Transnational management of fish stocks must focus on the impacts of climate change


As oceans warm and marine species cross international borders, fish stocks will face additional pressures.

Photo: Pixabay/Quang Praha

Shared fish stocks of hundreds of marine species have historically been exploited by many countries around the world.

As the oceans warm and marine species move across international borders into waters with more favorable environmental conditions, these fish stocks face additional pressures, further complicating the achievement of international sustainability goals.

The United Nations has set ambitious Sustainable Development Goals (SDGs), including SDG 14 – life below water – which includes the sustainable management of all fisheries by 2030. Achieving this goal will have benefits evident for several other societal SDGs such as zero hunger (SDG 2), reduce inequalities (SDG 10) and ensure good health and well-being (SDG 3).

However, to achieve this, we need anticipatory, equitable, adaptive and collaborative work at the international level, because the successful management of fish stocks shared between nations depends on it in a changing world.

No one asked the fish

In 1982, the United Nations created Exclusive Economic Zones (EEZs) – maritime zones that provide exploitation rights over marine and energy resources to coastal nations. One of the main reasons for this delimitation was to improve the management of fish stocks.

However, he did not take into account the natural geographic distribution of living marine resources – that is, no one asked the fish. And because the distribution of marine species in the ocean is partly shaped by environmental preferences, fish move freely through EEZs.

In this perspective, the UN has created the concept of shared fish stocks. Fish stocks that cross neighboring EEZs are called transboundary stocks. These transboundary stocks are exploited by several nations, each in its own EEZ. Recent research has revealed that fish stocks of 633 marine species have been exploited in these areas globally over the past 70 years.

These species include the Pacific salmon shared between the United States and Canada and the Peruvian anchovy shared between Chile and Peru, among other important commercially exploited fish. Between 2005 and 2014, national fleets targeting these cross-border species within EEZs caught an annual average of 48.5 million tonnes.

However, despite their economic importance, the state of exploitation of marine species is much worse when a stock is shared than when it is contained in a single EEZ. Although the sustainability of these stocks depends on international cooperation, it is a challenge when the stocks alter their distribution due to climate oscillation and global climate change.

Climate change is here to stay

The oceans are becoming warmer, less oxygenated and more acidic. In response, marine species move on, seeking new places with the environmental conditions they have historically preferred.

As stocks move across international jurisdictions, fisheries management plans for transboundary stocks may not be suitable to deal with species on the move.

Climate change will have profound impacts on the lives of fishing people around the world. (photo: Pixabay/trilemedia)

We can imagine that if a stock of fish moves from our EEZ to our neighbour’s, we will catch as many fish as possible before it leaves for good. In contrast, our neighbor has an incentive to save the stock due to its growing future stake.

My team estimates that 4,119 transboundary stocks will experience a similar change in 81% of the world’s EEZs by the end of the 21st century.

Although these fish have moved geographically since 2006, our models predict that most shared fish stocks will shift over the next two decades. Changes in catch proportion – the amount of shared stock each EEZ can take – will follow changes in the geographic distribution of fish stock for 85% of EEZs. Thus, if a fish stock moves south, the southern country will have more catches.

The distribution of changing shared fish stocks has led to international conflicts like the “mackerel war”, the overexploitation of important fish stocks like Pacific salmon, and the breaking of international treaties as in the case of Russia and Norway.

Existing international fisheries agreements need to be assessed for their ability to deal with the implications of transboundary changes induced by climate change. New agreements will need to anticipate these uncertain changes to be resilient to global change.

Assessment of management plans

Fisheries management plans that are not designed or prepared to respond to species on the move will be less resilient to climate change. Climate change must play a role in plans and agreements.

We need coping strategies such as strengthening current partnerships, for example by transforming verbal agreements into formal binding agreements. These strategies also include improving international cooperation and management rules that capture changes in the distribution of fish stocks, for example setting catch limits based on where the fish are located.

Quota allocation methods – the amount of fish we can take from the water – are often based on the fixed historical distribution of a stock, but need to be more nimble and potentially evolve into a dynamic method that captures the stock moving.

In some cases, rules will need to be implemented to deal with nations that were not part of the original agreement and wish to fish a stock that reaches their waters for the first time, or to establish management limits in newly occupied areas. However, the shift from historical to dynamic methods may encounter strong resistance from stakeholders who “lose” the benefits of a fishery to which they have historically been entitled.

Further research and documentation on how to move towards inclusive dynamic management (quota allocation formula, conflict management) is essential to adapt and build the resilience of transboundary fisheries management in the face of changing stocks .

Stepping into an uncertain future

The future is uncertain. We experience this on a daily basis, and probably even more now in the context of the COVID-19 pandemic. Climate change is no different.

While the latest report from the Intergovernmental Panel on Climate Change established that human activities have warmed the Earth over the past 50 years, the future also depends on global human actions, such as achieving the goals of the Paris Agreement.

Mathematical models help us understand the natural world, to imagine what the future will look like, but they can always be wrong. Just think of how many times you’ve been misled by your weather app, but you always bring an umbrella if there’s a slight chance of rain.

This means that developing anticipatory policies that address the evolution of transboundary fish stocks and the uncertainties associated with climate change are key to achieving the SDGs while ensuring effective governance of the world’s oceans.

This article was written by Juliano Palacios Abrantes, postdoctoral researcher at the Institute of Oceans and Fisheries at the University of British Columbia. It is republished from The Conversation under a Creative Commons license. Read the original article.

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