<
https://theconversation.com/lake-victoria-is-turning-green-the-deadly-bacteria-behind-it-249298>
"Lakes, natural and man-made, provide water, food and habitats for wildlife, as
well as supporting local economies. Around the world, though, there’s a growing
threat to lakes: toxic bacteria which turn the water green.
This is the same green as you see on stagnant ponds. It’s caused by tiny
organisms called cyanobacteria and can be deadly.
Cyanobacteria thrive in warm, sunny lakes and ponds that contain excess
nitrogen and phosphorus nutrients derived from fertiliser, manure and sewage.
When conditions are right, cyanobacteria multiply rapidly and form smelly green
scums on the water’s surface.
Known to science as cyanoHABs (cyanobacterial harmful algal blooms), the scums
are harmful to livestock, wildlife, pets, people and aquatic organisms like
fish. Toxins make untreated water unsafe to drink, swim in, or even touch.
Sometimes they can become suspended in air and be inhaled. The cyanoHABs also
harm ecosystems by depleting oxygen, killing off whatever lives in the water,
and disrupting food webs and fisheries.
CyanoHABs are a global threat and receive considerable scientific attention in
North America and Europe. Blooms are becoming more widespread worldwide because
rising temperatures promote cyanobacterial growth and more intense rainfall
delivers nutrients from the landscape. Only effective management of nutrients
can reverse this trend.
The problem is understudied in Africa’s main lakes, including its largest –
Lake Victoria. Past research on cyanoHABs has mostly used microscopy to study
the kinds found there, but microscopy cannot differentiate between toxic and
non-toxic cyanobacterial cells.
We are on a large project team of scientists who have been studying the
socioeconomic and environmental effects of cyanoHABs in the Winam Gulf region
of Lake Victoria in south-western Kenya.
Our latest study identified which cyanobacteria were the most abundant in the
gulf and which ones were producing the main toxin of concern.
These findings can improve public safety:
* local authorities can monitor for specific cyanobacteria and warn residents
to stay away when blooms are present
* cyanoHAB prevention practices (nutrient reduction, land-use practices) can
target the cyanobacteria that cause the problem."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
