Freshwater bodies such as the Kinneret have been compromised by the influx of human development and population. Run-off and phosphates enter the water, disrupting the ecological balance and often resulting in eutrophication. This means that the lakes and rivers become deficient in oxygen, but rich in other nutrients that allow plant-life, such as algae, to proliferate. Realizing this, scientists and water boards worldwide have stepped up efforts to reduce the flow of phosphates into water in order to stabilize the ecosystems. Even so, algae continues to bloom. Yehonatan Bar-Yosef with the Hebrew University, in conjunction with the Kinneret Laboratory of the Israel Institute of Limnology and Oceanography, may have discovered why.
Blooming in holy waters
The Sea of Galilee, that holy lake brimming with history, is also close to death overrun as it is with cyanobacterial blue-green algae known as Aphanizomenon ovalisporum. While Cyanobacteria accounts for 20–30% of Earth’s photosynthetic productivity, which is a good thing, we all know the adage about too much of good things.
First discovered in Lake Kinneret in 1994, the algae has continued to bloom every summer since, but researchers have not really understood why until recently, according to Jerusalem Post’s Ehud Zion Waldoks.
“Bar-Yosef has discovered that Aphanizomenon is known to produce the toxin cylindrospermopsin (CYN). Secretion of the CYN, Bar-Yosef found, induces phosphate-limitation responses in other microorganisms in the ecosystem, even in the presence of ample phosphate in the water. Phosphate is an essential nutrient for growth in many organisms,” writes Mr. Waldoks.
By inhibiting absorption of it in other organisms, greedy blue-green algae get fat on phosphates.
“The investigators have used the term “enslavement” to describe this novel interspecies interaction, mediated by CYN. This research provides an explanation for the significant rise in massive cyanobacterial bloom events worldwide,” according to Mr. Waldoks.
Freshwater resources are crucial to life, and increasingly taxed. With any hope, this new infusion of science will help international researchers restore our threatened watersheds.
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