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Appendix
C
Fisheries Case Studies
This appendix discusses case histories for three important recre-
ational fisheries in three different U.S. regions. These fisheries were
chosen because they represent a range of scale and management
intensity. (These histories were drawn from information available during
the summer of 2005; therefore, they may no longer represent the current
conditions. Nonetheless, these examples are useful to the larger dis-
cussion.) The case history for lingcod (Ophiodon elongatus) represents a
large-scale, federal stock assessment with coastwide management goals
set by the Pacific Fishery Management Council (PFMC); however, in-
season management is conducted by individual state agencies. The case
history for red snapper (Lutjanus campechanus) in the Gulf of Mexico
represents a large-scale fishery conducted in federal waters. Although
management goals are annual, in-season management has failed in this
fishery, and the Gulf of Mexico Fishery Management Council (GMFMC)
actually evaluates management on the same schedule as the stock
assessment--every three to five years. The case history for striped bass
(Morone saxatilis) represents an east coast fishery conducted primarily in
state waters with a coastwide stock assessment and annual management
objectives set by a regional advisory board with individual states over-
seeing annual management.
161
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162 APPENDIX C
LINGCOD
Life History
The lingcod (Figure C.1) is the largest member of the greenling fam-
ily. They occur from Kodiak Island, Alaska, to Baja California, Mexico,
in depths to 475 meters (m) (1,558 feet [ft]) but usually shallower than
300 m (984 ft) in rocky habitats and kelp beds. They attain a maximum
length of about 1.5 m (5 ft) and can weigh over 31.8 kilograms (kg) (70
pounds [lbs]). They are voracious predators on fish, shellfish, and
octopus. Lingcod are considered non-migratory; although, tag data show
some individuals may move great distances. Males and females tend to
be separated by depth, with females preferring deeper water. Males guard
egg clutches ("nests") until hatching, generally 711 weeks. During this
period, the males are territorial and very susceptible to harvest. If the
males are removed from the nest, other organisms consume the eggs. The
maximum published age is 20; however, lingcod have been aged to 26 in
Alaska.1 Richards et al. (1990) examine length and maturity relationships
of lingcod from three areas in British Columbia and find that males begin
to mature at 0.50 m (1.64 ft) and are all mature at 0.70 m (2.30 ft), and
females begin to mature at 0.50 m (1.64 ft) and are all mature at 0.75 m
(2.46 ft).
Current Stock Status and Management Authority
Lingcod along the U.S. west coast are managed as two distinct
stocks: the Lingcod-North stock (Washington and Oregon) and the
Lingcod-South stock (California). (Alaskan lingcod are not considered in
this case study.) Both stocks are listed as overfished and are subject to a
rebuilding plan. The latest assessment indicates that the lingcod stock has
achieved its rebuilding objective of B40% in the north (actually 28 per-
2
cent above B40%) but was at B31% in the south. PFMC sets quotas
1 Personal communication, Kristen Munk, Alaska Department of Fish and
Game, Juneau.
2 B represents the stock biomass (weight of a population of fish). The subscript
represents the percent of the stock relative to its unfished biomass. B40%, a proxy
for BMSY, is the biomass needed to sustain maximum sustainable yield (40
percent of the unfished biomass).
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APPENDIX C 163
FIGURE C.1 A young deckhand with a tagged lingcod (photo used with
permission from Charlie Wilber).
for lingcod fisheries, with in-season management by the individual
states.
Fishery Characteristics
There are both recreational and commercial fisheries for lingcod,
with recreational being particularly important in the southern area. In
2002, anglers landed 577 metric tons (mt) (1.3 million lbs) out of a total
optimum yield (OY) of 577 mt (1.3 million lbs) and a total postseason
catch estimated at 779 mt (1.7 million lbs) (51 percent over the
coastwide OY). Private vessels and rental vessels accounted for most of
the recreational catch, with the majority of the catch coming from
Oregon and northern California. Charter and party boats accounted for 7
percent of recreational catch in Washington, 43 percent in Oregon, 32
percent in northern California, and 14 percent in southern California.
Commercial lingcod fisheries along the west coast have been pre-
dominately trawl fisheries. Recently, restrictions in trawl fisheries have
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164 APPENDIX C
increased; therefore, roughly half of the commercial landings are now
from hook and line. Coastwide commercial landings totaled 223 mt
(492,000 lbs) in 2002 (Jagielo et al., 2003).
