Meta-Analysis of Finfish Abundance at Offshore Wind Farms

Offshore wind farms are becoming increasingly common in the coastal margins of marine ecosystems worldwide. Yet, the effects that wind farm structures have on fish populations remain unclear. To explore potential effects, a meta-analysis of studies that have examined the abundance of finfish inside of wind farms compared to nearby reference sites was conducted. Using well-established meta-analytic methods, the overall effect size across all studies was calculated, and then changes in effect size for soft-bottom and complex-bottom oriented species were explored in association with several covariates including characteristics of the wind farm (depth, distance from shore, wind farm age), the sampling design (season, gear type, and distance from the turbine sampled), and ecosystem level characteristics (functional feeding group and fishing presence/absence). The overall effect size was positive and significantly different from zero, indicating greater abundance of fish inside of wind farms. Likewise, positive and significant effect sizes were noted for several covariates for both soft-bottom and complex-bottom species. The findings of this study underscore the need for regional, national, and international collaboration on monitoring approaches and data sharing in order to develop a more holistic understanding of how offshore wind farms affect living marine resources.