Microplastics disrupt hermit crab shell selection

Microplastics (plastics < 5 mm) are a potential threat to marine biodiversity. However, the effects of microplastic pollution on animal behaviour and cognition are poorly understood. We used shell selection in common European hermit crabs (Pagurus bernhardus) as a model to test whether microplastic exposure impacts the essential survival behaviours of contacting, investigating and entering an optimal shell. We kept 64 female hermit crabs in tanks containing either polyethylene spheres (n = 35) or no plastic (n = 29) for 5 days. We then transferred subjects into suboptimal shells and placed them in an observation tank with an optimal alternative shell. Plastic-exposed hermit crabs showed impaired shell selection: they were less likely than controls to contact optimal shells or enter them. They also took longer to contact and enter the optimal shell. Plastic exposure did not affect time spent investigating the optimal shell. These results indicate that microplastics impair cognition (information-gathering and processing), disrupting an essential survival behaviour in hermit crabs

Modes of governing municipal waste

From recent debates on governance and governmentality, two key analytical imperatives arise: the need to engage simultaneously with the structures and processes of governing, and the need to recognise the plurality and multiplicity of governing sites and activities. In seeking to address these imperatives, we develop an analytical approach, the modes of governing approach, which engages with the rationalities, agencies, institutional relations, and technologies of governing that coalesce around particular objectives and entities to be governed. Drawing on the example of municipal waste management, we illustrate how this framework can illuminate the dynamic and multiple nature of governing, and outline the key modes of governing which currently shape the policy and practice of municipal waste