The New Guinea freshwater turtle, Elseya novaeguineae (senu lato) is a long-term, widespread resident of New Guinea and has been subject to substantial vicariance in one of the most geologically dynamic regions on earth. Thus, it should come as no surprise that the taxonomy of this turtle is poorly resolved. Elseya novaeguineae has long been recognized as a species complex, though which elements of this taxon warrant recognition as separate species has been debated. In this paper, we restrict Elseya novaeguineae to the Birds Head region of New Guinea, west of the Langguru Thrust and Fold Belt; we resurrect from synonymy Elseya schultzei for the populations north of the Central Ranges; and we describe a new species for the populations to the south of the Central Ranges. We revisit the classification of the genus Elseya throughout its range in the light of our work and recently published reports, and erect three subgenera that recognize the three major clades within this genus. Subgenus Elseya is the nominate subgenus, to which we assign Elseya dentata, E. branderhorsti and undescribed E. sp. aff. dentata [Sth Alligator]. Elseya novaeguineae, E. schultzei and our new species are assigned to a new subgenus, Hanwarachelys. Species of northern and eastern Queensland, E. albagula, E. irwini, E. lavarackorum and the fossil taxa E. uberrima and E. nadibajagu, are assigned to subgenus Pelocomastes, resurrected from synonymy.

Sawfish (Pristidae) are considered to be among the most threatened families of elasmobranch (sharks and rays). There is a need to gather information on the status of poorly known sawfish populations to assist in global recovery initiatives. This study used interviews with local fishers to investigate the presence of sawfish in southern Papua New Guinea (PNG) and their interactions with and uses and values for small‐scale fishers. A range of sawfish size classes are still encountered throughout southern PNG, while juvenile largetooth sawfish Pristis pristis were additionally reported in the freshwater reaches of all rivers surveyed. Reports of large size classes in estuarine and marine environments provide an optimistic outlook that sawfish populations persist throughout southern PNG. Most fishers that catch sawfish retain them for various uses including consumption and for the sale of meat, fins and occasionally rostra. Negative population trends including decreases in catch frequency and/or size classes were reported by 66% of interviewees, with the largest declines being reported in the Kikori River. The increasing technical capacity of small‐scale fishers, their preference for gillnetting and the emerging market for teleost swim bladder (a high‐value fishery product) present a major ongoing threat to sawfish in southern PNG. Furthermore, the tendency of fishers to kill or remove rostra from entangled sawfish results in high fishing mortality regardless of any use by the fisher. This study indicates that considerable community engagement will be necessary to manifest any legislative actions or increased enforcement on international trade regulations for sawfish in PNG. This is due to traditional land and waterway ownership values throughout PNG and the local perception of sawfish as a traditional food resource rather than an animal of intrinsic biodiversity value as perceived by global conservationists. Future research should consider exploring culturally appropriate conservation initiatives that are likely to achieve engagement and participation from local fishers.

The conservation of threatened elasmobranchs in tropical regions is challenging due to high local reliance on aquatic and marine resources. Due primarily to fishing pressure, river sharks (Glyphis) and sawfishes (Pristidae) have experienced large population declines in the Indo-Pacific. Papua New Guinea (PNG) may offer a refuge for these species, as human population density is low, and river shark and sawfish populations are thought to persist. However, few data are available on these species in PNG, and risk posed by small-scale fishers is poorly understood. This study observed elasmobranch catches in small-scale fisheries in riverine and coastal environments in the East Sepik (northern region), Gulf, and Western Provinces (southern region) of PNG. Surveys were conducted over a period of weeks to months in each region, during the dry season across seven field trips from 2017 to 2020. We observed a total of 783 elasmobranchs encompassing 38 species from 10 families. River sharks made up 29.4% of observations in the southern region, while sawfishes made up 14.8 and 20.3% in the northern and southern regions, respectively. River sharks were commonly caught by small-scale fishers in lower riverine environments in southern PNG, while sawfishes were generally less common and mainly observed through dried rostra. The primary threat to river shark and sawfish populations is their capture by small-scale fishers targeting teleosts for swim bladder. Persisting populations of river sharks and sawfishes indicate that PNG is the second known nation with viable populations of multiple species in the Indo-Pacific. However, populations are declining or at high risk of decline, and fisheries management and conservation are required to realize the potential of PNG as a long-term refuge.

The amphibian chytrid fungus Batrachochytrium dendrobatidis (chytrid) has caused the most widespread, disease‐induced declines and extinctions in vertebrates recorded to date. The largest climatically suitable landmass that may still be free of this fungus is New Guinea. The island is home to a sizeable proportion of the world's known frog species (an estimated 6%), as well as many additional, yet‐to‐be‐described species. Two decades of research on the chytrid fungus have provided a foundation for improved management of amphibian populations. We call for urgent, unified, international, multidisciplinary action to prepare for the arrival of B dendrobatidis in New Guinea, to prevent or slow its spread within the island after it arrives, and to limit its impact upon the island's frog populations. The apparent absence of the fungus in New Guinea offers an opportunity to build capacity in advance for science, disease surveillance, and diagnosis that will have broad relevance both for non‐human animal health and for public health.

Emerging infectious diseases threaten the persistence of biodiversity globally. The amphibian chytrid fungus, Batrachochytrium dendrobatidis, is one of the most widespread and damaging pathogens to biodiversity. New Guinea hosts 6% of the world's frogs and is the largest landmass where B. dendrobatidis remains undetected despite being largely climatically suitable for its persistence. We surveyed for B. dendrobatidis in Papua New Guinea, by swabbing live frogs in the Gulf Province and Eastern Highlands Province and by examining museum specimens from a range of sites and elevations. Here, we show that over a large geographical range, all 442 samples were negative for B. dendrobatidis. The spread of B. dendrobatidis to Papua New Guinea may have been thus far prevented by the remoteness of New Guinea and the hotter climate in its lowlands, which surrounds a more climatically suitable zone for B. dendrobatidis in the highlands. Alternatively, B. dendrobatidis may be present in isolated patches or at low levels and remain undetected, to date. Papua New Guinea remains at risk and would benefit from a national disease surveillance program for chytrid fungi and pre‐emptive actions, designed to reduce the risk of pathogen transmission. Measures should include improved biosecurity protocols for trade and travel and continued disease surveillance in areas of probable entry and spread.