Clearing sargassum comes with environmental risks

As thick mats of yellow seaweed continue to invade Cayman’s beaches, canals and harbors, environment officials are warning the cure could be worse than the problem.

The Department of Environment fears efforts to clear sargassum from Cayman’s coastline risk destabilizing beaches and crushing sea turtle nests.

Anyone seeking to use heavy machinery to remove the seaweed requires written permission from the DoE. Officials are also asking property owners to consult them before conducting any kind of clean-up.

The department generally advises people to leave sargassum seaweed where it is, as it is a naturally occurring phenomenon which can help nourish and stabilize beaches.

But the scale of the influx this year has caused problems for hotels, restaurants and businesses across Grand Cayman. The foul-smelling seaweed has clogged up the coastline, preventing people from swimming in some places and causing a range of other issues.

In West Bay, a kitesurfer had to be rescued by marine police after the lines of his kite got tangled in sargassum and he was unable to launch it, leaving him stranded at sea. Jhon Mora, who runs Kitesurf Cayman, said the incident had been swiftly dealt with by police and the man was not hurt.

He said the seaweed was causing real problems off Barkers and the school is advising kitesurfers to take extra precautions.

In Cayman Brac, sea turtle hatchlings attempting to make their way to the ocean became trapped in large banks of sargassum that had washed up on the beach.

Sargassum has clogged up the coastline from East End to West Bay.

Volunteers were able to find and rescue many of the hatchlings on this occasion, said Tim Austin, deputy director of the DoE. But he said the invasion did pose a real risk to hatchlings.

A bigger concern, though, is that clean-up efforts do not cause a worse problem. He said heavy machinery used to shift the seaweed could crush turtle nests completely.

Mr. Austin said the DoE’s phones had been “ringing off the hook” for the last week with reports about sargassum.

He said: “There is a disproportionately large amount of it out there and the big concern is how it is cleaned up.”

He said the DoE was working with the parks department to advise on the clean up of public beaches. Private property owners are also required to consult with the department.

“If people call us and consult with us, we have a very simple process. If it is not a turtle nesting beach, it is simply a matter of advising them what methods to use and ensuring people stay within those. If it is a turtle nesting beach we come out and mark the nests.”

The DoE has issued guidelines on how to remove sargassum from beaches, urging people to hand rake the seaweed rather than use machinery where possible.

It cites concerns that the over “grooming” of beaches can lead to erosion and suggests sargassum can be left alone.

“The experience in locations that have left the sargassum on the beach is that it will eventually get washed away or buried in the next storm, with rain easing the smell. Leaving sargassum on the beach has proven to be the simplest and lowest-cost approach, also helping to nourish the beach and stabilize the shoreline.”

If it must be moved, the department warns people to be very careful about what they take out of the water, noting that hundreds of species of juvenile fish and invertebrates live within the mats of sargassum.

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