Since 2004, PFMC has set two separate recreational fishery quotas
for the two stocks. In 2003, California exceeded the entire west coast
limit for lingcod that resulted in a coastwide late-season closure.
Consequently, in 2004, PFMC set separate state fishery targets (Pacific
Fishery Management Council, 2004); California is given statewide
recreational allocation, and Oregon and Washington are given a
combined recreational allocation. The recreational sector took 63 percent
of the total catch, and the California recreational fishery took 61 percent
of the coastwide recreational catch in 2004. In 2005, the recreational
catch guidelines were 422 mt (930,000 lbs) for California, 151 mt
(333,000 lbs) for Oregon, and 83 mt (183,000 lbs) for Washington. Size
limits, bag limits, depth limits, and seasons vary by state and within
state; in-season management action may be taken to prevent exceeding
annual quotas.
Oregon has committed to updating anglers on allowable catches on a
monthly basis during the season so data on catch are required in a timely
fashion. In-season changes are made in July if it appears that current
catch rates will cause an in-season closure.
Recreational Survey Methods
The recreational fishery survey for lingcod is multifaceted. The
Recreational Fisheries Information Network (RecFIN) program stores
the survey data, the Marine Recreational Fisheries Statistics Survey
(MRFSS) is used for the historical California data, field-intercept surveys
are administered by the Pacific States Marine Fisheries Commission, and
a random telephone survey of the coastal population is administered by a
National Marine Fisheries Service (NMFS) contract. Additionally, there
is the California Charter and Party Fishing Vessel effort survey (since
2001), the California Recreational Fisheries Survey (CRFS) (replaced the
MRFSS in 2004), the Oregon Recreational Boat Survey, and Washington
State's Ocean Sampling Program (OSP). The Oregon Recreational Boat
Survey includes a field-intercept survey for effort and catch of private
and rental boats and party and charter boats and a telephone survey of
license holders for shore and estuary boat anglers, and OSP includes a
seasonal exit count of vessels and an intercept sampling of catch.
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APPENDIX C 165
Stock Assessment Method
The catch-at-age model used is a multiple-fleet, age-, and sex-
structured model implemented in Coleraine (Jagielo et al., 2003). Cole-
raine is a general age-structured model used for fish-stock assessment
developed by Hilborn and colleagues; a manual and other information
are available through the University of Washington (2004). Several
weaknesses with the model include the lack of a recreational fishery
catch per unit effort (CPUE) index. Although recreational catch accounts
for most of the removals, recreational CPUE is problematic because
catch rates may be affected by variable target species, undocumented
search time, unreported discards, unknown spatial effort shifts, and bag
limit effects (Jagielo et al., 2003). These problems will be exacerbated by
changes in management, such as depth and seasonal closures.
Information on discard and discard mortality is difficult to estimate but is
important to the model. According to Jagielo et al. (2003):
MRFSS has collected B1 (reported by angler to be dead)
and B2 (reported by angler to be alive) catches since
1980. Estimates of lingcod discarded alive have in-
creased substantially in response to (1) management
changes in 1998 (the size limit increased from 22 to 24
inches) and (2) a seasonal closure in California waters
beginning in 2000... It is interesting to note that esti-
mates of fish discarded dead have decreased over time.
Estimated live lingcod discarded in southern California
was 306,000 fish in 2002. This compares to a total
landed catch of 25,000 fish. [Washington Department of
Fish and Wildlife] began collecting discard information
from the recreational fishery in 2002 and estimated that
57 percent of the catch was discarded. [Washington
Department of Fish and Wildlife] does not collect infor-
mation on the portion of the catch discarded live or dead.
Based on an earlier study..., the PFMC Groundfish
Management Team used a 20 percent inflation factor to
adjust landed catch to account for unobserved lingcod
mortality in the commercial fishery beginning in 2002.
Data collected by the Groundfish Observer program in
20012002 estimated that the percent discard of total
observed catch was 78.8 percent. Because lingcod lack a
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166 APPENDIX C
swim bladder, it is likely that there is a relatively good
survival rate for these fish.
In the models projecting future catch, both Washington and Oregon use 5
percent mortality for live discards, but this mortality is not incorporated
into the current year assessment. There have been no formal studies of
lingcod hooking mortality.
