Browsing All Posts filed under »water quality«

Urban trees protect local water bodies

September 25, 2017

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As a result of nutrient transfer from the land, urban waterways often have high concentrations of nitrogen and phosphorus, which can lead to algal blooms, low water clarity, oxygen depletion and species loss. Nutrient enrichment problems also extend to urban groundwater, where water quality can be compromised.  Although nutrients moving from land to groundwater water […]

A disturbing mix

June 19, 2017

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The common carp (Cyprinus carpio) has been introduced to many locations around the world and is highly invasive.  Its habit of foraging by digging in the bottom substrate significantly alters freshwater systems by uprooting plants, resuspending sediment, and increasing turbidity and the release of nutrients.  However, the extent to which aquatic nutrient flows are affected […]

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 […]