Effect size as a measure of biological relevance for offshore wind impact studies

Abstract There is an urgent need to translate the outcomes of offshore-wind-fisheries research and monitoring into information that is useful to decision-makers. Papers published in peer-reviewed journals typically report whether or not results are significant based on a statistical test and an associated P-value which is compared to a threshold (e.g. P < 0.05). However, statistical significance cannot tell us whether or not the observed results hold any biological relevance. The lack of a clear connection to biological relevance makes it difficult for decision-makers to interpret research findings and understand how a given study fits into the larger picture of offshore wind interactions with the ecosystem. Toward addressing this challenge, this paper makes the following recommendations to translate the outcomes of research and monitoring studies into information that is useful to scientists, fisheries managers, and other stakeholders: (i) report effect size(s) and associated confidence intervals associated with outcomes for research and monitoring studies alongside the results of conventional statistical tests of significance; (ii) consider the biological relevance of research and monitoring outcomes using scientific reasoning to assess the magnitude and direction of the effect size, the width of the confidence intervals, and the factors that may have affected them; (iii) advance cumulative science by reporting the components used to calculate effect sizes, namely the mean, standard deviation, and sample sizes for individual studies; (iv) publish raw data to new or existing open access data repositories following the FAIR guiding principles of data stewardship and management, i.e. data should be Findable, Accessible, Interoperable, and Reusable; and (v) conduct periodic meta-analyses of existing research to evaluate the mean, magnitude, and direction of the effect size to evaluate the overall mean effect of offshore wind development across studies.