Too much grass on the beach can be a bad thing, especially at surfing hotspots like Cocoa Beach, where Sargassum seaweed growls boards, snags surf fishing lines, and is a bane to all others who prefer weedless wading.
More is expected to drift our way in the coming weeks, scientists say.
Oceanographers are waiting Sargassum seaweed and other macroalgae are thickening on our beaches as more and more washes are carried out from record amounts already in the Caribbean Sea.
Combined, the total amount of weeds rose from 18.8 million tons in May 2022 to 24.2 million tons in June 2022, a new all-time high, according to scientists at the University of South Florida, alarmed by the new record.
USF’s most recent algae bulletin, July 31, predicts the continuation of “significant stranding events” from Sargassum in the Caribbean Sea.
While regional decreases in algal abundance have recently been observed in the tropical Atlantic, USF scientists say there have been no decreases in other waters closer to Florida.
“This indicates that significant stranding events are still ongoing around CS (Caribbean Sea) nations/islands,” the USF bulletin read. “Similarly, a moderate amount of Sargassum was found in the Florida Straits and along the east coast of Florida, indicating possible stranding events in Florida.”
For the future, total Sargassum tonnage will likely decline in coming months, however, based on historical seasonality, USF scientists say.
Beyond the usual Sargassumthat the Caribbean Sea delivers seasonally to the Gulf Stream and then to central Florida beaches, “filamentary” algae has also occasionally dominated the Brevard surf zone this summer, according to scientists at Florida Atlantic University.
Too much of a good thing?
Overall, the Sargassum and other seaweed it washes up in is a boon to the beach and wildlife.
Shorebirds feed on small animals that live in the Sargassum and other “kelp lines” of seaweed along the beach. Ghost crabs, beetles and other small animals feed on the fungus that grows in clumps of seaweed that line the beaches.
On the beach, clumps of seaweed collect windblown sand and plant seeds near the dunes, as well as nutrients for plant germination, promoting the formation of small dunes that help prevent erosion.
Offshore, Sargassum provides crucial early meals for hatchling sea turtles that swim to find things floating in the Gulf Stream.
Too much, however, can entangle hatchlings on their crucial first trip from the nest to the Gulf Stream, but they take the weed in stride this nesting season, says Brevard Beach Replenishment Coordinator Mike McGarry. Evolution has adapted them to such obstacles.
“Our latest monthly turtle monitoring reports (for June 2022) indicated no issues with hatching reaching the water as a result of Sargassum“Mcgarry wrote in an email, adding that nesting reports from July were pending.
Female turtles that crawl on the beach to nest do so successfully about half the time. “Nesting success is influenced by many factors, and often very dry weather results in reduced nesting success (more difficult to dig in dry sand),” McGarry wrote.
Stringy, smelly seaweed dominates the coastline from Cocoa Beach to Sebastian and beyond
Florida Atlantic University researchers have shown Sargassum here and in the tropical Atlantic has worsened in recent years due to increased nitrogen and phosphorus from discharges from the Congo, Amazon and Mississippi rivers, atmospheric Saharan dust falling on the water and vegetation burning in central and southern Africa.
USF plans more Sargassum updates by the end of this month.
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