The Prevalence of Algal Blooms/Economic Impact

 The Prevalence of Algal Blooms Nationally 

    The Centers for Disease Control (CDC) launched One Health Harmful Algal Bloom System (OHHABS) in 2016 to conduct surveillance of Harmful Algal Bloom (HAB) events and to inform/prevent human and animal illnesses associated with them. 18 states reported 421 HAB events, 389 cases of human illness, and 413 cases of animal illness for the duration of 2016-2018. The reporting of data to OHHABS is voluntary, thus not all states are currently reporting and gaps in total number of cases/events exist due to a lack of formal data reporting by most states (Roberts et al., 2020).  

(WHOI Report, 2021)

    It is important to note that different algal species contribute to different HAB events around the United States; furthermore, they produce disparate toxins, and the resulting illnesses are just as distinct. Human and animal exposure can also take place in a variety of ways: aerosolized toxins, consumption of shellfish, swimming in actively blooming waters. These details are listed and organized in the picture above. These disparities lead to erratic or non-existent reporting mechanisms and a resulting lack of available data on HAB effects. For these reasons stated above, a single annual estimate of the effects of HABs for the nation has been challenging. Efforts are underway to refine methods and make progress towards a precise estimate of the social and economic impacts of HABs at the US National Office for Harmful Algal Blooms at the Woods Hole Oceanographic Institution (WHOI). WHOI and other agencies held a workshop in 2020 and released a report to advance an assessment framework and a national research agenda that will lead to comprehensive evaluations of the socio-economic effects of harmful algal blooms (HABs) in fresh water/marine waters of the United States (WHOI Report, 2021). 

The Prevalence of Algal Blooms in the Gulf of Mexico 

    States in the Gulf of Mexico region are currently not reporting to the OHHABS, thus illnesses/relevant data associated with algal blooms are not available. Algal blooms of Karenia brevis (marine algae, commonly known as red tide) are a recurring event annually in the coastal regions of Florida and Texas (Diaz et al., 2019). Karenia brevis releases potent toxins known as brevetoxins during a red tide and cause morbidity in humans and sometimes mortality in marine mammals, seabirds, and other marine organisms. Inhalation of aerosolized brevetoxins during the events is linked to respiratory illnesses like asthma, bronchitis and chronic obstructive pulmonary disease. In addition, the consumption of shellfish contaminated with brevetoxins can lead to neurotoxic shellfish poisoning (Diaz et al., 2019). The long-term effects of these toxins for neurologic health have not been studied yet, but higher number of emergency department visits were associated with active red tide events, where patients presented with respiratory and digestive illnesses (Hoagland et al., 2014). For neurologic illnesses such as headache, a study by Diaz et al. did not uncover an increased risk of neurologic illnesses during red tide, even though prior research suggests that this risk may exist. This may also be because while older residents (>55) sought medical care, younger people did not seek medical help for headaches. Further research should be focused specifically on brevtoxin exposure related illnesses (Diaz et al., 2019).

The Economic Impact of HABs

(WHOI Report, 2021)

    The infographic above is taken from the WHOI report, it represents the economic impacts for historical examples of HABs beginning in the 1970s. The circles in the infographic represent estimates of economic scales, thus the size of the circles equals the size of the economic impact. While this infographic presents the collective economic impacts associated with HABs, the different costs can include the expense of medical treatment, environmental monitoring and forecasting, treatment of drinking water. The indirect impacts of HABs result in lowering the water-front property values, lost recreational/tourism opportunities (WHOI Report, 2021).

    Emergency department visits for respiratory illness related to Karenia brevis blooms in Florida’s Sarasota County alone ranged from $0.5 to $4 million, these costs are a conservative estimate of the total respiratory illness expense of HABs for the Florida Gulf Coast. It is important to understand that this is only a small portion of the total economic impact of a HAB event, the full scale of the economic losses can be enormous (Hoagland et al., 2009). According to the Global seafood website, HABs cause economic losses of up to $100 million on average to the aquaculture industry (Advocate et al., 2021). HAB events result in fishery closures and lead to losses, the more frequent and severe HABs driven by climate change will cause higher losses. According to a hedonic evaluation study that estimated the values of property near the coast in Southwest Florida, properties sold during months affected by HABs sold for 5%-7% less than the similar properties sold during periods of no blooms. The study focused on property prices over a sixteen-year period with four major blooms; overall, the property prices on the coast declined about 10% during a bloom (Bechard, 2020). 

