Tab C, No. 3
Revised 05/25/06
Summary of the
Gulf of Mexico Fishery Management Council
Ad Hoc Shrimp Effort Workgroup
NMFS Laboratory – Galveston, TX
April 27-28, 2006
ATTENDANCE
Panel Members
Others
Jim Nance, Chair
Walter Keithly, Vice Chair
Charles Caillouet, Jr.
John Cole
Wilson Gaidry, III
Benny Gallaway
Wade Griffin
Rick Hart
Sherry Larkin
Michael Travis
Corky Perret, Council Representative
Assane Diagne, Council Staff
Chris Dorsett, Ocean Conservancy
Elizabeth Fetherston, Ocean Conservancy
Vishwanie Maharaj, Environmental Defense
Robert Mc Farlane, Consultant
Richard Moore, Pisces
Russell O’Brien, Gulf S Atlantic Foundation
Michelle Padgett, NMFS
Frank Patella, FS
Ralph Rayburn, Texas Sea Grant
Charlotte Schiaffo, Council Staff
Louis Stephenson, Fisherman
The Ad Hoc Shrimp Effort Workgroup (AHSEWG) met to discuss shrimp effort in the
Gulf of Mexico. The meeting was held on April 27-28, 2006 at the National Marine
Fisheries Services Laboratory in Galveston, Texas. Corky Perret was the Council
representative.
Panel members discussed the Council’s charge to the workgroup and indicated that
optimal yield (OY) is not separated into a state waters OY and a federal waters OY. Thus,
the group would have to devise a method for the determination of OY in the exclusive
economic zone (EEZ). The Council member in attendance noted that the group should
also consider the links existing between the state and federal components. Members also
indicated that, though not explicitly mentioned in the Council’s charge to the group, the
focus will be on:
1- Penaid shrimp (white, brown, and pink shrimp); and 2- net economic benefits. Several
members noted that social benefits would be more difficult to assess. The Council
member concurred and indicated that the focus should be on economic benefits. Some
members suggested that the term “economic benefits” needed to be more clearly defined.
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That is, is the Council only referring to maximum economic profits (i.e. MEY), which is
a narrow but common definition of economic benefits, or should other economic factors
such as employment and the distribution of economic benefits be taken into account?
Jim Nance presented background information on shrimp effort in the Gulf of Mexico.
During his presentation, he discussed trends in shrimp effort, data collection, estimation
procedures, and possible sources of bias. He also discussed changes in management and
data collection and listed the type of data collected. The declining trend observed in the
percentage of trips interviewed was noted. The Council representative inquired about the
reasons behind the decrease in the percentage of trips interviewed; currently, about 2 to 3
percent of the trips are interviewed. Panel members indicated that it was mainly due to an
increase in the workload of port agents and to a lower cooperation by shrimpers at the
dock.
Benny Gallaway presented data collected through the electronic logbook (ELB) project
and discussed changes in shrimp effort in the Gulf of Mexico. His presentation
highlighted and explained challenges associated with effort calculation including, the
dispersion of the fleet, the non-uniform distribution of shrimp species, and, the need to
compute effort for small areas on a monthly basis. The discussion on the ELB data was
supported by computer animations tracking sampled vessels’ location and trawling
activities. Benny Gallaway compared effort assignments reported by NMFS port agents
with ELB-recorded data. He indicated that there were discrepancies between the recorded
data and assignments reported by port agents. Further, he noted that there were
systematic biases in the information reported by port agents. He also indicated that
offshore shrimp effort has significantly declined in recent years; current offshore effort
levels approximate levels recorded in the 1960’s.
Wade Griffin’s presentation focused on the effort estimation for the Gulf of Mexico
shrimp fleet. He presented changes in relative fishing power indices (RFP) and discussed
the distribution of interviewed trips. He then discussed several estimation techniques. He
compared his effort, catch per unit effort (CPUE), and revenue per unit effort (RPUE)
estimates to the ones obtained by NMFS. He noted that due to a decrease in real (inflation
adjusted) shrimp prices, a declining trend has been observed in real revenues per unit
effort. In response to a question about costs, Wade Griffin indicated that, in the past, he
evaluated the impact of changes in operating costs. He also noted that new data were
available and that he would conduct an updated cost analysis.
Following the presentations, the workgroup discussed possible ways to partition Gulf
waters into state waters and EEZ. Members indicated that data are currently collected by
statistical area and depth zone not by state versus EEZ. They also noted that the
COLREG line only divides Gulf waters into inshore and offshore waters. It was indicated
that previous work by Griffin and Travis could serve as a starting point to discuss the
partition of Gulf waters. The group evaluated the method proposed by Griffin and Travis
and agreed to use a modified version for the partitioning of Gulf waters. Several members
indicated that the Council’s charge may be difficult to meet because MSY for federal
waters is tied to what happens in state waters. For example, effort restrictions in federal
waters would lead to effort increases in state waters. Members then discussed possible
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impacts of effort restrictions in federal waters on the size distribution of shrimp harvests
and their associated impact on processing operations.
Alternative modeling approaches were then considered. Workgroup members discussed
the use of Nance’s pooled data approach and Griffin’s GLM models (with or without a
series of dummy variables accounting for gear, year, and species variations). It was
indicated that the pooled data model was the approach selected in the recent red snapper
stock assessment. The group indicated that, in accordance with Shrimp Amendment 13,
optimal yield (OY) will be set equal to maximum sustainable yield (MSY). Members
noted that effort will be measured in days fished. In addition, they recommended that
effort data, starting in 2004, be refined by including an adjustment factor based on
electronic logbook proportions. To capture species effects, the group suggested pooling
the data in three seasons. Due to management changes enacted prior to 1981 and
significant changes to the data collection system from 1976-1980, several group members
suggested that the evaluation should use a data series covering the period 1981 to present.
Some members indicated that it would also be informative to conduct the analysis
starting from 1960. Workgroup members noted that maximum benefits will vary when
operating costs or shrimp prices change. Members agreed that analyses based on the two
alternative modeling approaches (Pooled Effort and GLM Effort models) will be
conducted. Estimates derived will then be compared.
Prior to discussing work assignments among its members, the group indicated that
activities will be monitored by the whole group and that analysis results will be evaluated
by all members. Small working teams were suggested to tackle catch per unit effort
issues, effort calculations, and MSY estimation.
Unanimously, the group indicated that given the amount of work to be completed, the
second meeting scheduled for the end of May 2006 had to be postponed. Postponing the
meeting will also allow to obtain clarification from the Council regarding the nature of
the group’s charge.
Concerning the relationship between red snapper and shrimp effort, the group indicated it
will comment on research results (Dr. Diamond’s research) once they become available.
The group indicated that red snapper issues were not mentioned in the Council’s charge.
Group members discussed data needs and indicated that with the exception of Alabama
data for the last three months of 2005, everything was available.
Jim Nance, Chair of the workgroup indicated that he will attend the Council‘s June
meeting and will present a report on the shrimp effort group’s activities and relay the
observations made by members.
The meeting was adjourned at 11:00 a.m.
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