Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Harmful cyanobacteria benefit from global warming

08.04.2008
‘Blooms like it hot’, argue two prominent biologists in this week’s issue of Science. Global warming creates favorable conditions for harmful cyanobacteria, because they respond more strongly to rising temperatures than most other algal species. This is likely to affect the water quality of many aquatic ecosystems worldwide, especially during summer heatwaves.

Blooms of harmful cyanobacteria (also known as bluegreen algae) are a growing nuisance in many lakes in Africa, Australia, China, the USA, and in many European waters. Professor Hans Paerl of the University of North Carolina (USA) and professor Jef Huisman of the University of Amsterdam (Netherlands) conclude on the basis of several recent studies that the worldwide proliferation of harmful cyanobacterial blooms is linked to climate change.

Cyanobacteria flourish at high temperatures, especially in nutrient-rich waters with high concentrations of nitrogen and phosphorus. The surface water of lakes is heated during prolonged periods of warm weather. Warm water expands, and floats on the colder water underneath. This results in stratification of lake water, which suppresses vertical mixing. Cyanobacteria profit from these stratified conditions.

They make small gas vesicles inside their cells, providing buoyancy. Buoyant cycanobacteria float upwards when vertical mixing is weak and accumulate in dense surface blooms. These surface blooms shade underlying nonbuoyant phytoplankton (such as green algae and diatoms). Thus, surface blooms of buoyant cyanobacteria effectively suppress other species by monopolizing all available light.

Changes in precipitation patterns and summer droughts

Cyanobacteria also profit from changes in precipitation patterns and summer droughts. Climate models predict more intense precipitation interspersed by longer periods of drought as a result of global warming. Intense precipitation leaches nutrients from soils, flushing them into rivers and lakes. As the discharge subsides during subsequent periods of warm, dry weather, cyanobacteria can capture the extra nutrient load, promoting their bloom development.

Attempts to control the water table by closure of dams and sluices during summer droughts may further aggrevate the problem. This will increase the residence time of cyanobacteria in these stagnant waters, thus providing a longer time window for bloom development. Moreover, cyanobacteria appear to be more salt-tolerant than other freshwater algal species. Rising salinities due to increased evaporation or salt water intrusion from sea level rise may thus give cyanobacteria an additional competitive advantage.

Paerl and Huisman discuss the example of a tropical cyanobacterium responsible for a severe outbreak of hepatitis on Palm Eiland, Australia. This tropical species invaded southern Europe in the 1930s, and has subsequently expanded its range northwards to lakes in the Netherlands and Northern Germany. Likewise, the species also invaded Florida several decades ago, and is now widespread across the US southeast and midwest, where it proliferates in warm and nutrient-rich waters. ‘Water managers will have to anticipate a worldwide expansion of harmful cyanobacteria’, says Huisman. ‘This is another important reason to curb the emission of greenhouse gases’.

Cyanobacteria can produce a variety of different toxins, causing damage to the liver and nervous system of birds and mammals in particular. Ingestion of these toxins can be fatal to cattle, waterfowl, and pets, and is also a serious threat for human health. Bodies of waters are closed for recreation and agricultural use, when their concentrations of cyanobacteria exceed a critical threshold level.

Josje Spinhoven | alfa
Further information:
http://www.uva.nl

More articles from Ecology, The Environment and Conservation:

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

nachricht International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

'On-off switch' brings researchers a step closer to potential HIV vaccine

30.03.2017 | Health and Medicine

Penn studies find promise for innovations in liquid biopsies

30.03.2017 | Health and Medicine

An LED-based device for imaging radiation induced skin damage

30.03.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>