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