Our oceans are filled with seaweed. Besides the well-known plastic pollution, they are also experiencing nutrient pollution. This is an excess of nitrogen and phosphorus which depletes oxygen in the water. The problem is caused by chemical /pesticide runoffs from farms and yards. But seaweed is now becoming an asset in controlling them. These plants can capture nutrient pollution in marine environments. The process is called seaweed aquaculture.

Nutrient pollution that leeches into water causes what we often see as algal blooms. What we don’t see is the marine life it kills or how it worsens water quality. Cultivating seaweed would alleviate this problem. In an expanse of 63,000 square kilometers in the Gulf of Mexico seaweed aquaculture has been introduced. By cultivating seaweed, more oxygen is absorbed as well as some of the excess nutrients. This helps diminish the low-oxygen dead-zone, over 18,000 square kilometers. That polluted water comes from over 800 watersheds covering 32 states. However, in the U.S.-controlled section of the Gulf only nine percent would be effectively controlled. This water pollution solution needs more funding and research.

However, there are emerging water quality trading programs responsible for nutrient pollution limits. These limits are traded through the market. Credits are dependent upon the amount of pollutants released. A kind of carbon cap-and-trade system! But they may cause pollution hotspots. Traders can purchase credits, but not meet requirements. But the seaweed aquaculture program and its promise could work well under these circumstances and is receiving bipartisan support in the United States.

The potential benefits of seaweed are expanding and in demand. The Seaweed Working Group, an interdisciplinary group of researchers, is charting ecosystems service and economic advantages of this new industry. It is being used as a specialty food in restaurants: green seaweed (Sea grape) freshly harvested and consumed. Other uses would include developing it as a bio-fuel, fertilizer, and animal feed. It can be possible to use it as a viable carbon sink. But more research is needed to show how seaweed is integral to our oceans health.

About half of the oxygen we breathe comes from oceans.  Protecting them and making oceans viable for all the creatures living there is vital. What we desire is global conservation. The United States must sign the Global Ocean Treaty, a High Seas Treaty, being promoted by the United Nations now. It is hoped more nations will also sign it this year.

Elaine Peters for the Green Sanctuary Committee