FCRR
Preliminary Mass-Balance Model of Prince William Sound, Alaska, for the Pre-Spill Period, 1980-1989
Publication
1997
Report pages 1 - 16
Report pages 17 - 33
Note: This report was scanned from a hard copy.
ABSTRACT
A mass-balance model of trophic interactions among the key functional groups of Prince William Sound (PWS), Alaska, is presented, based mainly on published data referring to the period from 1980 to 1989, before the Exxon Valdez oil spill.
The functional groups explicitly included in the model are: detritus, phytoplankton, macroalgae, small zooplankton, large zooplankton, epifaunal benthos, infaunal benthos, intertidal invertebrates, demersal fish, herring, salmon fry from hatcheries, wild salmon fry, salmon, other pelagic fishes, birds, sea otters, other resident marine mammals, and transient marine mammals.
Balancing of the model required few steps that went beyond the available data; nevertheless, the model is preliminary in that additional ecological information is available on PSW and the functional groups of the organisms therein. Much of this information is not yet incorporated in the model. However, the purpose of this model is to serve as basis for further work, illustrated in two authored appendices, one showing the close match between the trophic levels estimated by the models and estimates based on stable isotope ratios, and the other documenting how inferences on the dynamics of PWS may be derived from its static representation.
TABLE OF CONTENTS
Abstract | V |
Director's Foreword | VI |
Table of Contents | VII |
List of Exhibits | VIII
|
Introduction | 1 |
Prince William Sound | 1 |
The Ecopath Approach and Software | 3 |
Preliminary Model Inputs | 5 |
Phytoplankton | 5 |
Macroalgae | 6 |
Detritus | 7 |
Zooplankton | 7 |
Benthic Invertebrates | 8 |
Intertidal Invertebrates | 9 |
Demersal Fish | 10 |
Herring | 11 |
Salmon Fry | 11 |
Adult salmon | 12 |
Miscellaneous small pelagic fishes | 13 |
Birds | 13 |
Sea otters | 16 |
Other marine mammals | 16 |
Balancing the Model | 17 |
Results and Discussion | 21 |
Acknowledgements | 25 |
References | 26 |
Appendix 1 | 32 |
Appendix 2 | 33 |

