1. Since the collapse of the Ostrea edulis stock in the mid-1800s the oyster has struggled to re-establish itself in self-sustaining assemblages in Europe. 2.It is now widely recognized that O. edulis is an integral component of a healthy biologically functional benthic environment and, as such, the restoration of wild stocks has become a matter of urgency. 3.A major limiting factor in O. edulis stock recovery is the availability of suitable substrate material for oyster larvae settlement.4. This research re-examined the larval settlement potential of several naturally occurring in-situ shell materials (e.g. Mytilus edulis, Modiolus modiolus, O. edulis), with the aim of determining which shell material is the most appropriate for large-scale restoration projects. 5.A positive correlation between available shell material and settlement was determined, and analysis using PERMANOVA did not identify an attachment preference by O. edulis to any particular shell type.6. The findings suggest that if restoration efforts were coordinated with applied hydrodynamic and habitat suitability modelling, in conjunction with naturally occurring shell substrate concentrations, a cost-effective recovery for O. edulis assemblages in the wild could be achieved.

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Biosecurity protocols designed to prevent invader spread have become integral to invasive species management strategies. However, application of many proposed spread-prevention practices is inhibited due to low practicality, high expense, undesirable non-target effects and a lack of known efficacy. Here, we examine the use of direct steam exposure to induce substantial fragment (i.e. propagule stage) degradation of seven invasive macrophytes: Ceratophyllum demersum, Crassula helmsii, Egeria densa, Elodea canadensis, Elodea nuttallii, Lagarosiphon major and Potamogeton crispus. Each species was independently exposed to steam treatments in loose clumps of three fragments, steamed at a distance of 2-3 cm from the source, for varied exposure times: 10 s, 30 s, 1 min, 2 min, and 5 min. Furthermore, we develop and apply a novel degradation scale describing visual tissue biodegradation stages and/or resumption of growth for fragmentary propagules. Steam treatments were observed to be highly efficacious, with total degradation being induced by 10 s of direct steam exposure. This was apparent for all species following a seven day recovery period, except C. demersum, which took until 21 days. Conversely, control specimens displayed excellent survival and/or viability (i.e. resumption of growth). Therefore, we argue that this innovative, yet simple technique can be used to improve biosecurity practices to inhibit the spread of invasive macrophytes.

To date there is no gold standard for sampling microplastics. Zooplankton sampling methods, such as plankton and Neuston nets, are commonly used to estimate the concentrations of microplastics in seawater, but their ability to detect microplastics is limited by their mesh size. We compared different net-based sampling methods with different mesh sizes including bongo nets (>500µm), manta nets (>300µm) and plankton nets (>200µm and >400µm) to 1 litre bottle grabbed, filtered (0.45µm) samples. Concentrations of microplastics estimated using net-based methods were ~3 orders of magnitude less than those estimated by 1 litre grab samples. Some parts of the world with low human populations, such as Ascension Island and the Falkland Islands, lack baseline data on microplastics. Using the bottle grab sampling method we found that microplastic litter was present at these remote locations and was comparable to levels of contamination in more populated coastal regions, such as the United Kingdom.