Fouling release coatings (FRCs) can become damaged and diminished over exposure. Quantifying adverse effect of scratches on FRCs is crucial for damage control. This study investigated the effect of four pre-defined scratches on the re-fouling of a silicone-based FRC (SiFR) undergoing underwater cleaning utilizing a novel automated underwater cleaning system (AUCS). Moreover, barnacle adhesion and coating detachment formation of scratched SiFR were evaluated. Field testing at the CoaST Maritime Test Centre (CMTC) demonstrated that the scratches varying in depths and widths can significantly affect the biofouling behavior and cleaning efficiency of SiFR surface. For wide scratches (i.e. 3-mm-wide), hard fouling (e.g. barnacles, mussels) was more prone to accumulate, and underwater cleaning was effective in preventing hard fouling but not soft fouling on SiFR surface. Additionally, the re-fouling and cleaning difficulty of hard fouling increased with the depth of wide scratches. For narrow scratches (i.e. <50-μm-wide), SiFR was primarily attached by soft fouling (e.g. biofilm, algae), and underwater cleaning performed positive fouling resistance of algae but not biofilm on SiFR surface. Besides, algae became difficult to remove with the depth of narrow scratches. Notably, biweekly cleaning proved to be highly effective in biofouling control of SiFR with narrow and shallow scratches.
The BBNJ Agreement will affect legal frameworks for the conservation of marine biological diversity in various regions of the world ocean and the marine Arctic is no exception. As biological diversity in the marine Arctic is particularly vulnerable, the implications of the BBNJ Agreement for the conservation of biological diversity in the marine Arctic deserves serious consideration. Of particular note is the procedure for an environmental impact assessment (EIA). Given that damage to the environment may be irreversible, it is a prerequisite to conduct an EIA before authorizing planned activities, with a view to preventing environmental harm. An EIA constitutes a crucial element in the conservation of the marine environment, including biological diversity. Hence, this article examines the potential implications of the procedure for an EIA as set out under the BBNJ Agreement for the conservation of biological diversity in the marine Arctic beyond national jurisdiction.
The effectiveness of fouling release coatings (FRCs) may diminish over time in the seawater. Underwater cleaning of FRCs in service is crucial for biofouling control. This study investigated the effects of cleaning parameters (brush moving speed, cleaning force and frequency) on a silicone-based FRC (SiFR) aged for 2 months (A2-SiFR) and 13 months (A13-SiFR), simulating the short-term and long-term FRCs in service. Fouling resistance, re-fouling and cleaning efficiency utilizing a self-designed automated underwater cleaning system (AUCS) were examined. Moreover, coating surface characterization, including visual appearance condition, roughness, water contact angle were evaluated on the testing surfaces. Field testing at the CoaST Maritime Test Centre (CMTC) demonstrated that underwater cleaning exhibited positive effect on the long-term fouling control performance of aged FRCs. Besides, stronger cleaning force, slower moving speed and biweekly cleaning led to better fouling resistance. No significant damages were observed on A2-SiFR surface, while regular spiral and circular scratches appeared on A13-SiFR surface. The damages led to adverse effects on fouling resistance, re-fouling and cleaning efficiency of algae on the cleaned A13-SiFR surface, affecting the coating performance more than cleaning parameters. Despite these damages, the cleaned surfaces still exhibited a higher fouling resistance compared with the ones without cleaning.
Antifouling properties of unmodified kraft lignin for potential use in marine coatings were investigated. The study was based on preliminary findings that pointed toward lignin’s efficacy against seawater organisms during laboratory tests. Coatings were formulated that contained lignin as a filler and had a pigment volume concentration above the critical pigment volume concentration. This ensured direct interaction between lignin and seawater organisms, as the lignin particles remained incompletely wetted by the binder. Moreover, all formulations were waterborne to mitigate the release of volatile organic compounds. Despite the initial promise, the antifouling performance of the formulated lignin coatings during field experiments at the CoaST Maritime Test Center was limited, and the anticipated mechanism must be reconsidered. Additionally, it was found that high lignin concentrations, while facilitating organism interaction, compromised the coating's mechanical properties. Nevertheless, the waterborne coating formulation introduced here might provide a foundation for other researchers to further investigate lignin’s potential as a bio-based pigment or a filler in coatings.
Despite the relatively rich literature on the omnipresence of microplastics in marine environments, the current status and ecological impacts of microplastics on global Marine Protected Areas (MPAs) are still unknown. Their ubiquitous occurrence, increasing volume, and ecotoxicological effects have made microplastic an emerging marine pollutant. Given the critical conservation roles of MPAs that aim to protect vulnerable marine species, biodiversity, and resources, it is essential to have a comprehensive overview of the occurrence, abundance, distribution, and characteristics of microplastics in MPAs including their buffer zones. Here, extensive data were collected and screened based on 1565 peer-reviewed literature from 2017 to 2020, and a GIS-based approach was applied to improve the outcomes by considering boundary limits. Microplastics in seawater samples were verified within the boundaries of 52 MPAs; after including the buffer zones, 1/3 more (68 MPAs) were identified as contaminated by microplastics. A large range of microplastic levels in MPAs was summarized based on water volume (0–809,000 items/m 3) or surface water area (21.3–1,650,000,000 items/km 2), which was likely due to discrepancy in sampling and analytical methods. Fragment was the most frequently observed shape and fiber was the most abundant shape. PE and PP were the most common and also most abundant polymer types. Overall, 2/3 of available data reported that seawater microplastic levels in MPAs were higher than 12,429 items/km 2, indicating that global MPAs alone cannot protect against microplastic pollution. The current limitations and future directions were also discussed toward the post-2020 Global Biodiversity Framework goals.
