Browsing All Posts filed under »habitat loss«

Springs – neglected ecosystems

March 26, 2022

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Springs can be defined as places on the Earth’s surface that are influenced by the exposure, and often the flow, of groundwater.  They support biodiverse ecosystems and have socioeconomic value as sources of water for drinking, agriculture, industry and recreation, , but they are often  highly vulnerable to human disturbance, such as groundwater depletion,  pollution, […]

Freshwater megafauna under threat

March 26, 2022

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Because large-bodied animal species tend to have a higher than average extinction risk, there are concerns that freshwater megafauna (species with body weights over 30 kg) are relatively vulnerable to human-induced disturbances such as reduced river flows, habitat fragmentation and pollution.  In the 40 years leading up to 2012, global populations of freshwater megafauna declined […]

Dams challenge platypus populations

March 26, 2022

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The construction of dams has many adverse effects on river hydrology and ecology.  Dams limit animal movements and reduce the cover of riparian vegetation, which leads to bank erosion and the filling of stream pools with sediment.  Dam-related impacts have been documented for many types of riverine animals, including macroinvertebrates, amphibians and waterbirds.  However, the […]

A lesson from fish: don’t let stress ruin procreation

March 26, 2022

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Annual fishes live in temporary ponds that dry out completely in summer.  As a result they have the shortest life spans of all vertebrates: after a few months they perish and the next generation depends on the survival of their drought-proof eggs, which hatch when the pond is eventually flooded.  As the shallow ponds dry […]

Gene flow in complex river systems

December 14, 2021

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Understanding how variations in habitat connectivity affect gene flow and possible genetic isolation in river systems is tricky because of the unique structural features of stream ecosystems, which are notoriously difficult to model: unlike terrestrial landscapes, they are linear branching networks, which means that overland distance is often a poor indicator of the correlation between […]

In-stream wood increases fish abundance

September 28, 2021

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Although fallen woody material provides many freshwater fish species with essential habitat for feeding, refuge and spawning, a lot of submerged wood has been removed from rivers in an attempt to prevent floods and improve boat passage. However, current best management practice is to reverse this historical trend by reintroducing wood to rivers and streams.  […]

Restoration of urban headwaters pays dividends

September 28, 2021

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Because urban streams are often ecologically degraded as a result of channelisation and pollution, restoration work is often attempted to improve ecosystem structure and function.  This usually involves remodelling of the stream channel.  Knowing that there are predictable shifts in ecosystem processes between headwater streams and the main body of the river, American ecologists investigated […]

Assessing human impacts on river systems

September 28, 2021

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Because many river systems have been significantly modified as a result of human activities, indicators of changing river structure and function are very helpful in guiding our efforts to manage rivers on a sustainable basis.  A number of different indicators based on the hydrology, chemistry or biology of rivers have been developed, but in many […]

Assessing river condition from the air

June 7, 2021

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Although attempts are commonly made to restore streams impacted by disturbance, follow-up monitoring to assess a project’s success is often minimal due to budget limitations.   However, new approaches involving the use of small unmanned aerial vehicles (drones) offer the possibilities for remote stream assessment, with potentially great gains in terms of cost-effectiveness and reduced field […]

Aquatic ecosystem services: impacts of land use

March 13, 2021

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Streams and riparian zones are seldom given priority in protected-area planning, and little is known about the effects of protection on the many ecosystem services that streams provide.  To help fill this knowledge gap, researchers studied differences in biodiversity and the ecosystem services provided by 28 streams in protected and unprotected watersheds in Quebec, Canada.  […]