Red Tide is further offshore. Thank the wind and sea currents.

MADEIRA BEACH — Late last week, Mayor John Hendricks felt encouraged but still nervous for his small beachfront city. Conditions on the shore had improved. There weren’t so many dead fish everywhere.

But Red Tide, the toxic algae bloom that has darkened Tampa Bay’s summer, still lurked a few miles offshore.

“(I’m) nervous,” Hendricks said. “It’s offshore now, but anything can change it. A tropical storm, westerly winds, which we’ve had lately. But luckily, they seem to be keeping it offshore.”

Red Tide can be fickle. This bloom is patchy, scientists have said, and in recent days its grip on the region has lessened. County water testing on Monday showed “low” or “very low” concentrations of the organism in Red Tide in several areas — including Treasure Island, Madeira Beach and Clearwater Beach — and a medium concentration by Honeymoon Island. Meanwhile, the Florida Fish and Wildlife Conservation Commission reported samples taken further off the coast earlier this month showed evidence of a bloom.

What can beachgoers thank? Several factors are at play, experts said.

Madeira Beach is positioned just south of an inflection point on the Pinellas County coast, which helps determine the water’s circulation, said Kate Hubbard, a research scientist with the Florida Fish and Wildlife Conservation Commission. Northbound currents transported Red Tide concentrations from Madeira Beach to Indian Rocks Beach, then to near Clearwater. The weekend brought easterly winds, which pushed the Red Tide-affected water further off the coast.

Blooms are patchy and notoriously difficult to track. Their locations can shift between beaches day by day. Recent data from the Florida Fish and Wildlife Conservation Commission show several medium concentrations that line up with Madeira Beach and Treasure Island. But beachgoers may not notice Red Tide’s effects, like fish kills and breathing irritation, if it stays four to 12 miles off the beach or if winds do not blow onshore.

“There’s so many factors that affect where they are in the water close or not close to shore, or up near the surface or down below,” said Frank Muller-Karger, a professor of biological oceanography and remote sensing at the University of South Florida. “It can change because of a large wind event or a storm or things are just standing still.”

The part of the bloom that sat near Clearwater last week has drifted over a wider area and is not as intense as it was previously, said Hubbard. “It’s moved around,” she said, and is now miles offshore but “still out there.”

The Red Tide outbreak peaked in Tampa Bay in early July and has more recently lingered on the Pinellas gulf coast. County crews had picked up 1,823 tons of dead sea life and debris as of earlier this week, said Pinellas spokesperson Tony Fabrizio.

Pinellas is already set to receive $902,500 from the Florida Department of Environmental Protection as a reimbursement for Red Tide-related expenditures. It is organizing an agreement with the City of St. Petersburg to share funds. The county is working on a supplementary request for all expenditures to date — currently $2.1 million, public works director Kelli Hammer Levy told county commissioners during a meeting Tuesday.

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“And then the question is ‘When will Red Tide end?’ ” Levy said. “And I can’t give you an answer to that because we don’t know. It’s still out there, it can come back.”

The state Conservation Commission posts water sampling updates to a map that is refreshed whenever test results come back. At a board meeting last week, Gil McRae, director of the state’s Fish and Wildlife Research Institute, said that the map is timely enough for “broad-scale patterns” but not always individual beach or canal conditions.

A forecasting tool from the Gulf of Mexico Coastal Ocean Observing System aims to factor in wind and tide conditions to get quicker forecasts for individual beaches. It builds upon water sampling results to predict what beach conditions will look like every three hours.

“Red Tide impacts can be really variable because of wind patterns,” said Barbara Kirkpatrick, executive director of the observing system in a Monday announcement for the full launch of the forecasting tool. “There are very few days when all beaches will be affected by Red Tide, and often your favorite beach is only affected for part of the day.”

• • •

Red Tide coverage

Tampa Bay has Red Tide questions. Here are some answers.

Is it safe to eat seafood? Here’s how Red Tide affects what you eat.

Can I go fishing? The state is limiting saltwater fishing.

Piney Point: The environmental disaster may be fueling Red Tide.

Red Tide resources

• The Florida Fish and Wildlife Conservation Commission has a website that tracks where Red Tide is detected.

• Florida Poison Control Centers have a toll-free 24/7 hotline to report illnesses, including from exposure to Red Tide: 1-800-222-1222

• To report dead fish for clean-up in Tampa Bay, call the Florida Fish and Wildlife Conservation Commission at 1-800-636-0511 or file a fish kill report online.

• In St. Petersburg, call the Mayor’s Action Center at 727-893-7111 or use St. Petersburg’s seeclickfix website.

• Visit St. Pete/Clearwater, the county’s tourism wing, runs an online beach dashboard at www.beachesupdate.com.

How to stay safe near the water

• Do not swim around dead fish.

• Those with chronic respiratory problems should be careful and stay away from places with a Red Tide bloom. Leave if you think Red Tide is affecting you.

• Do not harvest or eat mollusks or distressed and dead fish from the area. Fillets of healthy fish should be rised with clean water, and the guts thrown out.

• Pet owners should keep their animals away from the water and from dead fish.

• Residents living near the beach should close their windows and run air conditioners with proper filters.

• Beachgoers can protect themselves by wearing masks.

Source: Florida Department of Health in Pinellas County