World Aquaculture Magazine - September 2021

20 SEP TEMBER 2021 • WORLD AQUACULTURE • WWW.WA S .ORG production costs, equivalent to US$ 1.5 to 3 billion per year (Fitridge et al. 2012). In aquaculture, biofouling can also be used as a desirable process in farms, as it is the case with biofouling (bacterial biofilm) on moving bed bioreactors in recirculating aquaculture systems (McQuarrie and Boltz 2011). Yet, with human-made structures moving from one ecosystem to another in different parts of the world, biofouling has become one of the main sources for anthropogenic introductions of non-indigenous species, potentially including pathogens such as Bonamia or IHN virus (Howard 1994, St-Hilaire 2020) in the marine environment — the other sources of introductions being ballast water from ships (Drillet et al. 2019) and aquaculture itself through translocation of stock species. In the marine context, the issue of invasive species and pathogens is extraordinarily diverse and truly global in geographical scale. It also presents many challenges. What goes on under water can remain unseen until it is too late to address. Early stages of an invasion tend to be quite subtle and, to date, there is limited research and understanding of the interactions that underline the balance of marine habitats. The environmental and economic impacts are often substantial and can affect blue growth forecasts, with the aquaculture sector being particularly exposed to the transfer of disease potentially harbored in the biofouling of structures moved across ecosystems (ships, platforms, fishing gear, etc.). Invasive aquatic species have been hitchhiking as biofouling organisms across the globe since humankind started to navigate the seas. The globalization of the last few decades has gone hand in hand with rapid growth in maritime transport, so ships have been until now the main pathway. However, focus on the Blue Economy is increasing the number of maritime structures deployed by other industries such S ocioeconomic recovery from the coronavirus pandemic will be reliant on the Blue Economy, with ocean-based industries such as aquaculture, seabed mining and marine renewable energies expected to scale up operations. But this means that, more than ever, there is a global imperative to balance blue growth with measures that safeguard the health of marine ecosystems and encourage sustainable practices, particularly with projected expansion into sea areas beyond national jurisdictions. An important ingredient for the realization of sustainable blue growth expectations is the identification of synergies between different maritime industries and activities that, when combined, are likely to produce stronger results than the individual sum of their parts. One of the best examples of this perspective is a recent initiative geared at improving howmarine biofouling is managed to prevent the transfer of invasive aquatic species and pathogens to protect biodiversity and industries requiring stable water quality. Launched in December 2018, the GloFouling Partnerships ( www.glofouling.imo.org ) is a project spearheaded by the International Maritime Organization (IMO), with collaboration from the Intergovernmental Oceanographic Commission of UNESCO and UNDP and with funding from the Global Environment Facility (GEF). Biofouling is the natural process occurring on surfaces that are submerged in water —starting at the molecular level, evolving into biofilms (slimes) and eventually into macrophyte/hard fouling developments. Aquaculture producers around the world are well versed in managing this growth, be it on submerged equipment or on stock organisms themselves (e.g., oysters, mussels, etc.). Conservative estimates of the costs related to biofouling management in the aquaculture industry are consistently between 5–10 percent of the GloFouling Partnerships – Cross-sectoral Cooperation to Drive Improved Biofouling Management in Aquaculture John Alonso Biofouling of aquaculture gear deployed in the marine environment is a common occurrence (Photo: Justin McDonald). The ascidian tunicate Styela clava on shellfish culture gear (Photo: Department of Fisheries and Oceans, Canada).