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Algal Composition (algal + composition)
Selected AbstractsMARINE ALGAE ASSOCIATED WITH CARIBBEAN ROCKY SHORES, QUINTANA ROO, MEXICOJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Albert, E. M. & Lehman, R. L. Center for Coastal Studies, Texas A&M University-Corpus Christi, Corpus Christi, TX 78412 USA Rocky shores located on the east coast of the Yucatan Peninsula are typically high-energy habitats associated with fringing or barrier reef systems. They are phytokarstic (iron-shore) consisting of fossiliferous limestone that is composed of stony coral skeletons. This study compares the macroalgae from three rocky shores located on the east coast of the Yucatan Peninsula, Quintana Roo, Mexico. Fifteen 0.25m2 quadrates were randomly placed in the intertidal and subtidal zones and evaluated for dominant algal cover. In addition, fifteen 0.25 m2 quadrates of standing stock material was randomly collected and used to characterize algal composition, species richness, abundance, and biomass. A voucher collection including herbarium mounts and preserved specimens were prepared for all species encountered. Thirty-five species were identified representing three divisions: Rhodophyta, Chlorophyta, and Phaeophyta. Rhodophyta had the highest species richness with a total of fifteen taxa identified. Phaeophyta had the lowest species richness with seven taxa but dominated algal coverage at two of the three sites. Chlorophyta was represented by thirteen species. Species common to all points were represented by Digenia simplex, Laurencia poiteaui, Laurencia sp., Polysiphonia sp., Microdictyon marinum, Halimeda opuntia, Dictyosphaeria cavernosa, Padina sanctae-crucis, and Turbinaria tricostata. [source] EFFECTS OF NITRATE AND PHOSPHATE DISCHARGE FROM A FERTILIZER PRODUCTION PLANT IN A FJORDJOURNAL OF PHYCOLOGY, Issue 2001Article first published online: 24 SEP 200 Pedersen, A.1,2, Knutzen, J.2, Walday, M.2, Molvær, M.2 & Johnsen, T.2 1Department of Ecology and Evolutionary Biology, University of Connecticut at Stamford, Stamford, CT. 06901 U.S.A;. 2Norwegian Institute for Water Research, P.O.B. 173 Kjelsås, 0411 Oslo, Norway. "Hydro Agri Glomfjord" a fertilizer producer has been discharging large quantities of ammonium, nitrate and phosphate into Glomfjord (in northern Norway, N 66,48°, E 13,57°) since 1947. The effects of the nutrient load to the Fjord have resulted in classical eutrophication symptoms. Elevated nutrient levels have resulted in frequent plankton blooms and seasonally reduced O2 levels in the deep-water bodies as well as an eradication of the normal littoral assemblages. The fucoid belt had been replaced by various green algae 6 km from the outlet and outward the fjord. The effect is only seen on the northern side of the Fjord. After some improvement in the discharge loads in the 1980's, the condition in the pelagic column improved with regard to plankton blooms and deep water O2 concentration. The littoral communities didn't, show any indication of recovery and a pollution indication index based on algal composition, showed even increased eutrophication. [source] ALGAL-RELATED TASTES AND ODORS IN PHOENIX WATER SUPPLY: PRELIMINARY REPORTJOURNAL OF PHYCOLOGY, Issue 2000Q. Hu Frequent episodes of algal-related tastes and odors (T & O) in drinking waters in metropolitan Phoenix, Arizona prompted initiation of a three-year project in July 1999 to investigate the occurrence of T & O metabolites and to develop a comprehensive management strategy to reduce the problems in drinking water supplies in arid environments. Two metabolites, 2-methylisoborneol (MIB) and geosmin, have been identified as compounds responsible for the earthy-musty tastes and odors in water supplies. Both were detected in the water supply system, including source rivers, reservoirs, canal delivery system and water treatment plants. Higher concentrations of MIB and geosmin occurred in distribution canals than in the upstream reservoirs indicating that significant production of the T & O compounds occurs within the canal system. A baseline-monitoring program has been established for the complex water supply system, with special emphasis on the canal system. Efforts are underway to investigate possible correlations between physical/chemical parameters, algal composition and biomass, with the occurrence of MIB and geosmin. In addition, several physical and chemical treatments are planned for the canal system to reduce algal growth and related MIB and geosmin concentrations. [source] Impacts of differential consumption by the grazing fish, Plecoglossus altivelis, on the benthic algal composition in the Chikuma River, JapanPHYCOLOGICAL RESEARCH, Issue 2 2006Shin-ichiro Abe SUMMARY Grazing effects of ayu, Plecoglossus altivelis Temminck et Schegel, on the benthic algal assemblages were investigated in the Chikuma River, Japan. Comparison of the algal composition on boulders with and without intensively grazed patches indicated that fish grazing decreased the abundance of diatoms and prostrate filamentous cyanobacteria and caused upright filamentous cyanobacteria to predominate. Differential consumption by ayu was estimated by comparing the relative abundance of algae in the stomach contents of ayu and that in the algal assemblages within the grazed patches. The results showed that ayu consumed the prostrate filamentous cyanobacteria proportionally to their abundance, whereas they ingested diatoms and the upright filamentous cyanobacteria in a larger and lower quantity, respectively, than that expected from their abundance. Differential consumption would involve the change in the algal composition toward the predominance of upright filamentous cyanobacteria under fish grazing conditions. [source] | ||||||||||