A cost-effective method to quantify biological surface sediment reworking

We propose a simple and inexpensive method to determine the rate and pattern of surface sediment reworking by benthic organisms. Unlike many existing methods commonly used in bioturbation studies, which usually require sediment sampling, our approach is fully non-destructive and is well suited for investigating non-cohesive fine sediments in streams and rivers. Optical tracer (e.g., luminophores or coloured sand) disappearance or appearance is assessed through time based on optical quantification of surfaces occupied by tracers. Data are used to calculate surface sediment reworking (SSR) coefficients depicting bioturbation intensities. Using this method, we evaluated reworking activity of stream organisms (three benthic invertebrates and a fish) in laboratory microcosms mimicking pool habitats or directly in the field within arenas set in depositional zones. Our method was sensitive enough to measure SSR as low as 0.2 cm2.d-1, such as triggered by intermediate density (774 m-2) of Gammarus fossarum (Amphipoda) in microcosms. In contrast, complex invertebrate community in the field and a fish (Barbatula barabatula) in laboratory microcosms were found to yield to excessively high SSR (>60 cm2.d-1). Lastly, we suggest that images acquired during experiments can be used for qualitative evaluation of species-specific effects on sediment distribution

Gendered Risk Perceptions Associated with Human-Wildlife Conflict: Implications for Participatory Conservation

This research aims to foster discourse about the extent to which gender is important to consider within the context of participatory approaches for biological conservation. Our objectives are to: (1) gender-disaggregate data about stakeholders' risk perceptions associated with human-wildlife conflict (HWC) in a participatory conservation context, and (2) highlight insights from characterizing gendered similarities and differences in the way people think about HWC-related risks. Two communal conservancies in Caprivi, Namibia served as case study sites. We analyzed data from focus groups (n = 2) to create gendered concept maps about risks to wildlife and livelihoods and any associations of those risks with HWC, and semi-structured interviews (n = 76; men = 38, women = 38) to measure explicit risk attitudes associated with HWC. Concept maps indicated some divergent perceptions in how groups characterized risks to wildlife and livelihoods; however, not only were identified risks to wildlife (e.g., pollution, hunting) dissimilar in some instances, descriptions of risks varied as well. Study groups reported similar risk perceptions associated with HWC with the exception of worry associated with HWC effects on local livelihoods. Gendered differences in risk perceptions may signal different priorities or incentives to participate in efforts to resolve HWC-related risks. Thus, although shared goals and interests may seem to be an obvious reason for cooperative wildlife management, it is not always obvious that management goals are shared. Opportunity exists to move beyond thinking about gender as an explanatory variable for understanding how different groups think about participating in conservation activities

Designing marine reserves to reflect local socioeconomic conditions: lessons from long-enduring customary management systems

Coral reef conservation strategies such as marine protected areas have met limited success in many developing countries. Some researchers attribute part of these shortcomings to inadequate attention to the social context of conserving marine resources. To gain insights into applying Western conservation theory more successfully in the socioeconomic context of developing countries, this study examines how long-enduring, customary reef closures appear to reflect local socioeconomic conditions in two Papua New Guinean communities. Attributes of the customary management (including size, shape, permanence, and gear restrictions) are examined in relation to prevailing socioeconomic conditions (including resource users’ ability to switch gears, fishing grounds, and occupations). Customary closures in the two communities appear to reflect local socioeconomic circumstances in three ways. First, in situations where people can readily switch between occupations, full closures are acceptable with periodic harvests to benefit from the closure. In comparison, communities with high dependence on the marine resources are more conducive to employing strategies that restrict certain gear types while still allowing others. Second, where there is multiple clan and family spatial ownership of resources, the communities have one closure per clan/family; one large no-take area would have disproportionate affect on those compared to the rest of the community. In contrast, communities that have joint ownership can establish one large closure as long as there are other areas available to harvest. Third, historical and trade relationships with neighboring communities can influence regulations by creating the need for occasional harvests to provide fish for feasts. This study further demonstrates the importance of understanding the socioeconomic context of factors such as community governance and levels of dependence for the conservation of marine resources