Aquaculture: Cross-sectoral cooperation to drive improved biofouling management
As part of its support to GloFouling Partnerships, the World Aquaculture Society has published an article in its Magazine to raise the profile of the issue and calling to aquaculture sector companies to join the Global Industry Alliance (GIA) for Marine Biosafety.
Aquaculture producers around the world are well versed in managing biofouling growth, be it on submerged equipment or on stock organisms themselves (e.g. oysters, mussels, etc.). Biofouling of cages and nets in finfish aquaculture is a significant operational problem to the sector, resulting in the restriction of water exchange that may adversely affect fish health by the reduction in dissolved oxygen and the accumulation of metabolic ammonia. Biofouling is of further concern because it significantly decreases cage flotation, increases structural fatigue and cage deformation, and may act as a reservoir for pathogens.
In aquaculture, biofouling can also be used as a process in farms as it is the case with biofouling (biofilm/slime) on moving bed bioreactors in Recirculated Aquaculture Systems (RAS). Yet, with human-made structures moving from one ecosystem to another in different parts of the world, biofouling has also become one of the main sources for anthropogenic introductions of non-indigenous species, potentially including pathogens such as Bonamia or IHN virus that may impact stock species health.
Additionally, invasive species that are aggressive biofoulers are also an issue, particularly in shellfish aquaculture biofouling, where they affect stock growth or reduce its quality classification. Notable examples are the tubeworm Ficopomatus enigmaticus, the tunicate Didemnum vexillum or the ascidian Styela clava.
Despite this knowledge, there are few comprehensive studies that quantify the impact of biofouling on aquaculture. Some conservative estimates of the costs related to biofouling management in the aquaculture industry are consistently between 5–10% of the production costs - equivalent to US$ 1.5 to 3 billion per year, illustrating the need for effective mitigation methods and technologies. But more studies and accurate estimates are required to help industry operators to allocate cost-effective resources to prevent and manage biofouling.
All in all, the aquaculture sector stands to benefit considerably from improved biofouling management practices, particularly with the promising route for future expansion of offshore aquaculture. This growth should go hand in hand with improved strategies to prevent the introduction of invasive species and pathogens into new environments either directly or as stepping-stones for wider expansion.