Dissertation Proposal

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Dissertation Proposal
Oral Qualifying Exam Nov. 30, 2005 CCPO

• A Study of Physical and Biological Factors
  Determining West Antarctic Peninsula Adélie
  Penguin Population Dynamics
• Data Analysis
• Linking prey field to physical features (sea-ice)
• Modeling Study
• Foraging, chick growth and a population matrix
  simulations

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Outline

• General Interest and Research Philosophy
• Research trends (context)
• Environmental context
• Research Questions
• Research Plan

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General Research Interest

• The use of modeling and observational techniques
  to study the relationship between climate
  variability and ecosystem behavior.

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Research Philosophy

• Combine conservative and risky goals to maximize
  contribution and chances for successful
  completion of research.
• Maintain communication with expertise.
• Create environment that will allow for on-going
  critique and assessment of research.

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Marine Ecosystem Research

• Growing interest in the influence of Climate on
  Ecosystems.
• Interest in climate variability causing regime
  change among multiple stable-states.
• The west Antarctic Peninsula (WAP) is an
  excellent model where ENSO is known to influence
  atmospheric temperature and sea-ice.

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Top Predator and Southern Ocean Research

• Demographics and foraging behavior of seabirds
  are being used to index consequences of
  environmental variability.
• Long-term data-sets and availability of
  atmospheric variability indices facilitate
  time-series analyses.

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WAP Research

• Underlying mechanisms behind patterns are being
  investigated.

Fraser and Hofmann 2003, A predators perspective
on causal links between climate change, physical
forcing and ecosystem response. MEPS
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Environmental Context

• Warming (0.56 ºC decade-1 Turner et al., 2005)
• Maximum sea-ice coverage becoming less (15,000
  km2 year -1 Kwok and Comiso, 2002)
• Timing of sea-ice advance and retreat changing
  (duration down 0.3 days year -1 Smith et al.,
  2002)
• Krill populations declining (50 decline since
  1976 Atkinson et al., 2004 )
• Antarctic silverfish populations declining
  (Adelie diets, net tows Fraser, personal
  communciation)
• Anvers Island Adelie populations down (40 since
  1974 Fraser and Patterson, 1997)
• Avian Island Adelie populations up (100 since
  1974 Woehler, 2993 Fraser, unpublished data)

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Research Questions

• 1. How is the prey field affected by variation
  circulation and sea-ice?
• 2. How is Adélie foraging, chick growth and
  fledging weights breeding colonies affected by
  variability in the prey field?
• 3. Can these influences explain opposition
  population trajectories at ANV and AVI?
• 4. How are Adélie penguin population
  trajectories affected by variations in the
  environmental structure and prey availability?

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Atmospheric temperature
Antarctic krill distribution/abundance
Sea-Ice
Circulation
Antarctic silverfish distribution/abundance
Productivity
Adult foraging
Adult survival
Penguin population Trajectory
Chick growth
Death
Fledgling survival, recruitment
Fledge
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Atmospheric temperature
Antarctic krill distribution/abundance
Sea-Ice
Circulation
Antarctic silverfish distribution/abundance
Time-series correlation.
1
Productivity
Adult foraging
Adult survival
Penguin population Trajectory
Chick growth
Death
Fledgling survival, recruitment
Fledge
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Data Sea-ice, silverfish time-series

• Sea-ice data
• NSIDC passive microwave satellite derived ice
  concentration.
• 25km grid
• Daily and monthly data since Oct. 1978
• Antarctic Silverfish composition
• Diet sample data
• Weekly since 1986 at Anvers Island
• One-time samples from Avian Island since 1995

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100 km and 200 km ranges from colonies
lt15 ice coverage
gt15 ice coverage
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Data Processing Sea-ice, silverfish time-series

• Sea-ice
• Average percent coverage (gt15 ) within 100 km
  and 200 km of Anvers Island and Avian Islands
• Maximum sea-ice extent
• Antarctic silverfish
• Percent composition in Adélie diet
• Spearman rank correlation

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Anticipated Contributions Sea-ice, silverfish
time-series

• Advance understanding of the conditions
  surrounding disappearance of silverfish from diet
  at ANV.
• Identify the age-class of fish present in the
  diet at ANV, AVI?
• Results will suggest physical-biological
  processes affecting the distribution of
  silverfish on the peninsula.
• Results will help in parameterizing modeling
  efforts.

