In this fascinating book, Richard Barnes constructs a version of property rights which articulates both the public and private functions of property in the context of the international legal system.

This is a skilfully crafted foray into an under-researched area. Drawing on his expertise in the law of the sea, fisheries and marine protection, Barnes uses Hardin's 1968 “tragedy of the commons” to demonstrate why pressure on natural resources requires that a new property regime be developed if those resources are to be protected from extinction. Hardin argued that individual herdsmen will maximise their use of shared pasture because, being rational human beings, they know that they accrue benefits from this use of common property (e.g. increased stock) but the negative costs which accrue from such utilisation (e.g. overgrazing) will be shared.

Barnes applies this model to marine fish stocks. This common pool resource may be owned by the state, a community or an individual, or may be beyond the remit of property regimes (e.g. fish in the high seas), and in turn may be subject to regimes of open access, common property, collective property or private property. It is costly to exclude individuals from the resource through physical or legal means but the benefits consumed by one person are subtracted from the benefits available to others. Historically most common pool resources have remained so, largely because of the high cost and practical difficulties of regulating access to fisheries in hostile and often dangerous environments. At the same time, the customary norm, now enshrined in the 1982 United Nations Convention on the Law of the Sea, UNCLOS, of freedom of the high seas has perpetuated the open access system. This has led to overexploitation of the resource, initially in coastal waters and now on the high seas. Ineffective implementation and lack of enforcement, of many international conservation agreements has aggravated this. As a result, fish stocks have dwindled to the point of extinction in many regions.

All this suggest that an international management regime is sorely needed and the legal issues raised by such regimes are central to Barnes' analysis. While the regulation of natural resources as property has been a feature of common law for more than 800 years, it is unusual to analyse property in terms of international law. Indeed, the international legal system is not fundamentally designed to protect property rights above other rights. At its core are notions of state sovereignty. The United Nations and its agencies have, in the last fifty or so years, ventured into fisheries, food, flora, fauna and conservation but such activity is premised, however distantly, on the UN's fundamental commitment to international peace and security, not on the protection of fish stocks per se. Indeed, it is difficult to see how the international legal system could extend absolute protection to common pool fisheries. First, international law is a voluntary system, so fishing states that do not wish to be bound by the new convention can usually ignore it – and there is no reason to believe that fishing states which routinely breach other aspects of international law would honour international fisheries agreements. Second, a range of dispute resolution mechanisms already exists in international law. Each has advantages and disadvantages but it is difficult to see how international law on fisheries protection could implement the absolute prohibition of the fishing of certain species that may be necessary for the survival of that species, in the event that fishing was deemed necessary by a member state.

Barnes offers an immensely detailed analysis of the development of sovereign rights over ocean space, the scope of sovereignty, the limits of international environmental law and the domestic property rights-based fisheries management systems of Iceland, Australia, New Zealand, Canada and the United States. Having demonstrated that property possesses a dual function, facilitating both public and private interests, Barnes argues that the public function is often ignored or undervalued. Law, he suggests, as a form of practical reason operates by certain rules which determine the weight to be ascribed to particular claims and arguments. The rules of practical reason (e.g. universality of propositions, consequence sensitivity, coherence and reasonableness) may be used to explain how law resolves conflicts between private property rights and public interest demands. Together, Barnes suggests, these elements of legal and physical excludability confirm that a more complex form of property relationship – stewardship – may provide the appropriate relationship for the regulation of certain natural resources.

This is an intriguing argument. International law already places public-interest type limitations on the use of many natural resources by means of instruments such as the 1971 Ramsar Convention on Wetlands, 1973 Convention on International Trade in Endangered Species, 1979 Convention on Migratory Species and numerous smaller bilateral and regional instruments. The 1992 Convention on Biological Diversity moved the agenda forward from species protection to the protection of entire ecosystems and maintenance of biodiversity. A number of recent fisheries instruments, such as the Fish Stocks Agreement and the FAO Code of Conduct for Responsible Fisheries, adopt a much more precautionary approach than earlier agreements and require a higher degree of scientific input. Some states too have sought to use property rights to regulate common pool resources but it is not only private property rights that are capable of preventing the tragedy of the commons and some other forms of holding may be as effective as such rights while, at the same time, promoting other societal values. There are examples of traditionally managed resource use in indigenous communities which maintain the resource at sustainable levels while permitting a socially acceptable level of use.

All this demonstrates that certain existing rights in fisheries are not private property rights but are fundamentally linked to certain public interests (e.g. environmental protection). Given the complexity of such arrangements, these are, Barnes argues, better regarded as a form of stewardship. This is an immensely attractive argument and one which may offer potential to better hold and hence protect from extinction other flora and fauna. Using fisheries as a motif, Barnes has provided a tremendously valuable roadmap through public, private, domestic and international law. Would that the expertise, insight and creativity demonstrated by Barnes in this book be applied to the protection of other endangered species.