Removals
Recreational catch data for the lingcod assessment come from a
variety of sources. For California, the RecFIN database (including the
MRFSS) was used for 19801989 and 19932003. Oregon catch data
were provided by the Oregon Department of Fish and Wildlife. Wash-
ington catch data were obtained from the Washington Department of
Fish and Wildlife (WDFW) OSP. Beginning in 2004, CRFS has been
used in place of the MRFSS for California. Commercial catch data were
compiled from agency reports and personal communication for all years
preceding 1981. The Pacific Coast Fisheries Information Network
(PacFIN) database was queried for catch information in subsequent
years.
Demographics
The Lingcod-North population age data are available for recreational
fisheries for 1980 and 19862002 with sample sizes ranging from 226 to
1098. The Lingcod-South population age data are available for
recreational fisheries for 19921998 and 20002002 with sample sizes
ranging from 48 to 545. Weight is estimated using a von Bertalanffy
growth equation, which is updated periodically. Other sources used for
size and age data include the commercial fisheries, the triennial trawl
shelf survey, and the WDFW Cape Flattery Tag survey. The Stock
Assessment Review Panel (STAR Panel) suggested that more emphasis
needs to be placed on collecting biological data to improve fishery age,
length, and sex samples sizes and to improve geographic coverage
(Pacific Fishery Management Council, 2003).
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APPENDIX C 167
Abundance Indices
The 2003 stock assessment for west coast lingcod uses commercial
fishery and fishery-independent indices of abundance, such as the fol-
lowing:
· NMFS Triennial Shelf Trawl Survey (biomass and associated
coefficients of variation) (This survey does not cover rocky
habitat, a prime lingcod habitat and therefore has a habitat bias.)
· WDFW Cape Flattery Tag Survey (length composition used as a
recruitment index)
· Trawl fishery logbook CPUE index
Another index considered but not used is recreational CPUE, which
was not used because of high index variability, lack of a discernable
index trend, implausible temporal changes in abundance, and unresolved
input data assumptions. Data from Washington did not contain discard
information so there was no way to convert its data to total catch, which
is important in estimating a CPUE trend. Also, Jagielo et al. (2003) find
that "recreational CPUE data sets are often problematic for use as
unbiased indices of abundance because catch rates may be affected by
(1) variable target species by boat, (2) undocumented search time, (3)
unreported discards, (4) unknown spatial effort shifts, and (5) bag limit
effects." Because the recreational fishery now takes over 70 percent of
the total catch of lingcod, the lack of an abundance index for this sector
will continue to be problematic.
Recommendations for Data Collection
Jagielo et al. (2003) provide the following recommendations regard-
ing data collection for this resource:
· Improve fishery age-structure sampling size and geographic
coverage
· Conduct more frequent and synoptic fishery-independent surveys
for stock indices and recruitment index
· Analyze CPUE on a reef-specific basis for evaluation of an index
of abundance
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168 APPENDIX C
· Enumerate at-sea discards and mortality of released
recreational fish coastwide to account for total mortality
Economic and Social Information
Commercial landings of lingcod have been reduced greatly in recent
years by management actions. In 2004, 166 mt (366,000 lbs) of
commercial lingcod were landed on the west coast for an ex-vessel
(dockside) value of $412,000. No data are specifically available on the
economic value of the recreational fishery for lingcod. In 2003, there
were 1,283 angler trips directed for groundfish on the west coast and, of
these, 325 were charter trips, and 958 were private vessel trips.
RED SNAPPER
Life History
Red snapper (Figure C.2) are found along the Atlantic coast of North
America from North Carolina to the Florida Keys and along the Gulf of
Mexico from Florida to the Yucatan peninsula of Mexico (Robins et al.,
1986). Adults are found in submarine gullies and depressions; over coral
reefs, rock outcrops, and gravel bottoms; and are associated with oil rigs
and other artificial structures (Gulf of Mexico Fishery Management
Council, 2003). Eggs and larvae are pelagic while juveniles are found
associated with bottom features or over barren bottom. Spawning occurs
during the summer and fall over firm sand bottom with little relief away
from reefs. Adult females mature as early as two years, and most are
mature by four years (Schirripa and Legault, 1999). Red snapper have
been aged up to 53 years, but most caught by the directed fishery are 2 to
4 years old (Wilson and Nieland, 2001).
