A retrospective investigation of selectivity for Pacific halibut CAPAM Selectivity workshop 14 March, 2013 Ian Stewart & Steve Martell.

Slides:



Advertisements
Similar presentations
Modeling Recruitment in Stock Synthesis
Advertisements

An exploration of alternative methods to deal with time-varying selectivity in the stock assessment of YFT in the eastern Pacific Ocean CAPAM – Selectivity.
Sheng-Ping Wang 1,2, Mark Maunder 2, and Alexandre Aires-Da-Silva 2 1.National Taiwan Ocean University 2.Inter-American Tropical Tuna Commission.
Modeling fisheries and stocks spatially for Pacific Northwest Chinook salmon Rishi Sharma, CRITFC Henry Yuen, USFWS Mark Maunder, IATTC.
An evaluation of alternative binning approaches for composition data in integrated stock assessments Cole Monnahan, Sean Anderson, Felipe Hurtado, Kotaro.
An Overview of the Key Issues to be Discussed Relating to South African Sardine MARAM International Stock Assessment Workshop 1 st December 2014 Carryn.
Growth in Age-Structured Stock Assessment Models R.I.C. Chris Francis CAPAM Growth Workshop, La Jolla, November 3-7, 2014.
Black Sea Bass – Northern Stock Coastal-Pelagic/ASMFC Working Group Review June 15, 2010.
FMSP stock assessment tools Training Workshop LFDA Theory.
The current status of fisheries stock assessment Mark Maunder Inter-American Tropical Tuna Commission (IATTC) Center for the Advancement of Population.
Assessment of red shrimp (Aristeus antennatus) exploited by the Spanish trawl fishery: in the geographical sub-area Balearic Islands (GSA-5) and Northern.
Using CWT’s to assess survival, ocean distribution and maturation for Chinook stocks across the Pacific Northwest: Are there any predictive capabilities.
458 Fisheries Reference Points (Single- and multi-species) Fish 458, Lecture 23.
Case Study - Dover Sole Range from Baja California to the Bering Sea. On mud or muddy-sand, at 35 to 1400 m depths. Feed on polychaete worms, shrimp, brittle.
Hui-Hua Lee 1, Kevin R. Piner 1, Mark N. Maunder 2 Evaluation of traditional versus conditional fitting of von Bertalanffy growth functions 1 NOAA Fisheries,
Hierarchical Bayesian Analysis of the Spiny Lobster Fishery in California Brian Kinlan, Steve Gaines, Deborah McArdle, Katherine Emery UCSB.
Descriptor 3 for determining Good Environmental Status (GES) under the MSFD was defined as “Populations of all commercially exploited fish and shellfish.
The (potential) value and use of empirical estimates of selectivity in integrated assessments John Walter, Brian Linton, Will Patterson and Clay Porch.
Time-Varying vs. Non-Time- Varying Growth in the Gulf of Mexico King Mackerel Stock Assessment: a Case Study Southeast Fisheries Science Center Jeff Isely,
Richard Methot NOAA Fisheries Service Seattle, WA
WP4: Models to predict & test recovery strategies Cefas: Laurence Kell & John Pinnegar Univ. Aberdeen: Tara Marshall & Bruce McAdam.
Maximum likelihood estimates of North Pacific albacore tuna ( Thunnus alalunga ) von Bertalanffy growth parameters using conditional-age-at-length data.
Population Dynamics Mortality, Growth, and More. Fish Growth Growth of fish is indeterminate Affected by: –Food abundance –Weather –Competition –Other.
Pacific Hake Management Strategy Evaluation Joint Technical Committee Northwest Fisheries Science Center, NOAA Pacific Biological Station, DFO School of.
Surplus-Production Models
ASSESSMENT OF BIGEYE TUNA (THUNNUS OBESUS) IN THE EASTERN PACIFIC OCEAN January 1975 – December 2006.
Pacific Hake Management Strategy Evaluation Joint Technical Committee Northwest Fisheries Science Center, NOAA Pacific Biological Station, DFO School of.
Spatial issues in WCPO stock assessments (bigeye and yellowfin tuna) Simon Hoyle SPC.
Modeling growth for American lobster Homarus americanus Yong Chen, Jui-Han Chang School of Marine Sciences, University of Maine, Orono, ME
WP 2.4 Evaluation of NMFS Toolbox Assessment Models on Simulated Groundfish Data Sets Comparative Simulation Tests Overview Brooks, Legault, Nitschke,
Modeling Natural Mortality in Stock Synthesis Modeling population processes 2009 IATTC workshop.
FTP Some more mathematical formulation of stock dynamics.
ALADYM (Age-Length Based Dynamic Model): a stochastic simulation tool to predict population dynamics and management scenarios using fishery-independent.
