Barry H. Rosen, Ph.D.

The Ohio State University

Postdoctoral Research Associate

Electron Microscopist

1983

Rosen managed the transmission electron microscope facility in the Department of Botany at Ohio State University, supported by a grant from the National Science Foundation.

Bowling Green State University

Ph.D.

Biology

1982

St. Cloud State University

M.A.

Biology

1978

University of Connecticut

B.S.

Botany

1976

Animal and human health at risk from algal toxins in our water: neurotoxins, hepatotoxins and climate change

Tribal Lands and Environment Forum  Washington, D.C.

2016-01-01

Early detection and rapid response to harmful algal blooms using hydrogen peroxide and cyanotoxin genes

Florida Department of Environmental Protection

2020-01-17

This project is focused on early detection of the cyanotoxin genes, which will help guide treatment when toxin producing cyanobacteria are present.

Cyanobacterial blooms impact on human health and potential mitigation strategies

Florida Department of Health

2020-01-03

This project is designed to support the Centers for Disease Control and Prevention and its study of the health impacts from cyanobacteria.

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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

Benjamin J. Kramer,Timothy W. Davis,Kevin A. Meyer,Barry H. Rosen,Jennifer A. Goleski,Gregory J. Dick,Genesok Oh,Christopher J. Gobler

2018

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. Lucie River and Estuary, leading Florida to declare a state of emergency. This study reports on measurements and nutrient amendment experiments performed in this freshwater-estuarine ecosystem (salinity 0–25 PSU) during and after the bloom. In July, all sites along the bloom exhibited dissolved inorganic nitrogen-to-phosphorus ratios < 6, while Microcystis dominated (> 95%) phytoplankton inventories from the lake to the central part of the estuary. Chlorophyll a and microcystin concentrations peaked (100 and 34 μg L-1, respectively) within Lake Okeechobee and decreased eastwards. Metagenomic analyses indicated that genes associated with the production of microcystin (mcyE) and the algal neurotoxin saxitoxin (sxtA) originated from Microcystis and multiple diazotrophic genera, respectively. There were highly significant correlations between levels of total nitrogen, microcystin, and microcystin synthesis gene abundance across all surveyed sites (p < 0.001), suggesting high levels of nitrogen supported the production of microcystin during this event. Consistent with this, experiments performed with low salinity water from the St. Lucie River during the event indicated that algal biomass was nitrogen-limited. In the fall, densities of Microcystis and concentrations of microcystin were significantly lower, green algae co-dominated with cyanobacteria, and multiple algal groups displayed nitrogen-limitation. These results indicate that monitoring and regulatory strategies in Lake Okeechobee and the St. Lucie River and Estuary should consider managing loads of nitrogen to control future algal and microcystin-producing cyanobacterial blooms.

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Optical characterization of two cyanobacteria genera, Aphanizomenon and Microcystis, with hyperspectral microscopy

Paine, E.C., Slonecker, E.T., Simon, N.S., Rosen, B.H., Resmini, R.G., and Allen, D.W.

2018

Cyanobacterial blooms are a nuisance and a potential hazard in freshwater systems worldwide. Remote sensing has been used to detect cyanobacterial blooms, but few studies have distinguished among genera of cyanobacteria. Because some genera are more likely to be toxic than others, this is a useful distinction. Hyperspectral imaging reflectance microscopy was used to examine cyanobacteria from Upper Klamath Lake, Oregon, at high spatial and spectral resolution to determine if two species found commonly in the lake, Aphanizomenon flos-aquae and Microcystis aeruginosa, can be separated spectrally. Of the analytical methods applied, a spectral shape algorithm applied to the derivative was found to be most successful in classifying these species in microscope scenes. Further work is required to determine if the spectral characterization of cyanobacterial genera can be scaled up to remote sensing applications.

