In all, the team visited 10 central Amazonian lakes, finding that five experienced exceptionally high daytime water temperatures exceeding 37 degrees Celsius, far higher than the 29-30 degrees Celsius considered normal.
The most extreme reading came from Lake Tefe, which saw its surface area shrink by about 75%.
According to the Consumer Product Safety Commission, a hot tub is typically set between 100 and 102 degrees Fahrenheit, or just under 40 degrees Celsius.
Officials from the
World Wildlife Fund Brazil said 153 dolphins were found dead the week of Sept. 23, 2023, including 130
pink dolphins and 23
tucuxi dolphins. Both are listed as endangered on the IUCN Red List and the latter of which are considered "the guardians of rivers and a symbol of good luck," according to RiverDolphins.org.
"The climate emergency is here"
What made it even more remarkable, said Fleischmann, was that the same temperature was found not just at the surface but throughout the two-meter-deep water column.
Using computer modeling, the team identified four key drivers: strong solar heating, shallow waters, low wind speeds, and high turbidity — a measure of water haziness.
These factors reinforce one another. Shallowness increases turbidity, which traps more heat, while low wind carries less heat away, leaving the water more exposed to clear skies and intense sunlight.
Another stressor for aquatic life was the large swing between highs and lows, with the peak of 41C in Tefe followed by a nighttime low of 27C.
Though much of the national and global attention focused on the more than 200 dead dolphins recorded in under two months, they represented only the tip of a wider socio-ecological crisis, with fish also dying in droves.
There was even a phytoplankton bloom that turned the lake red as the algae came under stress -- the subject of another forthcoming paper Fleischmann co-authored.
To understand longer-term trends, the researchers combed back through NASA satellite data beginning in 1990, finding that Amazonian lakes have been warming at roughly 0.6C per decade, higher than the global average.
"The climate emergency is here, there is no doubt about it," said Fleischmann.
He added he would be attending the COP30 summit to advocate for long-term monitoring of the Amazon's lakes and for greater inclusion of local populations -- including Indigenous peoples, non-Indigenous riverine dwellers, and Afro-descendant communities -- in developing solutions.
Research published in the journal Hydrological Processes found that droughts "have significant implications for river water temperature extremes" as radiation during these periods is more intense while water levels are lower and river velocities slow.
"Rising river water temperatures can have significant and often detrimental implications for aquatic life, impacting both individual species and entire ecosystems," study co-author and University of Birmingham professor
David Hannah said. "Drought conditions often coincide with high atmospheric temperatures and such trends will become more intense and frequent with climate change."
www.cbsnews.com
. I wonder if there's any organisation of 'underground or otherwise' creators, or is this all a grassroots kind of cyberloosh goldrush?
