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.
The concept of 'seal-fishery conflict' is used when referring to the complex contradictions stemming from seals' impacts on fishing livelihoods, a pertinent social struggle between stakeholder groups of the Baltic Sea. Tensions are most remarkable between coastal fisheries and seal conservationists. As existing knowledge has been scattered and the conflict has become increasingly problematic, the RESOCO project compiled Nordic knowledge and best practices and built an interdisciplinary synthesis to set the stage for alternative solutions on how to effectively reconcile the seal-fishery conflict in the Baltic Sea. The report takes a pragmatic stand by turning the attention to approaches and instruments that have been suggested to be helpful or that have the potential to help mitigate the conflict. The report synthesizes knowledge and presents existing gaps and needs of further research.
Mobilization of residual oil droplets is the key process for enhanced oil recovery. Visualization of the droplet movement at a pore level provides insights on the underlying physical mechanisms. We couple a microfluidic droplet generator and a thin glass capillary to study the movement of oil droplets under salinity gradients with visualization of individual droplet movements. The driving forces that affect the movement of the droplets are discussed. We demonstrate experimentally that oil droplets in micro-confined channels can be mobilized and move against pressure under the concentration gradients of dissolved salts. The gradient-driven movement can be strong enough to drive a droplet through a narrow constriction in the middle of the capillary channel. The droplet movement can be understood by combining a Marangoni stress due to surfactant redistribution, electrostatic interaction and diffusiophoresis. This suggests that the abrupt change of salinity may be one of the physical mechanisms of smart waterflooding.
Numerical tests are performed to investigate wave transformations of nonlinear nonbreaking regular waves with normal incidence to the shore in decreasing and increasing water depth. The wave height transformation (shoaling) of nonlinear waves can, just as for linear waves, be described by conservation of the mechanical energy flux. The numerical tests show that the mechanical energy flux for nonlinear waves on sloping foreshores is well described by stream function wave theory for horizontal foreshore. Thus, this theory can be used to estimate the shoaled wave height. Furthermore, the amplitude and the celerity of the wave components of nonlinear waves on mildly sloping foreshores can also be predicted with the stream function wave theory. The tests also show that waves propagating to deeper water (de-shoaling) on a very gentle foreshore with a slope of cot(β) = 1200 can be described in the same way as shoaling waves. For de-shoaling on steeper foreshores, free waves are released leading to waves that are not of constant form and thus cannot be modelled by the proposed approach.
The latest IPCC report on Ocean and Cryosphere in a Changing Climate, which builds upon previous IPCC's reports, established a causal link between anthropogenic impacts and ocean acidification, by noting a significant decrease in the Ocean's uptake of CO2, with consequent damage to Earth's ecosystems, which in turn has traceable repercussions on the Arctic Ocean and then from the Arctic to the Planet Earth. The impact of ocean acidification is not only in the biological ecosystem but also on human activities, such as livelihood, food security, socio-economic security and developing communities. However, who can possibly be held ethically/legally responsible for ocean acidification from a climate justice perspective? Since what happens in the Arctic does not stay there, a more systematic law and policy approach to study options and responses in a multi-level, climate-ethical, global perceptive is needed. This paper sheds light on the legal responses available at global, regional and national levels to ocean acidification in a law of the sea and ocean context, both in the Arctic and from the Arctic. The gaps in legal and policy responses in connection to the ethical climate component will be identified. It will shed light on the planetary limits that humanity needs to stay within in order to maintain the future of the Earth. Since it touches upon questions of legal responsibility, on who is responsible for ocean acidification, it will connect to the “supply side” of fossil fuels production and global extraction projects causing anthropogenic CO2 emissions, one of the major causes of ocean acidification. It will also identify which actors, be they "officials" or "non-officials" (such as international organizations, states, regional institutes, Arctic citizens or even forums) should be held ethically responsible, and who should take action.
The power output from many wave energy converters (WECs) is limited by a finite stroke length in the power take-off (PTO) mechanism. As the PTO approaches its maximum stroke length, an end-stop system needs to be engaged to avoid damage to the machinery. Still the on-set of the end-stop is a nonlinear trigger force, a stiff point in the system. In this respect it is similar to how snap loads in the mooring cables affect the system after a period of cable slack. This paper presents a detailed study into the dynamics of end-stop events and snap loads for a WEC. The WEC is a bottom-mounted linear generator connected to a surface buoy via a steel wire. By comparing a linear spring model with three dynamic mooring line models we conclude that large differences are observed in the low-tension and slack regions of the cable during moderate wave loads, while minor differences are seen in the estimated peak tension. By further varying end-stop parameters we observe that the peak tension in the line changes mildly with the axial stiffness for moderate wave heights. The peak tension is surprisingly unaffected by the introduction of a critical damping level to the end-stop system, despite the significant increase in end-stop force which causes the translator to come to a sudden stop. We discuss how the connection between maximum line force and end-stop parameters is highly dependent on the buoy position in the wave at the instant of end-stop onset.
Fishing and sand mining in Cambodia may not appear to have much in common. However, digging deeper reveals important parallels. Both fishing and sand mining support livelihoods and are connected to a limited natural resource. Meanwhile, they are both typified by precarious livelihoods, on the one hand, and overexploitation, on the other. In bringing these two topics together, the paper combines empirical qualitative research from two separate studies conducted by the co-authors in Cambodia, one in coastal fishing villages and another in the sand mining industry along the Mekong River. We argue that the interplay between fishing and sand mining has paradoxical impacts on livelihoods, supporting one group while undermining another. Using a precarity analysis lens, we show how an unconventional, and largely invisible frontier of natural resource exploitation—sand mining—is intertwined with fisheries, and expands our understanding of the relationship between precarious labour, environmental change, and livelihoods.
This article contributes to the accelerating development of methods for sustainability assessment (SA) to support maritime spatial planning (MSP), by proposing an ecosystem services based framework for SA. MSP is generally seen as an important approach to promote a more sustainable use of sea space. However, so far all sustainability concerns are not equally well represented in planning practice; in particular, social sustainability aspects such as social justice and sociocultural values related to human-nature connectedness receive less attention. We first explored concepts and principles related to sustainability assessment and social sustainability in the scientific literature. Based on this, we analyzed how far the present approaches to assessments in Baltic Sea EU Member States have been extended from environmental concerns to towards broader sustainability concerns so far. Using current best practice in two pioneering countries (UK and Sweden), we illustrated how social sustainability principles could match with applied social impact criteria, and further, how such criteria can inform an ecosystem services-based impact assessment framework. Based on existing frameworks, including the DPSIR (driving forces, pressures, state, impact, response) environmental assessment framework and the ecosystem service cascade, we propose a sustainability impact assessment framework for MSP (MSP-SA) integrating across sustainability dimensions and including assessment of distributional aspects of marine ecosystem service benefits. Finally, we discuss the applicability and further development of the framework in relation to present day sustainability assessment practice in MSP.
A tension between two opposing forces, that is, the force of division and that of unity, is increasingly sharpened in the law of the sea today. An essential question that arises is how one can protect community interests in the divided ocean. The law of dédoublement fonctionnel advocated by Georges Scelle provides an insight into this question. According to Scelle’s theory of the law of dédoublement fonctionnel, State organs perform a dual function: the national function of protecting State interests and the public service function of safeguarding community interests. The law of dédoublement fonctionnel seeks to reconcile these functions. Scelle’s harmonistic vision of international law is well worth reconsidering in the law of the sea and beyond. This article examines the relevance of Scelle’s theory in the context of the law of the sea and explores two models for the protection of community interests at sea.
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.