Plastic litter is introduced into the oceans from land-based sources located in many countries around the world. Marine plastic pollution may therefore be attributable to multiple states, resulting in shared state responsibility. This article discusses the issue of shared state responsibility for land-based marine plastic pollution by examining (i) primary rules of international law concerning the prevention of land-based marine plastic pollution; (ii) secondary rules of international law on this subject; and (iii) possible ways of strengthening the primary rules. It concludes that the barrier for the invocation of state responsibility may become higher in cases of shared state responsibility. Three cumulative solutions to this problem are proposed: elaborating the obligation of due diligence, strengthening compliance procedures, and interlinking regimes governing the marine environment and international watercourses.
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 United Nations Convention on the Law of the Sea contains only general rules concerning the delimitation of the exclusive economic zone and the continental shelf. However, international courts and tribunals have, within their compass, elaborated the law of maritime delimitation through their jurisprudence, thereby maintaining the resilience of the Convention in a particular context of maritime delimitations. The jurisprudence is not a panacea, however. As regards the implications of maritime delimitation judgments for third States in the same region, for example, the jurisprudence has not been consistent. Lack of consistency of the jurisprudence may undermine the predictability of the law of maritime delimitation and weaken the resilience of the Convention. This article critically assesses the approach of the International Court of Justice to the presence of third States in the process of maritime delimitation, by analysing the Nicaragua v. Colombia case and the Costa Rica v. Nicaragua case, respectively.
This introductory note examines the development at the International Tribunal for the Law of the Sea for the year 2020. While there was no judgment in 2020, proceedings of two cases, the M/T “San Padre Pio” (No. 2) Case (Switzerland/Nigeria) and the Dispute Concerning Delimitation of the Maritime Boundary between Mauritius and Maldives in the Indian Ocean (Mauritius/Maldives), continue. Accordingly, this note discusses the issues of the two pending cases. Furthermore, there were some important events regarding the Tribunal in 2020. Among other things, this note focuses on an adoption of a Model Agreement between ITLOS and Singapore, the election of the seven members of the Tribunal, and amendments of the Rules of the Tribunal.
Purpose— The article presents a commentary on the case Alleged Violations of Sovereign Rights and Maritime Spaces in the Caribbean Sea (Nicaragua v. Colombia), aiming to deliver a comprehensive summary of the case and general commentary on the most relevant claims and the procedural history. Design, Methodology, Approach— The article comments on the case following a procedural structure, explaining the principal factual and jurisdictional issues, the application presented by Nicaragua, the preliminary exceptions, and the counterclaims presented by Colombia during the jurisdictional phase of the case leading to the judgment on jurisdiction in 2016, and the decision on the merits rendered by the Court in 2022. Findings— The commentary highlights the difficulties raised before the ICJ when entertaining the admissibility of counterclaims, and studies the factual pattern that led to Nicaragua’s application as a manifestation of a conduct of resistance to international courts and tribunals. Practical Implications— The article may provide readers with in-depth knowledge of recent litigation that is relevant to the law of the sea but also the authority of the ICJ and the effectiveness of its judgments. Originality, Value— The article is one of the few case commentaries on the procedural history and legal claims before the ICJ in this very recent case that was decided by the Court in 2022.
The interpretation of “disputes concerning military activities” under Article 298(1)(b) of the United Nations Convention on the Law of the Sea (UNCLOS) rests on a sensitive balance between the protection of strategic interests of States and the need for peaceful settlement of international disputes. There, an essential issue arises how an adjudicative body acting under Part XV UNCLOS should assess the nature of conducts of State for the purposes of Article 298(1)(b). This issue was vividly raised in the dispute between Ukraine and the Russian Federation with regard to the detention of Ukrainian naval vessels and servicemen. In this regard, both the International Tribunal for the Law of the Sea (ITLOS) and the arbitral tribunal set out in accordance with Annex VII UNCLOS wrestled with this issue. This article examines the manner of the interpretation of the concept of the military activities for the purposes of Article 298(1)(b) by comparing the approaches taken by ITLOS and the Annex VII arbitral tribunal.
