The purpose of this paper is to analyse which navigational rights are applicable to foreign commercial vessels performing trans-arctic shipping through the Northwest Passage and how this affects the potential for Canada, through article 234 of the United Nations Convention on the Law of the Sea (UNCLOS), to issue national environmental legislation regulating pollution from ships. This is done through the method of legal dogmatics, characterised by analysis of the sources of law and the hierarchy between them. In this paper, the main sources of law employed are UNCLOS and relevant case law from the International Court of Justice. The main conclusions presented in the paper are that the Northwest Passage consists of a combination of territorial sea and exclusive economic zone, which generally means that commercial vessels are allowed innocent passage through the parts of the passage forming the territorial sea and are largely subject to freedom of navigation through those parts that form the exclusive economic zone. However, it seems likely that the Northwest Passage is a strait used for international navigation, in which case, the vessels passing through it are instead subject to the regime of transit passage. This would negatively affect the possibility for Canada to issue national legislation to regulate pollution from foreign vessels. However, as long as the Northwest Passage is covered by ice for most of the year, article 234 UNCLOS allows Canada far more leeway in regard to issuing anti-pollution legislation, both in the territorial sea and the exclusive economic zone, regardless of whether the Northwest Passage is found to be a strait used for international navigation. The passage regime applicable to foreign commercial vessels under article 234 could be characterised as a sui generis passage.

The thesis deals with the preliminary reference procedure. There is outlined not only the characteristic of this procedure or its evolution, but also the interpretation of the term "court or tribunal of a Member State" or the Exceptions to the Duty to Refer. The following chapters are concerned with the statistical curiosities of the preliminary reference procedure or the ways of how to make this procedure more efficient. The last chapter is analysing the preliminary reference procedure from the Czech law's point of view. It deals with some Czech institutions as courts of the Member State, procedural aspects of this procedure or study of the Czech preliminary references. It also contains some cases of The Constitutional Court of the Czech Republic regarding with this procedure.

L’Arctique est victime de bouleversements majeurs en raison des changements climatiques. Contrairement au régime général pour la zone économique exclusive, l'article 234 de la Convention des Nations unies sur le droit de la mer de 1982 autorise les États côtiers à adopter et à imposer des standards nationaux (plutôt qu'internationaux) pour prévenir et maîtriser la pollution du milieu marin par les navires mais seulement dans les zones de leur zone économique exclusive recouvertes par les glaces « pendant la majeure partie de l'année ». Or, les données et rapports scientifiques prévoient qu'en raison du réchauffement climatique exacerbé dans la région, l'océan Arctique sera libre de glace pendant plusieurs mois chaque année, et ce, à compter de 2050. Une telle transformation physique semblerait remettre en cause l'applicabilité de l'article 234 et les droits qui en découlent pour les États côtiers. Le mémoire propose donc d'aborder cet enjeu en analysant le contexte et les motivations des États au moment où l'article 234 a été adopté. Une attention particulière sera portée à l’étude du développement du droit de la mer moderne ainsi qu’aux négociations entourant l’article 234, en vue de formuler des arguments en faveur de son applicabilité future, basés sur les méthodes d’interprétation des traités. / The Arctic region is the victim of major upheavals due to climate change. Unlike the general regime for the exclusive economic zone, Article 234 of the 1982 United Nations Convention on the Law of the Sea allows coastal states to adopt and impose national (rather than international) standards to prevent and control the pollution of the marine environment by ships, but only in areas of their exclusive economic zone covered by ice "for most of the year". However, the data and scientific reports predict that due to exacerbated global warming in the region, the Arctic Ocean will be free of ice for several months each year, starting in 2050. Such a physical transformation would seem to call into question the applicability of Article 234 and the resulting rights of coastal States. This thesis therefore proposes to address this issue by analyzing the context and the motivations of the States at the time when Article 234 was adopted. Particular attention will be paid to the study of the development of the modern law of the sea as well as to the negotiations around Article 234, in order to formulate arguments in favor of its future applicability, based on treaty interpretation methods.