Oceans are increasingly under pressure; be it for the multiplication and diversification of economic activities performed at sea, for the consequences of climate change, or for the deterioration of their environmental health. Several international bodies and a plethora of international instruments regulate, influence and shape what is happening in the oceans. Moreover, actors at different levels of governance participate in what it is commonly called ocean governance. But what is ocean governance? Which are the different actors and instruments involved? How do they interact in dealing with ocean affairs? Those are some of the questions that the Sustainable Ocean project (ERC grant agreement No 639070) deals with in order to answer the overarching research question: how can the law contribute to the sustainable use of the ocean and strike a balance between competing interests at sea?

Regime interaction is here analysed and used as a legal modus operandi, as an existing legal behaviour. We do not engage with the debate whether regime interaction is inherently beneficial or detrimental to the international legal order. Similarly, the research project adopts a concept of ocean governance which is mainly descriptive of processes, instruments and actors involved in oceans affairs and management.

In this presentation, I would like to present and discuss the partial results of our research which stem from a workshop we organised in April 2019 on ‘Regime Interaction in Ocean Governance: Problems, theories and methods’. The partial results can be synthesised in the this diagram that identifies three categories of interaction (interactive form; interactive substance; interactive process) and that proposes a lens through which analyse and handle instances of interaction.

Seline Trevisanut (PhD, Milan; MA, Paris I) is Professor on International Law and Sustainability at Utrecht University and currently principal investigator of the ERC Starting Grant Project ‘Sustainable Ocean’ (2015-2020). Before joining Utrecht in 2012, she taught courses and conducted research at Columbia University, at the European University Institute, at the Max Planck Institute for Comparative Public Law and International Law, at the National University of Singapore and at UC Berkeley. Her publications include inter alia edited volumes on Foreign Investment, International Law and Common Concerns (Routledge 2014), and on Energy from the Sea: An International Law Perspective on Ocean Energy (Brill 2015), and a forthcoming monograph on The International Law of Offshore Installations: Through Fragmentation Towards Better Governance (Cambridge University Press 2019).