Aquatic contaminants in Solomon Islands and Vanuatu: Evidence from passive samplers and Microtox toxicity assessment.

Water Quality issues in many Pacific countries are rising, with the increase in coastal populations and associated urban runoff but management requires contamination issues in the aquatic environment to be identified and prioritised. In Vanuatu and Solomon Islands there are few laboratories and resources to assess for the presence or impact of complex chemical contaminants. The extent and impact of chemical contamination of the marine and coastal environment is poorly described. Passive chemical samplers were used to measure a range of aquatic pollutants around the capital cities, Honiara (Solomon Islands) and Port Vila (Vanuatu). We detected a range of chemicals indicative of agricultural and industrial contamination and a few sites had concerning concentrations of specific hydrocarbons and pesticides. The rapid ecotoxicology test, Microtox, indicated toxic impacts in rivers, coastal sites and urban drains This work provides new data on chemical contamination and possible impacts of that contamination for both countries. The techniques could be applied widely across the region to generate critical data for environmental management, guide monitoring efforts and measure the impact of policy or land-use changes.

Quasi-Isotropic and Pseudo-Ductile Highly Aligned Discontinuous Fibre Composites Manufactured with the HiPerDiF (High Performance Discontinuous Fibre) Technology.

Conventional composite materials reinforced with continuous fibres display high specific strength but have a number of drawbacks including: the elastic-brittle behaviour, difficulties in producing defect-free components of complex shape with high-volume automated manufacturing processes, and inherent lack of recyclability. Highly aligned, discontinuous fibre-reinforced composites (ADFRCs) are truly beneficial for mass production applications, with the potential to offer better formability and comparable mechanical properties with continuous fibre-reinforced composites. In previous publications, the High Performance Discontinuous Fibre (HiPerDiF) technology has been shown to offer the possibility to intimately hybridise different types of fibres, to achieve pseudo-ductile tensile behaviour, and remanufacture reclaimed fibres into high-performance recycled composites. However, to date, the work has been conducted with unidirectional (UD) laminates, which is of limited interest in engineering applications with mechanical stresses acting across many directions; this paper reports, for the first time, the mechanical behaviour of quasi-isotropic (QI) ADFRCs. When compared with randomly-oriented discontinuous fibre composites (RODFRCs), QI ADFRCs offer enhanced stiffness (+26%) and strength (+77%) with higher consistency, i.e., a reduction of the coefficient of variance from the 25% of RODFRCs to the 6% of ADFRCs. Furthermore, hybrid QI ADFRCs retain the pseudo-ductility tensile behaviour previously observed in unidirectional (UD) lay-up.