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Cyanobacteria of the 2016 Lake Okeechobee and Okeechobee Waterway harmful algal bloom

Barry H. Rosen, Timothy W. Davis, Christopher J. Gobler, Benjamin J. Kramer and Keith A. Loftin

2017

The Lake Okeechobee and the Okeechobee Waterway (Lake Okeechobee, the St. Lucie Canal and River, and the Caloosahatchee River) experienced an extensive harmful algal bloom within Lake Okeechobee, the St. Lucie Canal and River and the Caloosahatchee River in 2016. In addition to the very visible bloom of the cyanobacterium Microcystis aeruginosa, several other cyanobacteria were present. These other species were less conspicuous; however, they have the potential to produce a variety of cyanotoxins, including anatoxins, cylindrospermopsins, and saxitoxins, in addition to the microcystins commonly associated with Microcystis. Some of these species were found before, during, and 2 weeks after the large Microcystis bloom and could provide a better understanding of bloom dynamics and succession. This report provides photographic documentation and taxonomic assessment of the cyanobacteria present from Lake Okeechobee and the Caloosahatchee River and St. Lucie Canal, with samples collected June 1st from the Caloosahatchee River and Lake Okeechobee and in July from the St. Lucie Canal. The majority of the images were of live organisms, allowing their natural complement of pigmentation to be captured. The report provides a digital image-based taxonomic record of the Lake Okeechobee and the Okeechobee Waterway microscopic flora. It is anticipated that these images will facilitate current and future studies on this system, such as understanding the timing of cyanobacteria blooms and their potential toxin production.

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Field and laboratory guide to freshwater cyanobacteria harmful algal blooms for Native American and Alaska Native communities

Barry H. Rosen and Ann St. Amand

2015

Cyanobacteria can produce toxins and form harmful algal blooms. The Native American and Alaska Native communities that are dependent on subsistence fishing have an increased risk of exposure to these cyanotoxins. It is important to recognize the presence of an algal bloom in a waterbody and to distinguish a potentially toxic harmful algal bloom from a non-toxic bloom. This guide provides field images that show cyanobacteria blooms, some of which can be toxin producers, as well as other non-toxic algae blooms and floating plants that might be confused with algae. After recognition of a potential toxin-producing cyanobacterial bloom in the field, the type(s) of cyanobacteria present needs to be identified. Species identification, which requires microscopic examination, may help distinguish a toxin-producer from a non-toxin producer. This guide also provides microscopic images of the common cyanobacteria that are known to produce toxins, as well as images of algae that form blooms but do not produce toxins.

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Is exposure to cyanobacteria an environmental risk factor for amyotrophic lateral sclerosis and other neurodegenerative diseases?

Walter G. Bradley, Amy R. Borenstein, Lorene M. Nelson, Geoffrey A. Codd, Barry H. Rosen, Elijah W. Stommel & Paul Alan Cox

2013

There is a broad scientific consensus that amyotrophic lateral sclerosis (ALS) is caused by gene-environment interactions. Mutations in genes underlying familial ALS (fALS) have been discovered in only 5–10% of the total population of ALS patients. Relatively little attention has been paid to environmental and lifestyle factors that may trigger the cascade of motor neuron death leading to the syndrome of ALS, although exposure to chemicals including lead and pesticides, and to agricultural environments, smoking, certain sports, and trauma have all been identified with an increased risk of ALS. There is a need for research to quantify the relative roles of each of the identified risk factors for ALS.

Recent evidence has strengthened the theory that chronic environmental exposure to the neurotoxic amino acid β-N-methylamino-L-alanine (BMAA) produced by cyanobacteria may be an environmental risk factor for ALS. Here we describe methods that may be used to assess exposure to cyanobacteria, and hence potentially to BMAA, namely an epidemiologic questionnaire and direct and indirect methods for estimating the cyanobacterial load in ecosystems. Rigorous epidemiologic studies could determine the risks associated with exposure to cyanobacteria, and if combined with genetic analysis of ALS cases and controls could reveal etiologically important gene-environment interactions in genetically vulnerable individuals.

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