1. Acceptable Biological Catch calculations for
Tier 3 Gulf of Mexico reef fish species
Gulf of Mexico Fishery Management Council
SSC Meeting August 2013
ABC Calculations 1/31
2. Background
MSA reathorization requires specification of
ABCs, ACLs, AMs for federally managed
stocks*
Implemented in Generic ACL Amendment
(GMFMC 2011)
Many stocks/species without stock
assessment (i.e., data poor)
ABCs for Tier 3 stocks set using historical
landings
Commercial
For-hire
Recreational
ABC Calculations 2/31
3. Data Improvements
Recreational data improved since
implementation of Generic ACL Amendment
(i.e., MRFSS –> MRIP)
Recreational landings estimates have been
re-estimated (MRIP program) 2004 - 2011
MRFSS (1986 - 2003) adjusted using MRIP
ratio estimators (MRIP Calibration
Workshop)
Commercial, headboat, and TPWD data
updated based on additional QA/QC
Data-poor ABCs and OFLs should be
re-calculated based on MRIP
ABC Calculations 3/31
4. MRIP Data 2004 - present
Objective: To provide more detailed, timely,
and reliable estimates of marine recreational
fishing catch and effort
MRIP estimates are available from 2004 -
present. These represent the best available
scientific data
This Amendment considers MRIP data from
2004-2008 to maintain consistent
methodology with Generic ACL Amendment
ABC Calculations 4/31
5. MRIP (1986 - 2003) = Recalibrated MRFSS
MFRSS historical data calibrated to MRIP
using ratio estimators
Methodology developed by SEFSC-SERO
group (August 2012) based on MRIP
workgroup recommendations
Apply ratio estimators based on ratio of means to
hind cast catch and variance estimates (1986 -
2003)
Developed MRIP/MRFSS ratio estimator using
MRIP and MRFSS data (2004 - 2011)
Hindcast catch and variance (1986 - 2003)
Ratios applied at each stratum (e.g., stock,
sub-region, year, wave)
Mean weights assigned to strata using SEFSC
weight estimation procedure
ABC Calculations 5/31
6. Ratio estimates
Apply ratio estimators based on ratio of means to hind
cast catch and variance estimates (1986 - 2003)
Ratios were applied at each stratum (species,
sub-region, year, wave, state, mode, and area) to the
A, B1, and B2 estimates and variances
1
1
when available, else use stock and subregion, stock
ABC Calculations 6/31
7. Overview of ABC Calculations
Used ABC control rule tier 3a
OFL = mean + 2 sd of annual landings
ABC = mean + 1 sd of annual landings
Same time series as specified in GMFMC
2011
Some species managed in groups (e.g.,
shallow-water grouper) established in
GMFMC 2011
ABC Calculations 7/31
8. Applicable Stocks
Species groups Individual species
Shallow-water grouper Gray snapper
Deep-water grouper Lane snapper
Tilefishes Cubera snapper
Jacks complex Hogfish
Mid-water snapper
ABC Calculations 8/31
11. Summary
Changes do not affect allowable recreational
effort
Changes do affect allowable commercial
harvest
Minimal impacts expected given the
small percent changes
MRIP may provide "official" re-estimates
prior to 2003 and thus may require additional
calibration
Consideration of other methods to establish
ABCs and ACLs for data-poor stocks may be
appropriate
ABC Calculations 11/31
