Browsing All Posts filed under »production«

How rivers befriend seabirds

January 14, 2019

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Where rivers flow into the ocean, the density fronts between fresh and salt water masses help to concentrate zooplankton and larval fish, making them more available to predators.  For example, freshwater discharge from the Columbia River creates a large brackish plume that can stretch for hundreds of kilometres along the North American coast, and nutrient […]

Turbulent times for freshwater plants

January 14, 2019

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Water movement is one of the most important factors affecting the distribution of aquatic plants, and has a beneficial or detrimental impact  depending on the magnitude of flow.  Japanese researchers compared the effects of steady flow and turbulence on three plant species with different types of morphology: western waterweed (Elodea nuttallii) with whorled leaves, curly-leaved […]

Top-down control varies within a species

January 14, 2019

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  Because consumer species can impose strong top-down effects on the structure and functioning of aquatic ecosystems, the loss or replacement of apex species may lead to dramatic alterations to the food web.  But can different forms of the same consumer species be sufficiently distinct that the replacement of one form by another triggers a […]

Research on insect emergence warms up

October 8, 2018

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Long-term data show that climate change affects ecosystem functioning and the body size distributions of animal species, but more information is needed to understand the mechanisms underlying these changes.  There’s a need for experimental studies that take account of linkages between the aquatic and terrestrial environment and that simulate changes in the intensity and frequency […]

Lakes are good for river species

October 8, 2018

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While it’s known that terrestrial landscape features, such as soil type, topography and land use, influence the abundance and distribution of stream fish, only a few studies have considered the possible effects of lakes on stream fish populations.  Biologists carried out a three-year study on native brook trout (Salvelinus fontinalis) in 36 streams in the […]

The magical diatom diet

July 5, 2018

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In forested headwater streams, detritus derived from decaying plant material is the primary source of energy driving the aquatic ecosystem, and most studies of such systems have focussed on the fate of leaf litter, the main resource.   However, because the food quality of detritus is extremely low it’s unclear how headwater streams support their  biological […]

Why are there so many crocodiles in tropical waterholes?

March 26, 2018

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Transfers of organic material from one aquatic environment to another (for example, through flood pulses or animal migrations) allow productive donor ecosystems to subsidise less productive habitats. However, there are big variations in the extent to which different animal species depend on production subsidies.  To explore such differences, Australian researchers collected a wide array of […]