Browsing All Posts filed under »flow«

The net effect: caddis flies and streambed flow

March 26, 2022

Comments Off on The net effect: caddis flies and streambed flow

The beds of streams are dynamic interfaces where water, nutrients and living organisms move between surface and sub-surface environments, and streambed permeability has a significant influence on processes such as nitrogen cycling and organic matter decomposition.  Although the physics of streambed exchange are well understood, interactions between physical and biological processes have received relatively little […]

To be continued: the legacy of the River Continuum Concept

December 14, 2021

Comments Off on To be continued: the legacy of the River Continuum Concept

A recent review examined the historical importance of the River Continuum Concept (RCC), which was introduced by Robin Vannote and co-workers in 1980.  This concept revolutionised stream ecology research by prompting a shift from a descriptive to a predictive approach and encouraging multidisciplinary collaboration between biologists, geomorphologists and geochemists.  The RCC became a key framework […]

How flowing water affects the schooling of fish

September 28, 2021

Comments Off on How flowing water affects the schooling of fish

In many species of fish, individuals group together in shoals or schools to benefit from shared information – for example, on food availability or the presence of predators.  There’s also evidence that fish gain hydrodynamic benefits by taking up certain positions relative to other individuals, but not much is known about how flowing water affects […]

Costs of laissez-faire stewardship

June 7, 2021

Comments Off on Costs of laissez-faire stewardship

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 […]

How rivers regulate fish numbers

June 7, 2021

Comments Off on How rivers regulate fish numbers

Recruitment processes, which determine the number of young animals entering a  population each year, are central considerations in our attempts to understand fluctuations in abundance.  Although recruitment has been a key focus of fisheries scientists for many years, most of their work has involved marine fish species, and there’s been no fully integrated and comprehensive […]

Sound directions for the freshwater sciences

June 7, 2021

Comments Off on Sound directions for the freshwater sciences

A recent issue of the journal Freshwater Biology was devoted to the emerging field of ecoacoustics (the study of the ecological role of sounds), an exciting area with many applications in freshwater science.  So far, passive acoustic monitoring has been used mainly in terrestrial and marine environments, but recent studies reveal that inland waters support […]

Aquatic ecosystem services: rethinking streamside planting

March 13, 2021

Comments Off on Aquatic ecosystem services: rethinking streamside planting

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

Comments Off on Restoring overheated rivers

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.  […]

What determines leaf length in aquatic plants?

March 13, 2021

Comments Off on What determines leaf length in aquatic plants?

Several genera of aquatic plants have very long strap-like leaves.  Leaf lifespan and growth are known to be influenced by plant life history and reproductive strategies, but there have been few attempts to understand the factors that regulate leaf size in aquatic plants.  Terrestrial plants have been better studied in this respect, but environmental factors […]

Water abstraction changes local food chains

March 13, 2021

Comments Off on Water abstraction changes local food chains

The alteration of river flows by damming or extracting water is a major threat to freshwater ecosystems that can lead to habitat changes and local species extinctions.  While the impacts of dams and large-scale diversions have been the subject of many studies, the cumulative effects of small water abstractions aren’t so well understood, even though […]