Survey and Density Estimation Methods Webinar Review Kickoff Monday September 16 2013 200 pm 500 pm Meeting Agenda 200 Overview of the Review Scope and Process 2 30 ID: 612249
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Slide1
Scientific Review of Red Abalone Survey and Density Estimation Methods
Webinar Review Kickoff
Monday, September 16, 2013
2:00 pm – 5:00 pmSlide2
Meeting Agenda
2:00
Overview
of the Review Scope and
Process
2
:30 Overview of Survey Design and Density Estimate Methods – Department of Fish and Wildlife (DFW)3:15 Opportunity for the Science Advisory Committee to ask DFW Questions4:00 Public Question Period*4:45 Wrap-Up and Next Steps
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.org
Send OST your name using the “chat” feature on WebExSlide3
Review Scope
Survey design, including strengths and weaknesses of current methods for estimating red abalone density;
The application of existing methods, including analysis of existing data, and interpretation of results; and
Uncertainty associated with existing methods for estimating red abalone density in northern California and its adequacy for informing catch limits and other management controls of the recreational red abalone fishery in northern California, as outlined in the Abalone Recovery and Management Plan (ARMP).
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.org
Send OST your name using the “chat” feature on WebExSlide4
Review Outcomes
Assessment
of the current practice used to estimate red abalone density
Whether
current methods could be
improved;
and If so, a list of ways the methods could be improved.
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.org
Send OST your name using the “chat” feature on WebExSlide5
Review Timeline
RR
Sept
Oct
Nov
Dec
First webinar
Final
document
to DFW
Second webinar
Technical Workshop
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.org
Send OST your name using the “chat” feature on WebEx
Review OngoingSlide6
SAC Members
Chair, Dr. Mark H. Carr University of California, Santa Cruz
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.org
Send OST your name using the “chat” feature on WebExSlide7
SAC Members
Dr. Karina J. Nielsen Sonoma State University
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.org
Send OST your name using the “chat” feature on WebExSlide8
SAC Members
Dr. Jeremy Prince
Murdoch University, Western Australia
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.orgSend OST your name using the “chat” feature on WebExSlide9
SAC Members
Dr. Peter Raimondi
University of California, Santa Cruz
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.orgSend OST your name using the “chat” feature on WebExSlide10
SAC Members
Dr. Stephen C.
Schroeter University of California, Santa Barbara
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.org
Send OST your name using the “chat” feature on WebExSlide11
SAC Members
Dr. Brian
Tissot Humboldt State University
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.org
Send OST your name using the “chat” feature on WebExSlide12
*For the public: OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at: abalone@calost.org
Send OST your name using the “chat” feature on WebEx
Tom Barnes
Marine Program Manager
California Department of
Fish and WildlifeSlide13
*For the public: OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at: abalone@calost.org
Send OST your name using the “chat” feature on WebEx
California Department of
Fish and Wildlife
Dr. Laura Rogers-Bennett
Senior Environmental ScientistSlide14
*For the public: OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at: abalone@calost.org
Send OST your name using the “chat” feature on WebEx
California Department of
Fish and Wildlife
Dr. Cynthia Button
Environmental ScientistSlide15
*For the public: OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at: abalone@calost.org
Send OST your name using the “chat” feature on WebEx
California Department of
Fish and Wildlife
