The other CO2 problem: Oceans are becoming more acidic

We often hear about climate warming and melting arctic sea ice in the news, but have you ever wondered what effect climate change is having on our oceans? 

Despite being a vital link in the world’s food web, we are often unaware of the effects our changing environment is having on Earth’s oceans. One specific impact which is concerning scientists is the falling pH level of the ocean’s waters; our oceans are gradually becoming more acidic. As CO2 concentrations are increasing in the air we breathe, they are also rising in our ocean’s waters.

The world’s oceans are typically slightly basic, with an average pH of 8.25. (On a scale from 1 to 14, a higher pH is more basic, a lower pH is more acidic. Freshwater has a neutral pH of 7.0). In the past 200 years or so, our ocean’s pH level has dropped from this average of 8.25 to 8.14. This may not sound like much, but pH is based on a logarithmic scale, just as earthquake intensities are, and this decrease indicates an exponential increase in acidity. 

In the past 200 years, our oceans have become 30 percent more acidic.

Studies show that more acidic waters make it difficult for tiny shelled organisms to build and maintain their shells. Increased acidity breaks down vital minerals needed for this process. This could have a profound effect on fish populations, and therefore our economy, which is largely driven by the fishing industry.

Alaska’s multi-billion dollar fishing industry is the largest private industry employer in Alaska and the world’s top producer of wild salmon. Many Alaskans rely on a substantial catch for their own subsistence and economic prosperity. Without healthy and productive oceans, this industry and the livelihood of many Alaskans could be at risk. 

Tony Lewkowski, a summer education intern at the Kachemak Bay Research Reserve, is a junior at the University of Alaska Anchorage, majoring in environment and society.