FTP Yield per recruit models. 2 Objectives Since maximizing effort does not maximize catch, the question is if there is an optimum fishing rate that would.
The Stock Synthesis Approach Based on many of the ideas proposed in Fournier and Archibald (1982), Methot developed a stock assessment approach and computer.
Fisheries Models: Methods, Data Requirements, Environmental Linkages Richard Methot NOAA Fisheries Science & Technology.
Workshop on Stock Assessment Methods 7-11 November IATTC, La Jolla, CA, USA.
Simulated data sets Extracted from:. The data sets shared a common time period of 30 years and age range from 0 to 16 years. The data were provided to.
USING INDICATORS OF STOCK STATUS WHEN TRADITIONAL REFERENCE POINTS ARE NOT AVAILABLE: EVALUATION AND APPLICATION TO SKIPJACK TUNA IN THE EASTERN PACIFIC.
M.S.M. Siddeeka*, J. Zhenga, A.E. Puntb, and D. Pengillya
The effect of variable sampling efficiency on reliability of the observation error as a measure of uncertainty in abundance indices from scientific surveys.
Extending length-based models for data-limited fisheries into a state-space framework Merrill B. Rudd* and James T. Thorson *PhD Student, School of Aquatic.
1 Yi-Jay Chang 2 Brian Langseth 3 Mark Maunder 1 Felipe Carvalho Performance of a stock assessment model with misspecified time-varying growth 1 – JIMAR,
Estimation of growth within stock assessment models: implications when using length composition data Jiangfeng Zhu a, Mark N. Maunder b, Alexandre M. Aires-da-Silva.
ASSESSMENT OF BIGEYE TUNA (THUNNUS OBESUS) IN THE EASTERN PACIFIC OCEAN January 1975 – December 2005.
Using distributions of likelihoods to diagnose parameter misspecification of integrated stock assessment models Jiangfeng Zhu * Shanghai Ocean University,
Selectivity and two biomass measures in an age-based assessment of Antarctic krill Doug Kinzey, George Watters NOAA/NMFS/SWFSC/AERD CAPAM Workshop, March.
MSE Performance Metrics, Tentative Results and Summary Joint Technical Committee Northwest Fisheries Science Center, NOAA Pacific Biological Station, DFO.
Yellowfin Tuna Major Changes Catch, effort, and length-frequency data for the surface fisheries have been updated to include new data for 2005.
Lecture 10 review Spatial sampling design –Systematic sampling is generally better than random sampling if the sampling universe has large-scale structure.
A bit of history Fry 1940s: ”virtual population”, “catch curve”
Empirical comparison of historical data and age- structured assessment models for Prince William Sound and Sitka Sound Pacific herring Peter-John F. Hulson,
Modelling population dynamics given age-based and seasonal movement in south Pacific albacore Simon Hoyle Secretariat of the Pacific Community.
UALG Statistical catch at age models Einar Hjörleifsson.
Influence of selectivity and size composition misfit on the scaling of population estimates and possible solutions: an example with north Pacific albacore.
CBSAC 2012 Blue Crab Advisory Report Figures. Figure 1. Winter dredge survey index of total blue crab abundance (density of males and females, all sizes.
Quiz 7. Harvesting strategies and tactics References Hilborn R, Stewart IJ, Branch TA & Jensen OP (2012) Defining trade-offs among conservation, profitability,
Data requirement of stock assessment. Data used in stock assessments can be classified as fishery-dependent data or fishery-independent data. Fishery-dependent.
Population Dynamics and Stock Assessment of Red King Crab in Bristol Bay, Alaska Jie Zheng Alaska Department of Fish and Game Juneau, Alaska, USA.
Survey Data Conflicts and Bias and Temporal Variation of Model Parameters of St. Matthew Island Blue King Crab J. Zheng, D. Pengilly and V. A. Vanek ADF&G,
Is down weighting composition data adequate to deal with model misspecification or do we need to fix the model? Sheng-Ping Wang, Mark N. Maunder National.
PRINCIPLES OF STOCK ASSESSMENT. Aims of stock assessment The overall aim of fisheries science is to provide information to managers on the state and life.
Fish stock assessment Prof. Dr. Sahar Mehanna National Institute of Oceanography and Fisheries Fish population Dynamics Lab November,
MARAM International Stock Assessment Workshop
Pacific-Wide Assessment of Bigeye Tuna
Selectivity.
Age-structured population assessment models
YIELD CURVES.
Bristol Bay Red King Crab Assessment in Spring 2019
Pribilof Island red king crab
Presentation transcript:

