Ecosystems and Climate – Protecting the changing environment

Climate change is transforming the ocean environment and the behaviour of tuna and other animals. The countries of the WCPO use science to understand how to manage and protect the fisheries.

Policy and Rules

WCPFC sets regionwide rules to protect marine life

Chinese longliners under a big sky in Suva Harbour, Fiji the changing climate is affecting island states and fishing operations. Photo: Francisco Blaha.

The major rules in the region for protecting marine ecosystems are decided by the Western and Central Pacific Fisheries Commission (WCPFC). It meets once a year to decide on rules and policies that support the management of the tuna fisheries of the Western and Central Pacific Ocean (WCPO). The rules are called conservation and management measures (CMMs). They are binding. The WCPFC also sets resolutions, which are recommended courses of action but are not binding.The WCPFC is made up of three groups of countries: members, cooperating non-members, and participating territories. They are known collectively as CCMs. Among the members are the 14 small island developing states (SIDS) of the WCPO.

WCPFC maintains all CMMs and resolutions.

Extra rules apply in waters governed by the Parties to the Nauru Agreement (see below).

CMMs to strengthen and protect marine ecosystems cover the marine environment as a whole, the tuna that live in them, the marine life that tuna depend on, and the animals that depend on tuna. They also cover the protection of other ocean life that is not targeted in fishing operations but is caught accidentally. These include seabirds and turtles.

There is also a CMM to cover marine pollution that originates in the sea and on land. Some examples are:

  • lost or discarded fishing gear and fish-aggregating devices
  • shipboard waste
  • spills of oil and other chemicals from operating ships and wrecks
  • plastics and microplastics in the water and on reefs and coastlines, whether from ships or washed out to sea from the land.

CMMs governing tuna ecosystems and climate change

2017-04, Marine pollution
  • CCMs will prohibit their fishing vessels from discharging any plastic while inside the Convention area. This excludes fishing gear.
  • They are also encouraged to prohibit their fishing vessels from discharging petrochemical products and residues, garbage, waste, fishing gear, incinerator ashes, cooking oil, and sewage.
  • CCMs are encouraged to develop frameworks to handle the reporting and sharing of information on the loss of fishing gear, to encourage their fishing vessels to retrieve gear and, where this is not possible, to accurately record what is lost and where,
  • CCMs are requested to provide facilities in port to accept waste, with SIDS being supported to do this by wealthy fishing nations.
  • WCPFC encourages all CCMs to ratify the International Convention for the Prevention of Pollution from Ships (MARPOL) and the London Protocol on prevention of marine pollution.

Read the CMM

2013-07, Special requirements of SIDS and territories
  • Promote the development and transfer of fisheries science and technology to SIDS for their economic and social benefit. This includes the capacity to conserve and manage oceanic fish stocks.

Read the CMM

Conservation of marine species and their environments

2019-04, Sharks
  • States the species of sharks the CMM applies to, and defines sharks as referring to all species of sharks, skates, rays and chimeras (in the scientific class Chondrichthyes)
  • CCMs will implement the FAO International plan of action for the conservation and management of sharks, and report to the Commission how they are doing this
  • Each CCM will submit data on the WCPFC Key Shark Species for Data Provision
  • Finning is prohibited
  • All parts of any sharks that are retained on board must be used
  • Each shark carcass must be kept, with its fins, in the same bag, preferably biodegradable. Each bag is to be identified clearly so that inspectors can verify the information. Each shark carcass must be landed or transhipped with its fins.
  • Lists requirements for specific sharks
  • This CMM replaced CMMs 2010-07, 2011-04, 2012-04, 2013-08 and 2014-05 on 1 November 2020

Read the CMM

2019-05, Mobulid rays
  • Notes international conservation conventions that list mobula and manta rays, and notes that they are vulnerable to overfishing
  • CCMs will prohibit their vessels from targeting mobulid rays, and will report to the Commission how they meet this CMM
  • They are prohibited from keeping on board, transhipping or landing any mobulid rays (whole or part animal)
  • Fishing vessels are to release any mobulid rays they catch promptly, alive and unharmed
  • Any ray that is unintentionally caught and landed must be surrendered to government authorities. These rays may not be sold or bartered, but may be given away for eating.

