According to new research, the amount of nitrogen introduced into the United States waterways has already been affected by the changes in temperature and precipitation.
Excessive nitrogen washed into waterways can lead to hypoxia, the occurrence of toxin-producing algal blooms or the low-oxygen dead zones.
Dead zones and algal blooms are occurring in the coastal regions and lakes across the United States for the past summers. In 2016, several beaches in Florida, including Palm Beach, were struck with a harmful algal bloom. The affected beaches were closed momentarily. Another instance of algal bloom occurred in the Western Basin of Lake Erie where the waterways of Toledo, Ohio was poisoned by the bloom of blue-green algae.
Anna Michalak and her team from Carnegie have spent several years dedicated to the study of the different effects of nitrogen runoff. In their study, scientists are also looking into the expected changes in precipitation patterns that are caused by climate change. Both factors are seen to cause decreased water quality.
Now that their research team is joined by Tristan Ballard, the lead author of the new study, their method entailed looking back to analyze the long-term trend in nitrogen runoff. They analyzed data gathered from the 1980s.
Ballard pointed out that their findings could improve the modeling of future risks and guide management efforts.
Later they found out that the key factor in the amount of nitrogen that ended up in the water system was the climate. Nitrogen runoff is directly affected when the temperatures were warmed up during springtime and later carried by storms.
Ballard pointed out that other than the climate, another factor, agriculture, plays a role in decreasing water quality. Farms are continually using fertilizers that could influence the presence of nitrogen in nearby bodies of water.
There are efforts being carried out to decrease nitrogen in the waterways however, unavoidable precipitation has increased so much that nitrogen still overflowed into the water system.
Michalak explained that the deteriorating lakes and coastal water quality is not only because of fertilizers used in the fields but also because of different human activity at a global scale that changes the rainfall and temperatures.
Sadly, the team pointed out that, according to their findings, simply decreasing the amount of nitrogen released by the industry will not be enough. However, decreased usage, and human activity that produces less nitrogen could possibly offset the current condition of water quality.
