Current Status of Accomplishment or Milestone: This modeling effort was proposed before the current Coastal Pelagics Species Plan Development Team was established. Due to the assignment of R. Parrish to the Plan Development Team and his subsequent writing assignments
for the biological sections of the Plan and for the first draft of the Essential Fish Habitat section of the Plan the development of the spatial model was postponed. The Team decided that the major modelling activity for the CPS Plan should be based on a model previously developed
by L. Jacobson, therefore R. Parrish and L. Jacobson modified this dynamic pool model to assess a wide range of management options, including temperature dependent control rules for the sardine resource. This work was completed in July and the Public Review Document for the Draft Amendment 9
was available to the public in early September. In mid-September the Pacific Fisheries Management Council will decide on a management strategy based on this modeling activity.
Background: The Pacific sardine fishery was once the largest fishery in the western hemisphere; this stock is also the primarily forage fish in the current system. The long-term collapse of this stock which occurred under very high exploitation rates has the potential to disrupt the productivity of many marine predators which relied upon this species for forage. The value of the sardine stock as forage has never been determined. The model to be developed in this project is designed to assess the geographical distribution of the natural mortality of sardine and to use this distribution to describe the value of this stock to the California Current Ecosystem.
Purpose of Activity/Goal of Project: Ecosystem management of fisheries is a long-term goal of NMFS; however, little work has been carried out to evaluate the ecosystem effects of fishery management policies. This project is designed to develop a spatial model of the migratory stock of Pacific sardine, the major forage fish in the California Current, which will assess the amount of sardines utilized as forage in 9 geographical regions of the California Current under a range of management options.
Description of Accomplishment and Significant Results: Due to the work described above the development of the spatial model was necessarily delayed for about 4 months. Work on the model was therefore not started until the CPSPDT modelling was completed in July. Since that time the development of the spatial model has centered on the migration and exploitation components of the model. Work on the recruitment component of the model has just started and it is expected that the full model will not be completed until December. Preliminary runs with the model show that the seasonal geographic distribution of sardine by age group can be achieved by using the observed SST in the 9 geographical regions utilized in the model and that the considerable inter-year variation in the distribution of sardine is well described.
Key Contact: Richard Parrish (831-648-9033, rparrish@pfeg.noaa.gov)