Florida's southwest coast has been ravaged by two unprecedented algae outbreaks that are killing wildlife, making people sick and crushing the crucial tourism industry.

Why it matters: The worst algae blooms in Florida's modern history have spurred political finger-pointing that could sway one of the country's most closely-watched Senate races this fall.

The big picture: The algae outbreaks are the largest and longest-lasting in years. Weather patterns coupled with pressures on land use are stoking long-held tensions over natural resources between two of the state's biggest industries — agriculture and tourism. And it's happening at a time when Florida is also seeing massive population growth.

What's happening: The crisis is caused by two separate but equally toxic algae blooms. One is a salt-water red tide in the Gulf of Mexico, while the other is fresh-water blue-green algae stemming from the inland waters of Lake Okeechobee. The inland algae is festering in the vast canals and winding inland waterways of Southwest Florida.

Red tide is caused by a flare of microorganisms, often in summer, that turns the water rust-colored. The inland event features guacamole-like, blue-green algae that started in giant Lake Okeechobee and spread to surrounding rivers and canals on the way to the coast.

by a flare of microorganisms, often in summer, that turns the water rust-colored. The inland event features guacamole-like, blue-green algae that started in giant Lake Okeechobee and spread to surrounding rivers and canals on the way to the coast. Each bloom , on its own, has turned water toxic and devastated marine life. Dozens of turtles, fish, dolphins, eels, manatees and even a whale shark have washed up dead on area beaches.

, on its own, has turned water toxic and devastated marine life. Dozens of turtles, fish, dolphins, eels, manatees and even a whale shark have washed up dead on area beaches. Scientists don't know why the blooms are so severe this year. They suspect it's a combination of record rainfall, high levels of nitrogen caused by agricultural run-off, warmer waters, and other human activity.

the blooms are so severe this year. They suspect it's a combination of record rainfall, high levels of nitrogen caused by agricultural run-off, warmer waters, and other human activity. Gov. Rick Scott has declared two emergencies to deal with the blooms, the first one related to Lake Okeechobee and the latest on Monday to help seven coastal counties with the cleanup effort.

Residents have held town halls and organized rallies to put pressure on elected officials to do more. As a result, candidates are making environmental issues a central part of their campaigns leading up to the August 28 Florida primaries.

In the Senate race, Scott, a Republican, is finishing his last term as governor and looking to take the Senate seat of Sen. Bill Nelson, a Democrat.

Scott faults Nelson for not doing more to solve the problem, since Lake Okeechobee's water levels are managed by the Army Corps of Engineers, a federal entity.

Nelson blames Scott, who's been attacked by environmentalists for cutting water quality monitors and water management programs, and repealing a law requiring septic tank inspections. Nelson is considered to be one of the most endangered Democratic incumbents in 2018.

In the governor's race, candidates are making environmental issues a central part of their campaigns.

All five Democratic candidates blame the sugar industry as a key source of waterway pollution.

blame the sugar industry as a key source of waterway pollution. Republican congressman and gubernatorial candidate Ron DeSantis has used his lack of ties to Big Sugar to distance himself from opponent Adam Putnam, currently the state's agriculture commissioner, who has received campaign contributions from sugar farmers.

What to watch: In states like Florida that are experiencing more extreme weather events, voters may coalesce around climate and environmental issues heading into the next election cycles.

"People in these places understand that things are changing rapidly right in front of their eyes, and it's raised awareness to a level it's never been before," Denis Dison of the Natural Resource Defense Council's Action Fund told the New Republic.

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