Stringy algae flood Brevard County beaches

This summer, some say things look a little – and smell a little – worse than usual. That’s because the coastline seems mostly awash in weeds, from Cocoa Beach to Sebastian Inlet and beyond.

There’s the usual sargassum, which the Caribbean Sea delivers seasonally to the Gulf Stream and then to the beaches of central Florida.

But certain “stringy” algae are dominating the surf zone this summer, to the detriment of anglers, surfers and anyone who prefers weed-free wading, according to scientists at Florida Atlantic University.

Boys playing in the waves at Jetty Park walk through the seaweed covering the park's beach.

Oceanographers expect Sargassum algae and other macroalgae to thicken on our beaches every year. It comes from the eastern Caribbean and spreads all over the east coast of Florida and elsewhere.

The winds dictate when these stringy weeds hit our shore.

Seasonal algae strike back: Tons of seaweed washes up on the Space Coast

Two boys playing at Jetty Park sink ankle-deep in the seaweed that covers the beach.

For centuries, pelagic sargassum, floating brown algae, has grown in the nutrient-poor waters of the North Atlantic Ocean, supported by natural sources of nutrients such as fish and invertebrate excretions and upwellings. oceanic. But as fertilizers, sewage and other human sources have increased nitrogen and phosphorus in the rivers, this algae too – like the filamentous type we see so much now – has spiraled out of control over the past decade.

Florida Atlantic University researchers have shown for years that seasonal Sargassum levels here and elsewhere in the tropical Atlantic have worsened in recent years due to increased nitrogen and phosphorus from discharges from Congo rivers, Amazon and Mississippi, atmospheric deposition of Saharan dust and combustion of biomass. vegetation in central and southern Africa,

Waves clouded by seaweed washed ashore at Jetty Park this week.

Sargassum from this summer has already set a record. Combined, the total amount of weeds rose from 18.8 million tonnes in May 2022 to 24.2 million tonnes in June 2022, setting a new all-time high, according to the July 2 bulletin from scientists at the University of South Florida on seaweed.

Given the all-time high mass of Sargassum in June, more seagrass beds could enter the Caribbean Sea and Gulf of Mexico in the following months, straddling major ocean currents, USF bulletin warns . USF operates a Sargassum monitoring system.

The University of South Florida expects the trend of increasing sargassum seaweed in the ocean to slow this month, but with the possibility of picking up after that.

A year ago, fed by sewage and fertilizers from Brazil and the surrounding area, the same algae kept coming all summer long. The FAU published a study at the time that suggested an increased availability of nitrogen from both natural and artificial sources, including sewage, fueling excessive Sargassum growth.

This image shows Sargassum abundance (warm color indicates higher abundance, dark blue means none) for the past week, for the week ending July 5, 2022.

According to the study, our waste can turn critical nursery habitat into toxic algal dead zones, “with catastrophic impacts on coastal ecosystems, economies and human health.”

FAU researchers used a unique historical baseline algal tissue from the 1980s to compare its chemical composition to samples collected since 2010. They found dramatic changes in the chemistry and composition of sargassum grass since the 1980s, “turning this vibrant living organism into a toxic ‘death zone,'” the FAU announcement said.

Their findings were published last year in Communication Nature.

Dust storms over the Atlantic Ocean and Caribbean Sea — like this one in June 2022 — can fuel the growth of sargassum algae that accumulates on Florida beaches.

Sargassum washed:Washed up Sargassum seaweed sometimes wreaks havoc and stinks; expect it for the next few weeks

Drawn from the waves:Several were pulled out of the waves after a boat capsized near Melbourne Beach

Last month, high winds blew a thick layer of dust from the Sahara Desert westward over the Atlantic Ocean. According to the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA’s Aqua satellite, which acquired a true-color image.

Biologists say the vegetation washing up on the Space Coast and shorelines across the state this month is generally good for the beach. It provides food for birds, crabs and other wildlife and a habitat to hide in. So raking things on the beach can be controversial, often pitting tourism against conservation interests.

But when the weed feeds too much on sewage, it can become toxic to some wildlife, FAU, and other research emissions.

Sargassum is a constant presence in the Atlantic. It usually drifts in long lines near the Gulf Stream and provides vital food for young sea turtles. In excess, however, things annoy tourists and those whose livelihoods depend on them, by sullying the beauty and air of the beaches.

Sargassum contains arsenic, which it absorbs from what is naturally found in ocean water. But arsenic levels have increased in algae as humans have added more nitrogen to the environment, according to the FAU researchers. As humans have added more nitrogen from fertilizers, sewage, deforestation, and other sources to coastal waters, algae and other aquatic plants seek out more phosphates to balance their nutrients. In doing so, plants absorb more arsenic because it is a molecular form similar to phosphate.

Sargassum, like other seaweed, releases hydrogen sulfide when it rots, which can cause eye and respiratory system irritation.

The recent stringy mess on Brevard County beaches reminds many on the beach side of the widespread Sargassum algae blooms that hit county beaches in 2014, 2015, 2018 and last year. Huge sargassum also bloomed on beaches along the east coast of Barbados and Puerto Rico in 2014. But 2018 was among the worst in Florida, Lapointe said, adding that this year could rival this year’s bloom. that year.

Jim Waymer is an environmental reporter at FLORIDA TODAY. Contact Waymer at 321-261-5903 or [email protected] Or find him on Twitter: @JWayEnviro or on Facebook: www.facebook.com/jim.waymer

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