Browsing All Posts filed under »pollution«

Unravelling trends in stream nitrogen

March 27, 2017

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Oxides of nitrogen derived from agriculture, industry and emissions from the burning of fossil fuels fall out from the atmosphere and enter terrestrial and freshwater ecosystems. Over the last century the deposition of reactive nitrogen has increased three to five times, and this is reflected in a general global increase in stream nitrogen concentrations. However, at […]

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 […]

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 […]

Counter-productive perspectives

March 23, 2016

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A central aim of freshwater research is to understand the processes that regulate biological productivity. However, while lake-based investigations have focussed heavily on controls on primary production, river-based researchers have tended to concentrate more on production limits imposed by physical habitat requirements. If lake and river researchers think about production in different ways, and concentrate […]

Waterbird numbers & fertilizer use

March 23, 2016

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Nutrients applied as fertiliser to farmland leach into rivers and streams and are transported to coastal waters, where concentrations of nitrogen and phosphorus are now respectively ten and three times higher than in pre-industrial times. While moderate rises in nutrient availability can have beneficial impacts on aquatic production, excessive nutrient levels lead to the eutrophication […]