Sponsored Research Archives - Page 20 of 37 - NCCOS - National Centers for Coastal Ocean Science

Archeolourinia shermani, a new genus and species of Louriniidae (Copepoda: Harpacticoida) from a Caribbean mesophotic zone

Mesophotic coral ecosystems (MCEs) are found on the insular and continental slopes of Caribbean islands and comprise mainly scleractinian corals, sponges and macroalgae. These species provide habitat for a highly diverse and specialized crustacean fauna. A new genus and species of the family Louriniidae is described from samples taken from an MCE in south-west Puerto … Read more

Small Spatial Scale Variation in Fish Assemblage Structure in the Vicinity of the Northwestern Gulf of Mexico Hypoxic Zone

Seasonal hypoxia [dissolved oxygen (DO)???2 mg?l?1] occurs over large regions of the northwestern Gulf of Mexico continental shelf during the summer months (JuneAugust) as a result of nutrient enrichment from the MississippiAtchafalaya River system. We characterized the community structure of mobile fishes and invertebrates (i.e., nekton) in and around the hypoxic zone using 3 years … Read more

Coordinated sampling of dynamic oceanographic features with underwater vehicles and drifters

We extend existing oceanographic sampling methodologies to sample an advecting feature of interest using autonomous robotic platforms. GPS-tracked Lagrangian drifters are used to tag and track a water patch of interest with position updates provided periodically to an autonomous underwater vehicle (AUV) for surveys around the drifter as it moves with ocean currents. Autonomous sampling … Read more

Mesozooplankton and Microzooplankton Grazing During Cyanobacterial Blooms in the Western Basin of Lake Erie

Lake Erie is the most socioeconomically important and productive of the Laurentian (North American) Great Lakes. Since the mid-1990s cyanobacterial blooms dominated primarily by Microcystis have emerged to become annual, late summer events in the western basin of Lake Erie yet the effects of these blooms on food web dynamics and zooplankton grazing are unclear. … Read more

Texas Coastal Hypoxia Linked to Brazos River Discharge as Revealed by Oxygen Isotopes

Hypoxic conditions in the coastal waters off Texas (USA) were observed since the late 1970s, but little is known about the causes of stratification that contribute to hypoxia formation. Typically, this hypoxia is attributed to downcoast (southwestward) advection of waters from the MississippiAtchafalaya River system. Here, we present evidence for a hypoxic event on the … Read more

Comparison of sandwich hybridization assay and quantitative PCR for the quantification of live and preserved cultures of Heterosigma akashiwo (Raphidophyceae)

In this study, we directly compared two molecular techniques, sandwich hybridization assay (SHA) and quantitative PCR (qPCR), for quantifying laboratory cultures of the ichthyotoxic raphidophyte Heterosigma akashiwo. To maximize comparisons, all experiments entailed raising H. akashiwo in the laboratory, generating cellular homogenates then splitting them such that for each sample, the same homogenate was analyzed … Read more

Environmental controls, oceanography and population dynamics of pathogens and harmful algal blooms: Connecting sources to human exposure

Coupled physical-biological models are capable of linking the complex interactions between environmental factors and physical hydrodynamics to simulate the growth, toxicity and transport of infectious pathogens and harmful algal blooms (HABs). Such simulations can be used to assess and predict the impact of pathogens and HABs on human health. Given the widespread and increasing reliance … Read more

A quantitative real-time PCR assay for the identification and enumeration of Alexandrium cysts in marine sediments

Harmful algal blooms (HABs) are a global problem that affects both human and ecosystem health. One of the most serious and widespread HAB poisoning syndromes is paralytic shellfish poisoning, commonly caused by Alexandrium spp. dinoflagellates. Like many toxic dinoflagellates, Alexandrium produces resistant resting cysts as part of its life cycle. These cysts play a key … Read more

Diversity and dynamics of a widespread bloom of the toxic dinoflagellate Alexandrium fundyense

Historically, cosmopolitan phytoplankton species were presumed to represent largely unstructured populations. However, the recent development of molecular tools to examine genetic diversity have revealed differences in phytoplankton taxa across geographic scales and provided insight into the physiology and ecology of blooms. Here we describe the genetic analysis of an extensive bloom of the toxic dinoflagellate … Read more

Exploring estuarine eutrophication sensitivity to nutrient loading

The sensitivity of surface chlorophyll (Chl) and bottom water dissolved oxygen (DO) to total nitrogen (TN) load was investigated using a Bayesian?based process model fit to data from a range of estuaries. The model was used to test if the sensitivity of DO depletion to TN loads is dependent only on factors controlling the sensitivity … Read more