Aquaculture in coastal urbanized areas: A comparative review of the challenges posed by Harmful Algal Blooms

Increasing global population has resulted in increased urbanization of coastal areas across the globe. Such an increase generates many challenges for sustainable food production and food security. The development of aquaculture has proven to be an extremely good option to ensure food security (uninterrupted supply and good quality of food) by many countries, especially those with urban areas affected by space limitations such as Singapore. However, the implementation of aquaculture is not without its challenges and impacts to the environment, with Harmful Algal Blooms (HABs) being one of the major concerns in coastal waters. In this review we analyze the development of the aquaculture industry with respect to HABs in Singapore and compare it to similar urban areas such as Hong Kong (SAR China), Salalah (Oman), Cape Town (South Africa), Valencia (Spain), Rotterdam (The Netherlands), Tampa bay (USA), Vancouver (Canada), and Sydney (Australia). Along with HABs, the abovementioned urban areas face different challenges in sustainably increasing their aquaculture production with respect to the economy and geography. This review further assesses the different production and monitoring strategies that have been implemented to counter these challenges while sustainably increasing production. The ongoing COVID-19 pandemic has affected the world with lockdowns and border closures resulting in logistical difficulties in seafood trade which has further accentuated the dependencies on food import. We conclude that the challenges faced by urban areas for sustainable achievement of food security through development of the aquaculture industry can be effectively managed through proper planning, management and collaboration of knowledge/skills on an international level.