ISSN 2070-7010

627

FAO
FA
FISHERIES ANDFISHERIES AN
AQUACULTURE
AQUACULTUTECHNICAL TECHNIC
PAPER
PAP

627 62
Impacts of climate change on fisheries and aquaculture – Synthesis of current knowledge, adaptation and mitigation options

Impacts
Impactsof climateof climatechangechangeon fisheries
on fisheries
and andaquaculture
aquaculture
Synthesis
Synthesisof currentof current
knowledge,knowledge,
adaptation
adaptationand mitigationand mitigation
options options

FAO

Barange, M., Bahri, T., Beveridge, M.C.M., Cochrane, K.L., Funge-Smith, S. &Poulain, F., eds. 2018.

Impacts of climate change on fisheries and aquaculture: synthesis of current knowledge,
adaptation and mitigation options.
FAO Fisheries and Aquaculture Technical Paper No. 627. Rome, FAO.

1

Chapter 14: Climate change
impacts, vulnerabilities andadaptations: Western and Central
Pacific Ocean marine fisheries
Johann D. Bell1,2, Valerie Allain3, Alex Sen Gupta4, Johanna E. Johnson5,6, John
Hampton3, Alistair J. Hobday7, Patrick Lehodey8, Andrew Lenton7, Bradley R.
Moore9, Morgan S. Pratchett10, Inna Senina8, Neville Smith3 and Peter Williams3
1.

Australian National Centre for Ocean Resources and Security, University of
Wollongong, Australia
2. Conservation International, Arlington, United States of America
3. Oceanic Fisheries Programme, Fisheries, Aquaculture and Marine Ecosystems
Division, Pacific Community, Noumea, New Caledonia
4. Climate Change Research Centre & ARC Centre of Excellence for Climate System
Science, University of NSW, Sydney, Australia
5. College of Marine and Environmental Sciences, James Cook University, Australia
6. C2O Pacific, Cairns, Australia and Port Vila, Vanuatu
7. CSIRO Oceans and Atmosphere, Hobart, Australia
8. Collect Localisation Satellites, Ramonville, France
9. Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
10. ARC Centre of Excellence for Coral Reef Studies, James Cook University, Australia

Key messages• Continued CO2 (and other greenhouse gas) emissions are very likely to affect theoutcomes of regional and national plans to maintain or improve socio-economic
benefits derived from industrial tuna fisheries and small-scale, coastal fisheries.
• Global warming is likely to affect food webs supporting tropical tuna species, andvery likely to cause changes in distribution and abundance of tuna by 2050 under
the RCP8.5 emissions scenario.
• Redistribution of tropical tuna is very likely to affect licence revenues from purseseine fishing, and shift more fishing into high seas areas.
• Harvest strategies for tropical tuna will very likely need to account for changes in
distribution and abundance resulting from climate change.
• Priority adaptations to maintain the economic benefits of industrial tuna fisheries
will need to focus on interventions to maintain licence revenues, and ensure
delivery of fish to local canneries.
• Global warming, extreme events, and ocean acidification are very likely to damage
coral reefs and other habitats underpinning small-scale, coastal fisheries for
demersal fish and invertebrates.
• Changes to coral reefs and other fish habitats, and the direct effects of CO2
emissions on fish and invertebrates, are likely to reduce harvests from small-scale,coastal fisheries by up to 20 percent by 2050, and by up to 50 percent by 2100,
under the RCP8.5 emissions scenario.
• Climate change is very likely to increase uncertainty in replenishment of coastal
fish stocks, requiring a more conservative community-based ecosystem approach
to fisheries management.

Impacts of climate change on fisheries and aquaculture2• Priority adaptations to maintain the benefits of coastal fisheries involve minimizing
the gap between sustainable harvests and the fish needed for food security, andfilling the gap mainly by increasing access to tuna for small-scale fishers.
14.1 Introduction
This chapter applies an end-to-end, climate-to-fish-to-fisheries, approach (Bell et al.,2013; Bell, Johnson and Hobday, eds., 2011) to assess the vulnerability of the region’splans to secure and increase the socio-economic benefits from fisheries to climatechange and ocean acidification. It begins by summarising the observed and projectedchanges to the physical and chemical features of the Western and Central Pacific Ocean(WCPO), and how these changes are expected to alter fish habitats. For each of themain types of fisheries in the WCPO, the chapter then explains how the direct andindirect effects of continued carbon dioxide (CO2) emissions are likely to affect the
distribution and abundance of fish stocks; the implications for economic development,
government revenue, food security and livelihoods; and the adaptations needed tominimize the threats and maximize opportunities.
The analyses presented here are based on global and regional modelling approaches
that use the representative concentration pathways (RCPs) from the Fifth Assessment
Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC), or emission
scenarios from the IPCC Fourth Assessment Report (AR4). The likelihood andconfidence ratings for the key messages have been attributed using the IPCC method.
14.1.1 Fisheries of the region
The Western and Central Pacific Ocean1 supports major industrial tuna fisheries anda variety of small-scale, coastal fisheries. The region’s industrial tuna fisheries are
the largest in the world, and make substantial contributions to government revenue,
gross domestic product (GDP) and employment in several Pacific Island countries
and territories (PICTs; Gillett, 2016; Williams, Terawasi and Reid, 2017; Figure 14.1).
The industrial surface fishery targets skipjack tuna (Katsuwonus pelamis) and juvenile
yellowfin tuna (Thunnus albacares) using purse-seine and pole-and-line fishingmethods to supply canneries in the Pacific, Asia and Europe. The industrial longline
fishery targets mature bigeye tuna (Thunnus obesus) and yellowfin tuna for the sashimi
trade and other high-value markets, and South Pacific albacore (Thunnus alalunga) for
canning. Around 60 percent of the tuna catch from the WCPO convention area is takenfrom the exclusive economic zones (EEZs) of PICTs (Williams, Terawasi and Reid,
2017). Industrial tuna fisheries also capture smaller quantities of other large pelagic fish.
Small-scale, coastal fisheries underpin fish consumption and livelihoods in mostPacific Island communities (Figure 14.1; Bell, Johnson and Hobday, eds., 2011; Gillett,2016). These fisheries target mainly demersal fish and invertebrates associated withcoral reefs, mangroves and seagrasses, and increasingly tuna and other large pelagic fishin nearshore waters (Bell et al., 2018; Bell, Johnson and Hobday, eds., 2011; Johnson
et al., 2017).

1

Defined for the purposes of this chapter as the area 25 °N to 25 °S and 130 °E to 130 °W, including
Northeastern Australia.

FIGURE 14.1

PALAU

PALAU

FISH AND FOOD SECURITY

FISH AND FOOD SECURITY

Fish consumption:
110 kg per person p.a.

Dark blue circles denote countries that are the Parties to the Nauru Agreement.
Source: Pacific Community and Conservation International.

Fish consumption:
33 kg per person p.a.

Government revenue: 52%
People employed: 397(US)

KIRIBATIJARVIS(US)PALMYRA(US)KIRIBATI

TONGA

FIJI

FISH AND FOOD SECURITY

FISH AND FOOD SECURITY

Fish consumption:
20 kg per person p.a.

