Zoos and aquariums have evolved significantly. From their origins as enclosures for the mere entertainment of the public, these institutions have undertaken new functions responding to the biodiversity crisis and social demands. Modern zoos and aquariums have the opportunity to educate people, contribute to species conservation, and produce animal-related research. However, there is increasing criticism toward the outcomes of their actions and the holding of species in their facilities. This review offers an integrated analysis of the state of knowledge about the role that zoos and aquariums play today. It describes their performance regarding their conservation, education, and research functions, highlighting general patterns and offering future perspectives. It identifies some challenges common to all these institutions, concluding that the way they keep up with the ever-growing social and environmental expectations will be decisive hereafter.

Global biodiversitytargets require us to identify species at risk of extinction and quantify status and trends of biodiversity. The Red List Index (RLI) tracks trends in the conservation status of entire species groups over time by monitoring changes in categories assigned to species. Here, we calculate this index for the world’s fishes in 2010, using a sampled approach to the RLI based on a randomly selected sample of 1,500 species, and also present RLI splits for freshwater and marine systems separately. We further compare specific traits of a worldwide fish list to our sample to assess its representativeness. Overall, 15.1% of species in the sample were estimated to be threatened with extinction, resulting in a sampled RLI of 0.914 for all species, 0.968 in marine and 0.862 in freshwater ecosystems. Our sample showed fishing as the principal threat for marine species, and pollution by agricultural and forestry effluents for freshwater fishes. The sampled list provides a robust representation for tracking trends in the conservation status of the world’s fishes, including disaggregated sampled indices for marine and freshwater fish. Reassessment and backcasting of this index is urgent to check the achievement of the commitments proposed in global biodiversity targets.