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MERHAB 2020: Project Summaries

MERHAB 2020:  Implementing Karenia brevis Respiratory Risk Forecast System in the Gulf of Mexico

Investigators: Barbara Kirkpatrick, Richard Stumpf, Katherine Hubbard, Rance Hardison, Wayne Litaker, Tony Reisinger

Institutions: Gulf Coast Ocean Observing System, NOAA NCCOS, FL Fish and Wildlife Research Institute, Texas A&M University

Abstract/project summary

Harmful algal blooms (HABs) of toxic dinoflagellates, in particular Karenia brevis, pose significant health risks along the coasts of the Gulf of Mexico and the Florida East coast. Brevetoxins, unlike many other marine algal toxins, can become aerosolized, resulting in a significant risk to people with chronic respiratory illnesses such as asthma, and results in substantial irritation to other people. As a result, K. brevis blooms cause considerable increases in emergency room visits, and they lead to extensive economic impacts. People who have experienced the unpleasant symptoms (similar to a severe cold) avoid all beaches and nearby businesses.

These blooms are patchy in both space and time. One area might experience a bloom and a nearby area will not, and conditions can change over the course of a day at a single site. The blooms can accumulate at the water’s surface and their transport is impacted by wind conditions. Aerosols also vary with wind intensity. Rapid, timely, and spatially extensive detection and monitoring of these blooms is vital for public health and safety. The current standard for monitoring K. brevis blooms involve identification and enumeration by light microscopy, which takes skill and time. Respiratory impacts of brevetoxin are provided on broad (day to week) scales, without information or consideration of spatial patchiness or variations in winds on shorter time scales.

This project will resolve these gaps. For K. brevis, recent improvements in weather models allows forecasts to be supplied at resolutions of several kilometers and a few hours, capturing such phenomena as sea breezes. The efficacy of this approach via implementation of respiratory forecasts every 3 hours through the day at multiple beaches using daily conventional cell counts has been demonstrated. Also demonstrated is a low cost ($400) field system, the “HABscope”, that uses a combination of traditional tools, a microscope, with the newest technologies, tablet computers and feature recognition software, to count K. brevis cells in <5 minutes. The recognition of individual cells is based on shape and swimming behavior (the latter is a characteristic of dinoflagellates). Such a system can be deployed by volunteers with limited training, allowing timely cell counts at individual beaches, each day. The project will establish a system to routinely forecast respiratory risk with a volunteer/citizen scientist system that substantially enhances existing monitoring programs, primarily dependent on satellite data and weekly monitoring with conventional microscopy.

This project will establish the reliability of HABscope and determine the lower limit of detection. It will establish a network that incorporates state monitoring partners and citizen scientists to show that the HABscope-based forecast system can provide robust, timely and useful bloom locations and respiratory forecasts. It will also demonstrate the potential broader utility of the HABscope by examining its ability to detect and quantify blooms of Pyrodinium bahamense, a toxic dinoflagellate of particular concern in Florida estuaries. P. bahamense produces saxitoxin, which can produce saxitoxin pufferfish poisoning, a public risk through recreational fisheries, and paralytic shellfish poisoning (PSP), which causes closures of shellfish harvesting.