Inclusion, exclusion, and screening
Prior to the search, we established inclusion and exclusion criteria. We
retained studies of marine invertebrates that had quantitative data on a
fitness measure during the life history—we therefore excluded
behavioural studies or qualitative descriptions. We first screened
records using the title and abstract, then imported relevant records to
EndNote (version X8.2) where full-text articles were assessed for
eligibility. In total, after 241 duplicates were removed, all search
terms resulted in 17,337 records screened at the title and abstract
level, 6,597 full-text articles checked for eligibility, and 1,716
references included in the final map (see summary in Figure S1 and ‘Data
Sources’, Supporting Information).