Current Stock Status and Management Authority
The red snapper stock is in an overfished condition and continues to
undergo overfishing (Gulf of Mexico Fishery Management Council,
2005a). This stock has been overfished since at least 1988. Currently,
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APPENDIX C 169
FIGURE C.2 Anglers with their red snapper (photo used with permis-
sion from Jon G. Sutinen).
it is under a rebuilding plan to end overfishing in 20092010 and to
rebuild the stock to BMSY by 2032 (Gulf of Mexico Fishery Management
Council, 2004a). The current population is now dominated by young
fish, creating a low spawning potential ratio. In addition to the mortality
associated with shrimp trawl bycatch, the population shows signs of
overharvest in the directed fisheries, with truncated ages.3
GMFMC establishes management plans and regulates the recrea-
tional red snapper fishery in U.S. federal waters. In the Gulf of Mexico,
bag and minimum size limits and area and season closures are used.
Individual states generally set regulations in state waters to comply with
the federal regulations. However, Texas has a different recreational size
limit and does not have a closed season to recreational fishing. Florida
opens the recreational red snapper fishing season six days earlier than in
federal waters.
3 Personal communication, Felicia Coleman, Florida State University, Talla-
hassee.
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170 APPENDIX C
Fishery Characteristics
The red snapper fishery occurs predominately in federal waters. Red
snapper have supported an important commercial fishery in the Gulf of
Mexico for more than a century, with 6,400 mt (14.1 million lbs) landed
in 1900. Documentation of the recreational fishery began on a regular
basis in 1981 with the MRFSS.
According to Schirripa (1999):
Management of the red snapper resource has meant
dividing the allowable fishing mortality between two
competing fisheries: the directed fishery, which consists
of a commercial and a recreational sector, and the
undirected shrimp fishery. The shrimp fleet harvests age
0 and 1 red snapper in the form of bycatch. These
vessels use bottom trawls to harvest shrimp, which share
a propensity for the same habitat as juvenile red snapper.
Although the discarded catch associated with shrimp
trawls is not counted toward the [total allowable catch],
it is included in the stock assessment as part of the total
fishing mortality. In 1991, turtle excluder devices (TED)
were mandated for all offshore shrimp boats operating in
the Gulf of Mexico. In 1998 all offshore shrimp boats
fishing in the western Gulf of Mexico were required to
use some form of bycatch reduction device (BRD) as
well. Several types of BRDs have been "certified" by the
U.S. fishery management authorities as reducing red
snapper bycatch by 30 percent to 50 percent with an
approximate 4 percent to 6 percent reduction in shrimp
loss.
However, at present, BRDs are estimated to reduce red snapper bycatch
by only 11.7 percent (Foster, 2004). Further reductions in overall red
snapper bycatch may have occurred as a result of reductions in shrimping
effort due to the depressed economic condition of the shrimp fishery and
due to the loss of shrimp vessels and processors from Hurricanes Katrina
and Rita in 2005.4
Red snapper is the most popular offshore recreational finfish fishery
in the northern and western Gulf of Mexico with 49 percent of the di-
4Personal communication, Steven Atran, GMFMC, Tampa, Florida.
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APPENDIX C 171
rected fishery's total allowable catch (2,041 mt [4.5 million lbs] in 2005)
allocated to the recreational sector. Fishing occurs off the coasts of
Florida, Alabama, Mississippi, Louisiana, and Texas. More than 70
percent of the recreational catch is taken by the for-hire sector (Gulf of
Mexico Fishery Management Council, 2004a). In addition to landed
catch, more than half of all recreationally caught red snapper are released
because of regulatory limits; release mortality for the recreational fishery
is estimated to range from 15 to 40 percent (Gulf of Mexico Fishery
Management Council, 2004b; Table C.1). Red snapper is listed as
overfished; therefore, staying within the total allowable catch is
particularly important (Gulf of Mexico Fishery Management Council,
2005a,b). During the 1990s and early 2000s, the recreational sector
exceeded its allocation 10 out of 12 years, often significantly (Gulf of
Mexico Fishery Management Council, 2004b). In response to such
frequent and large overruns, Congress, in the Sustainable Fisheries Act
of 1996, mandated that the recreational red snapper fishery in the Gulf of
Mexico be managed in-season with a quota and that the fishery be closed
when the quota is reached.
