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Abstract Research on marine microplastics continues to increase in popularity, with a large number of studies being published every year. However, with this plethora of research comes the need for a standardised approach to quantification and analysis procedures in order to produce comparative assessments. Using data collected from neuston nets in 2016, parameters for quantifying microplastics were compared. Surface area was the most accurate parameter to describe plastic size and should be used to describe plastic quantity (per km2 or m3), alongside abundance. Of the two most commonly used methods for calculating plastic concentration (flowmeter and ship's log), ship's log provided consistently smaller abundances, with the exception of one sample, calling for a standardisation in the techniques and measurements used to quantify floating microplastics. Highlights • Enumeration should not be used in isolation to quantify microplastics. • Surface area is the most accurate parameter for describing particle size. • Area sampled, measured via flowmeter and ship's log, cannot be reliably compared. • More detailed methodologies should be reported for data comparison to be possible. • Summary statistics and/or raw data describing whole datasets should be presented. [ABSTRACT FROM AUTHOR]

There is growing evidence of extensive pollution of the environment by microplastic, with microfibres representing a large proportion of the microplastics seen in marine sediments. Since microfibres are ubiquitous in the environment, present in the laboratory air and water, evaluating microplastic pollution is difficult. Incidental contamination is highly likely unless strict control measures are employed. Here we describe methods developed to minimize the amount of incidental post-sampling contamination when quantifying marine microfibre pollution. We show that our protocol, adapted from the field of forensic fibre examination, reduces fibre abundance by 90% and enables the quick screening of fibre populations. These methods therefore allow an accurate estimate of microplastics polluting marine sediments. In a case study from a series of samples collected on a research vessel, we use these methods to highlight the prevalence of microfibres as marine microplastics. [ABSTRACT FROM AUTHOR]

Bumblebees are ecologically and economically important, and some species have suffered dramatic population declines. The absence of morphological diagnostic characters for the identification of some species creates difficulties for basic ecological studies, and for conservation management. The widespread and commercially exploited bumblebee subgenus Bombus sensu stricto contains a cryptic species complex, known as the lucorum complex, which in Europe comprises B. lucorum , B. cryptarum and B. magnus . Little is known about these species and much of what has been reported is likely to have suffered from incorrect identification. Although the lucorum complex as a whole is common in Great Britain, we aimed to determine whether the populations of the individual species are vulnerable and require conservation action. Using genetic methods to distinguish them, we determined the geographic distribution and abundance of the lucorum complex species in Great Britain, and assessed the extent of niche differentiation between these species. We detected major differences in the geographic range, forage use and sensitivity to summer temperatures of the three species. Bombus lucorum was found to have the broadest distribution and diet, being present throughout mainland Great Britain, whereas B. cryptarum and B. magnus were absent from large areas of central and southern England. Bombus cryptarum and B. magnus were more likely to be found at sites with lower summer temperatures. Bombus magnus , the least abundant species, was found to exhibit an unusually tight biotope association with heathland habitat. This has conservation implications for B. magnus given the current threats to this habitat type. [ABSTRACT FROM AUTHOR]

• A rapid-assessment tool to support plastic pollution policy is presented. • Provides plastic waste flow analysis and visualization of policy instrument impacts. • Suitable for use in countries where data, technical and human capacity is limited. • Motivated Maldives Government to announce ambitious plastic phase out strategy. • Collaborative approach identified policies to achieve 85% less plastic pollution. Governments are increasingly supporting initiatives to address plastic pollution, but efforts are largely opportunistic or driven by national socio-political priorities. There is an urgent need to move away from piecemeal single product instruments (e.g. single use plastic bag taxes or plastic straw bans) to deliver system-wide strategies that minimise the most pervasive sources of plastic pollution. Developing a common understanding of a jurisdiction's plastic waste stream and the solutions available to decision-makers is vital to build consensus across stakeholders and to align on an evidence-based portfolio of priority instruments. This paper presents the Plastic Drawdown framework as a boundary-spanning tool to quickly create a coherent, relevant, and credible analysis and visualisation for stakeholders of plastic waste, leakage hotspots and minimisation opportunities. Using a new plastic waste modelling framework with a consultative structure, Plastic Drawdown explores plastic waste and leakage over a ten-year period and assesses impacts of policy instruments on this projection. Plastic Drawdown is adaptable to the data poor environment typical of many countries and designed as a rapid assessment tool to support the decision making of governments operating in a highly resource-constrained context. The Maldives is used as a case study to show the utility of the tool, where it highlighted strategies with the potential to reduce leakage of plastic waste into the marine environment by up to 85% by 2030. Plastic Drawdown built the case for phasing out single-use plastic waste across the Maldives and supported the Government's decision to set ambitious targets, as announced at the United Nations General Assembly in 2019. [ABSTRACT FROM AUTHOR]

