Global Harmful Algal Blooms

Overall objective: To develop cross-community understanding of the economic impacts of HABs and hence to define methodologies and criteria capable of robustly assessing (at both regional and local levels) the economic costs of HABs, as well as the costs of methods to predict and mitigate HABs. 


Rationale. HABs have the potential to negatively affect the economies of the regions in which they occur. Much of the scientific literature on the economic impacts of HABs has employed relatively crude measures and methodologies, the results of which often are difficult to compare (Davidson et al. 2014). The economic effects of HABs arise from public health costs, commercial fishery and aquaculture closures and fish kills, insurance costs, possible medium and long-term declines in coastal and marine recreation and tourism, and the costs of monitoring, management and mitigation. Estimates of the economic impacts of HABs should (but often do not) account for all of the mentioned aspects (Morgan et al. 2010). Quantification of the so-called “halo effect” offers a means to evaluate the indirect impact of HABs, but a consistent and accepted methodology to achieve this is lacking. Aggregating economic effects – both within and across these categories – can also be problematic with current data and currently used methodologies (Hoagland et al. 2002). 




The economic cost of freshwater HABs in drinking water reservoirs has been indicated in Theme 5. Freshwater HABs. In marine systems, an example of an economic evaluation of HABs at a regional level was given by Anderson et al. (2000), who estimated the economic effects of HABs in the United States to be US$49 million per year (at the 2000 value of the dollar), which amounts to US$100 million per year in 2012 dollars (Davidson et al., 2012). The proportional breakdown of these costs were as follows: 45% for public health costs, 37% in terms of the costs of closures and losses experienced by commercial fisheries, 13% for the impact on lost recreation and tourism opportunities, and 4% for monitoring and management costs. Multiyear losses from several countries bordering the North Pacific Ocean were analyzed and reported at the PICES “Workshop on Economic Impacts of Harmful Algal Blooms and Aquaculture” (Trainer and Yoshida 2014). Among the presented data, the total economic losses in farmed fish and shellfish production was estimated as US$94.0 million for Korea, Japan and China from 2006 to 2012. Furthermore, the increasing magnitude of macroalgal (Ulva, Sargassum) HABs is dramatically impacting the economy of countries highly dependent on tourism and coastal fisheries (e.g., Smetacek and Zingone 2013). Revision of regional estimates with more modern environmental economic methodologies is required, as are more local evaluations in regions of particular concern or economic value. Moreover, many parts of the world report, at best, only ad hoc estimates of impacts stemming from HAB events and hence lack even basic data on HAB costs. Environmental evaluation of HABs also needs to be extended to ensure that the less tangible benefits of HAB mitigation are included, for example, the value in terms of health and well-being of eating seafood and of maintaining sustainable employment in remote regions to foster their sustainable development. More robust economic evaluations of the costs of HABs will allow for more robust management decisions to be taken by the aquaculture industry, their insurers and coastal zone managers, and will allow better decision making on scientific priorities. 



Specific objectives 

  • Undertake capacity-building activities to foster links and common understanding of HAB problems, associated financial risks and economic methodologies between the HAB research community, the environmental economic research community, the aquaculture industry, the insurance industry, seafood and coastal zone regulators and other stakeholders. 
  • Identify regional differences in economic priorities and responses related to HAB events and their impact on economic assessment (e.g., explore the advantages and problems associated with the use of clay to mitigate some HAB events). 
  • Evaluate the economic cost/benefit of early warning and mitigation methodologies, taking into account regional differences in priorities and sharing best practice. 
  • Develop guidelines for the application of economic assessment of HABs at both regional and local levels. 


Example tasks 

  • A comprehensive review of publications and data relating to the economic impacts of HABs identifying methodologies used, estimated costs, regional differences, data gaps, and methodological deficiencies. 
  • A joint science and stakeholder forum consisting of representatives of the HAB research community, environmental human health economists, the aquaculture industry, the insurance industry and coastal zone managers, to identify strategies to assess the economic impacts of HABs. 
  • A working group containing representatives of the HAB research community, environmental human health economists, the aquaculture industry, the insurance industry and coastal zone managers, to address the study of the impacts of particular HABs in specific areas. 
  • Dissemination and outreach activities on the economic impacts of HABs, including the available knowledge, research priorities and policy needs. 



  • A position paper on the economic impact of HABs: knowns and unknowns. 
  • A best practice manual for the environmental evaluation of HABs that outlines the potential costs of HABs and methodologies to evaluate the cost/benefit of different response strategies. 
  • INFORMATION FOR POLICY MAKERS: An evidence-based perspective of the economic impact of HABs and methods to predict and mitigate their occurrence, including regulatory and industry-based monitoring. 




Fish products are a source of both basic nutrition and significant income for many communities in the Pacific region.

© Institut Louis Malardé (Tahiti, French Polynesia)



The complete list of references can be found here.

User Location