Most fisheries management studies ask: what will happen if we keep fishing as we do? We asked a different question, putting the goal first: What needs to change for both marine biodiversity and fisheries´profit to increase?
We fed two decades of fisheries science into a Bayesian network adapted to EU fisheries. Then we made the best outcome certain and let the model work backwards. This “reverse engineering” showed us what a successful future would look like.
The answer was indicative. Fishing effort on benthic habitats would need to go down. Of 100 possible futures where biodiversity and profit both rise in the EU, 73 include a cut in benthic effort. Almost none include more of it. For the pelagic fleet, 53 out of 100 successful futures show reduced effort. In those successful futures, habitat damage also falls from 77% to 48%. The sea recovers. So does profit.
We also tested the worst case. More benthic effort would lead to profit loss in 61 of the 100 possible futures, and biodiversity loss in 81 of them.
Both tests agree: The path to success would run through less benthic effort. Strong policy would make it happen. If we want more from the sea, we will likely need to leave more of the sea alone.
See the “reverse engineering” (i.e. work backwards to move forward!) study here (Open Access Version) and cite it with:
Bastardie, F., & Brown, E. J. (2021). Reverse the declining course: A risk assessment for marine and fisheries policy strategies in Europe from current knowledge synthesis. Marine Policy, 126, 104409. https://doi.org/10.1016/j.marpol.2021.104409
This is part of the narrative around the virtuous circle: Effort cuts avoid damaging the seafloor integrity > Habitats support the fish we want to catch > Recovered species make each unit of effort more productive > Lower costs stack on top of higher value > etc.
However, the trap is timing. Individual fishers benefit from fishing less only after the stock has recovered, but recovery requires everyone to ease off at once. The market doesn’t provide that coordination. Strong regulation would instead likely provide it.
(Disclaimer: This study was a synthesis of existing knowledge expressed as probabilities… of course not a forecast)