TAMPA, Fla. (WFLA) — Aerial photos revealed massive plumes of red tide stretching along much of southwest Florida’s coast days after Tropical Storm Nicole passed over the state.

Photos released by Calusa Waterkeeper showed a deep reddish-brown discoloration of the water near Naples and Sanibel due to the presence of red tide “and other phytoplankton species,” the non-profit organization said in a Facebook post.

According to the Florida Fish and Wildlife Conservation Commission, beaches from Sarasota to Port Charlotte vary between low, medium, and high levels of red tide.

The harmful algal blooms are commonly known to cause mild and short-lived respiratory symptoms in humans such as eye, nose, and throat irritation like those associated with the common cold or seasonal sinus allergies, the Florida Department of Health said.

Blooms are also known to last for months, depending on wind conditions.

Last, week WFLA Meteorologist Amanda Holly predicted onshore winds would bring respiratory irritation and red tide smells inland.

“It really helps to bring a red tide smell,” Holly said. “It can cause irritation if you’re affected by it.”

Scientists have been trying to determine if recent activity in the tropics has led to an increase in red tide advisories. Runoff, from heavy rains, for example, is one of the major factors that can exacerbate a bloom.

As rainfall runoff moves into the Gulf of Mexico, it brings with it nutrient-rich water necessary for algal growth.

Health officials recommend people who are sensitive to red tide or are experiencing symptoms avoid the beach or go into an air-conditioned space.