This paper summarises the work conducted within the 1st FOWT (Floating Offshore Wind Turbine) Comparative Study organised by the EPSRC (UK) ‘Extreme loading on FOWTs under complex environmental conditions’ and ‘Collaborative computational project on wave structure interaction (CCP-WSI)’ projects. The hydrodynamic response of a FOWT support structure is simulated with a range of numerical models based on potential theory, Morison equation, Navier-Stokes solvers and hybrid methods coupling different flow solvers. A series of load cases including the static equilibrium tests, free decay tests, operational and extreme focused wave cases are considered for the UMaine VolturnUS-S semi-submersible platform, and the results from 17 contributions are analysed and compared with each other and against the experimental data from a 1:70 scale model test performed in the COAST Laboratory Ocean Basin at the University of Plymouth. It is shown that most numerical models can predict similar results for the heave response, but significant discrepancies exist in the prediction of the surge and pitch responses as well as the mooring line loads. For the extreme focused wave case, while both Navier–Stokes and potential flow base models tend to produce larger errors in terms of the root mean squared error than the operational focused wave case, the Navier-Stokes based models generally perform better. Given the fact that variations in the solutions (sometimes large) also present in the results based the same or similar numerical models, e.g., OpenFOAM, the study highlights uncertainties in setting up a numerical model for complex wave structure interaction simulations such as those involving a FOWT and therefore the importance of proper code validation and verification studies.
Existing energy management strategies (EMSs) for hybrid power systems (HPSs) in hydrogen fuel cell vessels (FCVs) are not applicable to scenarios with multiple hydrogen fuel cells (FCs) and lithium batteries (LBs) in parallel, and are difficult to achieve real-time control and optimization for multiple objectives. In this paper, a bi-layer real-time energy management strategy (BLRT-EMS) is proposed. Compared with existing EMSs, the proposed BLRT-EMS implements different control/optimization objectives distributed in the execution layer EMS (EL-EMS) and the decision layer EMS (DL-EMS), which can significantly reduce bus voltage fluctuations, decrease hydrogen consumptions, improve the system efficiency, and have potential for engineering applications. In the first EL-EMS, a decentralized optimal power allocation strategy is proposed, which allows each FC system to allocate the output power ratio according to their generation costs, ensuring consistent performance of multiple FC systems (MFCS) under long-term operating conditions, and thus delaying the degradation rate of FCs. In the second EL-EMS, a distributed cooperative control strategy is proposed to achieve dynamic SoC equalization, proportional output power allocation, and accurate bus voltage restoration among multiple battery storage systems (MBSS) to extend the service life of batteries. In the DL-EMS, an energy coordination optimization strategy between MFCS and MBSS is proposed to achieve hydrogen consumption reduction and system efficiency improvement, thus enhancing the endurance performance of FCV. Finally, test results based on the StarSim experimental platform show that the proposed BLRT-EMS has faster SoC convergence speed, smaller bus voltage deviation, lower hydrogen consumption, higher system efficiency, and lower operation stress than the state-of-the-art methods.
The present study investigates three-dimensional gap resonance between two fixed side-by-side barges under combined wave and uniform current excitation using a fully nonlinear numerical wave tank based on the Navier–Stokes equations. It examines how currents aligned with regular waves affect the gap response under head and beam seas. In beam seas, the free surface in the gap primarily exhibits a modal-type response in the form of a standing wave. The maximum gap response, consistently occurring at the midpoint of the gap, increases gradually with the current speed. Conversely, in head seas, the maximum response decreases slightly with increasing current speed, and the occurring location shifts downstream. Moreover, resonant free-surface responses along the gap in head seas manifest as propagating waves rather than modal-type standing waves, consisting of a wider spectrum of wave components around the resonant ones and traveling faster than the incident waves regardless of current speed. The wavelengths of those resonant waves tend to increase with increasing current speed. Additionally, the presence of current significantly enlarges the transverse first-harmonic and mean-drift wave forces on the barges under beam-sea conditions. The study highlights the necessity of considering current effects on three-dimensional gap resonances in marine operations at coastal and offshore locations.
We investigate piston-mode fluid resonance within the narrow gap formed by two identical fixed barges in a side-by-side configuration, utilizing a two-dimensional fully nonlinear numerical wave tank. The focus is on examining the effects of uniform and shear currents. Under ‘wave+uniform-current’ conditions, a certain current speed is identified, beyond which the gap resonance reduces dramatically and monotonically with the current speed. This reduction is attributed to a stronger increase in damping compared to wave excitation, qualitatively explained by a linearized massless damping lid model. Furthermore, we study the effects of waves propagating on shear currents, maintaining an identical ambient current speed at the gap depth. Complementary to previous studies on this topic, our study reveals that the velocity profile of the studied shear current has an insignificant effect on the resonant gap amplitudes. The ambient current velocity at the gap depth is a more important key parameter to consider when assessing wave-induced gap responses, leading to a non-negligible increase in the resonant gap response. Consequently, disregarding the influence of currents in engineering practices is not a conservative approach.