Coastal ‘Dead Zones’ Are Multiplying. Seaweed Farms May Be the Solution | Bloomberg

MBL aquaculture specialist Gretchen Grebe comments on the use of seaweed for pollution remediation. Grebe works with MBL Associate Scientist Loretta Roberson, who is leading a large Department of Energy-funded project to cultivate seaweed in U.S. tropical waters for remediation and for biofuels production.

In May 2019, the Mississippi River dumped a daily average of more than 5,000 metric tons of nitrate and 800 metric tons of phosphorous into the Gulf of Mexico, the highest levels in the last 40 years. These excess nutrients from Midwest farm fertilizer and animal waste rob the waters off Louisiana, Mississippi and Texas of oxygen, fueling toxic algal blooms and causing what’s come to be known as a dead zone.

The size varies each year, but this particular patch’s five-year average hovers at about 5,000 square miles. To date, a U.S. government task force has made little if any progress toward the goal of reducing it to 2,000 square miles. …

But there may be a solution on the horizon. A new study makes the case that the Gulf of Mexico could trade in its slimy algae for silky green seaweed, which if planted in sufficient numbers could soak up much of that damaging waste.