Ecological stoichiometry can be a powerful tool to understand food web consequences of altered biogeochemical cycles as well as consequences of biodiversity loss on biogeochemistry and has proved to be a suitable framework to predict effects of consumers on the nutrient content of their prey. However, predictions from ecological stoichiometry have mainly been tested using single consumer specie...

Nutrient enrichment in coastal marine systems can have profound impacts on trophic networks. In the Baltic Sea, the population of Great Cormorant (Phalacrocorax carbo sinensis) has increased nearly exponentially since the mid-1990 s, and colonies of these seabirds can be important sources of nitrogen enrichment for nearby benthic communities due to guano runoff. In this study we used stable iso...

Water quality, periphyton, and invertebrates were determined for the Little Miami River above and below a municipal wastewater outfall during July-September 1984. The primary impact of the effluent on water quality was to increase nitrogen-containing compounds. Organosphosphate and chlorinated insecticides were non-detectable in any water sample and levels of potentially toxic metals were low. ...

Background: Direct impact of inorganic carbon (i.e., carbon dioxide (CO2)) on the periphyton community is important to understand how and to what extent atmospheric conditions can affect the structure and dynamics of these communities in lotic systems. We investigated the influence of elevated CO2 concentration on the periphyton community in the artificially constructed channels during the wint...

The relative contribution of aquatic vs. terrestrial organic matter to the diet of consumers in fluvial environments and its effects on bioaccumulation of contaminants such as mercury (Hg) remain poorly understood. We used stable isotopes of carbon and nitrogen in a gradient approach (consumer isotope ratio vs. periphyton isotope ratio) across temperate streams that range in their pH to assess ...

A method is described that allows the measurement of river periphyton chlorophyll a and pheophytin a both on rocks and in soft sediments. The method involves successive extractions directly from frozen samples with boiling methanol. Pigments are estimated by optical density measurements before and after acidification. Methanol is superior to acetone for the distinction of chlorophyll a and pheo...

Trophic resource partitioning is one of the main drivers adaptive radiation. The evolutionary diversification large African barbs, genus Labeobarbus, seems to be related mouth polymorphism. chisel-mouthed or scraping phenotype has repeatedly evolved within Labeobarbus. At least five ecomorphs with a morphology were detected in waters Ethiopian Highlands and can provisionally classified into two...

A small hydrological basin (Lerma, NE Spain), transformed from its natural state (steppe) to rain-fed agriculture and recently to irrigation agriculture, has been monitored across four seasons of an agricultural year. The goal of this study was to assess how and whether agricultural activities impacted the nearby freshwater ecosystems via runoff. Specifically, we assessed the toxicity of three ...

We tested the recolonization of the phytobenthic community in the tailwaters of Glen Canyon Dam following longand short-term experimentally induced desiccation. The response of Cladophora glomerata, Oscillatoria spp., miscellaneous phytobenthos species and periphyton was studied over 18 weeks using three treatments: (1) undisturbed control cobbles from the submerged zone; (2) cobbles desiccated...

aquatic plants have a major influence upon other aquatic organisms, by altering both water chemistry and spatial structure of the habitat in shallow water bodies. some of them, such as stratiotes aloides l., may suppress algal growth. but how aquatic plants would ultimately influence the heterotrophic community and the aquatic ecosystem as a whole is far from clear. our microcosm-based study de...