Dr. Ian Taniguchi
Senior Environmental ScientistSlide16
Meeting Agenda
2:00
Overview
of the Review Scope and
Process
2
:30 Overview of Survey Design and Density Estimate Methods – Department of Fish and Wildlife (DFW)3:15 Opportunity for the Science Advisory Committee to ask DFW Questions4:00 Public Question Period*4:45 Wrap-Up and Next Steps
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.org
Send OST your name using the “chat” feature on WebExSlide17
Abalone Density ReviewPresentation to OST, SAC and PublicDr. Laura Rogers-Bennett, CDFWSept. 16, 2013
Photo: R. TavernettiSlide18
WelcomeThank Ocean Science TrustFacilitation of the reviewThank Science Advisory CommitteeTime and expertise for this reviewThank members of the publicOngoing interest in abalone assessment methods Slide19
OverviewCalifornia Abalone FisheryDensity and Abalone ManagementDensity Survey MethodsResults of Density Surveys
SummarySlide20
California Abalone 7 species in CaliforniaRed abalone largest in the world
Abalone fishing important natural heritage in California2 spp endangered abalone in Ca
Haliotis rufescensSlide21
Abalone Fishery: NorthLargest recreational abalone fishery in the world
Important for coastal economy in the north35,000-40,000 fishers/year260,000 abalone/year
310 mt/year71% of fishers get daily bag limit – successful fisherySlide22
Recreational Abalone CatchSlide23
*total number of red abalone harvested = 1,352,353
Abalone Catch by County
(2002-2010)
Slide24
Abalone Recovery and Management PlanCombine Traditional Abalone ManagementSize limitDaily and yearly bag limitsSeason Closures
No Scuba allowedNetwork of MPAsAdaptive management based on DensitySlide25
Overall ConceptSlide26
Purpose of Density Monitoring Density data feeds back into managementDetermine if density changes over time and to what degree
If density declines 25% from baseline then fishery is reduced by 25%Slide27
Goals: Density MethodsKey Goal:Assess densities at index sites relative to previous levelsH
0 (Expectation): No change in average density through time (= sustainability)Time periods assessed:Most recent time period (2009-2012) Earliest time period (2003-2007)Slide28
Focus of Density ReviewDensity estimation methodsRandom depth stratified sampling designSample sizePower of sampling programComparison of densities between time periodsSlide29
Index Site Map8 Index SitesSonoma & Mendocino CountiesSites encompass 48% of the catchARMP – key fished sitesSlide30
Size of Index Sites
Area estimates are generated from 0 to 18m depth contourSlide31
Surveyed SitesSlide32
Random Stratified Design
Index sites: nearly 100% rocky reef subtidal habitats known to support red abaloneSlide33
Why Random Transects?Random transects ensure average is representative of the overall siteFixed transects are used to look at changes over time, at that transect, not at the site overallSlide34
Why Depth Stratified?Transects are randomly located and equally distributed in the following depth strata:
Depth Strata
Strata Depth Range
Shallow A
5 – 15 ft
Shallow B
16 – 30 ft
Deep C
31 – 45 ft
Deep D
46 – 60 ft
Abalone density varies by depthSlide35
Sample Size and CycleSample SizeGoal: 36 transects per site9 transects per depth stratumTransects are 30 x 2m
Survey Cycle3 to 5 years to complete 8 index sites Sites surveyed when wave ht. <6 feet
Approx 576 UW diver hours (14.4 diver weeks) per cycleSlide36
Data SheetSlide37
Data Processing (QAQC)Verification of data with divers on the boatTwo people enter data into databaseThird person independently double checks the data entryData are graphed to look for outliers
Raw data sheets are maintainedSlide38
Power of the Sampling ProgramAll five are interrelated:Alpha level (set significance p < 0.05)
Power level (set 1-beta > 0.80)Size of the effect (percent change)Variance sample
Sample sizeSlide39
Use of Statistics
Use statistics to support management
Use statistics to detect strong patterns in the data Determine if the average densities are statistically significantly different over time
