REVIEW PAPER Eating in an acidifying ocean: a quantitative review of elevated CO 2 effects on the feeding rates of calcifying marine invertebrates Jeff C. Clements . Elizabeth S. Darrow Received: 12 March 2018 / Revised: 18 May 2018 / Accepted: 22 May 2018 Ó Crown 2018 Abstract Feeding is fundamental for all hetero- trophic organisms, providing the means to acquire energy for basic life processes. Recent studies have suggested that experimental ocean acidification (OA) can alter the feeding performance of marine calcifying invertebrates, but results have been inconsistent. While several reviews pertaining to the biological effects of OA exist, none provide a synthesis of OA effects on feeding performance. Here, we provide a quantitative analysis of published experiments testing for effects of elevated CO 2 on feeding rates of marine calcifying invertebrates. Results revealed that suspen- sion-feeding molluscs and predatory and grazing echinoderms experienced depressed feeding rates under elevated CO 2 , while arthropods appeared unaf- fected; larval and juvenile animals were more suscep- tible to CO 2 effects than adults. Feeding strategy did not appear to influence the overall taxonomic trend, nor did habitat, although exposure time did have an effect. AIC model selection revealed that Phylum best predicted effect size; life stage and exposure time were also included in candidate models. Based on these results, we synthesize potential physiological attri- butes of different taxa that may drive OA sensitivi- ties in feeding rates, which could potentially result in community-level impacts. We also discuss CO 2 effects on calcifier feeding in the context of elevated temperature and other global marine change stressors, and highlight other areas for future research. Keywords Carbon dioxide Á pH Á Invertebrate Á Global change Á Physiology Introduction Maintaining energy balance in the face of environ- mental stressors is fundamental to life. The amount of food an animal consumes, when balanced with energetic losses (due to various functions such as metabolic processes, growth, development, repair, activity, reproduction, homeostatic maintenance, ther- mal regulation), can dictate the animal’s energy Handling editor: Iacopo Bertocci Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10750-018-3665-1) con- tains supplementary material, which is available to authorized users. J. C. Clements (&) Aquaculture and Coastal Ecosystems Section, Fisheries and Oceans Canada, Gulf Fisheries Centre, 343 Universite ´ Avenue, Moncton, NB E1C 9B6, Canada e-mail: jefferycclements@gmail.com E. S. Darrow Department of Biology and Marine Biology, Center for Marine Science, University of North Carolina Wilmington, 5600 Marvin K. Moss Lane, Wilmington, NC 28409, USA 123 Hydrobiologia https://doi.org/10.1007/s10750-018-3665-1