Low Oxygen Dead Zones in the Pacific Ocean are Growing

Every year, we see wildfires wreak havoc on large regions of the western United States, and each year scientists attempt to forecast exactly how bad the upcoming fire season is going to be by assessing things like weather, climate change, moisture levels, and a bevy of different factors. Unfortunately, now the fire season is not the lone annual environmental occurrence that poses potential catastrophic effects—we also have the tornado and hurricane seasons, just as an example. Well now a new one can be added to the list and that is hypoxia season, thanks to the same culprit that has most likely been helping cause the fire seasons.

Evidence of More Low Oxygen Dead Zones

On the Western Coast, there have been low-oxygen levels forming in the ocean at the bottom layers. These are called hypoxia and are becoming a huge concern for fishers and scientists alike—everyone know that crabs and fish are critical to research, ecosystems and the whole industry. “We’re always on the lookout to see, is this going to be a bad year?” claimed Francis Chan, who is a marine ecologist from Oregon State University that examines ocean chemistry. And by every account, the year 2017 has been a very bad year.

Researchers originally received reports of dying crabs in pots located off the coast of Oregon in year 2002. Ever since that time, there have been years when oxygen levels in a few areas have dropped to zero and even remain at that level for weeks and possibly even months. Many marine animals are pretty resilient, but whenever the oxygen level gets low and stays there for a while, like they did in the year 2006, claims Chan, “very few things make it.” This summer, we have seen a dreadful hypoxia season which appears to have begun in July, when scientists started noticing crabs had died inside a research pot. Cameras that were trained on this pot “caught the low-oxygen zone red-handed.” Scientists began collecting samples of juvenile fish and could hardly catch anything at all. It was not until the middle of September, after a sea storm had stirred the ocean layers, before oxygen levels returned to normal.

The thing is that the low oxygen levels are not occurring out in open waters. “Right past where the waves are breaking, that’s where it starts,” Chan pointed out. Even though these effects are primarily seen next to the shoreline, hypoxia is believed to be tied to water chemistry changes that are occurring   in the middle of the Pacific Ocean. “Our coastal ocean is connected to the global ocean in a very intimate way,” he stated.

In order to monitor ocean oxygen and chemistry levels, researchers began placing sensors that are capable of measuring oxygen levels, currents, and temperatures. “This gives us a good idea of how things are evolving,” noted Chan. They are also taking note of what is reported by fishers and crabbers. “We don’t have sensors everywhere,” he claims, thus, whenever they hear of dead crabs this can quickly inform them exactly where low oxygen pockets are located.

Only One Reason for Low Oxygen Dead Zones

So when the fire seasons get more intense and become more widespread every year, hypoxic conditions become more and more common and last longer. The one thing that Chan notices when he studies water data that were taken in the 1950s and 1960s, he notes, “I can’t find the low oxygen values that we’re seeing today on a regular basis.” The fact is that ocean water is becoming warmer and therefore, holds less oxygen. Shifting weather patterns are influencing the way that ocean layers mix, and determining exactly where low oxygen pockets will form. In the end, Chan claim that there is really just one reason for all this: “The culprit we point to is a changing climate.”