Miami Herald (Sunday)

RED TIDE IN WINTER?

- BY RYAN BALLOGG rballogg@bradenton.com

A red tide has persisted in Southwest Florida and Tampa Bay area waters since October 2022.

If you’re wondering why there are dead fish in the water or irritation in your throat when you visit the beach, look no further than Karenia brevis, the microscopi­c alga responsibl­e for red tide. It produces toxins that can cause trouble for marine life and people.

The 2022-23 red tide has so far been mild compared to extremely potent bouts that have hit Florida’s Gulf coast over the past decade, including severe blooms between 2017-19 and in 2021.

But even at lower levels, red tide can cause a nuisance. When

Imagine a world where global warming on Earth has meaningful­ly diminished. Fossil fuels are on the back burner. Affordable renewable energy sources run most of our activities. Oh, and there’s a cannon on the moon shooting lunar dust into space to help partially shield sunlight hitting will it go away?

Here’s what science tells us about how red tides start, how long they last and what causes them to end.

WHAT IS RED TIDE?

Toxic blooms: Red tides are a naturally occurring phenomena in the Gulf of Mexico.

“Red tides, also called harmful algal blooms (HABs), occur when microscopi­c algae multiply to higher-than-normal concentrat­ions, often discolorin­g the water,” the Florida Fish and Wildlife Conservati­on Commission (FWC)’s Fish and Wildlife

Research Institute says.

Anecdotal records of red tide date back to the writings of Spanish explorers in the 16th century, and it was first officially documented in Florida in 1844.

Other parts of the world have red tides caused by different algae species.

The trouble with K. brevis is the powerful neurotoxin­s that it produces. They can kill fish, seabirds and other marine life, including large mammals like manatees and dolphins, at high concentrat­ions. The toxins are a respirator­y irritant for people and can pose a danger to those with pre-existing conditions like asthma.

Seafood sickness: Red tide can also poison shellfish and cause people who eat it to get sick. Recent research points to further complicati­ons for human health from breathing the algae.

Growing evidence suggests that human pollution can make red tides more intense and long-lasting.

WHY IS THERE RED TIDE IN WINTER?

Arriving by winds and currents: There is a bloom of red tide in the Gulf of Mexico almost every year, according to Cynthia Heil, director of Mote Marine Laboratory’s Red Tide Institute in Sarasota.

The blooms begin far offshore before they are transporte­d to the coast by winds and currents. Many factors influence the duration and strength of a red tide bloom, including water temperatur­e, salinity, nutrient availabili­ty and the position of the Loop Current in the Gulf of Mexico.

The blooms typically start in the late summer or fall, and it’s not unusual for them to last into the winter or early spring.

HOW LONG DOES RED TIDE LAST?

Time span: Southwest Florida’s red tides can last anywhere

 ?? TIFFANY TOMPKINS ttompkins@bradenton.com ?? Red tide in Florida waters near Anna Maria Island beaches.
TIFFANY TOMPKINS ttompkins@bradenton.com Red tide in Florida waters near Anna Maria Island beaches.
 ?? NASA NYT ?? A photo provided by NASA shows Earth as seen from the Apollo 11 lunar mission in July 1969.
NASA NYT A photo provided by NASA shows Earth as seen from the Apollo 11 lunar mission in July 1969.

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