Which were the main methodologies to assess the value of food provision of fish and wave energy attenuation? For fish communities, could we add a monetary value only considering their trophic importance?
Both fish biomass and wave energy attenuation were valued using the replacement cost method. The first one, using the cost of producing 1kg of fish through aquaculture, the latter using the cost of implementation and maintenance of artificial reefs.
Considering the trophic level is important, but each level is equally important to the entire community. Looking at their function in the reef is more appropriate. If a function (e.g. herbivory) is only filled by one species, then we could assign a higher value to this species, because its loss would result in a dramatic shift in benthic and fish communities. Looking at the functional redundance or functional originality of species could be a different and interesting approach in valuing this service.
This is a nice approach. However, does the cost of producing 1kg of fish through aquaculture represent the value of fish for food consumption well? Because if fish disappear, we would need to buy fish from other regions. I am not an expert, but I assume that the market price will be much higher than the mere production in aquaculture, no?