Deep-water sedimentary habitats off Nova Scotia have only rarely been explored. The topographically and oceanographically complex shelf of Nova Scotia harbours two interesting topographic features, Emerald Basin, a sedimentary habitat reaching greater depths (max of 270 m) than the surrounding shelf and the Gully, the largest canyon in NW Atlantic. Emerald Basin is exposed to upwellings of slope water and harbours predominantly deep-sea hexactinellid sponges. Such distributional pattern resembles “deep-water emergence”. In this study an abundant benthic group, the polychaetes, were selected to test for such deep-water faunal link. Qualitative boxcores were collected from Emerald Basin (180 m depth, N  = 5) and the adjacent Gully Canyon (1600 m, N  = 3). At species level, there was no overlap in distribution between Emerald Basin (N = 73, S=29) and Gully Canyon (N = 351, S = 60) fauna based on morphological assessment of all specimens and molecular analysis (COI and 16S markers) of selected morphotypes. In an alternative approach, Multivariate analysis (nMDS, Cluster Analysis) of incidence data for polychaete genera (N = 179) from 24 Atlantic sites (5–1600 m) was carried out. These results showed a greater similarity of Emerald Basin polychaetes to bathyal sites (400–1000 m), particularly the 680 m site off Nova Scotia rather than shelf sites (5–80 m), including those on the Nova Scotia shelf. Thus, at 1600 m, the Gully Canyon samples were likely “too deep” for our comparative purposes and depths of < 1000 m should be targeted in the future. Our data also provide the first published assessment of polychaete diversity from the Gully Canyon, suggesting the presence of a diverse assemblage (S = 60). Unusually for a deep-sea site, the Gully Canyon polychaetes are mostly known taxa with wider distribution across bathyal NW Atlantic. Additionally, our molecular data provide an interesting insights into the distribution of several polychaete species commonly found in deep-sea (e.g Aurospio dibranchiata Maciolek, 1981; Ophelina abranchiata Støp-Bowitz, 1948) suggesting wide geographical distribution for some but revealing species complexes for others. [ABSTRACT FROM AUTHOR]

Abstract Zooplankton form a trophic link between primary producers and higher trophic levels, and exert significant influence on the vertical transport of carbon through the water column ('biological carbon pump'). Using a MultiNet we sampled and studied mesozooplankton communities (i.e. >0.2 mm) from six locations around Bermuda targeting four depth zones: ∼0–200 m, ∼200–400 m, ∼400–600 m (deep-scattering layer), and ∼600–800 m. Copepoda, our focal taxonomic group, consistently dominated samples (∼80% relative abundance). We report declines in zooplankton and copepod abundance with depth, concurrent with decreases in food availability. Taxonomic richness was lowest at depth and below the deep-scattering layer. In contrast, copepod diversity peaked at these depths, suggesting lower competitive displacement in these more food-limited waters. Finally, omnivory and carnivory, were the dominant trophic traits, each one affecting the biological carbon pump in a different way. This highlights the importance of incorporating data on zooplankton food web structure in future modelling of global ocean carbon cycling. Highlights • Zooplankton and copepod abundance decreased from 0 to 800 m in Bermuda. • Copepods dominated across all depths, followed by ostracods and chaetognaths. • Zooplankton diversity dipped at 600–800 m, while the reverse was true for copepods. • Omnivory and carnivory were the dominant trophic traits. • Zooplankton food web structure should be considered in ocean carbon cycling models. [ABSTRACT FROM AUTHOR]