In lakes and oceans, algae bloom if ingested and destabilize aquatic environments.
Paris, France:
Global warming is turning clear mountain lakes into green in the western United States due to an increase in “unprecedented” algal blooms, researchers reported on Tuesday.
Researchers at Colorado State University found that the concentration of algae in two distant mountain lakes has more than doubled in the past 70 years.
Their results, published in the British Royal Society’s Proceedings B, highlight the potentially harmful effects of climate change on pristine and remote ecosystems.
“Even in relatively distant lakes in protected areas … the fingerprint of human disturbance of the Earth’s system is evident,” chief researcher Isabella Oleksy of Colorado State University told AFP.
“The rapid warming of high altitude environments has resulted in rapid acceleration and the dominance of green algae, which until recently were found in low abundance in these lakes.”
The Oleksy-led team of scientists examined the levels of algae in lakes in a mountain range about 100 kilometers (65 miles) from Denver, using a tool called a gravity corer to collect sediment cores without damage the lake bed.
Building on measurements dating back to the 1950s, they found “dramatic changes” in the abundance of algae in the form of blooms of green algae called chlorophytes, which thrive in warmer temperatures.
The high level of algae “came as an ecological surprise,” said Oleksy.
She noted that the amounts of algae documented in the study would more generally be found in highly polluted areas, such as those prone to agricultural runoff, and not in unsullied mountain environments.
“Although we have documented these changes in two Colorado lakes, it is likely that this is not an isolated phenomenon,” she said.
The results are not a smoking gun, the researchers acknowledged, but indicate that climate change is causing excessive accumulation of nutrients – such as phosphorus and nitrogen – that cause algal blooms.
In lakes and oceans, algae bloom if ingested and destabilize aquatic environments by blocking sunlight, according to the United States Environmental Protection Agency on its website.
The proliferation of freshwater and seaweed has a huge negative economic impact, affecting fishing, tourism and human health.
(With the exception of the title, this story was not edited by GalacticGaming staff and is published from a syndicated feed.)
