Squaring the circle: reconciling fishing and conservation of aquatic ecosystems

Authors


  • Ghoti papers

    Ghoti aims to serve as a forum for stimulating and pertinent ideas. Ghoti publishes succinct commentary and opinion that addresses important areas in fish and fisheries science. Ghoti contributions will be innovative and have a perspective that may lead to fresh and productive insight of concepts, issues and research agendas. All Ghoti contributions will be selected by the editors and peer reviewed.

    Etymology of Ghoti

    George Bernard Shaw (1856–1950), polymath, playwright, Nobel prize winner, and the most prolific letter writer in history, was an advocate of English spelling reform. He was reportedly fond of pointing out its absurdities by proving that ‘fish’ could be spelt ‘ghoti’. That is: ‘gh’ as in ‘rough’, ‘o’ as in ‘women’ and ‘ti’ as in palatial.

Abstract

Size-at-entry regulations in fisheries cause major disruption to aquatic ecosystems, including truncation of age- and size-structures, destabilization of fish stocks, directional selection on phenotypic traits and a by-catch of unwanted species and sizes. Here, we use simple dynamic models of size-spectra to examine an alternative, so-called balanced harvesting. Balanced harvesting helps in retaining the approximate power-law size-structure of natural ecosystems, whereas size-at-entry regulations do not. Balanced harvesting is less likely to destabilize steady states than size-at-entry regulations set close to the size at maturation. Surprisingly, our numerical results suggest that steady-state biomass yield can be substantially increased by switching from size-at-entry to balanced harvesting. On the basis of these results, we argue that the goals of conservation and of greater yields seem less difficult to reconcile than have previously been thought. However, to work towards these goals require a change in our approach to fishing.

Ancillary