Read the CMM

2018-03, Mitigate the impact of fishing on seabirds
  • Notes in particular that albatrosses and petrels are threatened with extinction worldwide
    CCMs are to implement the FAOs International Plan of Action for Reducing incidental catches of seabirds in longline fisheries, and report to the Commission how they are doing this
    Specifies the measures longline vessels are to use to minimise the catch and harm of seabirds north and south of 23° of latitude
2018-04, Sea turtles
  • Notes that the five species of marine turtle found in the Convention area are threatened with extinction or are critically endangered, and notes that the Pacific leatherback has declined drastically in the past 30 years
  • CCMs are to implement the FAOs Guidelines to reduce sea turtle mortality in fishing operations, and report to the Commission how they are doing this.
  • Fishing vessels are to avoid encircling, entangling or hooking sea turtles.
  • Lists practices and equipment that purse-seine and longline vessels should use to protect turtles from capture or entanglement, and how to care for them and return them to the water safely.
  • All incidents that involve sea turtles are to be reported to the WCPFC committees to contribute to research on better ways to protect turtles.

Read the CMM

2014-06, Harvest strategies for key fisheries and stocks
  • Sets out the principles for setting and implementing reference points and harvest strategies for economically important fish species in the WCPFC. It aims to protect these species to care for marine environments and so that fishing will remain viable for generations.

Read the CMM

2013-05, Daily catch and effort reporting
  • Each vessel must report in the way specified on daily catch and effort, including days when no fish are caught and no fishing occurs
  • Catch information must include interactions with other species, particularly key shark species (see CMM 2010-07) and cetaceans (e.g. whales, dolphins), seabirds and turtles

Read the CMM



2019-01, Resolution on climate change as it relates to the WCPFC
  • The WCPFC will consider the effects of climate change on highly migratory fish stocks
  • It will also consider the effects of climate change on the economies of CCMs, and the food security and livelihoods of the people of CCMs, particularly those in the small island developing states
  • It will support more scientific research on the relationship between climate change and:
    target stocks
    non-target stocks
    species that belong in the same ecosystem as the target stocks, or depend on them in some way
    how species and oceanic environments interact
  • WCPFC will consider how climate change and fishing are related, and address unwanted effects
  • The WCPFC will reduce the environmental effects of its own operations

Read the CMM

2005-03, Resolution on Non-target fish species
  • CCMs are to encourage their fishing vessels operating in the Convention area to avoid the capture of all fish species that are not the target of fishing operations
  • Any that are caught are to be released back into the water unharmed as soon as possible

Read the CMM

OFMP3 – lessening the effects of climate change

One of the goals of the Pacific Islands Oceanic Fisheries Management Project (OFMP2) is that states work together to lessen the effects of climate change. The aim is to adapt national management and conservation efforts so they are harmonised across the region. With these tools, the states will protect stocks of tuna and other valuable fish, and the environment they live in, so that people can continue to harvest them for food and income. For local people, tuna also has cultural importance.

A related goal is for the countries of the WCPO and those that fish in the region to reduce marine pollution. This encompasses rubbish and waste in the open ocean and on reefs and along coasts. This will help rebuild degraded marine environment to protect fisheries. Nations are expected to do this by coordinating legal, policy and institutional reforms. The nations of the Western and Central Pacific Ocean are doing this through regional and sub-regional arrangements. As much as possible, countries will also align national reforms with these goals. It is also expected that states will take into account climate change and natural variability in the climate.

Subregional agreements on conservation of the environment

The Parties to the Nauru Agreement prohibits purse-seine vessels from settings nets on or around whale sharks when fishing in members waters. This is very similar to the region-wide rule described in the WCPFC CMM 2012-04.

Subregional agreements on climate change

The Pacific Islands Forum (PIF) has 18 members, plus Tokelau as an associate member. Members signed the Boe Declaration on Regional Security in 2018. It recognises climate change as the single greatest threat to the livelihoods, security and wellbeing of the people of the Pacific. It comes with an action plan.

Members agreed to implement the Paris Agreement of the United Nations Framework Convention on Climate Change. This commits the countries that sign it to contribute to worldwide effort to minimise the increase in global temperature. They aim to limit the temperature to 1.5 °C above pre-industrial levels. (The maximum allowed under the Paris Agreement is an increase of less than 2 °C above pre-industrial levels.)



Widespread climatic changes already occurring in WCPO

Global heating and climate change are creating widespread changes in the Western and Central Pacific Ocean (WCPO). Many of these changes interact with each other.

Locals in Tebikenikora village, Kiribati the people of low-lying islands like this one are concerned about rising sea levels and other effects of climate change. Photo: UN Photo/Eskinder Debebe (CC BY-NC-ND 2.0).

Some of the changes that affect the tuna fisheries of the WCPO are:

  • the temperature of the surface layer of ocean water is rising
  • the ocean is becoming more acidic
  • sea levels are rising
  • storms, floods, and cyclones are becoming more intense
  • rain patterns are shifting, and the amount of rain that falls is changing.

