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Population analysis of coastal pelagic species off the USA Pacific coast using age-structured statistical catch-at-age/length models. K. T. Hill and P. R. Crone NOAA Fisheries Southwest Fisheries Science Center 8604 La Jolla Shores Drive La Jolla, CA 92037, USA.
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Population analysis of coastal pelagic species off the USA Pacific coast using age-structured statistical catch-at-age/length models K. T. Hill and P. R. Crone NOAA Fisheries Southwest Fisheries Science Center 8604 La Jolla Shores Drive La Jolla, CA 92037, USA
Stock assessments for CPS in 2011 Presentation outline • Overview of stock assessment model development • From field to lab to analysis to management advice • Pertinent differences between current Pacific sardine and Pacific mackerel models • Data (time series) included in the model • Parameterization (stock parameter) considerations • P. mackerel and P. sardine stock assessments (overviews) • Management procedures • Pacific sardine as example • Future considerations • Model development for P. sardine and P. mackerel • International-based collaborative sampling/laboratory/modeling efforts for CPS
Stock assessments for CPS in 2011 Overview of stock assessment model development • Historical review of available data and modeling approaches over time • Fishery-dependent sample data largely collected by state (and international) agencies • Research survey data collected primarily by federal-based programs • Laboratory work conducted by state and federal research efforts • Formal population analysis conducted/coordinated by federal research programs • Management processes are addressed annually through regional Council activities
Stock assessments for CPS in 2011 Pertinent differences between current sardine and mackerel models • Data (time series) • Age/length distribution time series … length- vs. age-based • Index of abundance time series … research survey- vs. fishery-based • Parameterization (stock parameter) • Use of age and length data for evaluating selectivity, growth, etc. • Spawning stock—recruitment relationship
Pacific Mackerel Stock Assessment (2011) OR-WA Distribution Spawning Area Fisheries Monterey San Pedro San Diego Ensenada Bahia Magdalena
Pacific Mackerel Stock Assessment (2011) Data • Landings — USA from PacFIN/RecFIN and available at a fine scale • International landings availability … much improved over time • Biology — from state/federal sampling/laboratory programs and available at a fine scale, but … • Length … recreational fishery length information prior to 1992 (and you could even argue 2004) caveats • Age … no recreational fishery age information • Weight … see Length above • Maturity … ‘long in the tooth’ caveats • Indices of abundance — from state sampling programs and available at a fine scale, but … • CPFV logbook sampling program … future ‘applicability’ of this data source needs further review • CRFS program … long-term funding concerns
Age Distribution Time Series (1983-10)Commercial Fishery – Model XA fits
Length Distribution Time Series (1985-10, 2004-10)Recreational Fishery – Model XA fits/diagnostics
Selectivity – Model XA Commercial fishery Recreational fishery
Harvest Guideline Commercial landings (mt) and quotas
Estimated Biomass Time SeriesHistorical Assessment Period (2004-11)
“First and foremost, the population’s reproductive potential has been only lightly impacted from fishing pressure over the last decade, i.e., the estimated SPR time series, blah, blah, blah …” Brown bears – Cabinet Yaak Ecosystem Pacific mackerel – California Current Ecosystem California condors – So. CA Coastal Mountain Range Ecosystem Pacific bluefin tuna – North Pacific Ocean Ecosystem
Spawning Potential Ratio Time Series – Model XA Reeeally conservative benchmarks say … Real conservative benchmark say …
Ongoing Modeling Issues • Scaling the population from a fully-depleted condition (early 1980s) • Sensitivity to new data (e.g., SS model 2008) • Implausibly high F-rates (SS models 2009-2010): aerial survey biomass treated as absolute • Recent models had many selectivity parameters and time-varying elements resulting in model instability (i.e., over-parameterized) Changes from Previous Assessments NEW MODEL STRUCTURE Goal: more parsimonious model; robust to data/scaling; plausibleFestimates • Regional fisheries aggregated to MexCal and PacNW ‘fleets’ • Truncated time series (1993 start year) • Fewer time-varying elements (selectivity and growth) • Number of estimated parameters reduced from 132 to 61 NEW DATA SOURCES • Ensenada fishery composition (1989-2009) • SWFSC Acoustic survey time series (2006-2011)
British Columbia (BC) Pacific Sardine Recovery and Fishery Expansion 2000s Washington (WA) Oregon (OR) Monterey (CCA) 90s San Pedro (SCA) 80s Ensenada (ENS)
Fishery Compositions: Length, Age, & Selectivity Age (yr) Length (cm)
Estimated Stock Biomass and Recruitment Series from Current Base Model and Previous Stock Synthesis Models
Stock assessments for CPS in 2011 Future considerations • Model development • Using age- vs. length-based selectivity (sardine) • Down-weight fishery composition data per Francis (2011) • Time-varying selectivity/catchability considerations • Survey-based indices of abundance (mackerel) • International-based collaborative efforts • Synoptic CPS surveys • Adult sample collection & methods (ageing and reproductive biology) • Stock structure studies • Stock assessment workshops
Acknowledgments CDFO: Jake Schweigert, LinneaFlostrand, Jackie Detering NWFSC: Richard Methot, Ian Taylor, Ian Stewart, Bob Emmett WDFW: Carol Henry, Sandra Rosenfield, Jennifer Topping ODFW: Jill Smith, Keith Matteson, Sheryl Manley, Kelly Corbet, David Wolfe Wagman Northwest Sardine Survey, LLC: Jerry Thon, Tom Jagielo, Ryan Howe, Meghan Mikesell CDFG: Kirk Lynn, Dianna Porzio, Mandy Lewis, Bill Miller, Paul Ton, SantiLuangpraseut, Briana Brady, Ed Dunn, Sonia Torres, Lou Zeidberg SWFSC: Dave Griffith, Amy Hays, DimitryAbramenkoff, Sue Manion, Bill Watson, Elaine Acuña, Andrew Thompson, Sherri Charter, Sarah Zao, Noelle Bowlin, David Demer, Juan Zwolinski, Randy Cutter, Kyle Byers, Josiah Renfree, Steve Sessions, John Field, VardisTsontos IATTC: Mark Maunder and Alex Aires-da-Silva INAPESCA: Manuel Nevarrez (Guaymas) and Ensenada field staff CICIMAR: Roberto Felix-Uraga and CasimiroQuiñonez STAR Panels: Andre Punt, Ray Conser, Larry Jacobson, Chris Francis, Mike Okoniewski, Lorna Wargo, Jonathan Deroba, John Casey, Briana Brady