Climate change is likely to increase ocean dead zones, areas where depleted oxygen harms sea life, a Smithsonian study found.
In a study by two Smithsonian research institutes and the University of Maryland, scientists determined that the
formation of dead zones has increased, doubling every 10 years since the 1960s, the Smithsonian Magazine reported.
Although the oxygen-depleted zones can occur naturally, human activities can cause them to form or can make them worse, the magazine said. “For instance, dead zones often occur when runoff from farms and cities drains into an ocean or lake and loads up the water with excess nutrients such as nitrogen and phosphorus” the Smithsonian said. “Those nutrients feed a bloom of algae, and when those organisms die, they sink through the water column and decompose. The decomposition sucks up oxygen from the water, leaving little available for fish or other marine life.”
The study was published this week in “Global Change Biology,” and in it, researchers highlighted more than 400 dead zones in the world.
“Temperature is perhaps the climate-related factor that most broadly affects dead zones,” researchers wrote in the study, the Smithsonian reported.
"We've underestimated the effect of climate change on
dead zones," the study's lead author Andrew Altieri, a Smithsonian researcher, told the New Orleans Times-Picayune.
Ninety-four percent of dead zones are located in areas expecting to see average temperature increases of 4 degrees Fahrenheit by 2100, The Washington Post said. Those areas include the Chesapeake Bay, Black and Baltic seas, and the Gulf of Mexico, which has a dead zone off the Louisiana coast the size of Connecticut, the paper said.
Donald Boesch, a University of Maryland ecologist who did not work on the Smithsonian study, told the Times-Picayune that climate change is playing a role in the increasing incidence of dead zones.
"But he said the study is probably right in warning that future warming will make the problem even worse," the paper said.