Southeast Asia is considered a global hotspot of emerging zoonotic diseases. There, wildlife is commonly traded under poor sanitary conditions in open markets; these markets have been considered ‘the perfect storm’ for zoonotic disease transmission. We assessed the potential of wildlife trade in spreading viral diseases by quantifying the number of wild animals of four mammalian orders (Rodentia, Chiroptera, Carnivora and Primates) on sale in 14 Indonesian wildlife markets and identifying zoonotic viruses potentially hosted by these animals. We constructed a network analysis to visualize the animals that are traded alongside each other that may carry similar viruses. We recorded 6725 wild animals of at least 15 species on sale. Cities and markets with larger human population and number of stalls, respectively, offered more individuals for sale. Eight out of 15 animal taxa recorded are hosts of 17 zoonotic virus species, nine of which can infect more than one species as a host. The network analysis showed that long-tailed macaque has the greatest potential for spreading viral diseases, since it is simultaneously the most traded species, sold in 13/14 markets, and a potential host for nine viruses. It is traded alongside pig-tailed macaques in three markets, with which it shares six viruses in common (Cowpox, Dengue, Hepatitis E, Herpes B, Simian foamy, and Simian retrovirus type D). Short-nosed fruit bats and large flying foxes are potential hosts of Nipah virus and are also sold in large quantities in 10/14 markets. This study highlights the need for better surveillance and sanitary conditions to avoid the negative health impacts of unregulated wildlife markets.

Trophic levels can be applied to describe the ecological role of organisms in food webs and assess changes in ecosystems. Stable isotopes analysis can assist in the understanding of trophic interactions and use of food resources by aquatic organisms. The local ecological knowledge (LEK) of fishers can be an alternative to advance understanding about fish trophic interactions and to construct aquatic food webs, especially in regions lacking research capacity. The objectives of this study are: to calculate the trophic levels of six fish species important to fishing by combining data from stable isotopes analysis and fishers’ LEK in two clear water rivers (Tapajós and Tocantins) in the Brazilian Amazon; to compare the trophic levels of these fish between the two methods (stable isotopes analysis and LEK) and the two rivers; and to develop diagrams representing the trophic webs of the main fish prey and predators based on fisher’s LEK. The fish species studied were Pescada (Plagioscion squamosissimus), Tucunaré (Cichla pinima), Piranha (Serrasalmus rhombeus), Aracu (Leporinus fasciatus), Charuto (Hemiodus unimaculatus), and Jaraqui (Semaprochilodus spp.). A total of 98 interviews and 63 samples for stable isotopes analysis were carried out in both rivers. The average fish trophic levels did not differ between the stable isotopes analysis and the LEK in the Tapajós, nor in the Tocantins Rivers. The overall trophic level of the studied fish species obtained through the LEK did not differ from data obtained through the stable isotopes analysis in both rivers, except for the Aracu in the Tapajós River. The main food items consumed by the fish according to fishers’ LEK did agree with fish diets as described in the biological literature. Fishers provided useful information on fish predators and feeding habits of endangered species, such as river dolphin and river otter. Collaboration with fishers through LEK studies can be a viable approach to produce reliable data on fish trophic ecology to improve fisheries management and species conservation in tropical freshwater environments and other regions with data limitations.

Wildlife trade, both legal and illegal, is increasingly recognized as a key factor in the rise of emerging viral infectious diseases, and this is especially apparent in Asia, where large numbers of wildlife are openly offered for sale in bird markets. We here focus on the risk of Psittacosis becoming a zoonotic disease in the wildlife markets of Java and Bali, Indonesia. Psittacosis is particularly prevalent in parrots (hence the name), and the trade in parrots was instrumental in the Great Parrot Fever Pandemic in 1929/1930. Between 2014 and 2023, we conducted 176 surveys of 14 bird markets, during which we recorded 4446 largely wild-caught parrots for sale. On average, each market had nine genera on offer, and the diversity of genera increased with the increasing presence of parrots (up to 16 genera). For most of the bird markets during each survey, parrots from different genera and originating from different parts of the world, were offered for sale alongside each other. Genera offered for sale together did not cluster into natural (geographic) groups. We found no temporal difference in the sale of parrots. We conclude that the omnipresence of wild-caught parrots from various geographic regions in large numbers within the same bird markets increases the risk that psittacosis is present and that this poses a real risk for the zoonotic spread of avian chlamydiosis to humans.

Small-scale fisheries provide income and food security to local peoples around the world. In the Brazilian Amazon, the pescada (Plagioscion squamosissimus) is among the fishes that contributes most to catches in small-scale fisheries. Our main goal was to evaluate the abundance, size, relevance to small-scale fisheries and trophic ecology of P. squamosissimus in the Tapajós and Tocantins rivers, in the Brazilian Amazon. We combined data from fishers’ local ecological knowledge (LEK) and fish sampling. We expected that fishers in the Tapajós River, less altered by anthropic changes, would cite a higher abundance, larger size and more prey and predators of P. squamosissimus. We interviewed 61 and 33 fishers and sampled fish in nine and five sites in the Tapajós and Tocantins rivers, respectively. The comparison between fishers’ citations and fish sampled indicated a higher relevance of P. squamosissimus to fishers in the Tapajós River, where this fish had an average larger size and where the fishers mentioned more food items. This pattern could be partially related to the history of anthropogenic changes in the Tocantins River. These results indicated that P. squamosissimus is a generalist fish, which could be resilient to fishing and environmental pressures.