Clarifying trends in the density of Antarctic krill Euphausia superba Dana, 1850 in the south atlantic. A response to Hill et al

Abstract

A commentary by Hill et al. (2019) raised some questions concerning the analyses of trends in krill density presented in Cox et al. (2018). We have re-examined our analyses and conclude that our approach does not contain multiple errors as asserted by Hill et al. (2019). Specifically, we reiterate that our statistical analysis of the publicly available version of KRILLBASE does not support the notion of a precipitous decline in krill density between 1976 and 2016. We respond to the technical criticisms made by Hill et al. (2019) of our work. We include a section where we suggest some approaches to help build consensus on detecting ecological trends in the Southern Ocean in the future. These approaches include: integrated assessments incorporating all relevant data, utilising data that will become available in the future from emerging technologies, and suggestions of other potential population monitoring methods that may be effective for krill.