In many developing countries, aquaculture is key to ensuring food security for millions of people. It is thus important to measure the full implications of environmental changes on the sustainability of aquaculture. We conduct a double meta-analysis (460 articles) to explore how global warming and antimicrobial resistance (AMR) impact aquaculture. We calculate a Multi-Antibiotic Resistance index (MAR) of aquaculture-related bacteria (11,274 isolates) for 40 countries, of which mostly low- and middle-income countries present high AMR levels. Here we show that aquaculture MAR indices correlate with MAR indices from human clinical bacteria, temperature and countries’ climate vulnerability. We also find that infected aquatic animals present higher mortalities at warmer temperatures. Countries most vulnerable to climate change will probably face the highest AMR risks, impacting human health beyond the aquaculture sector, highlighting the need for urgent action. Sustainable solutions to minimise antibiotic use and increase system resilience are therefore needed.

Fish mucus layers are the main surface of exchange between fish and the environment, and they possess important biological and ecological functions. Fish mucus research is increasing rapidly, along with the development of high-throughput techniques, which allow the simultaneous study of numerous genes and molecules, enabling a deeper understanding of the fish mucus composition and its functions. Fish mucus plays a major role against fish infections, and research has mostly focused on the study of fish mucus bioactive molecules (e.g., antimicrobial peptides and immune-related molecules) and associated microbiota due to their potential in aquaculture and human medicine. However, external fish mucus surfaces also play important roles in social relationships between conspecifics (fish shoaling, spawning synchronisation, suitable habitat finding, or alarm signals) and in interspecific interactions such as prey-predator relationships, parasite–host interactions, and symbiosis. This article reviews the biological and ecological roles of external (gills and skin) fish mucus, discussing its importance in fish protection against pathogens and in intra and interspecific interactions. We also discuss the advances that “omics” sciences are bringing into the fish mucus research and their importance in studying the fish mucus composition and functions.

Aquatic animal diseases are one of the major limiting factors in aquaculture development, with disease emergence forecast to increase with global change. However, in order to treat increasing diseases in a context of global emergence of antimicrobial resistance and strengthening regulations on antimicrobial use, sustainable alternatives are urgently needed. The use of plant supplements to increase fish immunity and disease resistance has gained much popularity within the last decades. The use of functional supplements, such as plants, can also improve growth and feed assimilation, contributing to a better optimization of aquaculture resources (e.g. fish meal inclusion). We conducted a systematic review and meta‐analysis in order to identify the research gaps in the use of plant‐enriched diets in fish aquaculture and estimate, for the first time, the overall efficacy of plant‐enriched diets on fish growth, immunity and disease resistance as well as the effect of intrinsic parameters (fish trophic level, type of plant material, dosage, treatment duration and pathogen species) on the treatment efficacy. We found that plant‐enriched diets significantly enhanced growth, immunity and disease survival of treated fish, regardless of the fish trophic level, treatment duration and type of material used. We also show that plant supplements are a versatile alternative that can benefit different aquaculture sectors (from small‐scale fish farmers to intensive productions). Finally, we observed that studies need to improve the information reported about the plant material used (e.g. origin, identification, chemical composition), in order to allow the comparison of different experiments and improve their repeatability.

Non‐random community changes are becoming more frequent in many ecosystems. In coral reefs, changes towards communities dominated by other than hard corals are increasing in frequency, with severe impacts on ecosystem functioning and provision of ecosystem services. Although new research suggests that a variety of alternative communities (i.e. not dominated by hard corals) exist, knowledge on the global diversity and functioning of alternative coral reef benthic communities, especially those not dominated by algae, remains scattered. In this systematic review and meta‐analysis of 523 articles, we analyse the different coral reef benthic community changes reported to date and discuss the advantages and limitations of the methods used to study these changes. Furthermore, we used field cover data (1116 reefs from the ReefCheck database) to explore the biogeographic and latitudinal patterns in dominant benthic organisms. We found a mismatch between literature focus on coral‐algal changes (over half of the studies analysed) and observed global natural patterns. We identified strong biogeographic patterns, with the largest and most biodiverse biogeographic regions (Western and Central Indo‐Pacific) presenting previously overlooked soft‐coral‐dominated communities as the most abundant alternative community. Finally, we discuss the potential biases associated with methods that overlook ecologically important cryptobenthic communities and the potential of new technological advances in improving monitoring efforts. As coral reef communities inevitably and swiftly change under changing ocean conditions, there is an urgent need to better understand the distribution, dynamics as well as the ecological and societal impacts of these new communities.