Fish consumption:
21 kg per person p.a.

People employed: 4 332

ECONOMIC IMPORTANCE OF TUNA

People employed: 150

ECONOMIC IMPORTANCE OF TUNAFish consumption:
79 kg per person p.a.

FISH AND FOOD SECURITYNIUE

Fish consumption: 87 kg
per person p.a.

FISH AND FOOD SECURITY

People employed: 257

ECONOMIC IMPORTANCE OF TUNA

Population: 1 500
EEZ area: 296 941 km2Land area: 259 km2
Tuna catch: 293 Mt

Tropic of Capricorn

FRENCH POLYNESIA

SAMOA

Population: 187 400
Ocean area: 110 365 km2
Land area: 2 935 km2
Tuna catch: 2 554 Mt(5-yr average 2010 to 2014)

Fish consumption: 61 kg perperson p.a.

FISH AND FOOD SECURITY

People employed: 25

ECONOMIC IMPORTANCE OF TUNA

COOK ISLANDS

Population: 15 200
EEZ area: 1 996 948 km2
Tuna catch: 20 983 Mt(5-yr average 2012 to 2016)

Fish consumption:
200 kg per person p.a.

FISH AND FOOD SECURITY

Government revenue: 98%

ECONOMIC IMPORTANCE OF TUNATOKELAU

Population: 1 400
EEZ area: 320 392 km2
Tuna catch: 24 365 Mt(5-yr average 2012 to 2016)

Tropic of Cancer

Population: 880 400
EEZ area: 1 285 765 km2
Tuna catch: 8 685 Mt(5-yr average 2012 to 2016)

NIUE

COOK ISLANDSWALLIS &FUTUNA SAMOAAMERICANSAMOATOKELAU

Population: 289 700
EEZ area: 620 780 km2
Tuna catch: 6 972 Mt(5-yr average 2012 to 2016)

VANUATU

FIJI

FISH AND FOOD SECURITY

Government revenue: ~80%
People employed: 870

ECONOMIC IMPORTANCE OF TUNAKIRIBATI

Population: 113 400
EEZ area: 3 451 907 km2
Tuna catch: 530 378 Mt(5-yr average 2012 to 2016)

Fish consumption: 115 kg per
HAWAII person p.a. (rural areas)

HOWLAND& BAKER(US)TUVALUKIRIBATIVANUATUNEW
CALEDONIAECONOMIC IMPORTANCE OF TUNA

Government revenue: ~9%People employed: 1 824

NAURU

SOLOMON ISLANDS

Population: 10 100
EEZ area: 775 283 km2
Tuna catch: 82 271 Mt(5-yr average 2012 to 2016)

TUVALUPAPUA NEW GUINEA

WAKE
(US)

Fish consumption: 56 kg perperson p.a.

FISH AND FOOD SECURITY

Government revenue: 26%

ECONOMIC IMPORTANCE OF TUNA

NAURU

Population: 10 800
EEZ area: 309 888 km2
Tuna catch: 118 140 Mt(5-yr average 2012 to 2016)

MARSHALL ISLANDSECONOMIC IMPORTANCE OF TUNA

Population: 651 700
EEZ area: 1 604 980 km2
Tuna catch: 126 073 Mt(5-yr average 2012 to 2016)

GUAM

FEDERATED STATES OF MICRONESIA

AUSTRALIA

INDONESIA

Equator

SOLOMON ISLANDSFish consumption: 28 kg
per person p.a.
(urban areas)

FISH AND FOOD SECURITY

Government revenue: ~4%
People employed: 9 562

ECONOMIC IMPORTANCE OF TUNA

Population: 8 151 300
EEZ area: 2 403 322 km2
Tuna catch: 404 862 Mt(5-yr average 2012 to 2016)PAPUA
NEW GUINEAFish consumption:
33 kg per person p.a.

FISH AND FOOD SECURITY

Government revenue: 11%
People employed: 36

ECONOMIC IMPORTANCE OF TUNA

Population: 17 800
EEZ area: 606 847 km2
Tuna catch: 3 991 Mt(5-yr average 2012 to 2016)

NORTHERNMARIANAISLANDS

Fish consumption:
39 kg per person p.a.

Fish consumption:
69 kg per person p.a.
(rural areas)

FISH AND FOOD SECURITY

FISH AND FOOD SECURITY

Government revenue: ~12%
People employed: 1 318

Government revenue: ~40%
People employed: 194

ECONOMIC IMPORTANCE OF TUNA

Population: 55 000
EEZ area: 2 000 119 km2
Tuna catch: 58 965 Mt(5-yr average 2012 to 2016)

REPUBLIC OFMARSHALL ISLANDSECONOMIC IMPORTANCE OF TUNA

Population: 104 600
EEZ area: 3 005 200 km2
Tuna catch: 184 643 Mt(5-yr average 2012 to 2016)

FEDERATED STATESOF MICRONESIA

Key features of selected PICTs and the contributions of fisheries to government revenue, employment and food security

Chapter 14: Western and Central Pacific Ocean marine fisheries
3Impacts of climate change on fisheries and aquaculture

4

14.1.2 Strategic plans and management arrangements
Given the great significance of fisheries to Pacific Island people, a concerted effort
has been made by PICTs to understand the key drivers of the sector, and to develop
strategic plans to secure and increase the socio-economic benefits derived from marine
resources. These efforts culminated in the Regional Roadmap for Sustainable PacificFisheries2, endorsed by Pacific Island leaders. The Roadmap is designed to 1) optimize
the benefits of tuna resources for economic development, government revenue andemployment; 2) ensure that growing human populations have enough fish for foodsecurity; and 3) sustain livelihoods derived from small-scale fisheries.
The transboundary tuna stocks of the WCPO are managed cooperatively. The
Pacific Islands Forum Fisheries Agency (FFA) assists member countries to manage
tuna fishing operations by foreign and domestic fleets within their EEZs. The Officeof the Parties to the Nauru Agreement (PNA) allocates purse-seine fishing effort
across the EEZs of its member countries through the “vessel day scheme”. The broader
approach needed to co-ordinate tuna catches within EEZs with those made on the highseas is managed by the Western and Central Pacific Fisheries Commission (WCPFC).
These management arrangements are based on regular stock assessments for eachspecies of tuna by the Oceanic Fisheries Programme of the Pacific Community (SPC).
SPC and partners support PICTs to manage small-scale fisheries using a communitybased, ecosystem approach to fisheries management (CEAFM), underpinned bynational regulations to maintain harvests within sustainable bounds (e.g. spatial andtemporal fishing closures, size limits and gear restrictions). As a result of increased
demand for fish by rapidly-growing human populations in many PICTs, and limits tosustainable harvests from coastal fish habitats, small-scale fishers are also encouraged
to catch more tuna from nearshore waters (Bell et al., 2015, 2018).
14.2 Observed and projected effects of climate change
	on the WCPO
14.2.1 Effects on physical and chemical features of the ocean
The surface temperature of the WCPO has increased by more than 0.7 °C since 1900
(Bindoff et al., 2007). Projections based on a suite of global climate models from the
Climate Model Intercomparison Project version 5 (CMIP5) used for AR5 indicate
that, under the highly ambitious RCP2.6 emissions scenario, increases in average sea
surface temperature (SST) in the WCPO will remain below 1 °C by 2100 relative to2000 to 2010. However, with increased CO2 emissions corresponding to the “businessas-usual” RCP8.5 scenario, SST is expected to increase by 2.5 °C to 3.5 °C by 2100
(Table 14.1), and to rise most rapidly in equatorial waters (Figure 14.2). Critically, thislong-term warming is expected to cause more extreme marine heat waves, resulting
in much higher temperatures over short periods (Hobday et al., 2016). The warming
ocean, and higher projected rainfall, are expected to increase stratification of the watercolumn, reducing the supply of nutrient-rich water to the surface mixed layer (Bell etal., 2013; Bell, Johnson and Hobday, eds., 2011).
Globally, sea level has risen about 20 cm since the industrial revolution (Hay et al.,2015). Continued warming of the ocean to a depth of several hundred metres, together
with melting of glaciers and ice sheets, is expected to cause sea level to rise by 0.4 m by
the end of the century under RCP2.6, and by more than 0.6 m under RCP8.5 (IPCC,
2014).With the possibility of more rapid melting of the ice-sheets (not accounted forin climate models), sea level rise could be considerably greater, exacerbating the effectsof storm surges on coastal fish habitats.

