DOI: 10.3886/e219902
title: NWFSC/FRAM - Data Warehouse - GEMM

description: This is a backup of NWFSC/FRAM - Data Warehouse - GEMM Fact Layer. Date of download: April 22, 2025. This data is in the public domain and is unaltered. Original Webpage (4/22/2025): https://www.webapps.nwfsc.noaa.gov/data/metadata/observer.gemm_fact<br><br>Description: <br><br>December 2023 - Groundfish Expanded Mortality Multiyear (GEMM) This data product includes total estimated discard, discard with discard mortality rates (DMRs) applied, landings, catch (discard and landings), and mortality (discard with DMRs applied and landings) for all species and groupings recorded in A-SHOP, EM, PacFIN, RecFIN, and WCGOP data for the years 2002 to 2023. This data supercedes any other reports and is considered the most current and accurate estimate of mortality. All units are metric tons (mt). As well as adding 2023 data, values from previous years were re-calculated based on updated data and the most current procedures for estimation. The most current discard mortality rates approved and used by the GMT are applied to species discard estimates across all years, following methods used in Somers et al. 2024. We also include Pacific halibut commercial catch estimates from Richerson et al. 2024. In 2015, some portions of the catch shares fleet began using electronic monitoring rather than 100% observer coverage; catch and mortality in these sectors are reported separately from the 100% observer monitored portions of the fleet. Due to changes in EM video review timelines, at-sea discard mortality estimation methods for the shoreside-processed EM fleet in 2021 and beyond differ from other years and are described in detail in Somers et al. 2024. In 2017, the WCGOP first observed the directed Pacific halibut fishery. Previous versions of the GEMM incorporated those landings in the "Incidental Fisheries" sector and did not estimate discards. In this version, landings were estimated for all years. The California sea cucumber and ridgeback prawn fisheries are no longer observed by the WCGOP, so at-sea discards are not estimated; landings estimates are included in the "Incidental Fisheries" sector. Additionally, permitted research and recreational data are included for 2005 to 2023. Management groupings have not been applied retroactively in research mortality estimates, and non-groundfish species are reported inconsistently across research projects and should be interpreted with caution. Estimates of total catch and mortality of black rockfish, cabezon, china rockfish, and kelp greenling in the Oregon recreational fishery include data from the shore and estuary sector, which does not report discard and landed catch separately. References Richerson, K., J. Jannot, K. Somers, V. Tuttle, C. Colway, J. McVeigh. 2024. Pacific halibut bycatch in the U.S. west coast groundfish fisheries, 2002-2023. NOAA Fisheries, NWFSC Observer Program, 2725 Montlake Blvd E., Seattle, WA 98112. Somers, K.A., K. Richerson, V. Tuttle, and J. McVeigh. 2024. Estimated discard and catch of groundfish species in the 2023 U.S. west coast fisheries. NOAA Fisheries, NWFSC Observer Program, 2725 Montlake Blvd E., Seattle, WA 98112. Both reports are currently in review; draft versions are available in the briefing books for the September 2024 and November 2024 meetings of the Pacific Fishery Management Council.<br>