Harmful Algal Bloom
Name
Institution’s Name
Harmful Algal Bloom
The earth is a uniquely balanced ecosystem. In its natural form, it oozes magnificence with an order that is impossible to comprehend fully. The order transcends across all scopes, influencing both the macro and micro aspects of existence. While the more extensive, physical point of it is easy to decipher in general, its building blocks contain some of the most splendid sceneries. A significant proportion of the earth is covered in water. These waters harbour a diverse array of organisms, big and small. For a balanced system to be maintained there needs to be perfect harmonies among all the components contained therein. This balance is not only essential in ensuring the survival of organisms which habituate the water. It is critical in guaranteeing a mutually beneficial relationship between both terrestrial and aquatic lives. A crucial component of marine life that has the potential to affect other aquatic organisms, as well as terrestrial organisms, is the alga. Algae are organisms composed of simple plants that habituate the aquatic environment. Algae have uncountable benefits. However, sometimes their populations exponentially increase to detrimental proportions. This has been termed “algal bloom.” A harmful algal bloom has catastrophic effects on both aquatic and terrestrial environments and therefore needs to be managed accordingly.
Causes of Harmful Algal Bloom
As already noted, algae are a critical component of the natural aquatic environment. Their growth and reproduction are, therefore, of natural occurrence. Similarly, an overgrowth of these plants is also a natural component of the ecosystem. However, human activities can play a critical role in exacerbating role in the process (Lee & Lee, 2018). The availability of nutrients like phosphorus impacts a limiting factor typically to the growth of the algae. Therefore, human activities that cause an additive effect on this nutrients’ availability play a crucial role in the causation algal blooms. Such events may range from farming practices, waste disposal from households as well as waste disposal from industries (Lee & Lee, 2018)
Farming practices are amongst the most significant causes of harmful algal bloom (Bullerjahn et al., 2016). Fertilizers contain anthropogenic substances that stimulate the growth of algae. With the spread of wide-scale farming in present times, the methods of fertilizer application have gradually shifted to favour broadcasting. Broadcasting is a time and cost-efficient manner of fertilizer application suitable for large scale farming. However, when the technique is used shortly before the onset of rains, it offers a potent pool of nutrients that are washed down to water bodies, thereby causing an algal bloom. Nonetheless, other methods of fertilizer application can cause contamination of water source, but chronically. Fertilizers applied deep into the soil is adsorbed and retained by the earth for the long term. The process by which these nutrients find themselves in water bodies is similar to that observed in broadcasting. However, the amount is significantly less but is available in a steady stream.
Environmental effects that may or may not be affected by human activities also play a role in the development of harmful algal bloom. For instance, cyanobacteria undergo optimal reproduction in warmer water temperatures. As a result, the warming up of water bodies either by seasons or global warming plays a vital role in the hyperproliferation of algae (Lee & Lee, 2018). Furthermore, the flow and circulation of water in water bodies affect the spread, hence the population boom of the algae. As such, if circulation is reduced, the time in which the algae remain in the top water layers is enhanced, and this supports their rapid proliferation (Lee & Lee, 2018). On the other hand, if the currents are adequate, algae are transported to varying locations, limiting their growth and accumulation in specific areas.
Implications of Harmful Algal Bloom
Impact on aquatic life
A harmful algal bloom is detrimental to other aquatic populations. The overgrowth of algae has been documented to cause fish-killing for decades now. The first case was reported in the 1930s in Denmark (Svendsen, Andersen, Hansen, & Steffensen, 2018). Ever since several studies have been done t determine the scale and mechanisms by which the algae cause aquatic death. A better understanding is in place. A recent study demonstrated how the algae Pyrmnesium parvum was involved in the killing of rainbow trout fish. The type of algae is particularly a problem in the State of Texas but has also been associated with wide-scale global fatalities. The study found that the algae released substances known as pyrmnesins which were responsible for the deaths. Pyrmnesins were found to irritate the gills and to increase their permeability secondary toxins as well.
Furthermore, unlike preceding researches, it was established that even exposure to small amounts of the toxin for a short time caused irreversible damage to the gills (Svendsen, Andersen, Hansen, & Steffensen, 2018) Furthermore, the death of increased numbers of algae was associated with increased oxygen consumption. This increase eventually caused depletion of oxygen at specific areas which have been referred to as dead zones (SCOR-IOC, 2015). These zones are completely inhabitable to all obligate aerobes. Also, the overgrowth of algae has been found to inhibit and shade the growth of other aquatic plants competitively.