2

www.ffa.int/node/1569

Chapter 14: Western and Central Pacific Ocean marine fisheries

5

Increasing rates of ocean acidification in the WCPO through absorption of
atmospheric CO2 (Langlais et al., 2017) are reducing the aragonite saturation state,
the main form of calcium carbonate used by corals and other marine organisms tobuild hard skeletons and shells. Since the industrial revolution, ocean acidification
has reduced the pH of the upper water column by 0.1 (Royal Society, 2005) and thearagonite saturation level to 3.9 (Langdon and Atkinson, 2005). Aragonite saturationlevels greater than 4 are optimal for calcifying organisms, saturation levels between
4 and 3 are marginal to very marginal for calcification, and below 3 complex coral
reef systems do not occur (Langdon and Atkinson, 2005). Strong mitigation of CO2
emissions (RCP2.6), is expected to maintain aragonite levels at approximately 3.5(Figure 14.3), providing conditions adequate for some coral growth. In contrast, under
RCP8.5 it is very likely that aragonite levels in the WCPO will drop below 3 between
2050 and 2100, causing serious degradation of coral reefs.
The CMIP5 simulations indicate that winds and ocean circulation in the region
will also change significantly (Table 14.1; Figure 14.2). The northeast and equatorial
trade winds are projected to weaken, whereas the southeast trade winds are expected
to intensify. The South Equatorial Current and the associated New Guinea Coastal
Undercurrent are projected to increase, whereas the velocities of the South Equatorial
Counter Current and North Equatorial Counter Current are expected to decrease (Huet al., 2015; Sen Gupta et al., 2016; Figure 14.2). In turn, changes in ocean circulation
are expected to alter the location and strength of warm and cold eddies that reduce andenhance delivery of nutrient-rich water to the photic zone, respectively (Bell, Johnson
and Hobday, eds., 2011).

FIGURE 14.2

Projected mean changes in SST, and major ocean currents (solid lines) and undercurrents(heavy blue dashed line), in the Pacific Island region between 2000 to 2010 and 2090 to 2100.
The mean direction of currents is indicated by white triangles
Multi-model mean change in SST between 2000 to 2010 and 2090 to 2100
20 °N

Subtropical Gyre
North Equatorial Current

10 °N

LatitudeNorth Equatorial Counter Current
Equatorial undercurrent
0°South Equatorial Current

Papua New
Guinea10 °S

Port Moresby

South Equatorial Counter Current
New Guinea
coastal undercurrent

South Equatorial Current

Cairns20 °S

Australia

Subtropical Gyre

140 °E

160 °E180 °Intensification
Weakening

160 °W

Longitude
1.6

1.8

2

2.2

2.4

2.6

Change in SST (°C)

Source: Bell et al., 2013.

2.8

3

3.2

140 °W

Impacts of climate change on fisheries and aquaculture

6

Table 14.1

Multi-model median SST, wind stress, sea level, aragonite saturation and pH from the suite of
CMIP5 models averaged over the 2000 to 2010 period, and projected change in these ocean
variables by 2050 (2045 to 2055) and 2100 (2090 to 2100) for the RCP2.6 and RCP8.5 emissions
scenarios. All changes are expressed as the multi-model inter-quartile range, except foraragonite and pH which are the multi-model median changes
Ocean variable

Multi-model
median2000 to 2010

RCP2.62050

RCP8.5
2100

2050

2100

Sea surface temperature (°C)

27.4

+0.4–0.8+0.3–0.8+0.9–1.3+2.3–3.3

Maximum warm pool SST, warmest
10% region (°C)

29.4

+0.4–0.8+0.3–0.8+0.9–1.3+2.0–3.1

Warm pool edge, defined by 29 °C
isotherm (degrees longitude)170

180.8–191

179.5–193.3

187–205.3

213.3–EM3

Sea level rise (m)0+0.28–0.31+0.4–0.44+0.36–0.41+0.6–0.66

Aragonite

3.9

-0.32

-0.35

-0.63

-1.43

pH1,2

8.07

-0.06

-0.05

-0.12

-0.31

-32.6

-0.6– +3.3

0– +4.2-0.3– +4.5

-2.1– +7.5

1

1,2

Westward wind stress,
2 °S–2 °N, 130 °E–230 °W (10-4 Nm-2)
1

Averaged over full domain 25 °S to 25 °N, 130 °E to 130 °W.

2Dataset described in Lenton, McInnes and O’Grady (2015).

3

EM: eastern margin of Pacific basin.

14.2.2 Effects on biological and ecological features of the WCPO
Oceanic food webs
The predicted reductions of nutrients to the mixed layer (Section 14.2.1) have alreadyhad negative effects on phytoplankton production at various locations in the tropicaland subtropical Pacific Ocean (Boyce, Lewis and Worm, 2010; Signorini, Franz andMcClain, 2015). However, modelling of future phytoplankton production, and theknock-on effects on zooplankton and micronekton, indicates that changes in foodwebs supporting tuna are unlikely to be uniform across the region.
Spatial variability in the effects of increased SST and changes to ocean circulation on
oceanic food webs are expected because of differences between the ecological provinces of
the region (Bell et al., 2013). Impacts are likely to be much lower in the Pacific Equatorial
Divergence than in other provinces as a result of strong upwelling. Nevertheless,uncertainty remains. Some modelling suggests that there could be increases in primary
production of more than 25 percent in the subtropical North Pacific (Polovina et al.,2011). In the western tropical Pacific, other modelling indicates that little change may
occur in primary production by 2050 because increases in sub-surface phytoplankton
could offset declines in surface phytoplankton (Matear et al., 2015).
The considerable uncertainty in how food webs in the WCPO are likely to respondto climate change is related to the complexity of the ecosystem (Bell, Johnson andHobday, eds., 2011), and to difficulties in encompassing all mechanisms involved whenmodelling the effects of ocean warming (Evans et al., 2015). Improved modelling will
depend on a better understanding of prey-predator relationships between different
trophic levels (Behrenfeld, 2014), and their autonomous adaptation to environmental
change (Schaum et al., 2013). Improved simulations of responses of the micronektonic
food of tuna to climate change, and collection of better data (including acoustic andenvironmental DNA data) for model calibration, are particularly important.
The impact of ocean acidification on the food webs supporting tuna has yet to be
determined. However, in the productive Pacific Equatorial Divergence, calcareousorganisms represent only 1 percent to 5 percent of phytoplankton, approximately
6 percent of zooplankton and 2.2 percent of micronekton (Bell, Johnson and Hobday,eds., 2011). Thus, even severe ocean acidification may have limited impacts at thesetrophic levels.