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Atmospheric temperature
Virtual population analysis.
2
Antarctic krill distribution/abundance
Sea-Ice
Circulation
Antarctic silverfish distribution/abundance
Time-series correlation.
1
Productivity
Adult foraging
Adult survival
Penguin population Trajectory
Chick growth
Death
Fledgling survival, recruitment
Fledge
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Data Sea-ice, krill demographics time-series

• Sea-ice data
• NSIDC passive microwave satellite derived ice
  concentration.
• 25km grid
• Daily and monthly data since Oct. 1978
• Antarctic krill data
• Diet sample data
• Weekly since 1986 at Anvers Island
• One-time samples from Avian Island since 1995

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Data Processing Sea-ice, krill demographics
time-series

• Sea-ice
• Average percent coverage (gt15 ) within 100 km
  and 200 km of Anvers Island and Avian Islands
• Maximum sea-ice extent
• Antarctic krill
• Virtual Population Analysis
• Krill growth rates (between seasons (ANV, AVI),
  within seasons (ANV))
• Krill longevity (ANV)
• Recruitment events (ANV)
• Spearman rank correlation
• Krill growth rates only. Relationship between
  krill longevity and recruitment events assessed
  qualitatively.

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Fraser and Hofmann 2003
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d
Growth Rate
Relative presence
T1
T2
Krill length
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Anticipated Contributions Sea-ice, krill
demographics time-series

• Quantify the relationship between physical
  environment and vital rates in krill.
• Provide important relationship for use in model
  parameterizations.

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Atmospheric temperature
Virtual population analysis.
2
Antarctic krill distribution/abundance
Sea-Ice
Circulation
Antarctic silverfish distribution/abundance
Time-series correlation.
1
Productivity
Adult foraging
Adult survival
Penguin population Trajectory
Adult foraging model.
3
Chick growth
Death
Fledgling survival, recruitment
Fledge
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ADULT FORAGING MODEL SCHEMATIC
Prey Field
Ingestion, Penguin adult
- Ingestion, chick
Chick Growth Model
Ingested food beyond Individual needs
Assimilated mass
- Respiratory losses ( swimming resting
foraging)
Telemetry Data
Adult growth ( or -)
Estimate from literature
Survivorship (reproductive cost)
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Data Adult Foraging Model

• Telemetry studies (ANV, AVI1999 to present)
• Foraging location, duration
• Activity budget (time spent diving, swimming,
  resting)
• Energetics data
• BMR, Swimming, resting on ice, on land.
• Feeding rate
• Estimates from stomach mass, energetic
  expenditure during foraging trip (e.g. Chappell
  et al. 1993)
• Mass(t) of adult penguins (ANV 1986 to
  present?)

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Anticipated Contributions Adult foraging model

• Assess our knowledge of the linkage between
  physical-biological environment and foraging
  behavior
• Provide the mechanistic framework to test the
  influence of environmental conditions and
  variability on penguin foraging.
• Model may be modified to examine other processes
  of interest

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Atmospheric temperature
Virtual population analysis.
2
Antarctic krill distribution/abundance
Sea-Ice
Circulation
Antarctic silverfish distribution/abundance
Time-series correlation.
1
Productivity
Adult foraging
Adult survival
Penguin population Trajectory
Adult foraging model.
3
Chick growth
Death
Fledgling survival, recruitment
Fledge
Chick growth modeling.
4
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CHICK GROWTH MODEL SCHEMATIC
Adult foraging model
Ingestion, Penguin chick
Assimilated mass
Field collected data
Estimated from literature
- Respiratory loss
Net productivity
Chick growth
Fledge
Death
Recruitment
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Data Chick Growth Model

• Salihoglu parameterizations
• Field collected data.
• Feeding rate
• Daily weighing of marked chicks during crèche
  period to derive feeding rates, chick growth.
• Instantaneous growth measurements at AVI 1999
  to present.
• Caloric content of prey (t).
• Bomb calorimeter at ANV and AVI.

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Anticipated Contributions Chick growth model

• Will allow for investigation of the influence of
  diet complexity on the growth of chicks.
• The model will be parameterized to assess varied
  conditions and penguin prey field on the west
  Antarctic Peninsula.

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Atmospheric temperature
Virtual population analysis.
2
Antarctic krill distribution/abundance
Sea-Ice
Circulation
Antarctic silverfish distribution/abundance
Time-series correlation.
1
Productivity
Adult foraging
Adult survival
Penguin population Trajectory
Adult foraging model.
3
Chick growth
Death
Fledgling survival, recruitment
Fledge
Leslie Matrix Simulations.
Chick growth modeling.
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4
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Data Leslie Matrix Simulations

• Long-term demographic studies (circum-Antarctic)
• Modified to represent populations on west
  Antarctic Peninsula (banding studies at ANV)

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Linked Model Simulations

• Historical conditions at Anvers Island
• Current conditions at Anvers Island and Avian
  Island
• Future climate scenarios

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Anticipated Contributions Combined model
simulations

• Models could be modified and expanded to address
  future research questions.
• Will assess state of current knowledge.

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Questions? Comments? Concerns?