In-season management was attempted during 19971999 using
extrapolation of available data (Gulf of Mexico Fishery Management
Council, 2005b). During this period, the annual recreational catch was
based on the MRFSS, the Texas Parks and Wildlife Department's
(TPWD) coastal sport fishing survey, and NMFS's head boat survey;
discard information was collected in the MRFSS only. In-season
management was difficult because the recreational catch data are not
available for several months after collection. NMFS made projections of
the recreational catch using average catch data from the previous two
years from all three surveys. The data from the surveys done by Texas
and NMFS were not available in-season. When available, the MRFSS
data from the first two months of the current year replaced the projection
for those two months, and this continued as current data became
available but was limited to the first six months of the year; the last six
months were estimated using previous years' data (Gulf of Mexico
Fishery Management Council, 2005a). The recreational fishery was
closed in-season with three weeks notice on November 27, 1997;
September 30, 1998; and August 29, 1999; when the recreational sector
was projected to have reached its share of the total allowable catch.
These projections were not accurate, and the recreational sector
overharvested its allocation by 20 percent in 1997, 29 percent in 1998,
and 23 percent in 1999. In 2000, GMFMC abandoned in-season man-
agement of the recreational sector and moved to a shorter season, larger
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174 APPENDIX C
assessments where the number of fish discarded owing to minimum size
limits was determined by the probabilistic method of Goodyear (1997)
and then used along with indices of abundance in an age-structured
model (ASAP or Virtual Population Analysis [VPA]). The discards from
the recreational and commercial sectors during the open season were
assumed to occur predominantly due to the regulations on minimum size.
They were computed on a seasonal rather than annual basis to better
accommodate the rapid growth exhibited by younger red snapper.
Recreational catch data, recreational effort data, and age data from
recreational samples are all inputs into this model. Since 1981, the
annual recreational catch and effort estimates have been based on the
MRFSS, TPWD's coastal sport fishing survey, and the NMFS head boat
survey.
Removals
As stated in the Southeast Data, Assessment, and Review (SEDAR):
Commercial landings statistics are the quantities and
value of seafood products sold to established (licensed)
wholesale and retail seafood dealers. Currently, these
data are collected by trip ticket programs managed by
the state fishery agencies in Florida, Alabama, and
Louisiana [Gulf of Mexico Fishery Management
Council, 2004b]. Dealers in Mississippi and Texas are
required to submit monthly reports that provide quantity
and value by species. Prior to the implementation of the
trip ticket programs, landings statistics were collected by
[NMFS] and state employees that visited the seafood
dealers monthly and recorded the quantities and value
purchased for each species for a calendar month. In
addition, the agents would assign an estimate of the type
of gear and fishing area where the landings were caught.
The Southeast Fisheries Science Center (SEFSC) has
maintained the commercial landings statistics (also
known as general canvass landings statistics) in a re-
gional database since the mid-1980s. The states provide
the landings statistics from their trip ticket or monthly
program to the SEFSC, and these data are summarized
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APPENDIX C 175
and maintained in the same format as the historical
general canvass data. (Gulf of Mexico Fishery Manage-
ment Council, 2004b)
Directed commercial fishery discards are recorded on discard forms pro-
vided as part of a mandatory logbook requirement.
Recreational data were compiled for the three following sources:
· The MRFSS (19811998) with some exceptions: (1) no wave 1
data in 1981, (2) no Texas boat mode in 19821984, (3) no
Texas data after 1986, and (4) no head boat sampling after 1985
· NMFS's Beaufort Laboratory head boat survey for all states after
1985
· TPWD's coastal sport fishing survey
Data on recreational discards were collected by the MRFSS but were
not available for Texas landings or for landings from head boats. Red
snapper catches from Texas only account for about 2 percent of the
annual recreational landings gulfwide.
Demographics
According to Schirripa and Legualt (1999):
Morphometric, growth, and other biological character-
istics of red snapper were evaluated using a composite of
length and other measurements of Gulf of Mexico red
snapper that have been collected during research and
monitoring programs through the years. The present
evaluation combined the data from prior analyses with
more recent observations from a variety of sources. A
description of the earlier data and sources are given in
Parrack (1986a, b) and Parrack and McClellan (1986),
who obtained the data and prepared computer files of the
various data sets. In addition, data collected during the
trip intercept portions of the [MRFSS]; the [NMFS] head
boat survey; and samples of commercial and recreational
catches collected as part of the Trip Interview Program
(TIP) of the State/Federal Cooperative Statistics Pro-
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176 APPENDIX C
gram provided additional data sources. A biological
profiles sampling program by the [NMFS] Panama City
(Florida) Laboratory provided additional observations of
growth and fecundity, as well as morphometrics. Addi-
tional data were provided from research programs at the
University of South Alabama, Louisiana State Univer-
sity, the University of West Florida, and the Louisiana
Universities Marine Consortium.
