Microplastic ingestion induces asymmetry and oxidative stress in larvae of the sea urchin Pseudechinus huttoni.

Determining the effects of microplastic (MP) ingestion by marine organisms, especially during the sensitive larval stages, is an important step in understanding wider ecosystem responses. We investigated the ingestion, retention (1-5 µm), and short-term exposure effects (1-4 µm) of spherical MPs by larvae of the sea urchin Pseudechinus huttoni. Larvae ingested MPs in a dose-dependent manner and successfully egested particles after a short retention period. Survival was not significantly affected by exposure to MPs over the 10-day experimental period, however, a teratogenic response in terms of delayed development resulted in an increase of larval arm asymmetry. Additionally, MP exposure resulted in oxidative damage to lipids and proteins in larval body tissue despite a significant upregulation of antioxidant defences. The findings indicate MP exposure may impair cellular function, leading to negative consequences for an organism's fitness and survival.

Microplastic exposure interacts with habitat degradation to affect behaviour and survival of juvenile fish in the field.

Coral reefs are degrading globally due to increased environmental stressors including warming and elevated levels of pollutants. These stressors affect not only habitat-forming organisms, such as corals, but they may also directly affect the organisms that inhabit these ecosystems. Here, we explore how the dual threat of habitat degradation and microplastic exposure may affect the behaviour and survival of coral reef fish in the field. Fish were caught prior to settlement and pulse-fed polystyrene microplastics six times over 4 days, then placed in the field on live or dead-degraded coral patches. Exposure to microplastics or dead coral led fish to be bolder, more active and stray further from shelter compared to control fish. Effect sizes indicated that plastic exposure had a greater effect on behaviour than degraded habitat, and we found no evidence of synergistic effects. This pattern was also displayed in their survival in the field. Our results highlight that attaining low concentrations of microplastic in the environment will be a useful management strategy, since minimizing microplastic intake by fishes may work concurrently with reef restoration strategies to enhance the resilience of coral reef populations.

Self-harm: understanding the causes and treatment options.

Deliberate self-harm rates in the UK are the highest in Europe, and at present, this problem is poorly understood, as there has been little research available to shed light on why such a considerable number of young people are compelled to hurt themselves. The Mental Health Foundation and The Camelot Foundation recently launched a UK-wide inquiry into self-harm among 11-25-year-olds, which aims to produce a practical and thoughtful approach to the prevention and treatment of self-harm in young people, inform future education and training, and provide strategies for service providers.