Browsing All Posts filed under »water quality«

How river transport affects dissolved organic matter

December 13, 2016

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In most rivers, the downstream transport of dissolved organic matter (DOM) makes large amounts of energy available to aquatic ecosystems. The River Continuum Concept (RCC) of Vannote et al. (1980) provided a useful framework for studying the influence of organic material from headwater streams on the structure and function of downstream ecosystems. The RCC hypothesized […]

Polluting antidepressants are more potent in high-pH systems

December 13, 2016

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The increased use of antidepressants in society means that the pollution of freshwater systems by SSRIs (serotonin selective reuptake inhibitors) is becoming more prevalent. SSRIs persist in the environment, bioaccumulate in animals, influence a wide range of physiological and behavioural processes and are toxic at high concentrations. Although it’s been established that SSRI toxicity is […]

Top predator boosts species richness – but not in alien ecosystems

December 13, 2016

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The spiny water flea Bythotrephes longimanus is a large cladoceran, a specialised carnivore and a top predator. Invasions of North American lakes by Bythotrephes have been linked to dramatic changes in food web structure and reductions in species diversity, which seems to contradict the expectation that top predators increase the evenness and diversity of aquatic […]

The dynamics of habitat choice: low-oxygen areas can be safer

June 1, 2016

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Animals should spend more time in habitats where their predation risk is low and their foraging rewards are high. However, habitat use is also affected by the degree of physiological stress imposed by environmental factors such as oxygen, pH, salinity and temperature. Because prey are under greater selective pressure from being eaten than predators are […]

Remote surveillance: assessing water quality

June 1, 2016

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Remote sensing technology gives natural resource managers and landowners the ability to monitor environmental conditions in new and powerful ways. However, the remote assessment of water quality in lakes and ponds is complicated by wide variations in the inorganic and organic composition of suspended particles, which affect the optical environment, and the moderate- and medium-resolution […]

Volunteers collect high quality data

June 1, 2016

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Volunteer community groups are increasingly active in environmental monitoring, and often have the capacity to collect large amounts of data that can potentially complement or replace information gathered by management agencies. However, in some instances, scientists have expressed reservations about the reliability of community-generated data. New Zealand researchers compared the level of agreement between stream […]

Green covers improve drainage channels

June 1, 2016

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In urban environments, the ubiquity of impervious surfaces increases rainfall runoff and the risk of flash flooding. These problems can be addressed by widening and deepening drainage canals, but usually at the risk of further habitat degradation. As a result, there ‘s increasing interest in low-impact environmentally-sensitive designs that simultaneously improve flood control and ecosystem […]