Currently, there are only very limited data on sizes of live discards from
the recreational sector. This is important because 60 percent of recre-
ational catches are discarded gulfwide (Gulf of Mexico Fishery
Management Council, 2004b).
Abundance Indices
Abundance indices include four fishery-dependent sources and three
fishery-independent sources. The fishery-dependent indices are the
commercial handline logbook data (directed and bycatch), including the
eastern and western Gulf jig fishery and bottom longline data; bycatch of
red snapper in shrimp trawl fishery (pre-1990 when bycatch could be
sold); the MRFSS and TPWD's coastal sport fishing survey's CPUE
data; and the head boat catch rates from the NMFS head boat survey. The
fishery-independent indices are the Spatial Ecological Analysis of
Megavertebrate Populations (SEAMAP) database for shrimp and
bottomfish, for ichthyoplankton (under consideration as an index), and
for reef fish (under consideration as an index).
Economic and Social Information
Red snapper is the most valuable commercial reef fish fishery in the
Gulf of Mexico, with dockside landings worth over $9 million in 1998.
Individual fishing quotas are being considered in the directed com-
mercial fishery.
Red snapper is also a very important recreational species in the Gulf
of Mexico. Shifts in the recreational sector have occurred over the past
two decades; in 1981 and 1982, private anglers landed about 65 percent
of the recreational red snapper reported. However, presently, the for-hire
sector lands over 70 percent of the recreational catch, with charter
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APPENDIX C 177
vessels taking most of this catch (Gulf of Mexico Fishery Management
Council, 2004b). There are an estimated 3,220 recreational for-hire
vessels in the Gulf of Mexico (Federal Register, 2002). GMFMC began
notice of a federal for-hire sector moratorium in November 1998. Initial
implementation occurred in 2001, but due to an error in the public notice,
the application process was reopened in 2003 and again in 2005. The
intent is to limit the for-hire sector to the March 29, 2001, participation
level. Currently, approximately 1,554 vessels are licensed to participate
in the moratorium for reef fish (Gulf of Mexico Fishery Management
Council, 2005c). Compliance with the federal licensing requirement has
increased with the development of the moratorium.
STRIPED BASS
Life History
The Atlantic striped bass (Figure C.3) is a migratory species that
ranges from the St. Lawrence River in Canada to the St. John's River in
Florida. (The west coast population of striped bass, resulting from a few
hundred fish introduced from the Navesink River in New Jersey to San
Francisco Bay in the 1880s and now occurring from southern California
to British Columbia, is not considered in this discussion.) This species
can live up to 30 years and spends most of its adult life either in coastal
estuaries or in the ocean, migrating north in the summer and south in the
winter. Striped bass are anadromous, and in the spring, adults ascend
rivers to spawn. Along the U.S. Atlantic coast, the major part of the
migratory stock originates in the Chesapeake Bay spawning areas, with
significant contributions from spawning grounds in the Hudson and
Delaware Rivers. Fertilized eggs and larvae drift downstream to nursery
areas in river deltas, inland portions of coastal sounds, and estuaries
where they mature into juveniles. The juveniles remain in these areas for
two to four years and then join the coastal migratory population. Females
are highly fecund producing 0.5 million eggs at six years of age and 3
million at 15 years of age.
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178 APPENDIX C
FIGURE C.3 Striped bass caught by young anglers in Maryland's Ches-
apeake Bay (photo used with permission from the National Oceanic and
Atmospheric Administration).
Current Stock Status and Management Authority
The striped bass population has been increasing steadily since 1982
and, in 2004, the population was estimated to be 11 million fish higher
than the average stock size for the previous five years and 23.8 percent
higher than the population in 2003. The 2003 year-class was estimated at
22 million fish at age 1 and is the largest year-class in the time series
(19822003). The most recent full stock assessment (Northeast Fisheries
Science Center, 2003) determined that, in 2002, the stock was not
overfished and that overfishing did not occur. However, the Atlantic
Striped Bass Technical Committee reported difficulty in determining if
overfishing was occurring in 2003 because of divergent patterns in
fishing mortality estimates from VPA and analysis of tagging data. The
next scheduled full stock assessment will be in 2007.
