Sustainability is driven by the choices we make in terms of consuming products that are favorably in supply when compared to demand. The product chosen should be based on the level of control or traceability one has over the production process. The ability to actively enforce or regulate the industry should also play a vital role in this decision making process.
Given the option to choose between two items to consume. Item 1 produced by man and item 2 produced by GOD, (in this case we are referring to seafood). Think to yourself, which would you have more control over?
GOD MADE = WILD CAUGHT
MAN MADE = FARM RAISED (Aquaculture)
CONTROL | MONITORING
It may be the case that some farms do in fact negatively impact the environment. The main arguments at present are based on the issue of cross contamination, where the fish's excrement or parasites are transfered into the ecosystems of wild species and that of the feed used, generally a nutritional supplement made primarily from high growth wild caught sustainable fish species . Both seem overly pedantic when one looks at the environmental degradation caused by the fishing fleet of vessels currently operating in our ocean.
One cannot forget that when a fishing vessel departs from port. Those vessels discharge fuel (liquid and gas) into the ocean as well as disrupting natural ecosystems, through their engines and equipment used. This is not even accounting for the unchecked pollution spilt over board by the fisherman. We also have no real control over how much fish and by-catch is actually caught while handlining the "sustainable specie". The term,"out of sight out of mind" comes to mind.
Unlike a farm, this vessel is hundreds of miles out on the big blue yonder (ocean). On returning to port, we are expected to take the word of the fisherman that they did not land any endangered specie and did not throw their soda can over board during their fishing expedition. If economics and game theory have showed us anything, it is that there is a rather significant incentive to not state the complete truth in this situation. Now as for a farm, we can very easily monitor this land or ocean (generally a few miles from the coast) based aqauculture facility from every corner and at every level of the production process.
It is important to ensure a Macro view is taken whereby all direct and indirect economic and environmental costs are assessed to ensure the sustainability of the production process.
Again, ask yourself, if you wanted to truly monitor and control the means of production. Which of the two options would grant you this? Attempting to manage the wild fisheries of the ocean is almost equivalent to attempt to manage nature itself, this we have learnt (on occasion the hard-way) cannot come to pass.
At present the supply of Wild caught seafood is needed, and there are truly innovative ways to regulate and control this means of production. This, as we can all agree on, only takes place when the vessel is in port. Do we really know what goes on out in the big blue yonder where the vessel spends days, weeks if not months on end? Do we really know if the fishermen are releasing all by-catch as it is caught, thus alive? What are they dumping into the ocean while out there? Now ask yourself again, do we really have an all encompassing level of control over this production process at all times to allow enforcement procedures to in enacted?
With a farm, if they are not at least attempting to reach a satisfactory level of production in terms of their impact on the environment, the state could very easily shut off their water or electricity supply - true a little harsh but this could actually happen. Farms are made up of systems of controlled production processes. For them to achieve the quality required, their is a direct incentive for them to ensure the inputs used in the production process (Water, feed, nutrients etc) are of the highest quality available. If anything, our capitalistic market economies have shown that technology is a dynamic variable in any production process where change is continously spurred on by innovation. This is a given, just look at any form of technology around you. The fact that you are sitting behind some personal computer that is powder by a microchip the size of a quarter should prove this point.
By placing enough attention and support onto the farms that are doing it right, will inevitably encourage others to follow suit as market demand will tend favor the industry leaders producing the highest quality product. In most cases, they too will be deemed the most sustainable, lest we forgot the main issue at hand.