1. Pacific salmon and steelhead once contributed large amounts of marine-derived carbon, nitrogen and phosphorus to freshwater ecosystems in the Pacific Northwest of the United States of America (California, Oregon, Washington and Idaho). Declines in historically abundant anadromous salmonid populations represent a significant loss of returning nutrients across a large spatial scale. Recently, ...

An increasing number of studies use next generation sequencing (NGS) to analyze complex communities, but is the method sensitive enough when it comes to identification and quantification of species? We compared NGS with morphology-based identification methods in an analysis of microalgal (periphyton) communities. We conducted a mesocosm experiment in which we allowed two benthic grazer species ...

BACKGROUND The regression of similarity against distance unites several ecological phenomena, and thus provides a highly useful approach for illustrating the spatial turnover across sites. Our aim was to test whether the rates of decay in community similarity differ between diatom growth forms suggested to show different dispersal ability. We hypothesized that the diatom group with lower disper...

1. We asked whether unionid mussels influence the distribution and abundance of co-occurring benthic algae and invertebrates. In a yearlong field enclosure experiment in a south-central U.S. river, we examined the effects of living mussels versus sham mussels (shells filled with sand) on periphyton and invertebrates in both the surrounding sediment and on mussel shells. We also examined differe...

the influence of the herbivorous snail (physa sp.) on the algal periphyton community from thegamasiyab river, kermanshah province in western iran was examined by establishing a gradient of physa sp.density in artificial streams. the impact of physa grazing was evaluated by measuring dry mass, ash-free drymass (afdm) and chlorophyll a in the periphyton community. snails significantly depressed p...

Abstract: Aim We evaluated the periphyton on artificial substrate in treated sewage effluent, effluent patch, inside and after macrophyte stand a shallow hypereutrophic reservoir. Specifically, we investigated relationship between N P contents algal biomass with availability, focusing nutrient retention. Methods Periphyton sampling was performed at inlet, path, inside, two sites stand. 30 days ...

1. In large deep oligotrophic lakes, the shallow nearshore waters may provide the most important habitat for animals to feed and breed, and it is this area of the lake where humans are most likely to have initial impacts as the shoreline is developed. Nutrients in fertilizers, sediments and sewage effluents are likely to be rapidly intercepted by nearshore algae at the lake edge, having heterog...

The field of toxicology has traditionally assessed the risk of contaminants by using laboratory experiments and a range of pesticide concentrations that are held constant for short periods of time (1-4 days). From these experiments, one can estimate the concentration that causes no effect on survival. However, organisms in nature frequently experience multiple, applications of pesticides over t...

We evaluated several potential drivers of primary production by benthic algae (periphyton) in north-temperate lakes. We used continuous dissolved oxygen measurements from in situ benthic chambers to quantify primary production by periphyton at multiple depths across 11 lakes encompassing a broad range of dissolved organic carbon (DOC) and total phosphorous (TP) concentrations. Light-use efficie...