Managing Pyrodinium Outbreaks in the Indian River Lagoon

The Indian River Lagoon Estuarine System (IRLES) frequently experiences harmful algal blooms (HABs), with Pyrodinium bahamense (hereafter as ‘Pyrodinium’) as one of the major bloom-forming phytoplankton species. Pyrodinium produces saxitoxins (STX) in their growth phase. STX is a group of neurotoxins which cause paralytic fish poisoning (PSP) and shellfish poisoning- resulting in major economic losses for the Atlantic coast of Florida. HABs formed by Pyrodinium in the IRLES have been responsible for seafood contamination, including a 2002-2004 pufferfish poisoning event involving 28 human cases and fish STX concentrations nearly 300 times of the federal regulatory limit. Co-PI-Fire’s group has detected STX in several other commercially and ecologically important finfish and shellfish species in the IRLES, as well as in important marine sentinel species such as the bottlenose dolphin. Traditional methods to control HABs have proven to be either costly or ineffective. Thus, many important marine resources of IRLES (e.g., shellfish beds, aquaculture pens) are at risk of contamination during such STX-producing HABs. As a result, IRLES has been experiencing nearly 80% decline of profit from commercial harvested clams, oysters, crabs, and shrimps ($20.1 million in 1994 to $4.3 million). Not only on marine industries, HABs have shown serious impact on the recreation and visitor related sectors, resource management sector, and living resources sectors, which are the major fractions of IRLES’s income of $2.6 billion. Therefore, HABs were identified in the IRLES’s comprehensive conservation and management plan (CCMP) as one of thirty-two vital signs of IRL health. Each vital sign has been ranked based on 4 levels of estuary health concerns (critical, serious, stable, and undetermined). HABs were ranked as a “critical” estuary health issue: “Condition threatens immediate and long-term prognosis for Lagoon health. Indicators are unfavorable. Trend is negative. Immediate and aggressive intervention is urgently needed to stop and reverse trend”. In this FL Sea Grant project, we propose a systematic study to control IRLNEP’s HABs in an economically viable and environmentally sustainable manner. Therefore, our project aligns with the IRL CCMP – Looking Ahead to 2030. This project will also be aligned with two of the EPA goals for IRL namely, (a) Goal 2: To attain and maintain a functioning, healthy ecosystem which supports endangered and threatened species, fisheries, commerce and recreation; Goal 3: To achieve heightened public awareness and coordinated interagency management of the IRL ecosystem.