Small states work to protect boundaries as sea levels rise

Rising sea levels are a huge problem for the small island developing states (SIDS) of the WCPO. Many of these small nations are made up of low-lying islands surrounded by coral reefs. They are already losing land, which is disappearing under higher seas.

The change in coastlines may affect their exclusive economic zones (EEZs). The boundaries of EEZs were fixed under the terms of the 1982 United Nations Convention on the Law of the Sea (UNCLOS), the SIDS want to ensure these boundaries are kept even if their land masses shrink. This is important for their economies, because they control the fishing grounds inside their EEZs.

The security of their international boundaries is so important it is formalised in many regional and sub-regional agreements. The Pacific Island Forum (PIF) countries state in the Kainaki II Declaration refers to the UNCLOS EEZ provisions (clause 14 of Annex 1) that they:

aim to ensure that once a Forum Members maritime zones are delineated in accordance with the 1982 United Nations Convention on the Law of the Sea (UNCLOS), that the Members maritime zones could not be challenged or reduced as a result of sea level rise and climate change.

One of the six strategic areas of the Boe Declaration Action Plan is climate security. This also calls on EEZ boundaries to be protected.

The Kainaki II Declaration is the first time the Pacific Islands Forum has agreed and declared that there is a climate change crisis facing the Pacific Island nations. Clauses 1720 of the Kainaki II Declaration outline the members call for urgent, transformational action to address global climate change.

Best Practices

Management best practice for fish-aggregating devices

The FFA helps the small island developing states (SIDS) to develop plans for managing fish-aggregating devices (FADs). The devices affect how fish behave and how many fish are caught. FADs take advantage of the natural habit of some fish, including tuna, to group around objects floating in the water.

A Solomon Islands subsistence fisher at work. Photo credit: Francisco Blaha.

FADs are used to attract fish that naturally gather in dense schools. This means that less time is spent searching for them. The practice is particularly useful when fishing for highly migratory fish such as tuna. But FADs can:

  • reduce populations of bigeye and yellowfin tuna when purse-seine fishers catch juvenile fish that group around FADs
  • interfere with longline fishing, because they increase the risk fishing gear becoming entangled in the mooring ropes of FADs.

What are FADs?

Fish-aggregating devices are structures that float on or near the surface of the water where fish may congregate.

Most are made by humans. They may be free-floating or anchored to the seabed. Examples are buoys, floats, netting, webbing, plastics, bamboo and log. Fish sometimes also gather around whale sharks.

In 2012, the Pew Environment Group estimated that the number of drifting FADs put into the oceans each year ranges from 47,000 to 105,000.

FAD management plans:

  • limit the number of FADs used by purse-seining fishing vessels
  • modifying the design, operation, location and maintenance of FADs to minimise disruption to other fisheries.

Since 1 January 2020, it has been compulsory for all FADs (existing and new) to be designed and constructed so that they cannot entangle sharks, turtles, and other animals that are not the target of fishing operations. The WCPFC also recommends that they be made of biodegradable materials.

Marine Stewardship Council certification

An evaluation of the sustainability of global tuna stocks relative to the Marine Stewardship Council criteria (March 2020) provides a basis for comparing stock scores. It is a useful source document for future tuna certifications or when establishing tuna fishery improvement projects (FIPs) and offers a snapshot” of the current status of the stocks.

PNA best practices

The PNA has two main practices for conserving its fish stocks:

  • limiting the catch of all fishing vessels through the Vessel Day Scheme, which is explained in more detail under Catch & harvest
  • banning the use of fish-aggregating devices by purse-seine fishers for three months a year.
Research and Training

Movement and breeding of tuna already altered by climate change

Climate change has already altered the physical, chemical and biological characteristics of the ocean, and is likely to continue to do so.

Canning tuna. Photo: Francisco Blaha.

The changes influence the location and and behaviour of tuna, for example causing shifts in spawning conditions, and altering the suitability of habitat and the distribution of food. Where the different species of tuna live is influenced by temperature, oxygen in the water, prey and predators.

As well, catches and therefore revenue can fluctuate with phases of El Nio and La Nia.

Changes in the ocean environment mean that fishing grounds can move, fish may move deeper, the abundance of tuna may change, the proportion of tuna to bycatch may change, and shore facilities may be affected by rising sea levels or cyclones.

Modelling and research at sea used to study tuna

The Pacific Community, supported by OFMP2, researches the effects of climate change on tuna stocks, using a combination of research at sea and modelling. SPC researchers examine climate-change forecasts and assess the vulnerability of the region and its oceanic fisheries to such impacts. They:

  • use models such as SEAPODYM to examine the impacts of climate change impacts on target tuna species, on several scales from sub-regional to national
  • examine tuna diets to monitor how climate change affects food sources
  • write reports on how climate change affects oceanic fisheries, and make recommendations.

