Distributions and fates of oxygen in periphyton communities

Abstract

Direct measurements with oxygen microelectrodes demonstrated that the distribution of dissolved oxygen in periphyton communities varied on a diurnal basis and was markedly different among periphyton types. During illumination, photosynthesis in periphyton resulted in oxygen supersaturation in microzones that were subsaturated or anoxic during darkness. The fate of oxygen produced within periphyton depended on the relative rates of production and consumption, the diffusion characteristics of the periphyton, physical and chemical interactions with the substratum, and the transport rate across the boundary layer, which was affected significantly by water currents. During constant environmental conditions, steady-state oxygen distributions occurred within periphyton, but equilibrium with the surrounding water was rare.

Effects of algal turf canopy height and microscale substratum topography on profiles of flow speed in a coral forereef environment

“…Decreased momentum exchange within these depressions will likely result in microzones of anoxia, particularly at night, that could be important for both regenerative processes and rates of nitrogen fixation (Paerl et al 1989). The degree to which microscale oxygen dynamics affects regenerative processes has been well studied in soft-bottom habitats in freshwater environments (Revsbech and Jorgensen 1983;Carlton and Wetzel 1987) and in the marine pelagic environment (Paerl et al 1989), but has not been addressed in hard-bottom habitats like coral reefs.…”

The effects of nutrient enrichment on algae and macroinvertebrates in the everglades: A review

“…In shallow water, low flow conditions, 0 2 concentrations va~ over a small spatial scale and on a diel basis as a function of respiration and chemical oxidation versus photosynthesis (Van Meter 1965, Glcason and Spackman 1974, Carlton and Wetzel 1987. Temporal and spatial variation of oxygen is influenced by factors that regulate photosynthesis and respiration (e.g., water depth, temperature, shading, and current velocity) (Kushlan 1979, Carlton and Wetzel 1987, Riber and Wetzel 1987.…”

“…Temporal and spatial variation of oxygen is influenced by factors that regulate photosynthesis and respiration (e.g., water depth, temperature, shading, and current velocity) (Kushlan 1979, Carlton and Wetzel 1987, Riber and Wetzel 1987. Fluctuations at larger scales (e.g., air-water, sediment-water, and plant-water interfaces) are small compared to the greater variation at smaller scales (Jorgensen et al 1979, Jorgensen and Revsbech 1985, Carlton and Wetzel 1987. Benthic and epiphytic periphyton, including the cyanobacterial mat, are the primary sources of oxygen in open water habitats and for most of the Everglades ecosystem (Hunt 1961, Belanger et al 1989, SFWMD 1990.…”

Surface-hyporheic interactions in a Sonoran Desert stream: hydrologic exchange and diel periodicity

“…Die1 patterns of nutrient cycling in lakes and marine systems have implicated sediments and sub-surface areas as sources or sinks for dynamic solutes (Nixon et al, 1976;Dale & Gellespie, 1977;Andersen et al, 1984;Jensen et al, 1984;Carlton & Wetzel, 1987, 1988Kelderman et al, 1988). Recently, stream ecologists have recognized the interstitial spaces of stream beds, known as the 'hyporheic' zone (sensu Orghidan, 1959), as habitat for lotic invertebrates (Coleman & Hynes, 1970;Stanford & Gaufin, 1974;Williams, 1984;Stanford & Ward, 1988), as regions of groundwater-stream interaction (Wallis et al, 1981;Hynes, 1983;Rutherford & Hynes, 1987;Ford & Naiman, 1989), and as metabolically active regions affecting whole ecosystem energy flow and nutrient transformations (Grimm & Fisher, 1984;Munn & Meyer, 1989;Triska et al, 1989b;Coleman & Dahm, 1990;Valett et al, 1990;Grimm et al, 1991).…”