Skip to Content
Space

Satellites have spotted the biggest seaweed bloom in the world

Sargassum
SargassumBRIAN LAPOINTE

A vast, 8,850 -kilometer-wide, 20-million-ton cluster of Sargassum algae spanned the Atlantic in July 2018.

The news: There have been ever-increasing amounts of the seaweed in the ocean every summer since 2011, with the biggest ever bloom detected last year, according to a paper in Science this week. Although algae islands provide an important ecosystem for marine life, when they become too large they can smother corals and wreak havoc along the coastline. For example, it’s been a major problem for tourism-dependent areas in Mexico, where the seaweed washes up on beaches.

The research: A team at the University of South Florida used data from satellite instruments, which scan the ocean in visible and infrared light. Sargassum algae contains lots of chlorophyll-a, which stands out clearly at infrared wavelengths, in contrast to the water below.

The cause: We don’t entirely know, but the bloom is fed by nutrients, and there seem to be two major sources: discharge from the Amazon River and upwelling along West Africa’s coast (where surface waters are displaced by deeper, nutrient-rich waters, thanks to strong winds). Ultimately, these trends are caused by climate change, which affects precipitation and ocean circulation, according to coauthor Chuanmin Hu. “They are probably here to stay,” he said.

However, researchers will need to collect even higher-resolution satellite data to better understand what’s driving the blooms’ explosive growth, oceanographer James Gower told Science News.  

Sign up here to our daily newsletter The Download to get your dose of the latest must-read news from the world of emerging tech.

Keep Reading

Most Popular

How Rust went from a side project to the world’s most-loved programming language

For decades, coders wrote critical systems in C and C++. Now they turn to Rust.

The inside story of how ChatGPT was built from the people who made it

Exclusive conversations that take us behind the scenes of a cultural phenomenon.

Design thinking was supposed to fix the world. Where did it go wrong?

An approach that promised to democratize design may have done the opposite.

Sam Altman invested $180 million into a company trying to delay death

Can anti-aging breakthroughs add 10 healthy years to the human life span? The CEO of OpenAI is paying to find out.

Stay connected

Illustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.