Browsing All Posts filed under »physiology«

How fish negotiate culverts

March 27, 2017

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While culverts are designed to facilitate the movement of water by allowing it to flow under roads or other obstructions, they can place physiological and/or behavioural restrictions on the movements of fish. Although several studies have considered the implications of culvert design for fish passage, surprisingly few have tried to identify the factors that influence […]

How to predict water temperatures

March 27, 2017

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Because temperature is a key variable affecting a myriad of ecological processes, there’s a need for reliable ways of predicting the temperature of water bodies. Such temperatures can be influenced by both natural factors (e.g., air temperature, local topography, stream discharge, groundwater interactions) and anthropogenic factors (e.g., deforestation, thermal pollution, flow alteration, and runoff from […]

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 […]

Emergent wetland plants as conduits for methane

December 13, 2016

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Wetlands release more methane to the atmosphere than other any other type of ecosystem and wetland plants, especially those in the shallow fringing zones, play an important role in methane dynamics. However, aquatic plants can be damaged by the grazing activities of herbivorous animals. To examine the impacts of grazing damage on the release of […]

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 […]

Flow-on effects of water movement

March 23, 2016

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Although aquatic plants risk being uprooted in fast-flowing streams, if they’re capable of varying their growth form to suit the conditions they may be able to reduce the chance of dislodgement. To see if water plants can adapt to fast-moving water by increasing their strength and reducing their drag, Swedish researchers compared the growth of […]

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 […]