Jerald S. Ault, Steven G. Smith, James A. Bohnsack
Southern Florida Reef Fish Visual Survey
USA
Gulf of
Mexico
Ecological and fishery dynamics of southern Florida
Coral Reef
Fishery Ecosystem
Coral Reef Eco-“Systems Science”
80+
, , bays/rivers .and beyond.
35-50
Coastal Oceanography & “Habitat” Use Ontogeny
Coastal Oceanography
& Fate-Transport
Freshwater Inflows Regional Forcing (Oceanography
Coastal Development, etc.)
Fish Community Assessment • Exploited and Non-Target Species • Trophodynamic Levels (Predator-Prey) • Full Size Spectrum (Recruits, Adults, Exploited) Spatial Dynamics • Inside-Outside MPAs • Habitat Use Patterns/Movement Strategies
Fishery-Dependent Data Largely Inadequate
New Data Paradigm Required
Goal of Fishery-Independent Surveys: Estimate population & community metrics -- Accurate, precise, and cost-effective
Average Population Size
Diver Sighting (Catch) Equation (with negligible selectivity in exploited phase)
S
FM
NN
10
FM
N eFM
FNENNFYC
100
Baranov Catch Equation
FMN e
FM
Nq
f
Y
10
Relationship between Reef-fish Visual Census and Data Needs of Stock Assessment
600
700
800
900
1000
1100
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2
Fishing Mortality Rate
Ave
rage S
ize (TL,
mm)
0.00
0.01
0.02
0.03
0.04
486 556 626 696 766 836 906 976 1046 1116 1186 1256
Length (mm)
Fre
quen
cy
0.00
0.02
0.04
0.06
0.08
486 556 626 696 766 836 906 976 1046 1116 1186 1256
Total length (mm)
Fre
quen
cy
0.000
0.005
0.010
0.015
0.020
486 556 626 696 766 836 906 976 1046 1116 1186 1256
Length (mm)
Fre
quen
cy
Unexploited
MSY Exploitation
Current Exploitation
“Observable” Assessment Indicator Variables
40.6”, 42.8 lbs SPR = 100%
27.9”, 12.6 lbs SPR = < 6%
36.4”, 30.1 lbs SPR = 35.1%
λ
c
c
a
a
a
a
daN(a,t)F(t)
dataLtaNtF
tL
),(),()(
)(
Minimum Legal Size
(24 inches)
Indicators of Response & Impact
Limit-Control Rule Indicator
Gulf of Mexico
Visual Survey Sampling Area
Florida Straits
The Managed Florida Keys-Dry Tortugas Coral Reef Ecosystem
15
Martin
North Palm Beach
South Palm Beach
Deerfield
North Miami-Dade &Broward
Miami-Dade
Broward
Palm Beach
Martin
SEFCRI Region
Precise, Cost-Effective Survey Designs Stratification Scheme Partitions survey domain into subregions of low, moderate, and high variance Allocation Scheme Allocation based on stratum size and variance More samples in larger strata More samples in higher variance strata
0
5
10
15
20
25
INPR MCPR OFPR FRSH FRMDInshore Patch
Reefs
Offshore Patch
Reefs
Mid-Channel
Patch Reefs
Fore Reef
0-6 m
Fore Reef
6-18 m
Habitat Class
Den
sity
Yellowtail Snapper, Juveniles and Adults
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 60
Bay
Inshore Reefs
Offshore Reefs
Length (cm)
Fre
quenc
y
Newborn Juveniles Adults
Gray Snapper
Reef Terrace
Low-Relief Hardbottom
Rocky Outcrops
Pinnacle Reef
Low-Relief
Spur & Groove
Medium Profile Reef
High-Relief
Spur & Groove
Patchy Hardbottom in Sand
Reef Terrace Patch
Reefs
Florida
Dry Tortugas Miami
Dry Tortugas Region Reef Habitats
Tortugas Bank ER
Tortugas Bank Fished Dry Tortugas
National Park
FKNMS Boundary
Florida
Dry Tortugas Miami
DTNP RNA
Tortugas Region Management Boundaries
0%
20%
40%
60%
80%
100%
0 100 200 300 400 500 600 700 800
Florida Keys Sampling Design Efficiency 1979-2010
1989 1987
1980
1990 1986
1985
1982 1989
1991
1996
1992
1988
1994
1981
1993 1995
1983 1998
1997 1999 2000
2002 2001
Neyman Optimal Sampling Allocation
2003 2005
2004
2007
2006
RVC Samples (nm*)
Coeffic
ient
of V
ariation C
V
2008
2009
Smith, Ault et al. 2011. Fisheries Research 109(1): 25-41.