Statistical tools
ANOVA (MatLab)Slide40
Abalone Density
Averages are significantly different (ANOVA
p<0.001) – 35% change in overall density.Slide41
Abalone Density
Averages are significantly different across time periods by county (ANOVA
p
<0.001)
60% declineSlide42
Harmful Algal Bloom (Red Tide)Aug. 2011 - Abalone mortalityImpacted half of the fishing groundsSonoma County
Microalgae Gonyaulax membranaceaOngoing monitoring of both the abalone and algae
Photo: Nate Buck Fort Ross 2011Slide43
Density ResultsPower analysis results indicate we can detect changes in density >15%Fishery overall declined by 35%Decline statistically significantOverall decline driven by Sonoma Co. which declined by 60%Slide44
Summary Surveys provide a Relative measure of current density compared with previous densities to inform management
Surveys of fished index sites were sensitive to changes in density over timeSurvey results allowed detection of significant changes across time at the scale of the index sites as well as by county Slide45
AAUS diversUC Davis
Jason Herum, Henry Fastenau, Anthony Disbrow , David Dann, Greg Holzer, Olivia Rhoades, Sam Briggs, Tammer Barkouki, , Brian Sullivan, Ashley McDonough, Rietta Hohman, John Harreld, Angee Doerr, Brad Carter, Kristin Aquilino, May Roberts, Jonathan Clark, Joel Sharbrough, Bill Wagman, Athena Maguire, Scott Neifert, Nick Modisette
Humboldt State University Carl Anderson, Kristin Hubbard, Reed Gatton, Ryan Anderson, James Hansmeier, Lisa Nugent, Dan Cooke, Rachel Carlton, Kris Chamberlin, Mark Davis, Michael Tobin, Melissa Erkel, Nicole Lawrence, Simona Augyte, Sam Parker
San Francisco State University
CA State University, Monterey Bay
Chris Raleigh, Sophie Archambeault Ben WalkerUC Santa Cruz Stanford University Katharine Magana, John Harriman, Shelby Kawana Jennifer O’Leary, Kersten SchnurleUC San Diego San Diego State DiversChristina Bonsell, Cynthia Catton Julia Coates
Slide46
Partnerships/CollaborationsEnforcement Branch CDFWCDFW Dive ProgramAcademic Partners
UCDUCSCHumboldt StateBodega Marine Lab Dive ProgramSlide47
Thank You
Dr. Laura Rogers-Bennett - lrogersbennett@dfg.ca.gov
Cal. Department of Fish and Wildlife
OST: http://calost.org/science-advising/?page=scientific-reviewSlide48
Meeting Agenda
2:00
Overview
of the Review Scope and
Process
2
:30 Overview of Survey Design and Density Estimate Methods – Department of Fish and Wildlife (DFW)3:15 Opportunity for the Science Advisory Committee to ask DFW Questions4:00 Public Question Period*4:45 Wrap-Up and Next Steps
*For the public:
OST will keep a running queue of public commenter names and call each name in the order received. To enter the queue, please submit your first and last name at any time during the meeting by:
E-mailing OST at:
abalone@calost.org
Send OST your name using the “chat” feature on WebExSlide49
Note: the following slides are for use during the questions and answers sessionSlide50
Abalone Fishery by Species
METRIC TONS
0
500
1,000
1,500
0
500
1,000
0
500
1,000
0
100
1942
1996
YEAR
0
500
1,000
1,500Slide51
Abalone Density 2011
*Averages are significantly different (ANOVA p=0.0006) - 27% change in overall density.Slide52
Why is density important?Close together = high fertilization successFar apart = low fertilization successHigh density = reproductive population
Babcock and Keesing 1999Slide53
Distance and Density
Button and Rogers-Bennett in prepSlide54
Fishery Closure at Low Density
National Park Service surveys Channel Is.
Johnson’s Lee North
< 2,000 red ab/ha
Santa Rosa Island
1982 - 2010
0.15
0.1
0.05
0
Density (/m
2
)
YearSlide55
Case Study: Abalone Density
Digichrome 2007Slide56
Density Decline
Density (# / m
2
)
Survey Year
2004 2007 2010
2
2.5
1
0.5
0
Rogers-Bennett et al. 2013Slide57
Fishing: Report Card
Survey Years
opened
closedSlide58
Density Impact by Size
0.5
0.4
0.3
0.2
0.1
0
Density (# /m
2
)
Size (mm)
Legal Sizes
Sublegal Sizes
Cryptic Sizes
2004
2007
2010