EXECUTIVE SUMMARY

Papers in this report set out the sources and derivations of parameters for four Ecopath mass-balance models covering Newfoundland and southern Labrador's marine ecosystem (DFO statistical areas 2J3KLNO), referring to the historical times 1985, 1995, 1990 and 1450 (approximated as 3- to 5-year averages). The models have 50 compartments, including linked juvenile and adult life history stages for 6 groups of fish. The models include animals, such as walrus, that are locally extinct today. These models span a Newfoundland marine ecosystem that has changed greatly over the past 500 years. Anthropogenic changes were likely noticeable as soon as Basque whalers arrived, probably before 1500, while mass exploitation of seabirds in the 18th century resulted in extinction of the great auk. For several centuries cod fisheries were seemingly sustainable, but in the late 1980s they collapsed and have failed to recover. The precision of the models changes as we go back in time. While the 1990s and 1980s models, based on many recent scientific surveys and estimates, are likely a good approximation of the true ecosystem, the earlier models have an aproximatedate of refence, and are less certain, although a great deal of information from historical, archival and archaeological sources was incorporated. These static mass-balance models represent starting values for dynamic ecosystem simulations, which aim to determine sustainable and responsible fisheries that might be operated in ecosystems restored to these past states: part of 'Back to the Future' policy explorations.

CONTENTS

A Model of the Marine Ecosystem of Newfoundland and Southern Labrador (2J3KLNO) in the Time Periods 1985-1987 and 1995-1997
Johanna J. (Sheila) Heymans and Tony J. Pitcher Pages 5-43

A Picasso-esque View of the Marine Ecosystem of Newfoundland and Southern Labrador: Models for the Time Periods 1450 and 1900
Johanna J. (Sheila) Heymans and Tony J. Pitcher Pages 44-73