Potential effects of climate change on South African fisheriesMadoda KhumaloStrategic Services Executive

IntroductionSea Harvest Group

Sea Harvest Group

*Source: Nielsen, June 2016, 12mm

SOUTH AFRICA

INTERNATIONAL (AUSTRALIA)

The principal business of the Sea Harvest Group is fishing of Cape Hake and Shark Bay prawns, processing of the catch into frozen and chilled seafood, and the marketing of these products, locally and internationally

Key indicators H1 F17

Established 1964

Industry Fishing, Food, Agri

% of Hake TAC (SA)25.2% (plus 3% from

Vuna)% of Shark Bay prawn licenses (Aus)

56% (10 of 18)

No. of people employed ~3 000

No. of vessels 29

Factories 3

Fishing and processing operations

Saldanha Bay, Mossel Bay, Carnarvon

(Australia)Number of countries selling Sea Harvest products

22

Local market share* 41%

HeadingSUB HEADING

South Africa’s Marine Resources

Marine ResourcesSouth African Economic Exclusion Zone Resources

The 5 Most Economically Viable Marine Species (Catch-2014)

SA Coastline: 2,798 km

EEZ: 1,535,538 km2

Ocean Economy of South Africa

Wild Capture Fishing (~$540 million)

Aquaculture (~$40 million)

Petroleum Services (~$1.25 billion)

Ecotourism (~$150 million)

Hake Trawl Abalone Small Pelagics Squid West Coast rock lobster

127,974 tons 2,496 tons 200,000 tons 8,000 tons 2,450 tons

$220 million $83 million $119 million $30 million $40 million

Source: Unlocking the Economic Potential of South Africa’s Oceans, The Office of

the Presidency of RSA

Current StateEcosystems

Current State

• Two large marine ecosystems (dominated by 2 currents)

• Benguela and Agulhas Current Large Marine Ecosystems

• Interaction between the two is critical for the state of

renewable resources

• Both could potentially change dramatically into the 21st

century

South African Marine Ecosystems Benguela Current Large Marine Ecosystem

Sources: www.seos-project.eu/modules/oceancurrents/oceancurrents-c04-p05.html and MANAGEMENT OF SHARED HAKE STOCKS IN THE BENGUELA MARINE ECOSYSTEM (by Rashid Ussif Sumaila, Chris Ninnesand Burger Oelofsen)

Potential Future StatePotential Climate Change Impacts

*Agulhas Current Large Marine Ecosystem

1. Warmer and Stormier

2. Ecosystem currents will become stronger and

migrate further polewards

3. Prevailing hypothesis for most western boundary

currents except Gulf Stream which is thought will

become weaker

Benguela Current Large Marine Ecosystem

1. 2 hypotheses posed

2. Bakun (1990) hypothesized that upwelling will

increase

3. Roemmich and MacGowan (1995) hypothesized

that stratification will increase

*Source: Hu Yang et al (2016)

Eastern Boundary UpwellingSystems

EBUSThe four systems

Source: Messie and Chavez (2015); Pauly and Christensen (1995)

1. 4 major EBUS

2. Cover <1% of the ocean

but provide 20% of the

worlds capture fisheries

3. Dominated by cooler,

shallow and sluggish

currents

4. All are characterized by

upwelling and

subsequent production

spikes

Natural StateEBUS

1. Abiotic Signal 2. Biotic Signal

Natural Variability? Anthropogenic Effects?

Sources: NOAA and Encyclopaedia Britannica

Climate Change SignalsPotential Future State

Potential Future StateAbiotic Signal

Source: Krueger et al (2008); ESA, EPA and WOCE

1. Atmospheric Forcing

2. Ocean Temperature

3. Ocean Acidification

4. Dissolved Oxygen

Potential Future StateBiotic Signal

Source: Britannica

1. Productivity

2. Primary Consumer

3. Secondary Consumer (Small Pelagics)

4. Secondary Consumer(Large Pelagics and Demersal)

Potential Business Impact and Conclusion

Business ImpactPotential Climate Change Impacts

• Uncertainty in future global aquatic net primary production.

• Effects of climate and fishing impacts species through reducing their age, size and distribution

1. Increased productivity has potential positive impact on stocks at higher latitudes = more fish?

Conversely

Increased stratification influences the complete ecosystem potentially leading to greater “dead-

zones” = less fish?

2. Autonomous adaptive capacity of stock = impact is minimized

Conversely

Autonomous adaptive capacity of stock = impact is maximized

3. The potential warming and consequent changes in prey distribution = effect on catching efficiencies

(reduced cost per kilo to harvest?)

Conversely

The potential warming and consequent changes in prey distribution = effect on catching efficiencies?

(increased cost per kilo to harvest?)

Business ImpactPotential Climate Change Impacts

5. Studies for some species show positive effects on appetite and growth = business impact

dependant on target species

6. Regime shifts out of current jurisdictions = more or less target species?

Conclusion

• Is reducing fishing mortality one of the best means at reducing the impact of climate change?

• Development of more ecosystems-based approaches to fishing might help predict what is potentially

coming next

• Complexity and regional variability makes it difficult to predict with certainty the effect of the physics on

the biology of an ecosystem

• Difficult to resolve in current models whether the potential changes are linking to anthropogenic effects

(emissions and fishing pressure) or natural variability. More research linked to in situ data is required

Thank You