Treaties — Power to conclude — European Economic Community — Treaty-making powers of the Community and its Member States — Community possessing power to adopt internal legislation on subject — Whether possessing parallel power to conclude international agreements — Marine conservation — Community not yet exercising powers in this area — Whether Member States retaining power to act — Whether Member States under duty not to hinder future exercise of powers by the Community

Sea — Fisheries — Conservation — North-East Atlantic Fisheries Convention, 1959 — Effect on Member States of European Community — Whether conservation of fish stock matter for the Community or the Member States — Legislation by the Netherlands to implement recommendation of North-East Atlantic Fisheries Commission — Whether compatible with Community law — The law of the European Economic Community