The Ballast Water Management Convention (BWMC) establishes limits for viable organisms in discharged ballast water. However, organisms smaller than 10 μm are not considered in this regulation although they represent, in some regions, the majority of the phytoplankton organisms in marine water. The objective in this study is to assess three photosynthetic species smaller than 10 μm as potential standard test organism (STO) in experimentation focused on the inactivating efficacy of ultraviolet treatments (UV). A growth modelling method was employed to determine the reduction of the viable cell concentration under either light or dark post-treatment conditions to evaluate the importance of the photoreactivation. In spite of its moderate growth rate, the high UV resistance in combination with the abundance and worldwide distribution of Synechococcus sp. and the environmental importance of this species constitute important reasons for considering Synechococcus sp. as a valuable STO for ballast water treatment.

The Ballast Water Management Convention (BWMC) establishes limits for viable organisms in discharged ballast water. However, organisms smaller than 10 μm are not considered in this regulation although they represent, in some regions, the majority of the phytoplankton organisms in marine water. The objective in this study is to assess three photosynthetic species smaller than 10 μm as potential standard test organism (STO) in experimentation focused on the inactivating efficacy of ultraviolet treatments (UV). A growth modelling method was employed to determine the reduction of the viable cell concentration under either light or dark post-treatment conditions to evaluate the importance of the photoreactivation. In spite of its moderate growth rate, the high UV resistance in combination with the abundance and worldwide distribution of Synechococcus sp. and the environmental importance of this species constitute important reasons for considering Synechococcus sp. as a valuable STO for ballast water treatment. | This work has been co-funded by the 2014–2020 ERDF Operational Programme and by the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia (Spain). Projects Ref.: FEDER-UCA18 - 108023 and FEDER-UCA18-105151. | Peer reviewed

The Ballast Water Management Convention (BWMC) establishes limits for viable organisms in discharged ballast water. However, organisms smaller than 10 μm are not considered in this regulation although they represent, in some regions, the majority of the phytoplankton organisms in marine water. The objective in this study is to assess three photosynthetic species smaller than 10 μm as potential standard test organism (STO) in experimentation focused on the inactivating efficacy of ultraviolet treatments (UV). A growth modelling method was employed to determine the reduction of the viable cell concentration under either light or dark post-treatment conditions to evaluate the importance of the photoreactivation. In spite of its moderate growth rate, the high UV resistance in combination with the abundance and worldwide distribution of Synechococcus sp. and the environmental importance of this species constitute important reasons for considering Synechococcus sp. as a valuable STO for ballast water treatment.

Media attention to marine plastic pollution is increasing, yet it is unclear which topics are being discussed. This paper analyses all 2019 news articles referencing marine plastics in the four leading UK online newspapers. Examining 943 articles in a structural topic model, this is the first analysis to depict what is being reported and how this varied according to political alignment (right vs. left-wing), type (broadsheet vs. tabloid), and publication date. We identified 36 topics, suggesting a large variety in the coverage, with plastic pollution ranging from the primary focus to only mentioned in passing. Greater emphasis was on explaining current issues of marine plastics, with limited reference to actionable reduction measures or producer responsibility. Many topics' prevalence varied across the media outlets. We discuss how this coverage varies across media outlets, and how it relates to a broader context (i.e. potential links to behaviour and current policy efforts).

Media attention to marine plastic pollution is increasing, yet it is unclear which topics are being discussed. This paper analyses all 2019 news articles referencing marine plastics in the four leading UK online newspapers. Examining 943 articles in a structural topic model, this is the first analysis to depict what is being reported and how this varied according to political alignment (right vs. left-wing), type (broadsheet vs. tabloid), and publication date. We identified 36 topics, suggesting a large variety in the coverage, with plastic pollution ranging from the primary focus to only mentioned in passing. Greater emphasis was on explaining current issues of marine plastics, with limited reference to actionable reduction measures or producer responsibility. Many topics' prevalence varied across the media outlets. We discuss how this coverage varies across media outlets, and how it relates to a broader context (i.e. potential links to behaviour and current policy efforts). [Abstract copyright: Copyright © 2021 Elsevier Ltd. All rights reserved.]

Although mercury (Hg) in polar ecosystems has been well-studied, there is little information on Hg in the Arctic during low-productivity seasons like the polar night. We quantified Hg concentrations, carbon, and nitrogen stable isotope ratios (δ¹³C and δ¹⁵N) in the muscle of polar cod (Boreogadus saida), Atlantic cod (Gadus morhua), and capelin (Mallotus villosus) sampled from the North-West and North-East Barents Sea during November–December 2019. Hg concentrations varied between species (14–175 ng/g dw), dependent on region, but were well below the toxicity threshold for fish health and the EU-accepted threshold for human consumption. Interspecific differences were observed only in the North-East region, with Atlantic cod having highest Hg concentrations, explained by its larger size, higher trophic position and benthopelagic feeding. Spatial differences in polar cod with higher Hg concentrations in the North-East than the North-West were likely due to a combination of differences in food web structure and Hg exposure.

Although mercury (Hg) in polar ecosystems has been well-studied, there is little information on Hg in the Arctic during low-productivity seasons like the polar night. We quantified Hg concentrations, carbon, and nitrogen stable isotope ratios (δ13C and δ15N) in the muscle of polar cod (Boreogadus saida), Atlantic cod (Gadus morhua), and capelin (Mallotus villosus) sampled from the North-West and North-East Barents Sea during November–December 2019. Hg concentrations varied between species (14–175 ng/g dw), dependent on region, but were well below the toxicity threshold for fish health and the EU-accepted threshold for human consumption. Interspecific differences were observed only in the North-East region, with Atlantic cod having highest Hg concentrations, explained by its larger size, higher trophic position and benthopelagic feeding. Spatial differences in polar cod with higher Hg concentrations in the North-East than the North-West were likely due to a combination of differences in food web structure and Hg exposure.

One of the ambitions of the UN Decade of Ocean Science is stakeholder interaction to co-produce new ideas and solutions for policy action plans to ensure that environmental challenges are mitigated in a timely manner. Regulations around the release of microfibres are largely lacking, and we are at an excellent point of departure to test integrative methods of such co-production. We co-designed conceptual maps and Bayesian Belief Networks with probabilistic future scenarios within both inter- and intra-sectoral workshops with industry and scientific stakeholders to gain comparable results of policy action scenarios for curbing the challenge of microfibre pollution within this context. We found that when scientists worked on this alone, their focus was different than when working together with industry directly. Scientists focused on methods for avoiding release into the environment from a technical vantage point, whereas industry emphasized regulatory requirements needed to avoid ambiguity within the sector.

One of the ambitions of the UN Decade of Ocean Science is stakeholder interaction to co-produce new ideas and solutions for policy action plans to ensure that environmental challenges are mitigated in a timely manner. Regulations around the release of microfibres are largely lacking, and we are at an excellent point of departure to test integrative methods of such co-production. We co-designed conceptual maps and Bayesian Belief Networks with probabilistic future scenarios within both inter- and intra-sectoral workshops with industry and scientific stakeholders to gain comparable results of policy action scenarios for curbing the challenge of microfibre pollution within this context. We found that when scientists worked on this alone, their focus was different than when working together with industry directly. Scientists focused on methods for avoiding release into the environment from a technical vantage point, whereas industry emphasized regulatory requirements needed to avoid ambiguity within the sector. | publishedVersion