How is Climate ChangeHow is Climate Change Expected to Impact Expected to Impact FisheriesFisheries

Neil A. BellefontaineNeil A. Bellefontaine

World Maritime UniversityWorld Maritime University

June 07, 2007.June 07, 2007.

Climate Change Impacts on Climate Change Impacts on FisheriesFisheries

• The last decade was the warmest in the The last decade was the warmest in the Northern Hemisphere over the past 1000 Northern Hemisphere over the past 1000 years and air temperature is predicted to years and air temperature is predicted to increase even more in the future, especially increase even more in the future, especially in winter (IPCC 2001).in winter (IPCC 2001).

• The World ocean is also warming and not The World ocean is also warming and not just near surface water (Levitus 2006).just near surface water (Levitus 2006).

Levitus, S. et al. Warming of the World Ocean. Science 287: 2225-2229

Upper 300 m

Upper 3000 m

Hea

t C

onte

nt A

nom

aly

(102

2 J

)

Oceans are warming from surface to bottom

1950 1970 1990

1950 1970 1990

1950 1970 1990

.

Arctic Sea Ice

1979 2003

3% decrease per decade in sea ice extent.

Melting of this icecap represents a large freshwater source.

Climate Change Predictions for Natural Climate Change Predictions for Natural SystemsSystems

• Poleward shifts in distribution of marine Poleward shifts in distribution of marine resources.resources.

• Extreme changes at range boundaries of Extreme changes at range boundaries of certain species (uncertainty in numbers and certain species (uncertainty in numbers and extent).extent).

• Habitat shrinkage of northern species and Habitat shrinkage of northern species and replacement by southern species. replacement by southern species.

• Earlier spring events and later autumn events.Earlier spring events and later autumn events.• Risks of large-scale, possibly irreversible Risks of large-scale, possibly irreversible

impacts are yet to be quantified.impacts are yet to be quantified.

Parmesan, C. and G. Yohe. 2003. A globally coherent fingerprint of climate change impacts across natural systems. Nature 421:37-42.

What is at Risk?What is at Risk?• World production from Fisheries and World production from Fisheries and

Aquaculture reached almost 142 million Aquaculture reached almost 142 million tonnes in 2005.tonnes in 2005.

• Aquaculture accounted for 47.8 million Aquaculture accounted for 47.8 million and the remainder 93.8 million tonnes and the remainder 93.8 million tonnes came from wild capture fisheries.came from wild capture fisheries.

• Of the total, 103.1 million came from Of the total, 103.1 million came from marine and 38.5 from inland waters.marine and 38.5 from inland waters.

• China remains the worlds largest fish China remains the worlds largest fish producer with 47.5 million tonnes (16.9 producer with 47.5 million tonnes (16.9 mt wild capture and 30.6 mt aquaculture).mt wild capture and 30.6 mt aquaculture).

World Wild Capture Fisheries World Wild Capture Fisheries and Aquaculture (FAO 2006)and Aquaculture (FAO 2006)

World Fisheries by Ocean World Fisheries by Ocean Region (FAO 2006)Region (FAO 2006)

What are the Specific What are the Specific Fisheries Problems most Fisheries Problems most

likely to be associated with likely to be associated with Climate Change ? Climate Change ?

Shifts in Species Shifts in Species DistributionDistribution

Pacific Salmon in the North Pacific

Distribution changes 2X CO2

David Welch, DFO, Nanaimo

ExtremeExtreme ChangesChanges atat RangeRange BoundariesBoundaries

Ken Drinkwater, IMR, Bergen

Cod are wide ranging across the N. Atlantic

Response to temperature depends on location

N - limit

S - limit

2°C Temperature Increase

Increase

No change

Decrease

Collapse

Ken Drinkwater, IMR, Bergen

Expected Change in stock size:

