Browsing All Posts filed under »biodiversity«

When drought eliminates fish…

March 30, 2019

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  Droughts can lead to lasting changes in the condition of wetlands.  For example, as drying occurs water levels drop and light penetration improves, which allows aquatic plants in the seed bank to germinate.  By stabilizing sediments, outcompeting algal plankton and  providing refuge to zooplankton grazers, newly established stands of aquatic plants can cause originally […]

How fire affects stream communities

March 30, 2019

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  By removing riparian vegetation, wildfires can have significant effects on river ecology, especially in headwater systems where fringing plant life helps to regulate stream temperature and provides a source of carbon in the form of leaf litter and woody debris.  To help understand the impacts of fire on streams, and the length of time […]

Restoring urban streams: a new twist

March 30, 2019

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  Urban stream environments typically display symptoms of degradation – such as increased temperatures, nutrient and chemical pollution, simplified habitat structure and reduced biodiversity – that are collectively referred to as the Urban Stream Syndrome.  Freshwater scientists generally accept that urban stream degradation is driven mainly by hydrological changes associated with stormwater runoff over impervious […]

Getting river history right

March 30, 2019

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  Information on past climate patterns can prove invaluable when assessing the responses of freshwater ecosystems to environmental change, but what are the implications for ecological understanding if beliefs about climate history are incorrect?  This question has been explored by scientists who used the Murray River, Australia’s largest river system, as a case study.  Hydrologically, […]

Putting aquatic animals back in place

March 30, 2019

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  The practice of replacing species that have been lost from degraded environments has become widespread over the last two decades, but most animal reintroductions have involved vertebrate rather than invertebrate species, and reintroductions are still relatively rare in freshwater settings.  However, because there’s often a lack of source populations in the vicinity of river […]

Recognising the biodiversity value of ponds

January 14, 2019

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Although pond habitats have been relatively neglected by conservationists, several studies have shown that ponds can contribute more to regional biodiversity than running waters.  Because they are isolated, small in size and often poorly protected by conservation programmes, pond ecosystems are highly vulnerable to environmental threats such as those presented by urbanisation.  To help provide […]

Wetland fish sampling

January 14, 2019

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How best to sample fish communities in lakes and wetlands?  Canadian biologists set out to develop a cost-effective sampling strategy that captured a high proportion of fish species.  Using a 9 m × 1.8 m seine net with 3 mm mesh, they collected fish from wetlands in Lake Ontario, Lake Erie, Lake Huron and the upper […]