In a scientific article published in PLoS Biology, researchers argue that the best way for dwindling stocks of high-value migratory pelagic species, such as tuna, to recover is to completely close the high seas to fishing.
While 58% of the seas and oceans are high seas and open to access from all nations, more than 150 national exclusive economic zones (EEZs), created by the United Nations Convention on the Law of the Sea (UNCLOS), comprise the remaining 42% of the ocean. The authors of the article highlighted that the open access nature of the high seas has led to unregulated fisheries, leading to over-exploitation of the high seas fisheries. They commented, “For decades, hundreds of attempts have been made at multilateral agreements primarily through regional fishery management organizations, which aim to coordinate fishing across EEZs and on the high seas. While some exceptions exist, these efforts are widely regarded as a failure.” In the researchers’ model, should there be a complete closure of the high seas, stocks would increase throughout the oceans, eventually by 400% on the high seas and 30% within EEZs. Monetary profit would more than double and yield would increase by more than 40%.
Looking at implementation challenges, the authors highlight that “there inevitably will be distributional impacts”. Countries such as Japan, China and Spain, whose current fishing fleets specialise in fishing tuna in the high seas, may be harmed by the closure, but these losses “may be offset by enhanced fishing opportunities in their EEZs as stocks rebuild”. Developing countries whose stocks are depleted by over-exploitation of the high seas but who have not invested in high seas fleets may benefit most from such a closure.
Exploitation of high seas fisheries resources is more complicated to manage then in the EEZs since it depends on good cooperation between fishing and coastal states, and is more difficult to regulate. Limiting fisheries to the EEZs may guarantee better management and control of the use of fisheries resources, and may bring increasing benefits to coastal states, but only if coastal states fulfil their responsibilities. Therefore, a pre-requisite is to ensure coastal states, such as ACP countries, have the capacity and political will to adopt robust fisheries policies for migratory species that move between the high seas and EEZs. The creation of marine protected areas (where fishing is forbidden) beyond national jurisdiction is already a matter discussed within some regional fisheries management organisations, but it has proved difficult to reach consensus, as fishing nations have to agree upon such restrictions which must also be enforceable.