Chapter 14: Western and Central Pacific Ocean marine fisheries

7

Coastal fish habitats
The coral reef, mangrove and seagrass habitats supporting small-scale fisheries in theregion are already under stress from climate change and other anthropogenic impacts(Bell, Johnson and Hobday, eds., 2011; Johnson et al., 2017). Live coral cover has
declined by 1 percent per year since 1980, extensive coral bleaching has occurredon Australia’s Great Barrier Reef since 2015 (Hughes et al., 2018), and a vast area ofmangroves was killed by heat stress in Northern Australia in 2016 (Duke et al., 2017).
The projected increases in air temperature, turbidity from more extreme rainfall,
SST, marine heatwaves, ocean acidification, sea level, and physical damage from more
intense cyclones are expected to cause further reductions in the extent and qualityof coastal habitats (Bell et al., 2013; Johnson et al., 2017). Modelling of the future
frequency of coral bleaching resulting from increased SST indicates that coral reefs in
all PICTs and on the Great Barrier Reef will experience severe annual bleaching by
2050 under the RCP8.5 emissions scenario (van Hooidonk et al., 2016).
The combined effects of more regular, severe bleaching and ocean acidification are
expected to reduce live coral cover by 50 percent to 75 percent by 2050, and as much as
90 percent by 2100 under a high AR4 emissions scenario (Bell, Johnson and Hobday,eds., 2011). As a result, macroalgae are expected to dominate reefs by 2100.
Sea level rise is expected to cause significant reductions in the area of mangroves
because the trees cannot tolerate extended immersion in sea water. The steep terrainof islands in the Western Pacific, where most mangroves in PICTs occur, will prevent
landward migration of mangroves as sea level rises in many places. Where the terrain issuitable, rapid sea level rise could outstrip the capacity of mangroves to migrate. By 2050,
the area of mangroves across all PICTs could be reduced by 50 percent under a high AR4emissions scenario (Bell, Johnson and Hobday, eds., 2011). The area of seagrass is also
expected to decrease significantly (5 percent to 35 percent) by 2050 across the region
under a high AR4 emissions scenario because of increased runoff from more extreme
rainfall, as well as increases in cyclone intensity (Bell, Johnson and Hobday, eds., 2011).
FIGURE 14.3

Projected changes in aragonite saturation for the RCP2.6 (grey) and RCP8.5 (red) emissions
scenarios averaged across the Pacific Island region until 2100
4.5

4

3.5

3

2.5

2000

2020

2040

2060

2080

2100

Impacts of climate change on fisheries and aquaculture

8

14.3

Effects of climate change on industrial tuna fisheries

14.3.1 Observed and projected effects on distribution and abundance
The effects of climate change on tuna3 have been difficult to observe because of thestrong influence of climate variability on their distribution (Hobday and Evans, 2013).
Skipjack tuna is a prime example. The locations where the best catches of this species
are made in the WCPO can vary by up to 4 000 km of longitude between strong El
Niño and La Niña events (Lehodey et al., 1997).
Projected responses of tuna in the WCPO to long-term climate change (Figure 14.4),
and the combined effects of climate change and potential increased fishing effort, havebeen modelled using SEAPODYM4. An eastward and poleward shift in distribution,and reductions in total biomass, are projected for both skipjack and yellowfin tunaunder the RCP8.5 emissions scenario, driven mainly by changes in larval survival
and spawning location (Lehodey et al., 2013, 2017). Decreases in biomass of these
two species in most EEZs west of 170 °E, and increases in EEZs east of 170 °E, arealso expected. Projected percentage decreases by 2050 and 2100 relative to 2005 areparticularly marked for Papua New Guinea, the Federated States of Micronesia, Nauru
and Palau. However, for Papua New Guinea, it is important to note that the modelling
does not yet take account of possible beneficial effects of increased nutrients ofterrestrial origin from higher rainfall (Bell et al., 2013). Substantial percentage increases
in biomass relative to 2005 are projected for skipjack tuna in Vanuatu, New Caledonia,
Pitcairn Islands and French Polynesia, and for yellowfin tuna in French Polynesia.
Somewhat different responses are projected for bigeye tuna and South Pacificalbacore. For bigeye tuna, strong decreases in biomass are expected to occur in the
EEZs of all PICTs, with the declines exceeding 60 percent in several EEZs by 2100
(Figure 14.4). For South Pacific albacore, the distributions of larvae and juveniles are
expected to shift south towards the Tasman Sea after 2050 (Figure 14.4). Densitiesof early life stages are projected to decrease in their core area (Coral Sea) by 2050,
resulting in a stabilized adult biomass approximately 30 percent lower than in 2000.
However, the North Tasman Sea could emerge as a new spawning ground after 2080,
reversing the downward trend in abundance (Lehodey et al., 2015).
14.3.2 Comparative effects of non-climate stressors
There are few concerns about the effects of other drivers on the supply of tuna fromindustrial tuna fisheries. Notwithstanding the need to reduce the impact of tuna fisheries
on the ecosystem (FAO, 2003; Pikitch et al., 2004), the management arrangements
described in Section 14.1 and associated harvest strategies should maintain stocks above
the limit reference points for each tuna species.
14.3.3 Implications for economic development
Redistribution of skipjack and yellowfin tuna (Figure 14.4) is expected to result in lower
catches across the prime fishing grounds by 2050. Ultimately, reduced catches are also
expected to affect licence revenues and the existing plans to increase employment basedon industrial fishing and processing in Papua New Guinea and Solomon Islands. This
employment risk is tempered, however, by the fact that recent average tuna catches
in the EEZs and archipelagic waters of Papua New Guinea and Solomon Islands (seesupplementary material in Bell et al., 2015) well exceed the capacity of existing andproposed fish-processing facilities. Nevertheless, changes in licencing conditions may
be needed to ensure that more of the fish caught within the EEZs of these countries3

4

For the purpose of this chapter, “tuna” also includes other large pelagic fish, such as wahoo(Acanthocybium solandri), mahi mahi (Coryphaena hippurus) and billfish (Family Istiophoridae).
A Spatial Ecosystem and Populations Dynamics Model; https://doi.org/10.1016/j.pocean.2008.06.004

