Each year fishery managers convene to plan the next fishing season of salmon fisheries. This pre-season planning process is generally known as the “North of Falcon” (NOF) process, referencing the region north of Cape Falcon Oregon which marks the southern border of active management for Washington salmon stocks. The NOF planning process coincides with the March and April meetings of the Pacific Fishery Management Council (PMFC) but includes additional public meetings as well as government to government negotiations. Final FRAM model runs are a joint exercise which encompass fisheries from both the PMFC and NOF pre-season negotiations and are usually completed at the end of the April PMFC meeting.
A wide range of model inputs are compiled and processed for FRAM pre-season model runs. Model inputs are received from the respective government agencies/tribes in Canada (Department of Fisheries and Oceans, DFO), Alaska (Alaska Department of Fish and Game, ADFG), Washington state (Washington Department of Fish and Wildlife, WDFW), twenty Western Washington treaty Indian tribes (member tribes of the Northwest Indian Fisheries Commission, NWIFC), the Columbia River Intertribal Fish Commission (CRITFC), Oregon (Oregon Department of Fish and Wildlife, ODFW), and California (California Department of Fish and Game, CDFG).
The process of developing the FRAM model inputs begins with the forecasting of hatchery and wild/natural stock abundances during January-February. From February through April, fishery inputs for FRAM are generally developed and updated through the pre-season process following technical staff discussions and manager agreement for ocean fisheries through the PMFC and for Puget Sound tribal or state fisheries through NOF. Fishery-related mortality parameters, such as release mortality rates, drop-off, sublegal/legal ratios, and mark-selective fishery parameters, are reviewed and confirmed at the start of the annual management cycle.
A variety of methods are used to forecast Chinook abundances. These forecasts are usually developed by local/regional technical staff during one or more technical meetings where relevant forecasting information is exchanged. Final agreed-to forecasts are published in the PFMC Salmon Technical Team Pre-season Report 1; Stock Abundance Analysis and Environmental Assessment Part 1 (Stock Assessment and Fishery Evaluation; SAFE).
Abundance forecasts vary in units of measure. For example, there are forecasts of salmon returning to a terminal area (which implies some accounting for pre-terminal fishery levels), forecasts of ocean abundance (which is commonly fishery impacts plus escapement), and forecasts of abundances prior to any fishing impacts (which includes natural mortality and non-landed fishery related mortality). In the case of Chinook, the forecasts of fish returning to the terminal area need to account for pre-terminal fishing impacts or impacts that occurred in previous seasons.
Although abundance forecasts vary in units of measure, the preferred units for Chinook are either Terminal Run Size (TRS) or Extreme Terminal Run Size (ETRS). The FRAM stock terminal run sizes are imported into FRAM via an external ChinRSScalarsMR.xlsm file and the TAMM stock terminal run sizes are copied from the ChinRSScalarsMR.xlsm file into the “Input Page” sheet of the TAMM file. TRS forecasts are then run through a “backwards” model run using the BkFRAM utility (Chinook Model Detail Chapter 6), which then generates the starting cohorts for the abundance at age of each stock prior to fishing and natural mortality. This model run uses agreed-to average observed fishery input data from a set of prior years to represent pre-terminal fishery levels when deriving the starting FRAM abundances from the original terminal run size forecasts. This particular model run is commonly referred to as the initial “average run” prior to any regular pre-season modeling. Abundance of age 2 fish are either forecasted separately and provided as a model input or can be generated using an “age 2 from 3” utility feature in FRAM (see FRAM User Manual).
Chinook FRAM is the primary tool used to plan and assess pre-season fishery packages for ocean fisheries through the PFMC process and for Puget Sound fisheries through the NOF process. While a variety of methods are used to model fisheries in a pre-season context, the methods used for each fishery are generally consistent between years.
Puget Sound fishery inputs for FRAM and TAMM are shared, discussed, and agreed-to by salmon co-manager technical staff in the NOF annual process. Puget Sound fisheries are modeled using a variety of the available FRAM methods. PMFC managed ocean fisheries are modeled by the Salmon Technical Team (STT). For PMFC fisheries north of Cape Falcon, which are managed based on a total allowable catch limit, quota inputs are used for both commercial troll and recreational fisheries.
Fisheries south of Cape Falcon are modeled using fishery scalers, as these fisheries are generally managed as a season. The fishery scalers are calculated as the expected number of vessel fishing days for troll fisheries or angler trips for recreational fisheries divided by the base period average effort levels. Effort expectations for each pre-season fishery package are provided from output of the Klamath Ocean Harvest Model.
Fisheries north of the border between Washington and Canada are modeled based on the framework under which they are managed. Fisheries that are subject to Aggregate Abundance Based Management (AABM) per the provisions of the Pacific Salmon Treaty (PST) Agreement are managed based on catch limits set annually by the Pacific Salmon Commission (PSC). For Southeast Alaska, the total all gear (troll, net, sport) annual catch limit is determined based on the catch per unit effort observed during the winter troll fishery. Catch limits for the Canadian AABM fisheries (Northern B.C. and WCVI troll and sport) are derived annually from preseason “abundance indices” produced by the annual calibration of the PSC Chinook Model. Catch limits for all AABM fisheries are allocated to gear and time period based on recent year averages and modeled as quotas. Catch limits for the Canadian AABM fisheries are not available until the PSC Chinook Model calibration is completed, usually by April 1. For model runs conducted prior to this, Canadian AABM fisheries are modeled using fishery scalers from the previous year’s preseason model run, which can result in increased uncertainty during the early stages of the annual assessment process. For the remaining Canadian fisheries that are managed to the Individual Stock Based Management (ISBM) provisions of the PST Agreement, fishery inputs are received from ADFG and DFO via their respective PSC Chinook Technical Committee (CTC) members. Thus, Chinook FRAM relies on fishery estimates derived from the PSC Chinook model to support FRAM model inputs for Alaskan and most Canadian fisheries. The PSC Chinook model has better stock representation in these northern fisheries and consequently is assumed to provide a better representation of fishing effort changes relative to the base period.
FRAM fishery input methods for retention fisheries includes quotas (as a fixed catch), fishery effort scalers (e.g., Puget Sound marine sport) or terminal fishery harvest rates used during TAMM processing (e.g., Puget Sound terminal net). Chinook non-retention fishery mortalities are primarily modeled using estimates of sublegal and legal-size encounters.
Although Chinook FRAM is primarily used for U.S. pre-season fishery impact assessment, it can also be used in a post-season context. These post-season model runs are used for several purposes: as a tool to evaluate the model’s performance by comparing model estimates to independently derived estimates, to evaluate the performance of the fishery management system towards meeting conservation objectives for key stocks, to develop stock-specific management objectives, and to assess stock status.
Post-season FRAM model runs assess what occurred in previous years based onco-manager agreed-to observed input values and the associated estimated abundances. These runs use the “backwards” BkFRAM utility that finds FRAM starting abundances using inputs of observed estimates for terminal run sizes and fishery catches (landed and non-retention). For Chinook FRAM, the postseason model runs are often referred to as “validation runs,” and are usually run by U.S. salmon co-managers for U.S. domestic management evaluation every two years (in even numbered years; e.g., in 2020 for all fishery years 2018 and prior). Post-season model runs are often lagged by several years due to data availability issues.
To cite this page:
Salmon modeling and analysis
workgroup. 2023. Chinook FRAM Applications in FRAM
Documentation. https://framverse.github.io/fram_doc/ built September
21, 2023.