Impact on humans
The hazards of the harmful algal boom can manifest in humans acutely and chronically. Humans get exposed to the toxins produced by the algae through directly drinking contaminated water, swimming in contaminated water or eating contaminated seafood. In other instances, inhalation of air contaminated by the algae has been observed to cause adverse effects (National Institute of Environmental Sciences, 2020). Furthermore, it has been noted that boiling of water or cooking of contaminated seafood does not destroy toxins obtained from the algae. The effects of the toxins on humans range from mild symptoms to serious and possibly fatal ones. For instance, toxins from the alga Alexandrium are responsible for paralytic shellfish poisoning. This poisoning has been associated with catastrophic paralysis, which has been recorded to cause death (National Institute of Environmental Sciences, 2020). On the other hand, domoic is a toxin produced by Pseudo nitzschra. Domoic has been associated with gastrointestinal symptoms like nausea, vomiting and diarrhoea. It also affects the central nervous system by causing convulsions and some loss of orientation. Furthermore, it causes cognitive impairment by permanently affecting short term memory loss, besides being associated with fatal outcomes at increased concentrations. Long term exposure to toxins from the algae has been associated with ALS-parkinsonism dementia complex. This was first observed in Guama between 1950 and 1960. Furthermore, algal blooms have been associated with the independent development of ALS in countries like Japan and France (Torbick et al., 2017)
Economic impact
A harmful algal bloom has severe financial ramifications on the economy. This is because the bloom impacts a natural material that has wide-scale use in day to day activities. For instance, water is a necessity used for drinking by all animals. It also has been used for recreational purposes. Besides, clean water is an essential aesthetic adjuvant in the environment. The bloom seriously alters the taste and odour of water, making it unfit for human and animal consumption (Dodds et al., 2009). Additionally, people are less likely to participate in recreational activities such as swimming, fishing boating and surfing in contaminated waters. Furthermore, the value attached to properties also tends to dip with decreasing water clarity. In general, the combination of all these factors was projected to cost the USA more than 2.2 billion dollars (Dodds et al., 2009). This is money that would be of enormous use if injected in the economy
Solution to Harmful Algal Bloom
As noted earlier, the harmful algal bloom is a natural phenomenon that can occur without human interference. However, certain human activities can cause a worsening of the situation. These can be modified. For instance, broadcast fertilization can be replaced with injection or banding methods (Bullerjahn et al., 2016). If the broadcast method must be used, it is prudent to avoid fertilizer application shortly before the commencement of rains. Also use of cover crops would be beneficial in preventing wash-off of fertilizers into water bodies (Bullerjahn et al., 2016). Other strategies that have been employed in other countries include artificial mixing of water bodies to imitate currents and the use of hydrogen peroxide to kill algae. However, these methods cannot be used on a wide scale. In larger water bodies, these methods can be employed in specific sections to preserve the integrity of drinking water. This is because they have been found to have minimal if any, side effects. (Bullerjahn et al., 2016)
Conclusion
An overgrowth of algae causes a harmful algal bloom. This overgrowth negatively impacts the aquatic environment by killing fish and disrupting the growth of other fauna. It also has both acute and chronic effects on human health, besides causing notable economic losses. Human activities that exacerbate such factors as proper farming practices can control the bloom, and artificial methods like mixing of water bodies and use of hydrogen peroxide to kill the algae.
References
Bullerjahn, G. S., McKay, R. M., Davis, T. W., Baker, D. B., Boyer, G. L., D’Anglada, L. V., … Wilhelm, S. W. (2016). Global solutions to regional problems: Collecting global expertise to address the problem of harmful cyanobacterial blooms. A Lake Erie case study. Harmful Algae, 54, 223–238. https://doi.org/10.1016/j.hal.2016.01.003
Dodds, W. K., Bouska, W. W., Eitzmann, J. L., Pilger, T. J., Pitts, K. L., Riley, A. J., … Thornbrugh, D. J. (2009). Eutrophication of U.S. Freshwaters: Analysis of Potential Economic Damages. Environmental Science & Technology, 43(1), 12–19. https://doi.org/10.1021/es801217q
Lee, S., & Lee, D. (2018). Improved Prediction of Harmful Algal Blooms in Four Major South Korea’s Rivers Using Deep Learning Models. International Journal of Environmental Research and Public Health, 15(7), 1322. https://doi.org/10.3390/ijerph15071322
National Institute of Environmental Sciences. (2020, March 2). Algal Blooms. Retrieved May 26, 2020, from https://www.niehs.nih.gov/health/topics/agents/algal-blooms/index.cfm
SCOR-IOC. (2015). Harmful AlgalBlooms. Retrieved from https://unesdoc.unesco.org/in/documentViewer.xhtml?v=2.1.196&id=p::usmarcdef_0000233419&file=/in/rest/annotationSVC/DownloadWatermarkedAttachment/attach_import_944add1d-2705-4c49-8428-9f257b742a42%3F_%3D233419eng.pdf&locale=en&multi=true&ark=/ark:/48223/pf0000233419/PDF/233419eng.pdf#%5B%7B%22num%22%3A15%2C%22gen%22%3A0%7D%2C%7B%22name%22%3A%22XYZ%22%7D%2Cnull%2Cnull%2C0%5D
Svendsen, M., Andersen, N., Hansen, P., & Steffensen, J. (2018). Effects of Harmful Algal Blooms on Fish: Insights from Prymnesium parvum. Fishes, 3(1), 11. https://doi.org/10.3390/fishes3010011
Torbick, N., Ziniti, B., Stommel, E., Linder, E., Andrew, A., Caller, T., … Shi, X. (2017). Assessing Cyanobacterial Harmful Algal Blooms as Risk Factors for Amyotrophic Lateral Sclerosis. Neurotoxicity Research, 33(1), 199–212. https://doi.org/10.1007/s12640-017-9740-y