Jeff Miller Talks Sargassum Abundance at Audubon Meeting


A blanket Sargassum seaweed covers a large area in John’s Folly.


U.S.V.I. Waters — St. John is not alone in its Sargassum infestation, the weed has been washing ashore across the Caribbean and even piling up on the Texas Gulf Coast shoreline.

To hear more about the Sargassum weed amassing on St. John coastlines, Virgin Islands Audubon Society members invited fisheries biologist Jeff Miller to speak at their Tuesday, November 18, meeting at The Marketplace in Cruz Bay.

“I actually had more questions than answers for the group,” said Miller, who works for the U.S. National Park Service on St. John. “We know this is happening all across the Caribbean, not just here. We’re seeing this from all down island to Barbados, the Dominican Republic and Haiti and I’ve talked to guys in Texas who are getting slammed with this.”

“The weed they get on their shore in Texas comes from down here,” Miller said. “They found a camera in a bunch of weed that came from Grand Cayman.”

Except for the stink, the abundance of Sargassum doesn’t have any adverse environmental effects, Miller explained.

“It just smells bad,” he said. “There are no harmful effects and it can even be turned into fertilizer. That takes getting some of the salt out of it and breaking it up to get the sand and other desiccated little critters out of it.”

Scientists are exploring other uses for Sargassum as well, from cattle feed to beer, according to Miller.

“The iodine makes it unpalatable, but at Texas A&M they are trying to get the iodine out of it so they can use it as cattle feed,” said the fisheries biologist. “They are working on a steaming process to leach the iodine out. If they can get that worked out, it would a great market.”

“Other people are looking at making beer out of it, so maybe the Tap Room guys could look into that,” Miller said.

Sargassum weed originates in the Sargasso Sea, a little whirlpool in the Atlantic Ocean, explained Miller.

“It comes and goes and it seems to be that we are in a pattern where it’s coming out of the sea and drifting this way,” he said. “It comes from the Sargasso Sea, this slow whirlpool in the middle of the Atlantic that is sometimes called the ‘Golden Rainforest.’ There is a large community there of this weed.”

“There are weather patterns and low and high pressure systems that affect this sea and every so often, if the weather happens to be right or wrong, it will burp out some of this Sargassum,” said Miller. “Then current, wind and waves blow it our way.”

The big question scientists are asking about the abundance of sargassum is if the weed is growing faster due to increased sea surface temperatures and non-point source pollution from major state-side metropolitan areas, according to Miller.

“The big question is if the increased nutrients in the water due to runoff from metropolitan areas and increased sea surface water temperatures are increasing the productivity in the Sargasso Sea,” Miller said. “Is the weed growing faster so there is more of it in the first place?”

Scientists at Texas A&M have devised a forecast model, called the Sargassum Early Advisory System, for predicting when beaches in their area will be impacted by the weed, the fisheries biologist added.

Anyone who missed last week’s Audubon meeting should be sure to catch one of Miller’s weekly talks at Cinnamon Bay Campground this season. Starting in late December, Miller will give a presentation on marine ecology each Tuesday night at 7:30 p.m. either in the campground’s amphitheater or restaurant.

“Things are only going to change if people understand what is going on with our marine system,” said Miller. “It only makes sense if we get everyone to buy in and help out. If folks don’t know what is going on, they can’t be expected to comply with what we’re asking.”

“If people understand what is going on, they are going to comply with the rules because they want to,” he said. “People want to make a difference once they understand the long-term affects of their actions.”

While marine ecology is in a perilous situation, Miller’s presentation leaves the audience with concrete ways to help, the scientist added.

“People feel powerless sometimes, so one thing I stress is the top 10 things you can do to help protect reefs,” said Miller. “You’re not just getting pummeled with all this useless information. There are things you can do to help out.”