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Fisheries and Climate Change: the IPCC Second Assessment Dr. John T. Everett IPCC Convening Lead Author - Fisheries National Marine Fisheries Service National.

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Presentation on theme: "Fisheries and Climate Change: the IPCC Second Assessment Dr. John T. Everett IPCC Convening Lead Author - Fisheries National Marine Fisheries Service National."— Presentation transcript:

1 Fisheries and Climate Change: the IPCC Second Assessment Dr. John T. Everett IPCC Convening Lead Author - Fisheries National Marine Fisheries Service National Oceanic and Atmospheric Administration United States Department of Commerce

2 Intergovernmental Panel on CC Mission: provide an authoritative statement of scientific opinion on CC Several hundred scientists serve on 3 WGs Broadly peer reviewed plus govmt review WG I: science of climate change itself WG II: impacts and response strategies WG III: broad socioeconomic issues

3 Fisheries Lead Authors Dr. John T. Everett, CLA Dr. Daniel Lluch Belda Washington, USALa Paz, BCS, Mexico Dr. Andre KrovninDr. Henry A. Regier Moscow, Russia Toronto, Canada Dr. Ezekiel OkemwaJean-Paul Troadec Mombasa, KenyaBrest, France

4 Physical Changes Climate change will come with changes in temperature, circulation, sea level, ice coverage, wave climate, and extreme events, Affecting ecosystem structure & function

5 Temperature Ave. temp. to increase 1-3.5° C by 2100 High n. latitudes warm more than average Nights & winters warm more than average Ocean changes lag land by 10 years Exceptions: delay or cooling in belt around Antarctica and in high N. Atlantic In high latitudes, the growing period and productivity should increase

6 Currents & Upwelling A weakening of the global thermohaline circulation may occur Competing arguments on oceanic & coastal upwelling increase or decrease No reliable forecasts Forces driving natural variability not well understood

7 Storms and El Niño Changes in frequency & intensity of cyclones, storms, & El Niño uncertain No trends in storminess in last 50 years Some regional trends in storminess in both directions The post 1989 period of ENSO activity seems unusual, but may have happened before

8 Ice Cover Major loss of fresh & sea ice (up to 50 %) The NW Passage & N. Sea Route of Russia may have up to 100 days of shipping In the Antarctic, the main effect will be a retreat of the ice edge No evident trend in sea ice at either pole Ice coverage impacts ice-associated species, primary productivity, fishing and aquaculture

9 Sea Level Rise Up cm by 2100 From thermal expansion & melting of ice Regional variations due to wind and atmospheric pressure patterns, ocean density differences, land motion, currents Obs. show cm. rise since 1900 No acceleration has been detected Wetlands will decrease; sharply where there is shore protection

10 Precipitation A few percent increase More concentrated in time Increases in low and high latitudes Greater evaporation in mid-latitudes This can affect water salinity, watershed flows, turbidity, pollutant loading and related factors

11 UV-B Other groups, not IPCC, study ozone depletion Problem chemicals should peak about 2000 The ozone layer may return to normal about 2050 In clear waters, UV-B penetrates tens of meters In coastal waters, less than 1 meter Antarctic ozone hole is larger than Antarctica Ozone losses are up in mid-latitudes and the Arctic Growth rates of several chemicals have slowed or stopped

12 Species Sensitivities Changes: temperature, sea level, river flows, salinity, currents, winds, storms, and variability Species are dependent on one or more of above Species can move rapidly if habitat and paths exist Fish are cold-blooded. Life processes, like growth, are faster when warmer (within limits) Many species have narrow ecological niches, but there are many species to fill niches Small changes cause large disruptions to a species Mixes will change until stability is reestablished

13 Societal Sensitivities Species in more stable environments are usually more valuable Fishers can follow fish, communities wont Political borders or economics stop pursuit Developing nations dependent on fish as food or export earnings are most sensitive

14 Sensitivity Examples Scallop and fish eggs that rely on a gyre to return them to their habitat on a certain day or week Fish eggs in streams or on the sea floor that require a minimum current speed for oxygenation Species that require an influx of freshwater to induce spawning or to kill predators Temperatures above or below the stocks lethal limit Immobility of communities dependent on one species Societies without money to buy other foods Fishers unable to deal with new vessel/gear demands Species Societal

15 Important Findings Freshwater fisheries and aquaculture at mid to higher latitudes should benefit Saltwater fisheries should be about the same Fishery areas and species mix will shift Changes in abundance more likely near ecosystem boundaries National fisheries will suffer if fishers cannot move within and across national borders Subsistence/small scale fishermen suffer most

16 Important Findings-2 CC impacts add to overfishing, lost wetlands and nurseries, pollution, UV-B, and natural variation Inherent instability in world fisheries will be exacerbated by a changing climate Globally, economic and food supply impacts should be small. Nationally, they could be large Overfishing is more important than CC today; the relationship should reverse in years.

17 1. Small rivers and lakes, in areas of higher temperatures and less rain 2. Within EEZs, particularly where fishers cannot follow migrating fish 3. In large rivers and lakes 4. In estuaries 5. High seas CC Impact Ranking for Fisheries

18 Adaptation Options Establish management institutions that recognize shifting distributions, abundances and accessibility, and that balance conservation with economic efficiency and stability Support innovation by research on management systems and aquatic ecosystems Expand aquaculture to increase and stabilize seafood supplies and employment, and carefully, to augment wild stocks Integrate fisheries and CZ management Monitor health problems (e.g., red tides, ciguatera, cholera)

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