A retrospective investigation of selectivity for Pacific halibut CAPAM Selectivity workshop 14 March, 2013 Ian Stewart & Steve Martell

Overview 1) History 2) Contributing factors 3) 2012 Assessment investigation 4) Path forward

YearsModelIssues Pre-1977 Yield, yield-per-recruit, simple stock-production modelsNo growth or recruitment variability Cohort analysis, coastwide, natural mortality (M)=0.2Unstable estimates Catch-AGE-ANalysis (CAGEAN; age-based availability), coastwide, M=0.2 Migratory dynamics not accounted for CAGEAN, area-specific, migratory and coastwide, M=0.2Trends differ by area CAGEAN, area-specific, M=0.2, age-based selectivityRetrospective pattern Statistical Catch-Age (SCA), area-specific, length-based selectivity, M=0.2 M estimate imprecise SCA, area-specific, length-based selectivity, M=0.15Poor fit to data New SCA, area-specific, constant age-based selectivity, M=0.15 Retrospective pattern SCA, area-specific, constant length-based selectivity, M=0.15 Migratory dynamics created bias SCA, coastwide, constant length-based selectivity, M=0.15 Retrospective pattern Assessment model evolution

Retrospective I: Age-based selectivity

Interim: Length-based selectivity Figure from: Clark and Hare, A

Retrospective II: Age-based selectivity Figure from: Clark and Hare, A

Interim II: Length-based selectivity 3A Exploitable biomass (M lb) Figure from: Clark and Hare, 2004

Retrospective III: Length-based selectivity

Overview 1) History 2) Contributing factors 3) 2012 Assessment investigation 4) Path forward

Factors contributing to selectivity: - Highly dimorphic growth - Size-at-age: temporal trends and differences by area - Fishery minimum size limit - Hook-size effects – few small fish observed

Regulatory areas

Growth curves by area Age (years) Length (cm) Dimorphic and spatial variability

Historical weight-at-age (Ageing methods, sampling locations, selectivity itself, etc. may bias these trends)

Trends in size-at-age Minimum size limit

Trends in size-at-age (Age-11 male halibut) Minimum size limit

Directly observed gear selectivity (vulnerability) Based on Didson acoustic camera observations (S. Kaimmer; In prep)

Figures from: Clark and Hare, 2003 & 2004 Selectivity by area may differ ~40% Fishery Survey Fishery

Abundance by area has changed

Length-based selectivity: area (vulnerability) vs. coast-wide (vulnerability + availability) Changes in proportional abundance + Differences in: - Biology (age, length, length-at-age) - Vulnerability

Length-based selectivity: area (vulnerability) vs. coast-wide (vulnerability + availability)  Coast-wide “average” selectivity changes over time

Spatial approaches: Separate stocks < 2006 J.D. Herder 2008 Fishery J.D. Herder 2008 Survey J.D. Herder 2008 Survey J.D. Herder 2008 Fishery J.D. Herder 2008 Fishery J.D. Herder 2008 Survey J.D. Herder 2008 Survey J.D. Herder 2008 Fishery

Spatial approaches: coastwide dynamics J.D. Herder 2008 Fishery J.D. Herder 2008 Survey Population

Overview 1) History 2) Contributing factors 3) 2012 Assessment investigation 4) Path forward

Non-parametric length-based selectivity Inputs: Minimum size bin Bin at which selectivity = 1.0 Maximum size bin Type switch SD size SD time (added this year) Specifications: Operates on 10cm bins Sex-specific Type: Asymptotic, ‘Ramp’, or domed above size bin = 1.0 Smoother for second difference b/w adjacent sizes within year Smoother for second difference b/w adjacent years within size bin Years for which to estimate separate curves Scaled by sex-specific catchability (so values above 1.0 are ok, since that bin is fixed) Catchability (q) can also vary among years

Crux: There is no underlying growth model, nor distribution of lengths for a given age. The approach uses ‘true’ observed survey length-at-age to translate size- to age-based selectivity. This is done via interpolating the values at age from the values at each bin. Non-parametric length-based selectivity

Retrospective within the 2011 assessment (Sequentially removing data)

Retrospective: Symptoms Age-8 Recruits (millions)

Increasing penalty on large recruitment estimates

SSQs Increasing initial recruitment penalty  Males Females Total

Secondary exploration:  Investigate increasing the relative survey weight  Explore process error in selectivity (time-varying)

Increased survey index weighting

Three tests: similar results

Selectivity – implementations

Time-varying selectivity

Selectivity SD time : Base-case: (50% of smoothing over length)

Selectivity SD time :

Retrospective: Solution

(Data only through 2011)

Retrospective: Contributing factors 1)Transition from area-specific to coastwide model in 2006 (and retaining the assumption of constant availability) 2)Changes in the coastwide population distribution 3)Too much emphasis on the age data (and not the survey trend) 4) Short time-series

Looking forward: Comparison of spatial modeling approaches: - Coast-wide: time-varying selectivity - Implicitly spatial: fleets-as-time-periods fleets-as-areas - Explicitly spatial: Multi-area assessment  Once selectivity is treated as time-varying, either length- or age-based formulations can capture the process.

Questions?