FNI has been engaged in the study of marine affairs since its establishment in 1958. Since 1996, the Institute has initiated a range of international research projects on various aspects of the Law of the Sea and ocean governance. FNI's research focus in this field is a broad one, spanning from traditional topics such as shipping and fisheries to emerging issues such as sea-level rise and sustainable aquaculture.

Within the Law of the Sea, on-going FNI projects study the driving factors behind its development, including state practice, the role and decision-making of international institutions and the role and significance of international courts and tribunals; the interaction of the law of the sea with other branches of public international law; newly emerged issues such as marine bioprospecting; and the challenges for the current architecture of the law of the sea on the horison, such as the prospects of sea-level rise and broader questions related to the Anthropocene epoch possibly requiring new paradigms for the law of the sea.

The institute also has research activities focusing on fisheries management, aquaculture governance and marine/maritime security.

FNI has special regional expertise on the Barents Sea, the Norwegian and North Sea areas, the Southern (Antarctic) Ocean, and the Mediterranean including, in particular, the Adriatic Sea issues.