Chapter 14: Western and Central Pacific Ocean marine fisheries

9

is delivered to national canneries (Section 14.6). Other possible negative impacts on
economic development may occur from the eastward redistribution of bigeye tuna andpoleward movement of South Pacific albacore (Figure 14.4). In both cases, a greater
proportion of longline fishing is eventually expected to occur outside the EEZs of
PICTs, reducing government revenue from licence fees.
The projected eastward redistribution of skipjack and yellowfin tuna as a resultof climate change could result in opportunities for PICTs in the eastern WCPO,
e.g. French Polynesia, and PICTs in the subtropics, e.g. Vanuatu and Fiji, toobtain increased economic benefits. However, although modelling indicates that thepercentage increases in catch could be substantial in these EEZs, the scale of benefits islikely to be modest because present-day catches are low.
FIGURE 14.4

Average historical (2005) distributions of skipjack, yellowfin and bigeye tuna and South Pacific albacore(Mt/km2) in the tropical Pacific Ocean, and projected changes in biomass of each species relative to 2005
under the RCP8.5 emission scenario for 2050 and 2100, simulated using SEAPODYM. Isopleths in the
projections for 2050 and 2100 represent the relative percentage change in biomass caused by climate change

Skipjack
2050

2005

2100

40 °N

40 °N

40 °N
50
0

20 °N

20 °N

40 °S

40 °S
150 °E0160 °W

0

0.1

0.2

–0.3

0.3

–0.15

0

100

20 °S

0.3

100
100

100

150 °E

0.15

50

100

50

110 °W

0

0
100

50

40 °S
160 °W

50

50

0°

–50

150 °E

110 °W

100
50

50
100
100

20 °S

20 °S

20 °N

50

0

–50

0°

0°

100

50

-0.3

160 °W-0.15

0110 °W
0.15

0.3

Yellowfin
2005

2050
40 °N

40 °N

20 °N

20 °N

2100
40 °N

50

0

0

0

0

-50

50

50

100

20 °S

20 °S

20 °S

0
50

20 °N
0°

0°

0°

50

0

40 °S

0

40 °S
150 °E0160 °W
0.05

110 °W
0.1

0

–0.15

0.15

40 °S

50

0

150 °E

160 °W–0.075

0

50

0.075

100

0

0

150 °E

110 °W
0.15-0.15

160 °W-0.0750110 °W
0.075

0.15

Bigeye
2005

2050

40 °N

40 °N

20 °N

20 °N

2100
40 °N

0

20 °N

0

0°

0°

0

20 °S

20 °S

–50

0°
50

20 °S

0

50
50

40 °S

40 °S
150 °E00.01

160 °W
0.02

0.03

0.04

40 °S

0

150 °E

110 °W–0.05

0.05

160 °W–0.0250150 °E

110 °W
0.025

-0.05

0.05

160 °W-0.0250110 °W
0.025

0.05

South Pacific albacore
2005

2050

0°

0°

10 °S

10 °S

20 °S

20 °S

30 °S

30 °S

40 °S

40 °S

50 °S

50 °S
150 °E0160 °W
0.01

0.02

110 °W
0.03

0.04

2100
0°

–20

–40

10 °S

–40

–10

–0.04

–0.02

20

40 °S

–10

150 °E

–20

30 °S

–30

–10

–40

20 °S

–20
–10

160 °W

110 °W

0

0.02

–60

–40

50 °S

0.04

–0.04

0

0

150 °E

160 °W-0.02

0110 °W
0.02

0.04

10

Impacts of climate change on fisheries and aquaculture

14.3.4 Consequences for fisheries management
The modelling summarized in Section 14.3.1 indicates that an increase in fishing effort
will exacerbate the overall decreases in production of tuna species projected to occur as aresult of climate change. To minimize negative effects on tuna catches, fishing effort willneed to be constrained and future harvest strategies adjusted to account for alterations
in distribution and abundance of tuna species. The depletion-based reference points
used by WCPFC are well suited to adjusting management to cater for possible futurechanges in stock productivity because biomass levels are considered in relation tolevels that would have occurred in the absence of fishing. Other possible consequences
include 1) the need to transfer more management responsibility to WCPFC as a greater
proportion of the catch is made in high seas areas; and 2) eventual consideration of
Pan-Pacific tuna management through a merger of WCPFC and the Inter-American
Tropical Tuna Commission. The existing monitoring, control and surveillance of tuna
catches by FFA, PNA and WCPFC should help identify if and when such a change
in management would be appropriate. Because eastward redistribution of tuna can be
expected to increase the use of drifting fish aggregating devices (FADs) by purse-seine
vessels (Williams, Terawasi and Reid, 2017), management will also need to ensure thatthe effects of FAD fishing on associated species (e.g. sharks) and juvenile bigeye tuna(Hall et al., 2017) are mitigated effectively.
14.3.5 Vulnerability of fisheries and economies
The four species of tropical tuna are expected to have relatively low vulnerability to theprojected physical and chemical changes to the WCPO, and to alterations in oceanic
food webs, because they can move to areas with their preferred conditions. However,increased stratification could make the surface-dwelling skipjack and yellowfin tuna
more vulnerable to capture. This assessment is based on higher catch rates for yellowfin
tuna in the warm pool (see Table 14.1 for definition) during El Niño events, when
shoaling of the thermocline contracts the vertical habitat for this species (Johnson
et al., 2017). Increased vulnerability to capture by the surface fishery, and projected
decreases in availability of these two species across much of the region (Section 14.3.1),
underscore the need for effective management (Section 14.4.3). The small national
economies with a high dependence on licence fees are likely to be vulnerable to thesechanges by 2050. It is possible, however, that the plans to improve the value of tunain the Roadmap could maintain existing levels of government revenue from licencefees even though catches decline. The economies of Papua New Guinea and Solomon
Islands are expected to have low vulnerability because tuna fishing and processing makerelatively small contributions to GDP of these relatively large economies.
14.3.6 Recommended adaptations
Priority adaptations to maintain the contributions of purse-seine fishing to economic
development are based around continuing to 1) maintain licence revenue and distribute
it equitably among PNA members and other PICTs; 2) deliver the tuna required byexisting and proposed canneries in the region; and 3) finding ways to add more value
to the abundant skipjack tuna. These adaptations are summarized in Table 14.2 anddescribed in more detail in Bell, Johnson and Hobday, eds. (2011).
Two of the key adaptations are already in place. The VDS (Section 14.1.2) allows
licence revenues to be shared among PNA member countries regardless of El NiñoSouthern Oscillation phase and adjusts the fishing days allocated to countries as climatechange alters the distribution of tuna. The Interim Economic Partnership Agreementwith the European Union enables Papua New Guinea to source tuna for nationalcanneries from outside its EEZ, guaranteeing sufficient tuna for processing as the fish
move eastward. If needed, other adaptations that would help maintain the supply oftuna for canneries include reducing access for distant water fishing nations (DWFNs)

Chapter 14: Western and Central Pacific Ocean marine fisheries

11

to Papua New Guinea’s EEZ to provide more fish for national vessels, and requiring
DWFNs operating within the EEZ to land fish at local canneries. Finding ways to add
more value to skipjack tuna would allow PICTs to earn more from this resource inthe short-term, and help offset the consequences of lower projected catches caused byclimate change.
Table 14.2

Examples of priority adaptations and supporting policies to assist PICTs reduce the threats posedby climate change to the contributions of industrial tuna fisheries to economic development, andcapitalize on the opportunities. These measures are classified as “win-win” (W-W) adaptations,which address other drivers of the sector in the short term and climate change in the long term,or “lose-win” (L-W) adaptations, where benefits are exceeded by costs in the short term but
accrue under longer-term climate change (Chapter 25)
Adaptation options

Full implementation of the vessel day scheme (VDS)
to control fishing effort by the Parties to the Nauru
Agreementa (W-W).
Diversify sources of fish for canneries and maintaintrade preferences, e.g. an Economic Partnership
Agreement with the European Union (W-W).
Identify ways to add more value to skipjack tuna(W-W).
Continued conservation and management measures
for all species of tuna to maintain stocks at healthy
levels and make these valuable species more
resilient to climate change (W-W).
Energy efficiency programmes to assist fleets tocope with oil price rises, minimize CO2 emissions,and reduce costs of fishing further afield as tunamove east (W-W).