This paper presents a wave flume investigation of beaching times for buoyant microplastic particles dropped at various distance from the shoreline. The beaching times are used to quantify the cross-shore Lagrangian transport velocities of the microplastic particles. Results show that prior to breaking, there is little dependence on particle characteristics (e.g. their rise velocity), and the particles travel onshore with a velocity close to the Lagrangian fluid particle velocity. In the surf zone the Lagrangian transport velocities of the microplastic particles increase significantly, becoming closer to the wave celerity. Additionally, particle characteristics become important, as particles with low Dean numbers (high rise velocity) have a greater tendency to be captured by surface rollers relative to particles with larger Dean numbers (lower rise velocity). An empirical relation is formulated for predicting the cross-shore Lagrangian transport velocities of buoyant microplastic particles. The expression matches the present experiments well and is valid for both non-breaking and breaking irregular waves. These findings help in understanding the accumulation of microplastics at beaches due to the surf-zone processes, especially for buoyant particles.
The impact of the growing cruise ship industry on air quality levels was investigated at the port of Copenhagen, Denmark. In 2018, 345 cruise ships visited Copenhagen, emitting 291 tons of NOx near the city centre. A spatiotemporal cruise ship emission inventory was developed for 2018 based on port list information, engine data, main and auxiliary engine power functions, and NOx emission factors, and was implemented in the OML-Multi atmospheric dispersion model. Evident plume effects from the cruise ships, which were traced by introducing the concept of likely concentration contribution, were obtained in the modelled and measured concentrations at Langelinie Quay, which is the busiest cruise ship terminal in Copenhagen port. Hourly peak values of NOx well above 200 μg m−3 were obtained at the top of a residential building at Langelinie Quay. The emissions from cruise ships were increasing the annual concentration of NO2 in the port area by up to 31% at ground level, and 86% 50 m above the ground in comparison to the urban background level. No exceedance of the European annual limit value of NO2 was obtained. The short-term impact of cruise ships was more pronounced with local exceedances of the hourly European limit value for NO2. Increasing cruise ship activity in Copenhagen port leads to air quality deterioration on short time scales with implications for human health.
Aarhus University, DCE - Danish Centre for Environment and Energy, has prepared an overall assessment of the potential environmental impacts from a major release or spill of ammonia in relation to production and transportation of ammonia in a PtX plant or by shipping in Greenland. Three sites were included in the assessment: Kangerlussuaq (Sdr. Strømfjord), Kangerlussuatsiaq (Evighedsfjorden) and Nuup Kangerlua (Godthåbsfjorden). The overall findings shows that a large, worst-case ammonia spill could cause severe toxic damage to organisms during the passage of the ammonia cloud from within a few km to possibly more than 10 km from the source. This could lead to local loss of animal and plant abundance for some years. However, the ammonia will be quickly diluted and degraded and will not be transferred in the food web, and the mortality will not seriously impact plant and animal populations at a regional scale. There could be a fertilising effect of ammonia on the nutrient-poor terrestrial environment lasting for some years.
Rapporter fra flere globale miljøinstitutioner, her
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under den internationale science-policy platform
om biodiversitet og økosystemtjenester (herefter
IPBES), understreger behovet for genopretning af
økosystemer (1,2). Den seneste globale IPBES-rap
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port fra maj 2019 peger således på, at forringelser
af økosystemer på land og i havet underminerer
livsgrundlaget for 3,2 milliarder mennesker. Gen
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opretning bliver fremhævet som en af de vigtig
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ste handlemuligheder for effektivt at begrænse
tabet af biodiversitet og forbedre livsgrundlaget
for os mennesker ved at imødegå forringelser for
en række økosystemtjenester. Det nuværende årti
2021-2030 er af UNEP udpeget til årtiet for genop
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retning med det formål at genetablere ødelagte
eller forarmede økosystemer verden over.
IPBES rapporterne dokumenterer, at biodiversi
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tetskrisen er en altomfattende og global udfor
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dring, og at krisen er på linje med klimakrisen. De
tiltagende klimaændringer er ligeledes en af ho
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vedårsagerne til tab af biodiversitet (2). Der er af
hensyn til begge kriser behov for, at der beskyttes
og genetableres velfungerende og uforstyrrede
økosystemer. Der bør derfor ske en national ud
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møntning af resultaterne fra de internationale aftaler baseret på den bedst tilgængelige viden.
To achieve IMO’s goal of a 50% reduction of GHG emission by 2050 (compared to the 2008 levels), shipping must not only work towards an optimization of each ship and its components but aim for an optimization of the complete marine transport system, including fleet planning, harbour logistics, route planning, speed profiles, weather routing and ship design. ShipCLEAN, a newly developed model, introduces a coupling of a marine transport economics model to a sophisticated ship energy systems model – it provides a leap towards a holistic optimization of marine transport systems. This paper presents how the model is applied to propose a reduction in fuel consumption and environmental impact by speed reduction of a container ship on a Pacific Ocean trade and the implementation of wind assisted propulsion on a MR Tanker on a North Atlantic trade. The main conclusions show that an increase of the fuel price, for example by applying a bunker levy, will lead to considerable, economically motivated speed reductions in liner traffic. The case study sowed possible yearly fuel savings of almost 21 300 t if the fuel price would be increased from 300 to 1000 USD/t. Accordingly, higher fuel prices can motivate the installation of wind assisted propulsion, which potentially saves up to 500 t of fuel per year for the investigated MR Tanker on a transatlantic route.