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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