Fish harvesting advice under climate change: A risk-equivalent empirical approach

2.4 An R package to develop risk equivalent advice under CC We developed an R package Climate Change Conditioned Advice (ccca) to provide easy access to this method and for transparency (www.github.com/duplisea/ccca). Full instructions for loading the package and running examples with datasets included in the package are provided. This package is easily extendable to any environmental or ecosystem variable (E) for which a time series is available and hypothesised to affect fish production. 3 Results 3.1 Stock production-E variable relationship The relationship between Greenland halibut surplus production (production to biomass ratio: P/B) and the E variable was not very strong, but nonetheless showed a dome-shaped relation- ship where P/B was more negative at both extremes of the temperature range and peaked in the middle (Fig 3). The generalised additive model smooth fitted by the Rpackage mgcv had an Fig 3. The relationship between the production to biomass ratio (P/B) of Gulf of St Lawrence Greenland halibut and the environmental index (annual average temperature in the Gulf ablack) and the null model (grey) is where the E variable has no impact on the P/B. A generalised additive model smooth is shown fitted to the data series. https://doi.org/10.1371/journal.pone.0239503.g003 PLOS ONE Climate-change conditioned risk-equivalent fisheries advice PLOS ONE | https://doi.org/10.1371/journal.pone.0239503 February 19, 2021 9 / 22