3°C Temperature Increase

Increase

No change

Decrease

Collapse

Ken Drinkwater, IMR, Bergen

4°C Temperature Increase

Increase

No change

Decrease

Collapse

Ken Drinkwater, IMR, Bergen

HabitatHabitat ShrinkageShrinkage

Snow crab in the Southern Gulf of St. Lawrence

Adapted to live and breed in cold water

Optimal

Poor

Snow crab habitat index in 1993 – cold year

Snow Crab Habitat Index in 2002 – Warm Year-

J. Chase DFO Moncton.

Joel Chasse, DFO, Moncton

Atlantic Salmon Habitat ShrinkageAtlantic Salmon Habitat Shrinkagedue to Climate Change in Northwest due to Climate Change in Northwest AtlanticAtlantic

The Baltic SeaThe Baltic Sea• The 2007 HELCOM study of Climate The 2007 HELCOM study of Climate

Change in the Baltic Sea points to Change in the Baltic Sea points to significant potential change that will significant potential change that will affect fish and marine mammals, such as:affect fish and marine mammals, such as:

-food web disruptions due to lower -food web disruptions due to lower trophic variability (ie plankton species trophic variability (ie plankton species affected by water flows, composition and affected by water flows, composition and temperature changes).temperature changes).

-salinity declines will affect some -salinity declines will affect some species production and life cycles (ie cod, species production and life cycles (ie cod, flatfish, herring and sprat).flatfish, herring and sprat).

- marine mammals will be affected by - marine mammals will be affected by less ice, earlier break-up, and warmer less ice, earlier break-up, and warmer temperatures (ie ring, harp and grey temperatures (ie ring, harp and grey seals).seals).

Bothnian Bay

Bothnian Sea

Gulf of Finland

Gulf of Riga

Baltic ProperDanish Straits

Kattegatt

Species likely to be Impacted-

-Planktons,-Herring, -Sprat,-Cod,-Flatfish,-Salmon(?),-Seals

*2007 HELCOM Study on Climate Change by J.F. Pawlak et al.

Can Anything be done to Prepare Can Anything be done to Prepare Fisheries Resources for Climate Fisheries Resources for Climate

Change?Change?

Rehabilitation of Rehabilitation of Stocks/EcosystemsStocks/Ecosystems• What Nations and RFMOs can start now What Nations and RFMOs can start now

to:to:– Reduce non-climatic stresses such as pollution,Reduce non-climatic stresses such as pollution,

habitat degradation, to marine ecosystems,habitat degradation, to marine ecosystems,– Adaptive management to reduce fishing pressure Adaptive management to reduce fishing pressure

(Over fishing and Overcapacity),(Over fishing and Overcapacity),– Improve longer-term monitoring of fishery resources Improve longer-term monitoring of fishery resources

and ecological regions. and ecological regions.

• The The Benefits for Fishery Resources will be: Benefits for Fishery Resources will be: – Greater Stock biomass resilience( improved age and Greater Stock biomass resilience( improved age and

size structures, increased probability of better size structures, increased probability of better recruitment) to future impacts of climate change.recruitment) to future impacts of climate change.

SummarySummary• Scientists have yet to be able to Scientists have yet to be able to

comprehensively understand/predict comprehensively understand/predict impacts on marine ecosystems and impacts on marine ecosystems and fisheries of :fisheries of :

-Increased extreme events (storm activity, floods -Increased extreme events (storm activity, floods and soil erosion ,and soil erosion ,

- Longer-term impacts of droughts in certain - Longer-term impacts of droughts in certain freshwater regions (ie Caspian and Aral Seas).freshwater regions (ie Caspian and Aral Seas).

- Warming effects on coral reefs, mangroves and - Warming effects on coral reefs, mangroves and salt marshes (which are already occurring).salt marshes (which are already occurring).

- Sea level rise, and over the longer term- the - Sea level rise, and over the longer term- the slowing/collapse of the ocean circulation that slowing/collapse of the ocean circulation that transports heat to the North Atlantic.transports heat to the North Atlantic.