Supporting policies•

Strengthen national capacity to administer
VDS.

•

Adjust national tuna management plans
and marketing strategies to provide flexible
arrangements to buy and sell tuna.

•

Promote partnerships to process and market
skipjack tuna in new ways.

•

Include implications of climate change inmanagement objectives of the WCPFC.

•

Apply national management measures
to address climate change effects for
subregional concentrations of tuna inarchipelagic waters beyond WCPFC’s
mandate.

•Require all industrial tuna vessels to provide
operational-level catch and effort data to
improve models for projecting redistributionof tuna stocks during climate change.

Environmentally-friendly fishing operations (W-W).
Source: Bell et al., 2013, Bell, Johnson and Hobday, eds., 2011.

a= The Parties to the Nauru Agreement (PNA) are Palau, Federated States of Micronesia, Papua New Guinea,
Solomon Islands, Marshall Islands, Nauru, Kiribati and Tuvalu; more than 90% of the tuna caught from the watersof PICTs comes from the EEZs of PNA members.

14.4

Effects of climate change on small-scale fisheries

14.4.1 Observed and projected effects on distribution and abundance
Declines in abundance of coral reef fishes because of coral bleaching have been
observed on the Great Barrier Reef (Pratchett et al., 2011). However, climate change
and ocean acidification are projected to have a greater range of direct and indirect
effects on distribution and abundance of demersal fish and invertebrates in the WCPO.
The indirect effects will occur through changes to coastal fish habitats. The main direct
effects are summarized below.
Higher SST is expected to alter the metabolic rates, growth, reproduction andsurvival of demersal fish and invertebrates, resulting in changes in their abundance,
size and distribution (Asch, Cheung and Reygondeau, 2018; Munday et al., 2008).
Alterations to the strength of ocean currents are likely to affect the dispersal of larvae,
reducing recruitment success in some locations and improving success in others (Bell,Johnson and Hobday, eds., 2011). Ocean acidification has been demonstrated to affectthe behaviour (Munday et al., 2013), auditory responses (Simpson et al., 2011) andolfactory function (Dixson, Munday and Jones, 2010) of early life-history stages ofdemersal fish species. These changes are expected to alter the homing and settlement
success of juveniles and their ability to detect and avoid predators (Munday et al.,2013), with implications for population replenishment. Lower aragonite saturationlevels are expected to reduce calcification rates for gastropod and bivalve molluscs

12Impacts of climate change on fisheries and aquaculture

and echinoderms, making juveniles more vulnerable to predation (Bell, Johnson andHobday, eds., 2011).
The combined direct and indirect effects of climate change and ocean acidification
are estimated to reduce productivity of demersal fish in the region by up to 20 percent
by 2050, and by 20 percent to 50 percent by 2100, under a high AR4 emissions scenario(Bell, Johnson and Hobday, eds., 2011). The projected changes to coastal fish habitats(Section 14.2.2 – Coastal fish habitats) are also expected to alter the composition ofcatches. For example, herbivorous species are likely to be relatively more abundant ascoral cover declines and macroalgae increase (Bell, Johnson and Hobday, eds., 2011).
Recent modelling of expected changes in abundance and distribution of demersal fishin the tropical Pacific indicates that even greater decreases in production may occur,
exceeding 50 percent under RCP8.5 by 2100, especially in the west of the region (Asch,
Cheung and Reygondeau, 2018).
Productivity of invertebrates is projected to decrease by 5 percent by 2050, and by
10 percent by 2100 under a high AR4 emissions scenario, and their quality and size
is expected to be affected by reduced aragonite saturation levels (Bell, Johnson andHobday, eds., 2011).
The potential effects of climate change on coral reef fisheries are illustrated by
the projections for coral trout (Plectropomus spp.), which are heavily fished in
Northeastern Australia and elsewhere in the Indo-Pacific. The thermal optimum for
Plectropomus leopardus is 27 °C to 30 °C (Johansen et al., 2014), however, stocks
are now exposed to temperatures of more than 30 °C throughout much of theirrange. Although this species may be able to moderate its exposure and sensitivity toincreasing temperatures by moving to deeper water, reducing energetic expenditure
and adjusting food intake during periods of higher SST, ocean warming is expected toreduce sustainable harvests, especially at low latitudes (Johansen et al., 2015; Pratchettet al., 2017). The direct impacts of ocean warming will be compounded by degradationof coral reefs. In combination, these direct and indirect effects are expected to threaten
the viability and sustainability of commercial fisheries by 2050 (even under RCP2.6) at
low-latitude locations. At subtropical latitudes, fisheries for coral trout are expected to
become increasingly uneconomical towards 2100.
14.4.2 Comparative effects of non-climate stressors
Coastal fisheries in the WCPO are expected to be at much greater risk from drivers
other than climate change in the near term (Gillett and Cartwright, 2010). The strongest
drivers are those associated with rapid population growth (see supplementary material
in Bell et al., 2015), i.e. overfishing because of limited alternative sources of protein anddegradation of fish habitats caused by more intense land use and pollution (Gillett and
Cartwright, 2010).
The main challenges are to 1) keep coastal fish and shellfish stocks within sustainablebounds through conservative fisheries management approaches fit for purpose, e.g.
primary fisheries management (Cochrane, Andrew and Parma, 2011); and 2) manage
coastal fisheries to address the key drivers while simultaneously minimizing the risks
to stocks posed by climate change, and capitalizing on opportunities (Section 14.4.6).
14.4.3 Implications for food security and livelihoods
The implications of climate change for the important role that fish plays in local foodsecurity have to be placed in the context of the other factors affecting availability of fish.
In many PICTs, population growth alone creates a large gap between recommended
fish consumption for Pacific Island people (35 kg of fish per person per year) andsustainable harvests from well-managed coastal fisheries (Bell, Johnson and Hobday,eds., 2011).