Pre-Survey Analyses Habitat Characterization & Mapping
Species Lifestage-Habitat Associations
Pre-Survey Sampling Design Stratification & Spatial Allocation of Sampling Effort
Randomized Selection of Sampling Locations
Conduct Survey
Data Assimilation
Design-based Estimates
Multispecies Stock Assessments
Modeling of Spatial Management Alternatives
“Adaptive” Precision
Community Analyses
Data Applications
Source
Database
Metrics
Spatial Resolution
Commercial Fleet Florida Trip-Ticket Catch-per-unit-effort and size structured abundance
Florida-wide, but particularly focused on southwest and southern Florida
Trip Interview Program Catch length composition Florida-wide, but particularly focused on southwest and southern Florida
Recreational Fleet MRFSS/MRIP Catch-per-unit-effort, and size structured abundance
Florida-wide, but particularly focused on southwest and southern Florida
Fishery-Independent Reef Fish Visual Census (<35 m) NMFS Bottom Longline
Size-structured abundance Size-structured abundance
Southern Florida, Florida Keys & Dry Tortugas Florida-wide, but particularly focused on southwest and southern Florida
Reef Fish ROV and Drop Camera Surveys (>35m)
Size-structured abundance Pulley Ridge, Madison-Swanson reserve, W. FL Shelf
Source
Database
Data Types
Spatial Resolution
Recreational Fleet Headboat Survey Length compositions Florida-wide, but particularly focused on southwest and southern Florida
NPS Creel Survey Catch-per-unit-effort, and size structured abundance
Biscayne National Park
NPS Creel Survey Catch-per-unit-effort, and size structured abundance
Dry Tortugas National Park
Primary
Secondary
Fishery-Dependent & Fishery Independent Data Sources
(A) Empirical length frequencies
(B) Model-predicted length frequency at estimate F=0.38.
Standardization of Size-Structured Abundance Among Fleets
Commercial
Recreational
RVC
Modeled
Dry Tortugas Region--2010
Florida Keys Region--2010
Optimal Design of Marine Reserves
Rr
rarrar
Ss
aaccffssssq aaaaccffppqMin
SPR over
all species
Reserve
shape fishing
effort
Reef
area
Total
Reserve
area
Regional
Reserve
area
(C1) Reserves non-overlapping (C2) Pre-specified number of reserves (C3) Fixed proportion of SPR protected (C4) Maximum number of fishing vessels displaced by reserves (C5) Target area of coral reef area protected (C6) Target total area protected (C7) Distribution of reserves among regions of ecosystem (C8) Each reserve contiguous, compact, and desirably shaped
OBJECTIVE FUNCTION
CONSTRAINTS -- SUBJECT TO:
Meester, Mehrotra, Ault and Baker. 2004. Management Science 50: 1031-1043
(A)
Bank ER Density = 0.04
Occupancy = 5.3%
Bank Open Density = 0.19
Occupancy = 21.9%
Park Density = 0.10
Occupancy = 10.7%
2000
Spatial Impact of Reserve Implementation
(B)
Bank ER Density = 0.32
Occupancy = 42.6%
Bank Open Density = 0.27
Occupancy = 29.0%
Park Density = 0.26
Occupancy = 33.9%
2010
Dry Tortugas National Park:
22% of Survey Frame
Contains 33 - 50% of adult spawner abundance for
black and red grouper; yellowtail & mutton snapper.
These species are 55.5% of commercial reef fish
catch in the State of Florida!!
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0 25 50 75 100 125 150 175 200 225 250 275 300 325 350
n
CV
Caranx ignobilis, SPC
Bodianus bilunulatus, BLG
Stegastes fasciolatus, BSM
Projected Sample Size Requirements, 2-stage StRS
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0 25 50 75 100 125 150 175 200 225 250 275 300 325 350
n
CV
Caranx ignobilis, SPC
Bodianus bilunulatus, BLG
Stegastes fasciolatus, BSM
Projected Sample Size Requirements, 2-stage StRS
0.00
0.10
0.20
0.30
0.40
0.50
0 50 100 150 200 250 300 350
n*
CV
FFS PHR FFS07 PHR07
2007 Naso unicornis
Sample Size (i.e., Costs)
Sur
vey
Preci
sion
2000-2005 Baseline Design Analysis
Investigating Design Performance in Hawaii
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