The climate crisis is causing a massive drop in oxygen levels in lakes around the world, suffocating wildlife and threatening drinking water supplies. Declining levels of oxygen in the ocean had already been identified, but according to new research, the decline in lakes has been between three and nine times faster in the past 40 years.
Scientists found that oxygen levels had fallen by 19 percent in getting deep and by 5 percent on the surface. The main reason for this is the increasing temperature due to global warming, because warm water cannot hold much oxygen. In addition, rising heat makes the top surface of lakes warmer and less dense than the water below. The researchers investigated the density of dissolved oxygen, the most important gas in the aquatic ecosystem, along with the top water and deep water levels.
He explained that the imbalance in oxygen can have a negative impact on the biodiversity of flora and fauna. Oxygen levels have increased on the surface of some lakes. But these are likely due to higher temperatures induced by harmful algae. According to research published in the journal Nature, the proliferation of harmful algae by deoxygenation can harm both animal and human health. Prior to this research, this phenomenon had only been studied in the ocean, but the results suggest that anthropogenic climate change can affect lake ecosystems in similarly devastating ways.
Professor Kevin Rose, a US researcher, says that all complex life depends on oxygen and, when oxygen levels are low, you actually reduce habitat for many different species. He said that this research proves that the problem is even more serious in fresh water, posing a threat to our drinking water supply. The research found that deep-water lake habitats are particularly at risk, and deep-leaning trends indicate future losses of species sensitive to cold water and oxygen. They have already suffered greatly, with wildlife populations declining by 84 per cent since 1970.
In addition to global warming and overpopulation, causes include overuse of water for agriculture. For the research, the researchers analyzed a portfolio of 45,000 dissolved oxygen and temperature stored in 400 lakes around the world. They found that oxygen levels in the lakes dropped to low enough that phosphorus could be extracted from the sediment, providing essential nutrients to the bacteria. Scientists said cutting emissions, as well as reduction in agricultural fertilizer use and urban sewage pollution, are necessary to tackle the climate crisis as they also damage lakes.