Research on the ocean is expensive and is conducted in small, intense blocks of time. SPCs marine biologist Valerie Allain, who provides important insights to OFMP2 on the possible impacts of climate change, describes the team needed for such a trip (2.19 min).

Valerie also talks about the data researchers need to collect on research trips on the open ocean (2.50 min).

Valerie talks about the highs and lows of life on board a research cruise vessel (2 min).

Current research confirms earlier studies

Earlier scientific findings were described in the baseline report for the OFMP2 project. Predictions that tuna would move east was confirmed in a report presented to the Scientific Committee of the WCPFC in 2018.

Several factors influence where tuna are found and how abundant they are; they also affect other marine life, including fish that tuna eat. Using data and improved models, the scientists predicted that, as ocean temperatures increase, the ocean becomes more acidic, and the amount of oxygen that is dissolved in seawater changes:

  • Overall, concentrations of the most important tuna species will shift to the eastern Pacific Ocean.
  • Skipjack tuna stocks will slightly increase until 2050, and decrease after 2060. They will move east and into higher latitudes, as feeding and spawning become more favourable there and less favourable in the warmer waters of the western equatorial warm pool of the western Pacific Ocean.
  • Yellowfin tuna will also migrate east. Stocks are likely to drop slightly from 2050, and more markedly from 2080.
  • The total weight of South Pacific albacore tuna (their biomass) may increase in the EEZs of Pacific Island countries and territories (PICTs), although this is uncertain.
  • Bigeye tuna will also move east, but not as dramatically as skipjack and yellowfin. Water temperatures in the Western and Central Pacific will become too warm for spawning, and stock will be declining by the end of the century.

The research shows that, generally, tuna will become less abundant in the EEZs of Pacific Island states, as they move into the high seas.

The movement of tuna will affect island economies

The movement of tuna will cause reverberations around Pacific Island economies. So much so that Pacific region leaders meeting at the Forum Fisheries Committee Ministers Meeting in June 2019 said they considered climate change to be the single greatest threat to the security of Pacific Island countries”.

In 2021, researchers calculated that, if the ocean continues to warm at current rates, by 2050 the tuna catch in the combined waters of the Pacific small island developing states (SIDS) will decline by an average of 20%. This will have serious consequences for the Pacific Islands peoples, who rely on tuna revenue not just for livelihoods but also to fund programs in other sectors such as health and education.

Fisheries managers can change fishing rules to help sustain tuna

Fisheries managers can use new knowledge about the effects of climate change on tuna and their environment by adapting fishing policies, rules and practices. This will help them continue to sustain stocks of tuna.

One option is to win agreement from fishing nations that Pacific SIDS maintain current benefits once tuna have moved into the high seas. This would happen through the Western and Central Pacific Fisheries Commission (WCPFC) annual meetings. WCPFC has paved the way for this to happen through the Resolution on Climate Change accepted at its 2019 meeting.

The small island developing states (SIDS) of the WCPO have been preparing for changes brought by a changing climate for some years.

The 2014 Palau Declaration The Ocean: Life and Future called for strengthened regional efforts to fix baselines and maritime boundaries to ensure that the impact of climate change and sea level rise does not result in reduced jurisdiction. Strong boundaries (such as EEZs) are vital for the ocean-based economies of SIDS, giving them:

  • access to fisheries and other natural resources that secure food supplies
  • continued access to culturally important social activities and economic activities
  • continued revenue and livelihoods from tuna resources that exist in their waters.

The FAO has provided technical assistance to enable the SIDS members of FFA to develop a collective response to predicted changes in sea level due to climate change, as they are likely to affect maritime jurisdictional claims.

The Pacific Marine Climate Change Report Card 2018, produced by the UKs Commonwealth Marine Economics Programme, summarises the impacts of climate change on coasts and seas in the Pacific island region, and how the islands can respond. Several more detailed scientific reviews have been published under the same programme.

FAO released the report Impacts of climate change on fisheries and aquaculture in 2018. It is an overview of the global implications of climate change for all kinds of fisheries and aquaculture and for the millions of people who depend on these sectors for their livelihoods. The publication maps solutions that communities might use to adapt to climate change or lessen its impact. Chapter 14 deals with the WCPO. There is also a four-page summary of the report.


Resources on ecosystems and climate change in WCPO

You can find news stories, popular articles, opinion pieces and blog posts on ecosystems and climate, including the effects of the climate crisis, on the Ecosystems and climate news and views page.

Fact sheets

Tagging a live tuna during research at sea tagging helps scientists understand how tuna respond to a changing climate. Photo: SPC.

Technical papers

Posters and videos