Browsing All Posts filed under »restoration«

Lake management: are tipping points real?

December 14, 2021

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Freshwater biologists often seek to restore turbid shallow lakes dominated by phytoplankton to clear-water systems with a high abundance of submerged plants.  The usual plan of operation, which is often guided by lake ecosystem modelling, is to reduce external inputs of nutrients (e.g., from agricultural runoff or urban waste streams) to a threshold level at […]

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 […]

Costs of laissez-faire stewardship

June 7, 2021

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Stream pollution and the degradation of freshwater ecosystems have often been linked to waste discharges from coal mines.  Pollution often continues to occur for many years after a mine is closed because the mine gradually fills with groundwater and eventually releases contaminant flows at the surface.  In Australia there are over 50,000 abandoned mines (coal […]

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.  […]

Aquatic ecosystem services: rethinking streamside planting

March 13, 2021

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Spatial patterns in the loss of natural land cover to agriculture have a significant effect on ecosystem services, including those provided by landscape features that interrupt runoff flows to rivers.  For example, the number, size and location of woodland patches all have an impact on ecosystem services such as sediment trapping, pollutant retention and the […]

Restoring overheated rivers

March 13, 2021

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One of the features of the so-called “urban stream syndrome” is thermal pollution caused by warm  environments in built-up areas, which can increase stream temperatures above the tolerance threshold for aquatic organisms.  The good news is that urban stream temperatures can be reduced by re-naturalisation measures designed to improve flood control, water quality and habitats.  […]

Biodiversity offsets: compliance doesn’t guarantee ecosystem function

March 13, 2021

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When human activities impair habitats and reduce biodiversity, environmental offsets, such as the creation of new wetlands and the planting of native vegetation, can help to preserve ecosystem function and services.  However, the success of offsetting projects depends on the extent to which the required measures are complied with, and compliance is often poor.  This […]