Research

Changes in epiphytic algae in the Colorado River in Glen Canyon

In collaboration with Dr. Larry Stevens at the Springs Stewardship Institute, we are assessing the assemblage of epiphytic diatoms and other algae occurring on submerged macrophytes that constituted the primary foodbase for aquatic consumers in the tailwaters of the Colorado River ecosystem downstream from Glen Canyon Dam.

Ecology and biogeography of freshwater Phaeophyceae

We are conducting studies on freshwater member of the Phaeophyceae, a class of algae that occurs
almost entirely in marine waters.  Freshwater phaeophytes form conspicuous crusts or cushions in many streams, as well as in the littoral zone of lakes, but their biology is fairly obscure to most phycologists and ecologists.

Effects of dams on the spread of the invasive diatom Didymosphenia genminata

Didymosphenia geminata is an diatom that forms benthic algal blooms in low-nutrient streams and produces extensive extracellular polysaccharide stalks that cover streambeds. We are investing whether dams or impoundments favor its  growth in streams and rivers.

Field and experimental studies on harmful cyanobacteria blooms

We are examining the causes and consequences of cyanobacteria blooms using field studies, microcosm experiments and laboratory bioassays.  We are addressing the effects of N and P concentrations, N:P ratios, and different forms of nitrogen on cyanobacteria dominance in urban and suburban lakes in the NYC region

Nutritional ecology and ecological stoichiometry of algae in stream food webs

Growth and production of invertebrate consumers
in streams can be limited by both the quantity
and quality of food they encounter. We employ fatty acid and elemental stoichiometry to asses the relative importance of algae, detritus and other basal food sources for stream ecosystem function.

Algal assemblages in North American springs

Springs are unique habitats for freshwater algae: isolated or distant from other populations, often thermally constant and chemically stable. Research on algae in non-thermal springs in North America lags far behind work conducted in European springs. Current studies are beginning to fill this gap.