How often does one spot a floating carpet of algae at the Olympic Games? That was a question that Qingdao government officials had, when the city’s Olympic sailing venues were struck by unprecedented HAB formation in 2008 — the first such event in the Olympic Games’s 112-year history. The rapid spreading of algal bloom not only posed threats to aquatic species by releasing toxic hydrogen sulphide during decomposition (Glibert, 2014), but also disrupted sailing training and test events. As such, this warranted the implementation of large-scale mitigation strategies, which unfortunately proved ineffective as they overlooked the root cause of HAB growth — anthropogenic water pollution.
The strategies adopted by Qingdao officials were primarily focused on clearing existing traces of algal bloom, given their priority to reduce event disruptions and maintain their image as a competent host city. As reported by Hu and He (2008), the immediate measure taken was to dispatch manpower to dredge the waters, with nearly 10000 locals and 1000 vessels being roped in. Following this massive clean-up exercise, where over 700000 tons of algae were collected (Hu and He, 2008) and $100 million of losses was incurred (Glibert, 2014), officials deployed containment booms to protect sailing areas against HAB infestation. Approximately 24 kilometres of containment booms, which refer to floating barriers typically used to contain oil spills, were used (Hu and He, 2008).
Massive numbers of vessels — and even bulldozers — were deployed to dredge the algae-infested waters in Qingdao’s sailing venues (Cohen, 2008)
However, these measures turned out ineffective, with traces of algal bloom reemerging shortly after affected areas had been weeded (Cohen, 2008). While clean-up and containment strategies were admittedly necessary as HAB growth was disrupting the running of the Olympic Games, they failed to address the central role of water pollution in facilitating such growth. As mentioned previously, HABs develop when surplus nitrate and phosphorus from fertilisers or organic waste lead to nutrient excesses crucial for HAB formation (Hill, 2012). This shows that HAB formation in Qingdao was not the result of algae invasion from offshore areas as officials had suggested (Leliaert et al., 2008), but rather, the localised dumping of waste. These findings are supported by Leliaert et al. (2008), who argue that HABs in Qingdao were triggered by eutrophication — the process where water bodies continually receive nutrient input and eventually disappear (Hill, 2012).
Hence, it was unsurprising that officials’ mitigation strategies failed as point sources were not regulated, resulting in high HAB growth rates of 21.9% daily (Smetacek and Zingone, 2013). Specifically, officials could have advised farmers against dumping chemical waste into tributaries (Smetacek and Zingone, 2013) while investing in wastewater treatment infrastructure. By undertaking specialised treatment (Figure 1), where excess nitrate and phosphorus are thoroughly filtered out (they are only partially removed during primary treatment), eutrophication could have been prevented alongside HAB growth. Manpower could also have been significantly cut back on, bringing major cost savings for officials while making the 2008 Beijing Olympic Games a more financially sustainable one.
Figure 1: Wastewater treatment process (Hill, 2012)
References
Cohen, C. (2008, July 3). China’s blooming algae problem that’s swamping the Olympics. Daily Mail. https://www.dailymail.co.uk/news/article-1031444/Chinas-blooming-algae-problem-thats-swamping-Olympics.html
Glibert, P. M. (2014). Harmful Algal Blooms in Asia: an insidious and escalating water pollution phenomenon with effects on ecological and human health. ASIANetwork Exchange, 21(1), 1-17. https://doi.org/10.16995/ane.46
Hill, M. K. (2012). Water Pollution. In M. K. Hill (Ed.), Understanding Environmental Pollution (pp. 236-285). Cambridge University Press. https://doi.org/10.1017/cbo9780511840654
Hu, C., & He, M. X. (2008). Origin and offshore extent of floating algae in Olympic sailing area. Eos, Transactions American Geophysical Union, 89(33), 302-303. https://doi.org/10.1029/2008eo330002
Leliaert, F., Malta, E. J., Engelen, A. H., Mineur, F., & De Clerck, O. (2008). Quindao algal bloom culprit identified. Marine Pollution Bulletin, 56(9), 1516-1516. https://doi.org/10.1016/j.marpolbul.2008.08.004
Smetacek, V., & Zingone, A. (2013). Green and golden seaweed tides on the rise. Nature, 504(7478), 84-88. https://doi.org/10.1038/nature12860