How is Climate Change Expected to Impact Fisheries How is Climate Change Expected to Impact Fisheries Neil A. Bellefontaine Neil A. Bellefontaine World Maritime University World Maritime University June 07, June 07, 2007.

Climate Change Impacts on Fisheries The last decade was the warmest in the Northern Hemisphere over the past 1000 years and air temperature is predicted to increase even more in the future, especially in winter (IPCC 2001). The last decade was the warmest in the Northern Hemisphere over the past 1000 years and air temperature is predicted to increase even more in the future, especially in winter (IPCC 2001). The World ocean is also warming and not just near surface water (Levitus 2006). The World ocean is also warming and not just near surface water (Levitus 2006).

Levitus, S. et al. Warming of the World Ocean. Science 287: Upper 300 m Upper 3000 m Heat Content Anomaly (10 22 J) Oceans are warming from surface to bottom

. Arctic Sea Ice % decrease per decade in sea ice extent. Melting of this icecap represents a large freshwater source.

Climate Change Predictions for Natural Systems Poleward shifts in distribution of marine resources. Poleward shifts in distribution of marine resources. Extreme changes at range boundaries of certain species (uncertainty in numbers and extent). Extreme changes at range boundaries of certain species (uncertainty in numbers and extent). Habitat shrinkage of northern species and replacement by southern species. Habitat shrinkage of northern species and replacement by southern species. Earlier spring events and later autumn events. Earlier spring events and later autumn events. Risks of large-scale, possibly irreversible impacts are yet to be quantified. Risks of large-scale, possibly irreversible impacts are yet to be quantified. Parmesan, C. and G. Yohe A globally coherent fingerprint of climate change impacts across natural systems. Nature 421:37-42.

What is at Risk? World production from Fisheries and Aquaculture reached almost 142 million tonnes in World production from Fisheries and Aquaculture reached almost 142 million tonnes in Aquaculture accounted for 47.8 million and the remainder 93.8 million tonnes came from wild capture fisheries. Aquaculture accounted for 47.8 million and the remainder 93.8 million tonnes came from wild capture fisheries. Of the total, million came from marine and 38.5 from inland waters. Of the total, million came from marine and 38.5 from inland waters. China remains the worlds largest fish producer with 47.5 million tonnes (16.9 mt wild capture and 30.6 mt aquaculture). China remains the worlds largest fish producer with 47.5 million tonnes (16.9 mt wild capture and 30.6 mt aquaculture).

World Wild Capture Fisheries and Aquaculture (FAO 2006)

World Fisheries by Ocean Region (FAO 2006)

What are the Specific Fisheries Problems most likely to be associated with Climate Change ?

Shifts in Species Distribution

Pacific Salmon in the North Pacific Distribution changes 2X CO 2 David Welch, DFO, Nanaimo

Extreme Changes at Range Boundaries

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

Habitat Shrinkage

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 Shrinkage due to Climate Change in Northwest Atlantic

The Baltic Sea The Baltic Sea The 2007 HELCOM study of Climate Change in the Baltic Sea points to significant potential change that will affect fish and marine mammals, such as: The 2007 HELCOM study of Climate Change in the Baltic Sea points to significant potential change that will affect fish and marine mammals, such as: -food web disruptions due to lower trophic variability (ie plankton species affected by water flows, composition and temperature changes). -food web disruptions due to lower trophic variability (ie plankton species affected by water flows, composition and temperature changes). -salinity declines will affect some species production and life cycles (ie cod, flatfish, herring and sprat). -salinity declines will affect some species production and life cycles (ie cod, flatfish, herring and sprat). - marine mammals will be affected by less ice, earlier break-up, and warmer temperatures (ie ring, harp and grey seals). - marine mammals will be affected by less ice, earlier break-up, and warmer temperatures (ie ring, harp and grey seals).

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 Fisheries Resources for Climate Change?

Rehabilitation of Stocks/Ecosystems What Nations and RFMOs can start now to: What Nations and RFMOs can start now to: –Reduce non-climatic stresses such as pollution, habitat degradation, to marine ecosystems, habitat degradation, to marine ecosystems, –Adaptive management to reduce fishing pressure (Over fishing and Overcapacity), –Improve longer-term monitoring of fishery resources and ecological regions. The Benefits for Fishery Resources will be: The Benefits for Fishery Resources will be: –Greater Stock biomass resilience( improved age and size structures, increased probability of better recruitment) to future impacts of climate change.

Summary Scientists have yet to be able to comprehensively understand/predict impacts on marine ecosystems and fisheries of : Scientists have yet to be able to comprehensively understand/predict impacts on marine ecosystems and fisheries of : -Increased extreme events (storm activity, floods and soil erosion, -Increased extreme events (storm activity, floods and soil erosion, - Longer-term impacts of droughts in certain freshwater regions (ie Caspian and Aral Seas). - Longer-term impacts of droughts in certain freshwater regions (ie Caspian and Aral Seas). - Warming effects on coral reefs, mangroves and salt marshes (which are already occurring). - Warming effects on coral reefs, mangroves and salt marshes (which are already occurring). - Sea level rise, and over the longer term- the slowing/collapse of the ocean circulation that transports heat to the North Atlantic. - Sea level rise, and over the longer term- the slowing/collapse of the ocean circulation that transports heat to the North Atlantic.