Eiffel Over

Tag: ÎledeRé

  • Plenty more fish in the sea

    Yesterday’s post on the fish écluses on the Île de Ré speaks to the idea of creating straightforward connections between the resources that humans need to live and thrive. 

    As engineers (and other humans) we need to find ways to harvest the materials and energy we need in balance with what the living and mineral world can sustain. So to help us understand how this can work I’m sharing Donella Meadows’s example of fish stocks to help see how humans can live as part of a sustainable system of supply.

    Meadows’s model concerns the local fish population in an area of sea. Left to its own devices, the fish population is stable because there is only so much food to go around. Too many fish, less food per fish, some fish die. Too few fish, more food per fish, they reproduce more. This feedback loop stays in equilibrium around a mean.

    Now, the local fishing fleet gets involved. By harvesting a small number of fish, the population goes down, increasing the reproduction rate of the remaining fish, and the population returns to what it was. Fish too much, however, and the fish are further apart. Fish that are further apart take longer to reproduce! And so for a while, there are few fish, the nets are empty and the boats go back to port. During this time the fish population recovers, and eventually the boats can go back to sea.

    This simplified model beautifully illustrates how humans can harvest what they need while still living within the ecosystem’s limits.  The key characteristics here are a living system that regenerates itself – the fish; and a feedback loop between supply and those doing the harvest. Simply, when the catch is too low, the boats go home. 

    This feedback loop between supply and harvesting is what interests us in regenerative design. It is what allows us to harvest abundance, and even create abundance, all while living within the ecosystem’s limits. 

  • Stone circles on the beach

    Hundreds of years ago, the inhabitants of the Île de Ré, just off France’s Atlantic coast, developed an ingenious way to catch fish. At low tide, they built large stone circles, say 20 metres or more in diameter, and formed by a rock wall about 50cm high. At high tide these stone circles are completely submerged. But as the tide falls, water remains trapped in them, and so do the fish swimming in that water. At low tide the water eventually drains out of the walls, leaving the fish lying on the beach, for the local fishers to just pick up.

    These stone circles, or ‘écluses’ in French, were very effective in providing a local food supply. So much so that during the Napoleonic Wars, recruiting officers for the army tried to destroy the walls in an attempt to starve the local population and force them into joining the army. Later, the owners of commercial fishing fleets sought to have them shut down as they proved a risk to their own market domination.

    Through a regenerative lens, in this example we see:

    • A local population connected to a local source of supply. 
    • A low-tech method for harvest that the community itself can build and adapt.
    • The resilience that local supply can provide (and therefore why the army and larger commercial operations sought to remove it).
    • A scale of operation that is necessarily limited – they can only harvest fish that swim over the beach; there’s literally plenty more fish in the sea. This is in contrast to the super trawlers that can take far more than their fair share.

    Community, ecology, supply and resilience. These are the sorts of stacked, multiple benefits that we are seeking to create through regenerative design.

    Today, groups of volunteers are protecting and rebuilding the walls. Perhaps for posterity. And, or, perhaps they see a time in the future when harvesting in this way may return stacked, multiple benefits to their community and ecosystem.