Chapter 14: Western and Central Pacific Ocean marine fisheries

13

Based on the area of coastal fish habitats and the distance of these habitats from
population centres, PICTs fall into three groups with respect to their capacity toprovide the fish needed for food security (Bell, Johnson and Hobday, eds., 2011):
1) PICTs with coastal fisheries expected to meet increased demand for fish; 2) thosewith sufficient coastal habitat to produce the fish required, but where transportationof fish to urban centres will be difficult; and 3) PICTs where coastal fish habitats will
be unable to produce the fish required.
There are few implications of the projected decreases in coastal fish production
arising from climate change for PICTs in Groups 1 and 2. The main risk is for PICTs
outside the equatorial zone, where increases in ciguatera fish poisoning as a resultof degradation of coral reefs caused by ocean warming could result in localised
shortfalls in fish supply (Bell, Johnson and Hobday, eds., 2011). In such circumstances,
communities will need to rely more heavily on catching tuna in nearshore waters.
For PICTs in Group 3, the projected declines of up to 20 percent in coastal fisheries
production by 2050 and up to 50 percent by 2100 are expected to increase the gap only
marginally because the effects of population growth on availability of fish per capita
are so profound (Table 14.3). The main implications centre on the need to provide
better access to tuna to supply the fish required by growing populations (Bell et al.,2015). Developing fisheries for small pelagic fish (Bell et al., 2018) and expanding pondaquaculture (Johnson et al., 2017) will also be important (Section 14.4.6).
Maximising the number of livelihoods that can be sustained from coastal fisheries
resources will involve progressively transferring some effort from demersal fish totuna and small pelagic fish species (Bell et al., 2018; Bell, Johnson and Hobday, eds.,
2011), and switching some demersal fishing effort from resource “losers” to resource“winners”.
Table 14.3

Projected gap between recommended fish consumption of 35 kg per person per year, and theestimated annual supply of fish per capita from coastal fisheries, in 2050 and 2100 for selected
Pacific Island countries because of the effects of population growth (P) and the combined
effects of population growth and climate change (CC) under a high AR4 emissions scenario

Country

Papua New Guinea
Samoa

Estimatedsustainable
catch (Mt)*

83 500Population**

Total fish
available percapita per year(kg)

Gap in fish needed per
capita per year (kg)

2050

2050

2100

2050

2100

13 27121 125

6

4

2100

P

CC

P

CC

29

29

31

32

6100

210

240

29

25

6

11

10

16

Solomon Islands

27 605

1 181

1 969

23

14

12

15

21

24

Vanuatu

3 812

483

695

8

6

27

28

29

30

*Estimates assume sustainable median fisheries production of 3 Mt per km2 of coral reef per year (but also include
freshwater fisheries production for Papua New Guinea and Solomon Islands, and reef habitat to depth of 100 m for
Samoa).
**Estimates provided by the Pacific Community’s Statistics for Development Division (source: Bell et al., 2013).

14.4.4 Consequences for fisheries management
The direct and indirect effects of climate change and ocean acidification are expected
to increase uncertainty in replenishment of coastal stocks (Bell, Johnson and Hobday,eds., 2011). Increased uncertainty will require changes to the CEAFM and primary
fisheries management approaches used by PICTs to keep coastal fisheries resources atsustainable levels. The reorientation of CEAFM needed to assist communities to adapt
to climate change involves 1) informing all stakeholders about the risks to fish habitats,stocks and catches and facilitating their participation in decision-making; 2) supportingImpacts of climate change on fisheries and aquaculture

14

the trans-disciplinary collaboration needed to monitor the wider fisheries system forclimate impacts and identify practical adaptations; and 3) providing the resources
needed to implement climate-informed CEAFM (Heenan et al., 2015).
The more conservative application of primary fisheries management needed toaddress the increased uncertainty is illustrated in Figure 14.5. Examples of the types ofmanagement changes likely to be needed are revised size limits to account for altered
growth rates and maturity schedules; and ensuring that the herbivorous species likely
to be favoured by climate change are not overfished. Healthy stocks of herbivores will
be needed to ensure that macroalgae do not unduly inhibit the growth and survival ofremaining corals (Bell, Johnson and Hobday, eds., 2011).
FIGURE 14.5

Primary

Secondary

Low

MediumTertiaryCC
Benefits

Uncertainty

General relationship between potential benefits from fisheries for coastal demersal fish
species and invertebrates (green line), and uncertainty in information for management(dashed line), as functions of costs, for primary, secondary and tertiary fisheries management.
The reduction in benefits under primary fisheries management as a result of the increased
uncertainty caused by climate change (CC) is indicated by the orange shading

Cost

High

Sources: Bell, Johnson and Hobday, eds., 2011; Cochrane, Andrew and Parma, 2011.

14.4.5 Vulnerability of fisheries and communities
The small-scale, coastal fisheries underpinning food and livelihoods across the region
have a moderate to high vulnerability to climate change for the following reasons:1) the majority of the catch is derived from coral reefs (Bell, Johnson and Hobday, eds.,
2011); 2) increases in SST will progressively drive many target species to higher latitudes(Asch, Cheung and Reygondeau, 2018); and 3) degradation of coral reefs is expected toreduce the productivity of species able to remain on reefs (Bell, Johnson and Hobday,eds., 2011). Even so, differences in vulnerability of the target species associated withcoral reefs are expected between the Pacific Island region and Northeastern Australia.
Coral-dependent species in PICTs are highly vulnerable (Table 14.4) because there
are significant constraints on latitudinal shifts, mainly as a result of a lack of suitable
habitat at higher latitudes. In Northeastern Australia, the vulnerability of reef-dependent
fish species is lower because the connectivity of the Great Barrier Reef over 2 300 km
should enable them to move to higher latitudes. The vulnerability of reef-associatedand generalist species is expected to be moderate to high by 2100 because of their lower
sensitivity to reduced live coral cover and structural complexity of reefs.
Many Pacific Island communities have a high vulnerability to decreases in productivityof demersal fish and invertebrates because they have few other sources of animal protein.
A participatory approach is needed to raise awareness of the risks and identify practicaladaptations to provide nutritious food for growing populations. The IPCC vulnerability

Chapter 14: Western and Central Pacific Ocean marine fisheries

15

framework and the Vulnerability Assessment and Local Early Action Planning Tooldeveloped by the US Coral Triangle Initiative have been incorporated into such an
approach for communities (Johnson et al., 2016). This approach scores and ranks thevulnerability of communities based on their exposure, sensitivity and adaptive capacity,using indicators of health, education, size of the economy and governance. This initiative
is complemented by the climate-informed ecosystem approach to fisheries management(Heenan et al., 2015), and by assisting communities to evaluate alternative sources offood, e.g. access to freshwater for pond aquaculture and availability of tuna in nearshore
waters (Bell, Johnson and Hobday, eds., 2011).
Table 14.4

Projected changes in productivity of the main types of demersal fish species associated withcoral reefs in the Pacific Island region under a high emissions scenario in 2050 and 2100
2050

2100

Coral-dependent

Type of species

-90%

-100%

Reef-associated-20 to -40%

-20 to -80%

Generalist

0%-10 to -20%

All demersal fish

-20%

-20 to -50%

Source: Bell, Johnson and Hobday, eds., 2011.

