Morgan L. Vis

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A legacy of pre-regulation coal mining in many areas has been acid mine drainage (metal-rich, low pH water). Today, numerous remediation strategies may be implemented, but there is little data on efficacy in restoring biological condition. Two alkaline doser projects in Ohio were assessed using diatom assemblages, and biofilm extracellular enzyme activities(More)
The freshwater red algal genus Batrachospermum has been shown to be paraphyletic since the first molecular studies of the Batrachospermales. Previous research, along with this study, provides strong support for the clade Batrachospermum section Helminthoidea. This study has found that heterocortication, the presence of both cylindrical and bulbous cells on(More)
Eighty-three infrageneric taxa of stream macroalgae have been reported from tundra regions of North America, composed of 32 cyanobacteria, 35 Chlorophyta, 10 Chrysophyta and 6 Rhodophyta. There are few if any endemics represented in this flora. The most widespread species are the cyanobacteria Rivularia minutula, Nostoc commune and Tolypothrix tenuis as(More)
Diatoms, microscopic unicellular algae, have been widely sampled from streams around the world because of their use in biological assessments, but as a result they are often only collected from epilithic habitats in riffles, which may lead to a substantial underreporting of their diversity and distributional patterns. The goals of this study were to(More)
Tens of thousands of stream kilometers worldwide are degraded by a legacy of acid loads, high metal concentrations, and altered habitat caused by acid mine drainage (AMD) from abandoned underground and surface mines. As the primary production base in streams, the condition of algal-dominated periphyton communities is particularly important to nutrient(More)
AIMS Algae are favourable as a biofuel source because of the potential high oil content and fast generation of biomass. However, one of the challenges for this technology is achieving high oil content while maintaining exponential or high growth of the organism. Introducing a two-stage reactor to optimize both growth and oil content of the algae could be a(More)
The red algae (Rhodophyta) are a lineage of primary endosymbionts whose ancestors represent some of the first photosynthetic eukaryotes on the planet. They primarily inhabit marine ecosystems, with only ∼5% of species found in freshwater systems. The subclass Nemaliophycidae is very diverse in ecological and life history features and therefore a useful(More)
Extracellular enzyme activity (EEA) is becoming increasingly common for measuring biofilm function in streams. Different methods for enzyme assays may yield results that cannot be compared among studies, and duration of sample storage may also affect EEAs, leading to erroneous conclusions. We compared two frequently used methods for measuring phosphatase(More)
Periphyton is a commonly used biomonitoring tool for streams. Often only one or few riffles are sampled and assumed to be representative of a stream reach. Current literature focuses on periphyton heterogeneity at small scales, on individual rocks within a riffle, and larger scales, within watersheds or ecoregions. The intermediate scales, within single(More)