Public Health Response
The climate impacts that lead to HABs are complex, making it difficult to directly address the problem at the source through climate mitigation techniques (Hinder et al., 2012). However, there are multiple climate adaptation methods that, when applied comprehensively, can lessen the human health impact of HABs related to respiratory illness. The first line of defense is the monitoring of
K. brevis
blooms to predict the human health impacts and management efforts. Florida is already undergoing a program where coordinated volunteer efforts manage an HAB monitoring program where they take direct microscopic counts of algal through water samples and report weekly numbers (Heil & Steidinger, 2009). While this effort has produced results, there is a need for more complex, real-time, remote monitoring. This type of monitoring can be done efficiently with satellite radiometer sensing. There have been promising results with a satellite Hybrid Scheme, measuring chlorophyll concentration through both water-leaving radiance and particulate backscatter.
Figure 7
demonstrates the strong positive relationship between chlorophyll concentration and cell concentration of
K. brevis
. The Hybrid Scheme accuracy was compared against
in-situ
measurements of
K. brevis
cell counts, proving its effectiveness in environmental monitoring of
K. brevis
(Carvalho, Minnett, Fleming, Banzon, & Baringer, 2010)
.
Figure 7. Relationship of chlorophyll-a (1 μg l−1) to cell concentration of
K. brevis
(100 cells ml−1) monitored off the coast of southwest Florida delineated by dotted line, to measure the extent of offshore harmful algal blooms (Stumpf et al., 2003).
Beyond the environmental modeling, it is also important to be able to classify algal blooms as harmful. There are technologies, including the Coastal Zone Color Scanner, which can use an algorithm to automatically classify deep and shallow water red tide clusters (Zhang, Hall, Goldgof, & Müller-Karger, 2000). The combination of these monitoring systems will assist professionals in implementing timely public health responses. It is also important to address the adaptation methods of reducing the occurrence of HAB events. One ongoing program, taking place in Florida that targets the growth of HABs is the Gulf Coast Oyster Recycling and Renewal (GOORR) Program. The GOORR Program promotes better water quality by using discarded oyster shells from restaurants as the foundation for new oyster reefs to reduce the nitrogen and phosphorus in the water, resulting in less eutrophication and growth of the algal that causes red tides (Hendricks, 2018; Kellogg et al., 2014).
Lastly, surveillance resources and education programs are needed to encourage people to participate in behavior that will protect them from being exposed to the aerosolized toxins. Florida has already implemented an Aquatic Toxins Hotline, where people can speak directly with trained Poison Information Specialists if they feel ill after being exposed to a red tide. An additional benefit to this hotline (which has received satisfactory ratings from its participants), other than access to information, is that all cases of HAB-related illnesses that go through this hotline are reported to the Florida Health Department, allowing for better surveillance of the human health impact (Timmons, Sweeney-Reeves, & Morton, 2018). Moreover, it is important for educational outreach programs to reach people before they become exposed to red algal blooms.
Figure 8
exemplifies signs posted along Florida beaches to inform the public of the respiratory symptoms of Red Tide exposure and provide resources for people to report their symptoms and result in better human health surveillance.
Figure 8. Example of signs posted at Florida beach in response to a Red Tide occurrence targeted towards education and human health impact surveillance (Florida Dept of Health, START, Mote Marine, University of Miami Oceans & Human Health Center, Florida Poison Information Center, and Ms Wendy Stephan MPH) (Fleming et al., 2011).
Additionally, a Louisiana study found that distributed educational brochures were effective in informing those who viewed them about the potential harm of HABs (Smith, Blanchard, & Bargu, 2014). Other measures could include distributing informational material online and specifically targeting messages to those with pre-existing conditions at health clinics. The combination of environmental monitoring, reducing HAB incidence, surveillance, and education programs will help with the climate adaptation of HABs and their effect on human health.
