrophic dinoflagellate can be promoted by excessive nitrogen (N) loading, it is unclear whether these effects are direct (nutrient stimulation of Dinophysis) or indirect (nutrient stimulation of … Read more

Identification of Azadinium species and a new azaspiracid from Azadinium poporum in Puget Sound, Washington State, USA

The identification of a new suite of toxins, called azaspiracids (AZA), as the cause of human illnesses after the consumption of shellfish from the Irish west coast in 1995, resulted in interest in understanding the global distribution of these toxins and of species of the small dinoflagellate genus Azadinium, known to produce them. Clonal isolates … Read more

A decade and a half of Pseudo-nitzschia spp. and domoic acid along the coast of southern California

Blooms of the marine diatom genus Pseudo-nitzschia that produce the neurotoxin domoic acid have been documented with regularity along the coast of southern California since 2003, with the occurrence of the toxin in shellfish tissue predating information on domoic acid in the particulate fraction in this region. Domoic acid concentrations in the phytoplankton inhabiting waters … Read more

Space-Time Geostatistical Assessment of Hypoxia in the Northern Gulf of Mexico

Nearly every summer, a large hypoxic zone forms in the northern Gulf of Mexico. Research on the causes and consequences of hypoxia requires reliable estimates of hypoxic extent, which can vary at sub-monthly time scales due to hydro-meteorological variability. Here, we use an innovative space-time geostatistical model and data collected by multiple research organizations to … Read more

In situ, high-resolution time series of dissolved phosphate in Green Bay, Lake Michigan

In nearly every instance in which the environment has been sampled on a higher resolution in time or space, fundamental processes have come to light that were previously undetected or unobserved. In this study, an autonomous dissolved phosphate sensor was deployed at the Entrance Light station in lower Green Bay, Lake Michigan in 2012 and … Read more

Variations in chemical speciation and reactivity of phosphorus between suspended-particles and surface-sediment in seasonal hypoxia-influenced Green Bay

Water, suspended-particles, and surface-sediment samples were collected from Green Bay, Lake Michigan, for the measurements of phosphorus (P) species, including dissolved/particulate-P, inorganic/organic-P, and five different forms of particulate-P, namely exchangeable- or labile-P (Ex-P), iron-bound-P (Fe-P), biogenic-apatite and/or CaCO3-associated-P (CFA-P), organic-P (Org-P) and detrital-apatite-P (Detr-P) to elucidate their reactivity and transformation pathways in the water column. … Read more

Evidence of persistent, recurring summertime hypoxia in Green Bay

Six years (2009–2015) of temperature and dissolved oxygen profile data show hypoxic conditions are common in the bottom waters of southern Green Bay, Lake Michigan during the summer. Depleted oxygen concentrations (<5 mg L−1) affect nearly 70% of the 38 stations sampled representing an area of ~500–600 km2. Stratification typically lasts 2+ months, from late … Read more

Green Bay, Lake Michigan: A proving ground for Great Lakes restoration

Green Bay has sometimes been referred to as the largest freshwater “estuary” in the world. Its watershed, much of it in intensive agriculture, comprises one-third of the Lake Michigan basin and delivers one-third of the lake’s total phosphorus load. At one time, the major tributary, the Fox River, was considered the most heavily industrialized river … Read more