By Aaron McNevin*
One could even ask a child who cuts lawns in the summer and it would be the number of lawns mowed and the price per lawn. How do we measure the environmental impact of an aquaculture operation? I would offer that the most common ways we gauge the environmental impact of aquaculture is by assessments, permits, management plans, “adoption” of better management practices (BMPs) and the like. However, this is not measuring. Would it be reasonable to have the car salesman be evaluated on the presence and thickness of the standard operating procedures (SOPs) for the dealership? If so, could the car salesman be considered successful if the SOPs were perfectly implemented, yet the salesman sold no cars? Could an aquaculture operation cause significant environmental impacts and be considered appropriate as long as there were a book of BMPs on the shelf, legal permits obtained, and the most brilliant of environmental and social impact assessments present? The answer is yes.
There is a need to return to fundamentals and first principles in the environmental management of aquaculture. The industry, as a whole, has gotten better, but there is also more competition for natural resources and it is necessary for the industry to utilize these resources in an increasingly sparing amount as with any food production system. Thus, improved performance is necessary, but it will always be necessary.
How do we evaluate whether an aquaculture operation has improved its performance? Let’s first start with the notion of “improvement.” Stating a farm is “better” or has a “reduced” impact, just the same as stating the farm has “improved,” carries with it inherent quantification. If a farm is “better,” what is it better than? If a farm has “reduced” impact, what has it been reduced from? If a farm has “improved,” what has it improved from? It has become commonplace in permitting, regulatory enforcement and certification to use subjective protocol to serve as proxies for impact. We have become slaves to documentation rather than results.
What we do not measure we cannot quantify and if we cannot quantify, it is impossible to determine if a farm has “improved.” For example, a law may require that an aquaculture operator have a water management plan. This plan may call for a description of how water is moved around a farm, how much waste accumulates in the water, how water is treated prior to discharge, how frequently and in what volumes water is discharged, the biochemical composition of effluent and how preventative measures are in place to avoid deleterious impacts on the receiving water body. This sounds wonderful, but what is the impact of the effluents on the receiving water body? While there may be no easy mechanism for attribution of a farm’s impact on receiving water bodies, the environmental condition of the receiving water body can be determined. While assimilative capacities of dynamic water bodies are challenging to determine, we do know that if the dissolved oxygen concentration has large swings from day to night it is indicative of a eutrophied system. Regardless of how small or large a farm’s discharge is into a eutrophied system, should the system condition itself be the indication of the health of the environment rather than the documentation at the farm level?
Another common example comes from certification programs. Feed efficiency is one of the most important aspects to reduce the impacts of feed ingredient procurement and production and to minimize water quality deterioration which can lead to water pollution if water is discharged and result in disease outbreaks at the farm level. Development of a feed management plan may assist in the calculation of the efficiency of feed used, but the FCR is the result of implementing any measure related to improving feed use efficiency. Thus, it is painfully obvious that the most appropriate means of evaluating the level of feed efficiency at the farm level is quantifying and reporting the FCR. Presence of a feed management plan does not constitute an optimal FCR.
The obvious question is if those most influential in developing regulatory policy, certification standards and permitting requirements have the adequate knowledge to effectively put in place the main components that quantify environmental impact. Further, the efforts to satisfy the large amount of reporting, assessment and management plan requirements detract from the ability of the producer to implement practical efforts to actually minimize impact. Could the monetary expenditure to provide this reporting be better spent on other activities that may prove more beneficial?
It is interesting to note that while the fingers are pointing in all directions to lay blame for this situation, it doesn’t really matter who or what groups have generated these burdens. It is in the best interest of the environment that results-based measures are used to evaluate environmental impacts of aquaculture operations. Furthermore, it is in the best interest of the aquaculture operators to eliminate much of the nonsensical and ineffective reporting requirements that detract from the ability of producers to innovate and develop lower-impact methods of culture.
It is inappropriate, and more importantly, ineffective to continue reinventing the flat tire for every aspect of environmental management. If maintenance of receiving water quality is desired – measure the condition of the receiving water body; if reduced use of feed is desired – measure the FCR; if reduced use of wild fish is desired – measure the wild fish utilized in feed; if energy reduction is desired – measure the amount of energy used; if lower land conversion is desired – measure the production per unit area. Simplicity needs to be rediscovered for the sake of the environment and the business of producing farmed seafood. If it cannot be found, the documentation burdens currently required will cause the addition of deforestation to the list of environmental impacts of aquaculture.
Dr. Aaron McNevin directs the aquaculture program at the World Wildlife Fund (WWF). He received his MS and PhD from Auburn University in Water and Aquatic Soil Chemistry. Aaron has lived and worked in Indonesia, Thailand and Madagascar and currently manages various projects throughout the developing world. He previously worked as a professor of fisheries science, and is the co-author of the book Aquaculture, Resource Use, and the Environment.