Significance: High concentrations of floating plastic debris have been reported in remote areas of the ocean, increasing concern about the accumulation of plastic litter on the ocean surface. Since the introduction of plastic materials in the 1950s, the global production of plastic has increased rapidly and will continue in the coming decades. However, the abundance and the distribution of plastic debris in the open ocean are still unknown, despite evidence of affects on organisms ranging from small invertebrates to whales. In this work, we synthetize data collected across the world to provide a global map and a first-order approximation of the magnitude of the plastic pollution in surface waters of the open ocean.

Atlantic surface circulation transports high loads of plastic debris to remote Arctic waters.

The increasing number of invasive species and their effects on wildlife conservation, together with a lack of public resources, make it necessary to prioritize management actions. In practice, management decisions are often reached on the basis of subjective reasoning rather than scientific evidence. To develop a more evidence-based and efficient management of biological invasions, decision tools (e.g. multi-criteria frameworks) that help managers prioritize actions most efficiently are key. In this paper we review to what degree such decision tools are currently available. We used a literature search to identify relevant studies. Our analysis indicates that available studies are largely biased towards risk analysis and that only a few authors have proposed cost-benefit or multi-criteria frameworks for decision making. Until now, these frameworks have only been applied at limited regional scales but they could be applied more widely. Our review also shows critical biases in the geographical focus, habitats, and taxonomic groups of available studies. Most studies have focused on Europe, North America or Australia; other continents have largely been ignored. The majority of studies have focused on terrestrial plants; other habitats and taxonomic groups have been poorly covered. Most studies have focused on a single invasive species but practical management tools should consider a wide variety of invaders. We conclude with suggestions for developing improved decision tools.