Red Tide 2018

What is red tide?

Red tide is a toxic algae that has seasonal blooms which can cause harm to surrounding areas. Specifically, Florida red tide is caused by Karenia brevis, which is just one of the many types of algae that can cause red tide. While Karenia brevis naturally exists in the Gulf of Mexico, its great blooms can expand out and affect areas beyond the Gulf. These blooms, which have been documented since as far back as the 16th century by Spanish explorers, release toxins that can cause paralysis when ingested in high concentrations. The accumulation of algae on the ocean surface can cause the water to appear red, brown, or green.

Dr. Chuanmin Hu and Dr. Bob Weisburg, both professors at the University of South Florida, St. Petersburg, have been researching Florida red tides. They discuss what red tides are, what causes them, and the environmental effects of red tide here in Florida.

Rick Falkenstein, St.Pete Beach Commissioner and Co-Owner of Pass-A-Grille's local Hurricane restaurant, discusses the history of red tide and the influence it has on the local economy.

How does red tide impact our ecosystem?

At its natural levels, Karenia brevis doesn't have a major effect on the surrounding environment. However, when it blooms and achieves "Red tide" status, there is great danger to marine ecosystems. Since Florida red tide produces neurotoxins, animals that ingest the red tide algae are harmed. Frequently, fish are killed and wash up on beaches. In addition, the toxin can accumulate in animals lower down the food chain, killing the predators that feed on them. This has lead to the death of seabirds, sharks, and dolphins. Endangered animals, including multiple species of Florida sea turtles, are also at risk due to red tide.

How does red tide impact people on the beaches?

While red tide can kill smaller organisms and sea life that ingest high volumes of fish infected by its neurotoxins, it isn't fatal for humans. The most severe human cases are in those that have eaten shellfish containing high concentrations of the neurotoxin, leading to a condition known as Neurotoxic Shellfish Poisoning (NSP). NSP can result in nausea and vomiting in minor cases, and can lead to partial paralysis and respiratory distress in more severe cases. It is important to note that there are no recorded cases of death from NSP or any other effect from Florida red tide. In addition, strict laws regulate the harvesting of shellfish, and shellfish beds can not be harvested during times of red tide. Thanks to these precautions, NSP is relatively rare.

Red tide can also cause minor effects even for those who do not consume shellfish. The brevetoxins that Florida red tide produces can become airborne, causing allergy-like symptoms like lung irritation, eye irritation, and coughing; but, like in NSP, the concentrations are too low to pose any serious risk for most healthy individuals. However, those with asthma, COPD (Compromised Obstructive Pulmonary Disease) or prior lung conditions should take special caution if going to the beaches during periods of red tide.

Dr. Echardt, a pulmonologist at Morton Plant Hospital whose primary outpatient population consists of about 50% patients with COPD or asthma, does not notice any exacerbation of asthmatic symptoms beyond what patients usually have when they come in contact with a respiratory irritant. In general, red tide Brevetoxin, while irritating, does not require hospitalization with prolonged exposure. Dr. Echardt explained that the Brevetoxin activates a histamine response in the body that correlates to bronchial constriction, which can cause shortness of breath, wheezing, and coughing. However, these symptoms are easily avoided by the use of an inhaled corticosteroid (ie. Albuterol), and most asthmatics and COPD patients are already on a regimented corticosteroid to aid proper breathing. Thus, there is very little threat to the general health and safety of individuals who visit or live by the coast during a red tide.

Regardless, it is generally not advised to swim in waters affected by red tide. In higher concentrations, the toxin can cause skin irritation, and accidental ingestion of the water can lead to health problems.

How does red tide Impact business?

The effects of red tide, such as large fish kills that wash up on shore, and noxious airborne toxins that can cause irritating symptoms, heavily discourage both locals and tourists from visiting the nearby beaches. As a result, local businesses often see a reduction in clientele during a red tide. Waterfront restaurants, whose draw is tasty seafood and beach-side seating, take an especially hard hit. Because tourism is one of Florida's leading industries, and an important source of revenue for Pinellas County's gulf coast towns, prolonged red tides can have wide-ranging economic impacts.

As of October 2018, Pinellas County businesses had reported over $1.5 million in lost revenue due to red tide.

We spoke with Rick Falkenstein, who provided greater detail on how red tide affects business and tourism in Pass-A-Grille, Florida. See our interview with him below.

How Is red tide affected by human activity?

Red tide is a natural phenomenon that occurred before Europeans settled in North America. The extent to which human activity influences red tide is still hotly debated among both the public and the scientific community.

During red tides, nitrogen and phosphorous are major contributors to the longevity of the bloom. Both are found abundantly in fertilizer and sewage runoff. During heavy rains, excess fertilizer not consumed by terrestrial plants can seep into lakes, streams, and eventually the Gulf. Inadequately treated sewage and leakage from septic tanks can also make their way into the ocean.

Many believe that this nutrient pollution causes greater and more prolonged algae growth than would otherwise be possible. In addition to fertilizer run-off, global warming may also take part of the blame. Karenia brevis grows better in warmer water, and the Gulf of Mexico's temperatures have been rising in recent decades. However, the exact magnitude of these effects is still unclear.

REd tide of 2018

Florida has seen a particularly brutal and prolonged red tide in 2018, with high concentrations of algae in the Gulf leading to large fish deaths. With the stench of rotting fish permeating the beaches and driving tourists away, it is estimated that this red tide has caused $150 million in lost revenue statewide. There has been a significant loss of marine life and many environmentalists worry about endangered species, such as manatees and sea turtles. In addition, politicians have attempted to politicize the environmental issue, with many placing the blame on Florida Governor Rick Scott. Scott has been criticized by some for his budget cuts to environmental agencies and refusal to allocate government funds to purchase land that was producing excess pollution.

Below, Dr. Hu discusses how red tide has changed over the years.

Oral History: Rick Falkenstein

In this interview, Rick Falkenstein, City of St. Pete Beach Commissioner and part-owner of the Hurricane Restaurant in Pass-A-Grille, provides more insight into the effects of red tide on local businesses. He also addresses the role that news media may play in public perceptions of red tide.

(Link to transcript of Mr. Falkenstein's interview)

Drs. Chauanmin Hu and Bob Weisberg

Professors Chuanmin Hu and Bob Weisberg from USF, St. Petersburg shared their expertise on red tide, including its causes, its history, and the effects it has here on Florida's gulf coast. See the full interviews with Dr. Hu and Dr. Weisberg here:

(Link to transcript of Dr. Hu's interview)

(Link to transcript of Dr. Weisberg's interview)

Dr. Echardt

Dr. Echardt, a pulmonologist at Morton Plant Hospital in Clearwater, knows a thing or two about respiratory conditions. We caught up with Dr. Echardt to learn about how red tide affects human health. Access the full interview below.

(Link to transcript of Dr. Echardt's interview)

(Link to audio of Dr. Echardt's interview)

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