    The full extent of the HAB impacts is not known and future research efforts are being made by the government. This is an ongoing issue and results/data vary from year to year based on average temperatures and other factors. The National Oceanic and Atmospheric Administration (NOAA) has announced $15.2 million in funding for future research on HABs (Advocate et al., 2021). This research will help with detection and monitoring as well as better understanding the affects of HABs nationwide.

References

Advocate, R. S., Author , Responsible Seafood Advocate , & [103. (2021, November). NOAA invests millions to take on harmful algal blooms - responsible seafood advocate. Global Seafood Alliance. Retrieved July 30, 2022, from https://www.globalseafood.org/advocate/noaa-invests-millions-to-take-on-harmful-algal-blooms/#:~:text=In%20May%202021%2C%20Chilean%20salmon%20farmer%20Salmones%20Camanchaca,HABs%2C%20with%20blooms%20reported%20in%20nearly%20every%20state.

Bechard, A. (2020). External costs of harmful algal blooms using hedonic valuation: The impact of Karenia brevis on Southwest Florida. Environmental and Sustainability Indicators, 5, 100019. https://doi.org/10.1016/j.indic.2020.100019

Centers for Disease Control and Prevention. (2021, September 30). One Health Harmful Algal Bloom System (OHHABS). Centers for Disease Control and Prevention. Retrieved July 30, 2022, from https://www.cdc.gov/habs/ohhabs.html

Diaz, R. E., Friedman, M. A., Jin, D., Beet, A., Kirkpatrick, B., Reich, A., Kirkpatrick, G., Ullmann, S. G., Fleming, L. E., & Hoagland, P. (2019). Neurological illnesses associated with Florida red tide (Karenia brevis) blooms. Harmful Algae, 82, 73–81. https://doi.org/10.1016/j.hal.2018.07.002

Happening Now: Dead Zone in the Gulf 2021. (2021, October 18). [Video]. YouTube. https://www.youtube.com/watch?v=mo_rG7KCc4A

Hoagland, P., Jin, D., Beet, A., Kirkpatrick, B., Reich, A., Ullmann, S., Fleming, L. E., & Kirkpatrick, G. (2014). The human health effects of Florida Red Tide (FRT) blooms: An expanded analysis. Environment International, 68, 144–153. https://doi.org/10.1016/j.envint.2014.03.016

Hoagland, P., Jin, D., Polansky, L. Y., Kirkpatrick, B., Kirkpatrick, G., Fleming, L. E., Reich, A., Watkins, S. M., Ullmann, S. G., & Backer, L. C. (2009). The costs of respiratory illnesses arising from Florida Gulf Coastkarenia brevisblooms. Environmental Health Perspectives, 117(8), 1239–1243. https://doi.org/10.1289/ehp.0900645

Roberts, V. A., Vigar, M., Backer, L., Veytsel, G. E., Hilborn, E. D., Hamelin, E. I., Vanden Esschert, K. L., Lively, J. Y., Cope, J. R., Hlavsa, M. C., & Yoder, J. S. (2020). Surveillance for harmful algal bloom events and associated human and animal illnesses — one health harmful algal bloom system, United States, 2016–2018. MMWR. Morbidity and Mortality Weekly Report, 69(50), 1889–1894. https://doi.org/10.15585/mmwr.mm6950a2

Woods Hole Oceanographic Institution, & U.S. National Office for Harmful Algal Blooms. (2021). (rep.). Proceedings of the Workshop on the Socio-economic Effects of Harmful Algal Blooms in the United States. 

   (Happening Now: Dead Zone in the Gulf 2021, 2021)

Discussion Question

Based on the temperatures and drought conditions this summer, what do you expect in terms of algal bloom activity this year?