Conservation aquaculture, defined as cultivating aquatic organisms to manage or replenish natural populations, has been advocated as a strategy to enhance fisheries production and help restore declining populations. Culture is especially compelling for species in steep decline and for which there is established methodology. The queen conch Aliger gigas is an example of a species with widely overexploited populations, with attempts to culture the species commercially ongoing for > 40 years. However, hatchery-releases have shown low survival from post-settlement to near maturity, leading to low conservation aquaculture potential. When this is viewed alongside large-scale fishery extractions, it is apparent that it is not commercially feasible to replace wild harvest nor ecologically feasible to replenish queen conch populations using existing aquaculture approaches. An age-based mortality model estimates the magnitude of culture required to replace a single adult of reproductive age. Extrapolations from catch–weight relationships highlight the scale of facilities and costs required to partially offset the harvest in a typical Caribbean fishery. Estimates of reproduction to achieve replacement suggest a greater yield from properly protecting natural breeding aggregations. Queen conch aquaculture is useful for scientific inquiry, community engagement and education, but not for stock enhancement or population restoration without more practical and cost-efficient options. Therefore, protecting breeding aggregations should be prioritized for the ecological viability of the species, as well as for its economic value for the people and industries that rely upon it.

The Critically Endangered Arabian leopard Panthera pardus nimr was believed to be absent from the Nejd region in Dhofar Governorate, Oman. However, a scat confirmed by DNA analysis in 2011 and camera-trap images from 2014 confirmed the presence of the leopard in this region. During 2014–2021, our camera traps documented at least eight individual leopards, demonstrating the species is resident and breeding in the region. This finding extends the Arabian leopard's known range in Oman by c. 40 km northwards. To improve detection probability, we recommend that camera-trap surveys for the leopard in the Arabian Peninsula are of at least 18 weeks duration. We advocate the designation of central and western areas of the Nejd as a National Nature Reserve, to protect critical habitat for the Arabian leopard and for other species in this region.

Ensuring the demographic and genetic viability of small populations of threatened primates requires a range of management approaches. Here we describe a novel mixed in situ and ex situ management project that was developed to restore a population of the Critically Endangered northern muriqui Brachyteles hypoxanthus. This isolated population, located in Ibitipoca, Lima Duarte, Minas Gerais, Brazil, had declined to two adult males and would have gone extinct without intervention. A first attempt at in situ management in 2017 involved the translocation of a solitary female from another region, but this female did not associate or interact with the males and disappeared after 9 months. We thus initiated a second and ongoing ex situ management project that involved constructing a complex consisting of a large, open-air enclosure abutting a small patch of forest surrounded by an open area in the process of restoration, all of which is protected by electric fencing. The entire area within the fencing is called Muriqui House. The two Ibitipoca males and two solitary, wild females from another location were captured and released into the enclosed part of Muriqui House between March 2019 and January 2020 and into the forested part of Muriqui House in February 2020. The birth of an infant in this group in November 2020 and the acceptance by the group of a third female translocated from another area in January 2021 demonstrate the potential of this approach for the recovery of this isolated population, with positive implications for the conservation of the species.

Seahorses Hippocampus spp. are commercially and culturally important to many communities. Although seahorses are widely used in traditional medicine, as curios and as aquarium fishes in Southeast Asia, documentation on the current nature and extent of culturally motivated seahorse uses in Malaysia is lacking. To examine how ethnicity and other socio-demographic drivers shape traditional medicinal use and underlying cultural beliefs involving seahorses, we administered a questionnaire-based survey during March 2021–April 2022 to members of the general public and fishers in Malaysia. Approximately one-fifth (21.0%) of respondents reported consuming seahorses (34.4% of these used seahorses for medicinal purposes, 55.2% for other non-medicinal uses and 10.4% for both types). Consumers of seahorses were from all ethnic groups except for Indigenous groups. In the general public group, medicinal use was more common amongst the Chinese respondents, whereas in the fisher group, other uses were more common amongst the Malay respondents. Amongst the threats facing seahorses, which include overfishing, habitat destruction, bycatch and ocean plastic pollution, only bycatch was perceived as a major threat by most of the general public and fisher respondents. The relatively low prevalence of reported seahorse use amongst Malaysians is an encouraging finding from a conservation perspective. However, the high proportion of non-medicinal uses indicates the need to focus on such other uses to ensure the sustainability of seahorse use in Malaysia.

The Critically Endangered white-bellied heron Ardea insignis is a large-bodied, range-restricted, piscivorous bird of the Himalayan mountains. With fewer than 60 individuals remaining globally, regular monitoring is required for this rare species. We present the results of surveys during 2017 and 2023–2024 in Namdapha Tiger Reserve, Arunachal Pradesh, India. The encounter rate of white-bellied herons in 2017 was 0.55 individuals per km of river, but we did not detect the bird during intensive surveys in the same location during 2023–2024. The surveyed area within the Reserve was once a stronghold for the species, but its population appears to be declining. Monitoring the population has helped reveal this decline, but identifying and conserving stretches of river still utilized by the remaining individuals is now critical.