Welcome to the <em>Exxon Valdez</em> Oil Spill Trustee Council Home Oil Spill Facts Habitat Protection Restoration Projects Recovery Since 89
Restoration Projects

Project Information

Title: An Ecosystem Model of Prince William Sound Herring: A Management & Restoration Tool

Project Year and Number: 2007: 070810

Other Fiscal Years and Numbers for this Project: None

Principal Investigator (PI): Dale Kiefer, University of Southern California

Assisting Personnel: Evelyn Brown, Frank O'Brien, Vardis Tsontos

Research Location: Analysis/Modeling of data from Prince William Sound & Gulf of Alaska

Restoration Category: General Restoration

Injured Resources Addressed: Pacific Herring

Abstract: Over a three-year period, we propose to develop a life-stage specific, ecosystem based model of the Prince William Sound (PWS) herring that will aid in the integration of ecological data that has been gathered on herring over the last 2 decades, evaluation of proposed restoration activities, and attempt to simulation of the processes that cause the chronic decrease in herring stocks since the 1989 spill. More specifically, it will be used to test the unresolved hypotheses of why the herring have not recovered to pre-spill densities. The model and associated data will be housed in a geographic information system that we have developed specifically for marine applications. The geo-spatial information from field surveys and simulations with the model will available for interactive viewing and downloading of files over the Internet. The model will provide a mathematical description of the population dynamics of annual herring cohorts as they mature through their life stages. In particular we will focus on arrival of larvae to the Bays of PWS, the maturation and survival of juveniles in these bays, and the survival and reproductive success of adults as they move seasonally from spawning grounds, feeding grounds and wintering grounds. The system of coupled differential equations that describe these processes will be tuned to prove a best fit between model calculations and field and laboratory measurements. In its final form the model will consist of 3 sets of such equations that will simulate the unique conditions found in herring habitats of the eastern, northern and southwestern regions of PWS. Most importantly, the model will be formulated according to the principals of the trophic trap in which 2 metastable states for herring exist, low-density and high-density. We propose that a sequence of events following the spill drove the herring from high-density to low-density and a trophic trap prevents stocks from recovering. Thus, we will tune our model to both high-density and low-density states and then run the tuned models in the forward or backward direction to identify both the most probable causes of the injury and the most promising approaches to restoration. Our team has the scientific and technical experience to succeed, and we will work closely with researchers from the other herring projects, especially those working on larval drift, disease, otolith marking, and intervention. Our web-based system will promote such collaboration particularly with such groups as PWSFRAP and with the PWS Science Center.


Geographic Regions Prince William Sound
Species Fish - Herring
Fields of Expertise Ecology
Management & Policy
Population Biology
Resource Management
Technological Methods Data base management
Geographic information systems/Mapping
Remote sensing – Satellite imagery
Professional Activity Data Management
Data Synthesis/Visualization
Fishery management
Ecosystems Marine – Benthic
Marine – Nearshore
Marine – Pelagic
Species Specific Research Issues Fish - Disease
Fish - Distribution and abundance
Fish - Fishing effects and harvest strategies
Fish - Habitat
Fish - Population dynamics
Fish - Predator-prey interactions

Proposal: View PDF (573 KB)

Funding Recommendations: View

Funding Detail For: 2007 , 2008 , 2009

Quarterly Project Tasks For: 2007 , 2008 , 2009

Other materials associated with this project: View

Annual Reports: 2007: View (443 KB) 2008: View (481 KB) 2009: View (326 KB)

Final Report: Final Report Not Available - For Current Status Please Contact Us

Publications from this Project: None Available