According to a recent research, algal blooms in world’s lakes could jump 20% over next century due to warming waters. Scientists explained that the situation could lead to more dead-zones within lakes caused by lack of oxygenation and put in peril local ecosystems.
Researchers found that the areas with the most extreme temperature jumps are lakes. Of 235 surveyed lakes, over 50 percent saw average temperature increase 0.61 degrees F (0.35 degrees C) every ten years. Although the change may seem minor, study authors noted that the swing is significantly bigger than any changes observed in the air or world’s oceans.
This is why the recently-reported changes in lakes could have long-term consequences on animals and humans’ drinking supplies, and food stock. Animals could find it hard to survive in oxygen deprived lakes as more dead zones emerge.
Catherine O’Reilly, lead author of the study and researcher at the Illinois State University, explained that the recent findings suggest world’s lakes are under a lot of stress. She is concerned that problems observed just in some locations could soon become widespread.
The study which was sponsored by the National Science Foundation and NASA, was recently unveiled at the annual gathering of the American Geophysical Union. Researchers based their study on satellite and ground data on temperatures that were collected over the last two decades.
The research revealed that there is a warming trend in the world’s major lakes including Lake Baikal in Russia, Lake Tahoe, and the Dead Sea. But the most sudden changes were observed in cold, deep lakes. For instance, Superior, which is the coolest and deepest lake of the Great Lakes, saw its average temperatures jump threefold than the global average in recent years.
But not only air temperatures contribute to warmer lakes. Many lakes, especially in the cold regions, lose winter ice faster, while others are no more blanketed by clouds, thus, being directly exposed to solar heat.
Warm waters are an welcoming environment for algae. This may explain why the recent study tied warming lakes to a jump of 20 percent in algal blooms and a 5 percent rise in toxic algae blooms.
Toxic algae are dangerous not only to fish but to humans, too. For example, more than a year ago one such bloom deprived 400,000 Ohio residents of tap water for a couple of days.
Nevertheless, there are more reasons why algae choke lakes and waterways. An oversupply of nutrients caused by nitrogen and phosphorous pollution and waste waters also helps them thrive.
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