Human impacts and Anthropocene environmental change at Lake Kutubu, a Ramsar wetland in Papua New Guinea.

The impacts of human-induced environmental change that characterize the Anthropocene are not felt equally across the globe. In the tropics, the potential for the sudden collapse of ecosystems in response to multiple interacting pressures has been of increasing concern in ecological and conservation research. The tropical ecosystems of Papua New Guinea are areas of diverse rainforest flora and fauna, inhabited by human populations that are equally diverse, both culturally and linguistically. These people and the ecosystems they rely on are being put under increasing pressure from mineral resource extraction, population growth, land clearing, invasive species, and novel pollutants. This study details the last ∼90 y of impacts on ecosystem dynamics in one of the most biologically diverse, yet poorly understood, tropical wetland ecosystems of the region. The lake is listed as a Ramsar wetland of international importance, yet, since initial European contact in the 1930s and the opening of mineral resource extraction facilities in the 1990s, there has been a dramatic increase in deforestation and an influx of people to the area. Using multiproxy paleoenvironmental records from lake sediments, we show how these anthropogenic impacts have transformed Lake Kutubu. The recent collapse of algal communities represents an ecological tipping point that is likely to have ongoing repercussions for this important wetland's ecosystems. We argue that the incorporation of an adequate historical perspective into models for wetland management and conservation is critical in understanding how to mitigate the impacts of ecological catastrophes such as biodiversity loss.

The cascading pathogenic consequences of Sarcoptes scabiei infection that manifest in host disease.

Sarcoptic mange, caused by the parasitic mite Sarcoptes scabiei, causes a substantive burden of disease to humans, domestic animals and wildlife, globally. There are many effects of S. scabiei infection, culminating in the disease which hosts suffer. However, major knowledge gaps remain on the pathogenic impacts of this infection. Here, we focus on the bare-nosed wombat host (Vombatus ursinus) to investigate the effects of mange on: (i) host heat loss and thermoregulation, (ii) field metabolic rates, (iii) foraging and resting behaviour across full circadian cycles, and (iv) fatty acid composition in host adipose, bone marrow, brain and muscle tissues. Our findings indicate that mange-infected V. ursinus lose more heat to the environment from alopecia-affected body regions than healthy individuals. Additionally, mange-infected individuals have higher metabolic rates in the wild. However, these metabolic demands are difficult to meet, because infected individuals spend less time foraging and more time inactive relative to their healthy counterparts, despite being outside of the burrow for longer. Lastly, mange infection results in altered fatty acid composition in adipose tissue, with increased amounts of omega-6 acids, and decreased amounts of omega-3 acids, a consequence of chronic cutaneous inflammation and inhibition of anti-inflammatory responses. These findings highlight the interactions of mange-induced physiological and behavioural changes, and have implications for the treatment and rehabilitation of infected individuals.

A bioarchaeological analysis of oral and physiological health on the south coast of New Guinea.

OBJECTIVES: The south coast of New Guinea has a complex prehistory known for its exchange systems that linked distinct cultural groups living along the coast, inland, and on offshore islands. Here we compare the palaeohealth of two relatively contemporaneous skeletal samples from the south coast of New Guinea (850-200 BP) that were from two ecologically different sites (one inland and one offshore island) and likely represent distinct cultural groups. We aim to elucidate health patterns that may provide information about the specific lifeways and quality of life of each community. MATERIALS AND METHODS: Oral conditions (caries, calculus, alveolar lesions, and antemortem tooth loss [AMTL]) were analyzed macroscopically to assess possible intra- and inter-population variation in oral and physiological health. The frequency of linear enamel hypoplasia (LEH) was also used as a nonspecific indicator of stress to assess childhood health at each site. RESULTS: The inhabitants from the small offshore island of Motupore, thought to be associated with Austronesian-speaking Motu tribes, displayed different patterns of oral pathological conditions (more carious lesions on the tooth crown and calculus) and LEH (lower frequencies) compared with inland people residing at the site of Nebira. DISCUSSION: It is suggested that the causes for the variation in oral and physiological health were likely multifactorial and potentially associated with variables such as the ecological and geographical settings of the sites, cultural differences, infectious disease, differential fertility and, potentially, diet. This research provides previously unknown information about possible culturally-moderated practices that affected health in the past. Am J Phys Anthropol 160:414-426, 2016. © 2016 Wiley Periodicals, Inc.