Sargassum Overload

Sargassum Overload

I’m McKensie Daugherty, your host for On the Ocean. You’re likely to find more than sand and seashells, beach combing in the North Atlantic. Seaweeds of all shapes, sizes, and colors wash ashore everyday, but one of these types is not like the others. Unlike most seaweeds, which are usually found on the seafloor, the golden-colored Sargassum or “Gulf weed” can be found floating on the surface waters of the Caribbean, Gulf of Mexico, and Sargasso Sea. By using gas filled floats, Sargassum flourishes at the surface where it supports a diverse community of fauna. Sargassum provides a protective home for a wide range of animals ranging from small invertebrates, like shrimp and crabs, to juvenile sea turtles and serves as hunting grounds for predators like seabirds, tuna, and mahi mahi. When Sargassum washes ashore in small amounts, it provides nutrients to beaches and helps prevent erosion. However, in the last five years, much larger quantities of Sargassum have been washing ashore with disastrous effects. Cleanup of Sargassum from beaches is expensive and is often damaging. For sea turtles, blooms of Sargassum and subsequent cleanup efforts can destroy their nests. Scientists do not yet know why these blooms are occurring, but their consequences are far reaching. To understand why these blooms are happening, scientists are using satellites and Sargassum collections to determine where it’s coming from. Recent findings suggest that these large blooms originate in North equatorial waters, further south than Sargassum is usually seen. More research is needed to understand why these blooms began, and how they will affect other natural and human communities. Sargassum plays a unique role in our oceans and we must understand in order to predict and mediate future changes to this vital ecosystem. This has been On the Ocean, a program made possible by the Department of Oceanography and a production of KAMU-FM on the campus of Texas A&M University in College Station. For more information and links, please go to ocean.tamu.edu and click On the Ocean.

Contributing Professor: Dr. Amy Siuda

Script Author/Contributing Graduate Student: Lindsay Martin

 

A juvenile sea turtle uses a Sargassum mat as a nursery habitat in the Gulf of Mexico.

© Lindsay Martin 2015

 

MantaSargassum-15
MantaSargassum-12

Thousands of fish school beneath a mat of Sargassum in the Gulf of Mexico.

© Lindsay Martin 2015