Ramping up the fight against Florida’s red tides

Abstract

The words "red tide" routinely generate red alerts among Florida's fishermen, coastal property owners, tourism operators, and health officials. This past summer and fall were no exception. These toxic algal blooms-which often tinge the water red but sometimes turn it brown, orange, or even slightly greenishclose beaches, kill innumerable fish, and taint filterfeeding shellfish such as oysters, rendering them inedible. The neurotoxins generated by the phytoplankton that create red tides also affect birds, marine mammals, and sea turtles and can harm human health. Breaking surf lofts toxin-filled droplets of sea spray that can irritate lungs and severely aggravate lung conditions, such as emphysema or asthma. Adding to their devastation, red tides can seem random. Some years, as in 2017 and 2018, they persist for months; in others, they may hardly make a showing or bloom and then fade only to return with a vengeance. Scientists now have a decent sense of when and where red tides will appear, but new data-gathering efforts could help monitor the blooms as they develop, providing more accurate red tide forecasts for coastal areas. And researchers are starting to devise and test ways to mitigate or control Florida's red tides to improve the quality of life in the state's coastal communities. But the age-old phenomenon of red tides continues to present scientists and policymakers with complex research and management challenges. Born At Sea Although the most distressing effects of red tides manifest themselves in coastal waters, these harmful algal blooms are often born far out at sea. And like Toxic algal blooms known as red tide, which often tinge the water red but sometimes turn it brown, orange, or even slightly greenish, close beaches, kill fish, and taint shellfish. The bloom pictured took place in September of 2016 in the Gulf of Mexico in the coastal waters of southwestern Florida. Image credit: Mote Marine Laboratory & Aquarium.

Microbial and chemical dynamics of a toxic dinoflagellate bloom

“…S1). While this bloom would ultimately turn into a severe, widespread, and long-lasting ecological phenomenon (Perkins, 2019), the early stages featured coastal areas differentially impacted by K. brevis. We sampled from sites of varying bloom levels in and around Sarasota Bay and Tampa Bay to assess microbiome and metabolome composition across a gradient of K. brevis cell concentration.…”

Prescreening-Based Subset Selection for Improving Predictions of Earth System Models With Application to Regional Prediction of Red Tide

“…The mechanisms of initiation, growth, maintenance, and termination of red tides have not been fully understood. Yet Loop Current, which is a warm ocean current that moves into the Gulf of Mexico, is an important factor that controls the occurrence of red tide ( Weisberg et al, 2014 ; Maze et al, 2015 ; Perkins, 2019 ). Maze et al (2015) shows that the difference between time intervals of large blooms and no blooms is statistically significant for the Loop Current’s position.…”

“…Along the West Florida Shelf in the Gulf of Mexico, red tide occurs by the increase of the concentration of Karenia brevis , a toxic mixotrophic dinoflagellate. This study focuses on Loop Current (LC), which is one of the main drivers of red tide in the West Florida Shelf ( Weisberg et al, 2014 ; Maze et al, 2015 ; Perkins, 2019 ). LC is a warm ocean current that penetrates and loops through the Gulf of Mexico until exiting the gulf to join the Gulf Stream.…”

Evaluating red tide effects on the West Florida Shelf using a spatiotemporal ecosystem modeling framework

“…Nutrient enrichment from human activities has also been identified as a potential driver of red tide blooms, especially in areas with high agricultural production 16 , 17 . Red tides have attracted major attention of policymakers, the scientific community, and society due to the complexity of the process and negative effects on the environment, human health, and coastal economies 18 , 19 .…”