LESSONS IN CLIMATE CHANGE LESSONS IN CLIMATE CHANGE PROJECTIONS AND ADAPTATION:PROJECTIONS AND ADAPTATION:From One Living Resource To AnotherFrom One Living Resource To Another

Dr. John T. Everett and Dr. H. Suzanne Bolton

National Marine Fisheries Service

16: FISHERIESIPCC, 1995: Scientific-Technical Analyses of Impacts, Adaptations,

and Mitigation of Climate Change

Dr. John T. Everett, Convening Lead Author

National Oceanic and Atmospheric Administration United States Department of Commerce

Lead Authors

Dr. Jean-Paul Troadec Dr. Ezekiel Okemwa

Brest, France Mombasa, Kenya

Dr. Henry A. Regier Dr. Daniel Lluch Belda

Toronto, Canada La Paz, BCS, Mexico

Andre Krovnin

Moscow, Russia

Examples of Sensitivities

Species

• 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 stock’s lethal limit

Societal

• Immobility of communities dependent on one type of species

• Societies without money needed to buy replacement foods

• Fishers unable to deal with new vessel and gear demands

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.

Million Tons

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1957....1958....1959....1960....1961....1962....1963....1964....1965....1966....1967....1968....1969....1970....1971....1972....1973....1974....1975....1976....1977....1978....1979....1980....1981....1982....1983....1984....1985....1986....1987....1988....1989....1990....1991....1992....

MarineGlobal Total

FreshwaterAq.

USA

Aquaculture and USA figures are non-additive

Fisheries Production

Societal Sensitivities

• Species in more stable environments are usually more valuable

• Fishers can follow fish, communities won’t

• Political borders or economics stop pursuit

• Developing nations dependent on fish as food or export earnings are most sensitive

Important Findings

• Freshwater fisheries and aquaculture at mid to higher latitudes should benefit from climate change

• Saltwater fisheries production should be about the same

• Locally, fishery areas and species mix are expected to shift

Important Findings #2

• Climate impacts add to those of overfishing, lost wetlands and nurseries, pollution, UV-B, and natural variation

• Inherent instability in world fisheries will be exacerbated by a changing climate

• Overfishing is more important than climate change today; as progress accelerates, the relationship should reverse in 50-100 years.

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

Adaptation Options

1. Establish better fishery management institutions to reduce societal impact

2. Adapt processing plants and infrastructure to increase flexibility

3. Expand aquaculture to increase seafood and employment stability

4. Monitor several health problems (red tides, ciguatera, cholera)

5. Intervene to redistribute species

6. Manage coastal development to maintain habitat

Oceanography

Hydrodynamic predictions are limited with little guidance on:• Upwelling

• Storms and ENSO

• Strength and direction of currents

Sea Level will rise globally, but vary regionally in:• Uniformity

• Pollution effects

• Habitat loss

Oceanography

• Global climate is warming; in question is:

• rate of change

• manner of change (smooth or fits and starts)

• extreme events (frequency and strength)

• Polar ice masses will shrink; in question is:

• extent of melting and calving

• timing

Global Climate Model Limitations

• Areal specificity of results

• Robustness of ocean/atmosphere linkage

• Infancy of ecological models

• Neglect of indirect effects of changing temperature

• Difficulty in factoring variabilities of living organisms

• Limitation of data predicting species interactions

BIOLOGY Climate Change and Species Reproduction

• Time factor favors existing plasticity, not evolution

• Broad ranging distributions favored over narrow

• Environmental change miscues window of reproductive opportunity

• Progeny number/size varies with adult/young heat sensitivities

• Sex ratio, mode, or opportunity (asexuality, hermaphrodism) can change

• Reproductive sensitivities increase with an increase in UV-B

BIOLOGY Changes in Habitat

• Affect availability of environmental cues and food during migrations

• Foodweb members respond independently to changing habitat

• Shifting populations may favor “exotic” competitors or opportunists

• Altered habitat and populations may complicate conservation efforts

• Shrinking polar habitats threaten established foodwebs and available platforms

• Alteration in upwellings disrupt communities

BIOLOGY Behavioral Strategies versus

Climate Change

• Relocating dependent upon availability of favorable temperature range

• Sessile forms release motile larvae at whims of currents

• Migratory routes shift with changing circulation patterns, temperature, and food availability

• Inter-specific behavior disruptions as species vary independently

BIOLOGY Impact on Biochemical Processes

• Temperature affects protein, lipid, nucleic, and hormonal activities

• Environmental factors trigger alternate pathways

• Metabolic regulation exacts costs on organisms

• Eurythermal organisms more adaptive than stenotherms

• Endothermal organisms more adaptive than ectotherms

• Sensitivity of processes may vary with age

BIOLOGY Changing Ecosystem Interactions

• Ecosystems tend to respond as individuals not as community

• Difficulty in studying complex and diverse ocean ecosystems

• Subtle climate change may alter niche and cascade events

• Shifting environmental cues may decouple timed events

• Understanding of complex interrelationships hampers predictions

BIOLOGY Indirect Effects

• Erosion, runoff, melting, and inundation increase contaminant input

• Introduced toxins and pathogens thrive in warmer medium

• Loss of pathogens/parasites with narrow life requirements

• Conservation efforts complicated by changing habitat

IMPLICATIONS FOR CETACEANS Ocean Chapter Predictions

Predicted Impacts on Marine Mammals and seabirds

• Loss of habitat (ice edge, haul-outs)

• Shift in trophic structure and productivity centers

• Increase in disease and biotoxins

Cannot predict the MAGNITUDE and SIGNIFICANCE of these changes

IMPLICATIONS FOR CETACEANSReproduction

Large mammals not well adapted to withstand extreme events

• slow growth

• slow maturation

• low fecundity

Genetic diversity and numbers are key to survival

IMPLICATIONS FOR CETACEANS Habitat and Migratory Routes

• Changing polar and migratory foodweb and environmental cues

• Loss in Arctic ice edge, polynyas, and timing of phytoplankton bloom

• Continued Antarctic recession and calving alter krill-based feeding

• Altered trophic structure:

- Emigration of non-endemic species

- Migration and reduction of ice-dependent prey poleward

• Change in circulation patterns jeopardizing nutrient flow

• Increased UV-B effects on plankton and land-based mammals

IMPLICATIONS FOR CETACEANS Behavioral and Metabolic

• Increasing metabolic expense of accommodating climate change

• Changes in lipid composition with change in foodweb

• Shifting of ranges to accommodate climate and trophic changes

• Loss of some habitat ( e.g., polynyas) requires behavioral change

IMPLICATIONS FOR CETACEANS Ecosystem

Changes in habitat trophic structure

Arctic

- to open water zooplankton-base

Antarctic

- to higher trophic prey if herbivores decrease

Migratory

- to higher trophic prey if upwellings and circulation alter

IMPLICATIONS FOR CETACEANSEcosystem (con’t.)

• Increase in metabolic stress:• Pathogens and parasite interactions increase risk of disease

• Anthropogenic contaminants compromise immune systems

• Increase competition with man• Directly by fishing competition

• Indirectly

» by conflict with needs of mariculture

» by pressures to conserve habitat

Management Suggestions

• Elevate importance of maintaining sustainable fish populations

• Advocate interdisciplinary ecosystem research

• Expand definition of sustainable level to accommodate climate change pressures

• Emphasize flexibility in the design of open ocean sanctuaries

• Increase role in planning, regulating, and managing land and marine resources