1. Individual-based Models Three Examples

2. Presentation Outline Individual based models Three examples Approach
Model Structure
Limitations
Three examples
Calanus finmarchicus (two examples)
Adelie penguin (Pygoscelis adeliae)

3. Georges Bank Miller et al. (1998,Fish. Oceanogr.)
Examine the potential of Gulf of Maine and Scotian shelf as sources of C. finmarchicus
Species is important
component of larval
diet of cod, haddock
and yellowtail
flounder

4. Model Set Up Animal life history provides model framework
Defined particular attributes for each stage – used available data to set up parameterizations for simulating attributes – tracked attributes in space and time

5. Model Set Up Characteristics of life history stages
Each requires data and functional
form
Each is tracked

6. Results
Verify that population structure and timing

7. Results
Spatial distribution of life history stages

8. Limitations
Assumed that growth and reproduction were controlled only by temperature
Food quantity and quality important for C. finmarchicus growth – not included
Assumed light controlled emergence from diapause
No feedbacks between zooplankton and environment

9. Carlotti et al. (1998, Fish. Oceanogr.)
North Atlantic
Carlotti et al. (1998, Fish. Oceanogr.)
Examine effect of C. finmarchicus on pelagic ecosystem
Retained the life history structure – different stages have different effects

10. Model Set Up Animal life history provides framework
Defined particular attributes for each stage –
Individual particles – combined to form a population – Lagrangian ensemble particles
Multiple food sources – varying quality in terms of lipid

11. Model Set Up Connections – ingestion, mortality, egestion
Defined particular attributes for each stage –

12. Model Set Up Processes of particles – based on life stage/age
Equations – testing for different situations (if, then, else)

13. Results
Ecosystem model, zooplankton particle model, zooplankton population model
Estimated grazing control on blooms

14. Results
Ecosystem model, zooplankton particle model, zooplankton population model
Estimated growth, reproduction survival

15. Results
Ecosystem model, zooplankton particle model, zooplankton population model
Estimate biomass distribution

16. Limitations
Food quantity and quality important for C. finmarchicus growth – focus only on lipid
Include carbohydrate, protein – somatic growth
Limitation of numbers via Lagrangian ensemble particles
Limited role of physical environment in zooplankton distribution
Analysis of variability

17. Salihoglu et al. (2001, Polar Biology)
Adelie Penguin Chick
Salihoglu et al. (2001, Polar Biology)
Conceptual model based on life history – chick

18. Model Set Up
Observed chick fledging weight relatively constant at 2.8 to 3.2 kg in spite of varying environmental conditions and food supply
Chicks modify energetic and/or metabolic demands to attain an optimal mass that potentially enhances their survival after fledging
Parent can modify the timing and frequency of food delivery to the chick to compensate for variations in food supply

19. Model Set Up
Observed chick fledging weight relatively constant at 2.8 to 3.2 kg in spite of varying environmental conditions and food supply
Chicks modify energetic and/or metabolic demands to attain an optimal mass that potentially enhances their survival after fledging
Parent can modify the timing and frequency of food delivery to the chick to compensate for variations in food supply
Modify time of fledging

20. Model Set Up Antarctic krill primary food supply for chicks
Food quality varies with krill size

22. Model Set Up Relate age determined from culmen length
Growth based on Assimilation – Respiration
Track energy

23. Results
88/89
89/90

24. Limitations Only one prey item – fish possible prey
Thermoregulation effects important
Trade-offs in physiology – imposed
Role of habitat – land and ocean
Project climate change effects need to understand life history, physiology, ecology and interaction with habitat

25. Vertical Velocity, Size,
Model Framework
Genetics Model
Circulation Model
(3D and time)
LARVAL MODEL
Atmospheric
Tides
River Discharge
Temperature
Salinity
Currents
Temperature
Salinity
Larval
Growth
Particle Tracking
Module
Larval
Behavior
Settlement
330 um
Modified Particle
Tracking Module
Vertical Velocity, Size,
Temperature, Salinity
Post-settlement
Population

26. Slide from D. Costa 2007 Elephant seal Crabeater seal Weddell seal
Animation

27. Animals and nutrient cycling
Krill release iron from phytoplankton when they feed.
Krill may feed in the sediments at depth and then return nutrients to the surface.
Fish and whales have an effect on the ocean carbon budget
Sperm whales can return significant amounts
to the surface layer.
Vertically migrating animals have access to nutrients in a deeper layer than phytoplankton.
(Slide from D. Costa)

28. Concluding Remarks Model frameworks apply across range of species
Approaches needed to extend IBM results to population – genetic variability
Need habitat models – account for variaiblity in habitat use and foraging – especially important for large vertebrate species
Approaches for linking food web and biogeochemical models

29. QUESTIONS?