Fishy on a closed-loop dishy
Closed-loop systems in agriculture are not new. Like the Ancient Romans recycling glass the forbears of waste management principles in the fishing industry are Chinese who fed carp on nymph and silkworm poo. Fish farming is itself an ancient industry, potentially extending as far back as 6000 BC when Australian Aboriginals harvested eels.
Fish lend themselves more readily to agricultural practices than land animals (disease transmission being one factor) and more than 10x as many fish species vs land animals have been farmed. So how do modern methods of zero waste principles apply to fish?
The first thing to note is the global demand for protein and how this has decimated fishstocks globally. Like other extractive industries it’s a common theme of an imbalance of power between economic/human demand and what nature can provide. In a classic case of political short-termism EU fishing quotas protect jobs today at the long-term expense of the entire European fishing industry. Glimmers of hope do exist with efforts to increase protected zones and reform of policies.
Within the sector there are various methods which mimic natural ecosystems with monoculture examples of Mariculture and greater levels of environmental integration with IMTA and Aquaponics. It is the latter two which are of relevance to waste management principles through incorporating synergistic relationships between different species of aquatic plants and/or animals.
There are exciting opportunities for the development of such systems here in Scotland. One example involves new technology for an anaerobic digestion plant appended to a shrimp farm. Could East Lothian, which birthed the Scottish Agricultural Revolution, be the site of new innovation within the agricultural sector? If Scotland’s tomato growing record is anything to go by there is certainly a precedent for natively warm organisms thriving in cold environments…