14.4.6 Recommended adaptations
The priority adaptations to maintain the contribution of fisheries to food security
and livelihoods of coastal communities involve finding ways to 1) minimize the gap
between sustainable harvests from coastal fish habitats, and the quantities of fishrecommended for good nutrition of growing human populations; and 2) fill the gap(Bell et al., 2018; Table 14.5). Adaptations to minimize the gap centre on avoiding
and reversing degradation of coastal fish habitats and maintaining healthy stocks ofdemersal fish and invertebrates. Most of these adaptations are an integral part of coastalzone management and sustainable fisheries management (FAO, 2003, 2015). Climateinformed, ecosystem-based approaches to fisheries management (Heenan et al., 2015)
provide the most effective way forward. Adaptations to fill the gap will need to focus
largely on making it easier for small-scale fishers to access the region’s rich tuna
resources, developing fisheries for small pelagic fish, expanding pond aquaculture, andimproving supply chains to avoid waste (Bell et al., 2015, 2018; Johnson et al., 2017).
Table 14.5

Examples of priority adaptations and supporting policies to assist PICTs reduce the threats posedby climate change to the contributions of small-scale fisheries to food security and livelihoods,
and capitalize on the opportunities. These measures are classified as “win-win” (W-W)
adaptations, which address other drivers of the sector in the short term and climate change inthe long term, or “lose-win” (L-W) adaptations, where benefits are exceeded by costs in the shortterm but accrue under longer-term climate change (Chapter 25)
Adaptation

Supporting policies

Adaptations to minimize the gap

Manage and restore vegetation in catchments(W-W).

•

Avoid (and reverse) degradation of coastal fish
habitats (W-W).

•

Provide for landward migration of coastal fish
habitats (L-W).

•

Sustain production of coastal demersal fish
and invertebrates (L-W).

•

Maximize the efficiency of spatial
management (W-W).
Diversify catches of coastal demersal fish (L-W).

••

Improve governance for sustainable use andprotection of coastal fish habitats.
Strengthen fisheries legislation to apply communitybased management, founded on an ecosystemapproach and primary fisheries management.
Enhance national regulation of small-scale,commercial fishing.
Promote access to those groups of fish expected toincrease in abundance.
Limit export of demersal fish.
Develop ecotourism to relieve fishing pressure on
demersal fish stocks.

Impacts of climate change on fisheries and aquaculture

16

Adaptation

Supporting policies

Adaptations to fill the gap

Transfer coastal fishing effort from demersal
fish to nearshore pelagic fish (W-W).
Expand fisheries for small pelagic species(W-W)*.
Extend the storage time of nearshore pelagic
fish catches (W-W).
Increase access to small tuna and bycatch
offloaded by industrial fleets during transshipping operations (W-W).
Expand aquaculture of Nile tilapia andmilkfish (W-W).

•
•
•
•
•

Include nearshore FADs as part of the national
infrastructure for food security.
Transfer some access rights and revenues fromindustrial tuna fisheries to small-scale fisheries.
Evaluate whether industrial fishing exclusion zones
provide adequate access to tuna for small-scale
fishers.
Apply targeted subsidy programmes to support key
adaptations.
Limit tilapia farming to catchments with a shortageof fish and where tilapia are already established toreduce potential risks to biodiversity.

Source: Bell et al., 2013, 2018.
*Small pelagic fish are expected to be favoured by climate change only where changes to currents and eddies
deliver more nutrients to surface waters.

14.5 Capacity development and enabling environment
Despite the practicality of the adaptations for industrial tuna fisheries and small-scale,coastal fisheries outlined above, uncertainty and gaps in knowledge remain about how best
to apply them (Bell et al., 2013). Staged actions are needed to identify the research to bedone; create effective research partnerships; overcome constraints to sharing knowledge
and uptake of technology; and provide countries and communities with the resources
needed for effective adaptation. Potential social barriers to the uptake of adaptations
recommended for small-scale, coastal fisheries, e.g. cultural norms and gender issues that
could limit broad-based community participation, also need to be considered.
The region also recognizes the need to build capacity for an integrated approach
to climate change adaptation (CCA) and disaster risk management (DRM; Johnson,
Bell and De Young, 2013). Combining DRM and CCA is particularly pertinent in the
Pacific Island region, where there is a large overlap between the most common natural
disasters (cyclones) and the impacts of climate change on the fisheries sector. The
recent Framework for resilient development in the Pacific: an integrated approach toaddress climate change and disaster risk management5 provides strategic guidance forstakeholders about how to enhance resilience to climate change and natural disasters.
The Framework builds capacity to prepare for disasters, including those caused or
exacerbated by climate change. The disaster preparedness, response and recovery
initiatives in the Framework are designed to reduce undue human losses, and minimize
adverse consequences for the region’s social and environmental systems.
Ultimately, the most important ways for PICTs to improve the enabling environment
for maintaining the socio-economic benefits of their marine fisheries will be to prepare,communicate and maintain their Nationally Determined Contributions under the 2015
Paris Agreement to adapt to the impacts of climate change, and reduce national emissions(Chapter 28).
Supplementary material, providing more detail for several aspects of this chapter, canbe downloaded at http://oceanfish.spc.int/media/files/Supplementary%20Materials%20
Chapter%2014.pdf
14.6

References

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biodiversity, and fisheries maximum catch potential in Pacific Island countries andterritories under climate change. Marine Policy, 88: 285–294. (also available at https://doi.
org/10.1016/j.marpol.2017.08.015).
Behrenfeld, M.J. 2014. Climate-mediated dance of the plankton. Nature Climate Change,
4: 880–887. (also available at https://doi.org/10.1038/nclimate2349).
5

http://gsd.spc.int/frdp/

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Bell, J.D., Johnson, J.E. & Hobday, A.J., eds. 2011. Vulnerability of tropical Pacific fisheries
and aquaculture to climate change. Noumea, Secretariat of the Pacific Community,
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Bell, J.D., Ganachaud, A., Gehrke, P.C., Griffiths, S.P., Hobday, A.J., Hoegh-Guldberg,O., Johnson, J.E. et al. 2013. Mixed responses of tropical Pacific fisheries and aquaculture
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M. et al. 2015. Diversifying the use of tuna to improve food security and public healthin Pacific Island countries and territories. Marine Policy, 51: 584–591. (also available athttps://doi.org/10.1016/j.marpol.2014.10.005).
Bell, J.D., Cisneros-Montemayor, A., Hanich, Q., Johnson, J.E., Lehodey, P., Moore,
B.R., Pratchett, M.S. et al. 2018. Adaptations to maintain the contributions of smallscale fisheries to food security in the Pacific Islands. Marine Policy, 88: 303–314. (alsoavailable at https://doi.org/10.1016/j.marpol.2017.05.019).
Bindoff, N.L., Willebrand, J., Artale, V., Cazenave, A., Gregory, J., Gulev, S., Hanawa,
K. et al. 2007. Observations: oceanic climate change and sea level. In S. Solomon, D. Qin,
M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller, eds. Climatechange 2007: The physical science basis. Contribution of Working Group I to the Fourth
Assessment Report of the Intergovernmental Panel on Climate Change, pp. 385–428.
Cambridge, UK, Cambridge University Press. (also available at https://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch5.html).
Boyce, D.G., Lewis, M.R. & Worm, B. 2010. Global phytoplankton decline over the past
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