Fisheries and Climate Change: What We Think We Know

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Fisheries and Climate Change What We Think We
Know
Dr. John T. Everett Project Manager, United
Nations Atlas of the Oceans Former IPCC
Convening Lead Author (SAR) - Fisheries Former
Director, Division of Research, NOAA/NMFS
Ocean Associates Oceans and Fisheries
Consulting 4007 North Abingdon Street Arlington,
Virginia, USA JohnEverett_at_Comcast.Net
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This Presentation

• Is based largely on the IPCC 1995 Report
  Fisheries - Chapter 16. It is valid and best
  available
• The 2001 IPCC report of impacts is by region.
  There is little information specifically on
  marine fisheries
• The 2001 US National Assessment does not treat
  marine fisheries in depth (USNA)
• Physical changes reflect the 2001 IPCC report
  (IPCC 2001)

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Intergovernmental Panel on CC

• Mission provide an authoritative statement of
  scientific opinion on CC
• Broadly peer reviewed plus govmt review
• Several hundred scientists serve on WGs
• science of climate change itself
• impacts and response strategies
• broad socioeconomic issues

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Fisheries Lead Authors
Dr. John T. Everett, CLA Dr. Daniel Lluch Belda
Washington, USA La Paz, BCS, Mexico Dr. Andre
Krovnin Dr. Henry A. Regier Moscow, Russia
Toronto, Canada Dr. Ezekiel Okemwa Jean-Paul
Troadec Mombasa, Kenya Brest, France
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The Culprits
Source IPCC 2001
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Physical Changes

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

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Temperature

• Obs 1998 was hottest year in 1000. Global
  average land and ocean temperature was the
  warmest on record for January (NOAA CDC 2002)
• Proj Ave. temp. to increase 1.4-5.8 C by 2100
• High n. latitudes warm more than average
• Nights (2X) 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

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Temperatures are Rising - Recently
Source IPCC 2001
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Temperatures are Rising
Source IPCC 2001
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Warming is Uneven
Source IPCC 2001
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7 of 9 Models Agree on Warmer Winters Summers
in Northeast
Source IPCC 2001
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Currents Upwelling

• Proj A weakening of the global thermo-haline
  circulation may occur, reducing heat transport to
  the N. Atlantic
• Competing arguments on oceanic coastal
  upwelling increase or decrease
• No reliable forecasts
• Forces driving natural variability not well
  understood

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Ocean Conveyer Belt
Source US National Assessment
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Storms and El Niño

• Obs No trends in storminess in last 50 years.
  Some regional trends in storminess in both
  directions
• The post 1989 period of ENSO activity seems
  unusually high, but may have happened before
• Proj Changes in frequency intensity of
  cyclones, storms, El Niño uncertain

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Ice Cover

• Obs Two weeks less fresh ice in last 125 yrs.
  No evident trend in sea ice in Antarctic.
• Proj Glaciers and snow and ice coverage to
  continue retreat in N. hemisphere. Major loss of
  fresh sea ice
• The NW Passage N. Sea Route of Russia may have
  100 days of shipping. 40 thinner summer Arctic
  ice since 1960
• In the Antarctic, the main effect will be a
  retreat of the ice edge
• Ice coverage impacts ice-associated species,
  primary productivity, fishing and aquaculture

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Sea Level Rise

• Obs. show 10-25 cm. rise since 1900 1-2 mm/yr.
  10X faster than previous 3K yrs. No acceleration
  detected
• Proj. is 11 - 77 cm by 2100 from thermal
  expansion melting of ice. USNA 19 by 2100
• Regional variations due to wind and atmospheric
  pressure, ocean density, land motion, currents
• Wetlands will decrease sharply where there is
  shore protection
• Higher wave energy faster erosion
• USNA US National Assessment

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The Oceans are Rising
Source IPCC 2001
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Armored Coasts
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Precipitation

• Obs show several /decade greater air moisture
  precip up 1/decade in mid-high latitudes
• Proj A few percent increase
• More extreme, heavier precip events
• This can affect water salinity, watershed flows,
  turbidity, pollutant loading and related factors

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7 of 9 Models Agree on Wetter Winters in Northeast
Source IPCC 2001
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UV-B

• Other groups, not IPCC, study ozone depletion
• Obs ozone losses up in mid-latitudes Arctic
• Growth rates of several problem chemicals have
  slowed or stopped. Peak may be past
• Proj ozone layer may return to normal about 2050
• In clear waters, UV-B penetrates tens of meters,
  damaging eggs, larvae and zooplankton
• In coastal waters, less than 1 meter
• Antarctic ozone hole is larger than Antarctica

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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
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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
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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
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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

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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 50-100 years.

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CC Impact Ranking for Fisheries
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
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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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Understanding Requires a Broad ViewOceanwide
Synchrony in Pacific Sardines and the North
Pacific Index
Historical catches in the sardine fisheries of
Japan, California and Peru-Chile exhibit parallel
patterns, possibly in response to global-scale
changes in climate (modified from Kawasaki, 1992).
Negative NPI
Negative NPI
800
7
Peru/Chile
700
6
600
5
California Sardine Catch (Thousand Metric Tons)
500
California
4
Japan and Peru/Chile Sardine Catch (Million
Metric Tons)
400
3
300
2
200
Japan
1
100
0
0
1900
1910
1920
1930
1940
1950
1960
1970
1980
1990
2000
What comes first?
Sources U.S. GLOBEC, FAO 1998 North
Pacific Index (Atmos. Pressure)
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Where to get Information

• Intergovernmental Panel on Climate Change (IPCC)
  www.ipcc.ch/
• NMFS Pacific Fisheries Env Lab
  www.pfel.noaa.gov/research/climatemarine/
• U.S. Environmental Protection Agency (EPA)
  www.epa.gov/globalwarming
• U.S. Global Change Research Program (USGCRP)
  www.usgcrp.gov
• UN Atlas of the Oceans www.oceansatlas.org
• Primary References
• Everett, J.T., E. Okemwa, H.A. Regier, J.P.
  Troadec, A. Krovnin, and D. Lluch-Belda, 1995
  Fisheries. In The IPCC Second Assessment Report,
  Volume 2 Scientific-Technical Analyses of
  Impacts, Adaptations, and Mitigation of Climate
  Change (Watson, R.T., M.C. Zinyowera, and R.H.
  Moss (eds.). Cambridge University Press,
  Cambridge and New York, 31 pp.
• National Assessment Synthesis Team, 2001 Climate
  Change Impacts on the United States The
  Potential Consequences of Climate Variability and
  Change Foundation. US Global Change Research
  Program, Washington www.usgcrp.gov
• IPCC Working Group I, 2001. Climate Change 2001
  The Scientific Basis. Document of the
  Intergovernmental Panel on Climate Change
  www.usgcrp.gov