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APPENDIX C 179
The implementation of the fishery management plan is mandatory
under the Atlantic Striped Bass Conservation Act (P.L. 98-613). The
Atlantic States Marine Fisheries Commission's (ASMFC) Striped Bass
Management Board and Striped Bass Plan Review Team are responsible
for monitoring the implementation of the fishery management plan.
States are granted flexibility to deviate from the standards in the fishery
management plan by submitting proposals for review by the ASMFC
Striped Bass Technical Committee and Advisory Panel with approval
from the ASMFC Management Board.
Fishery Characteristics
The fishery is limited to state waters (no catch allowed in federal
waters). Much of the catch occurs in estuarine waters, but the MRFSS is
limited to saltwater and, thus, not all estuarine landings are surveyed. In
2003, the total catch, including landings and discards, was estimated to
be 4.7 million fish. The 2003 catch was above the 19962003 average of
4.0 million. Catch (2.4 million fish) and discards (1.2 million fish) from
the recreational sector accounted for 76 percent of the total 2003 catch.
Private and rental boats account for 80 percent of the recreational catch.
Maryland accounted for the largest portion of the recreational fishery
with 21.8 percent of total recreational landings, followed by Massa-
chusetts (16.9 percent), Virginia (16.7 percent), New Jersey (16.3 per-
cent), and New York (13 percent). The remaining states each landed 5
percent or less of the total recreational landings. In 2004, Massachusetts
took 17 percent of the landed catch, followed by North Carolina and
Maryland (Munger et al., 2005).
Commercial catch (0.86 million fish) and discards (0.27 million fish)
accounted for 24 percent of the total 2003 catch. Maryland commercial
fisheries caught 50.8 percent of the total commercial landings, followed
by Virginia (18.7 percent), the Potomac River Fisheries Commission (9.6
percent), New York (7.9 percent), and Massachusetts (6.4 percent). The
remaining states each accounted for 4 percent or less of the total
commercial landings.
As of January 1, 2004, all states are required to implement a two-fish
bag limit with a minimum size of at least 0.7 m (28 in) for their
recreational fisheries. Chesapeake Bay fisheries, AlbemarleRoanoke
fisheries, and states with approved conservation equivalency proposals
are exempt from these rules. The first two areas have more conservative
fishing mortality targets than those set by ASMFC and are allowed to set
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180 APPENDIX C
their own seasons, harvest caps, bag limits, and size limits as long as
their total catches stay below their targets.
Recreational Survey Methods
The MRFSS is used as a basis survey in most states. The shore and
private and rental boat fishing modes are surveyed using the MRFSS
coastal household telephone survey and the MRFSS intercept survey.
The for-hire sector is surveyed using the Vessel Frame Telephone
Survey, the Vessel Effort Validation Survey, and the MRFSS access-
point intercept survey.
Jurisdictions with significant recreational fisheries (Massachusetts,
Rhode Island, Connecticut, New York, New Jersey, Maryland, Virginia,
and the Potomac River Fisheries Commission) are required to follow
specific guidelines for supplementing the MRFSS collection of catch
composition data and catch and effort information from these fisheries to
achieve a 20 percent coefficient of variation, or propose specialized
striped bass surveys to better assess recreational catch.
Stock Assessment Method
The striped bass population dynamics are modeled using an
ADAPTVPA5 model and an integrated catch-at-age model. Both
models consist of a sequential population model which incorporates
catch-at-age time-series data and research vessel survey information. The
major differences between the two methods are that the integrated catch-
at-age model assumes that the catch-at-age data are measured with error,
and separability patterns are estimated as parameters. Data from eight
tagging programs, which are conducted by the U.S. Fish and Wildlife
Service Cooperative Striped Bass Tagging Program and have been in
progress for at least 11 years, were used to provide alternate estimates of
fishing mortality.
5ADAPTVPA models are used extensively for fisheries stock assessments.
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APPENDIX C 181
Removals
Given that the recreational fishery accounts for the largest portion of
the striped bass catches, the MRFSS data are essential for accounting for
total removals and for developing the catch-at-age information for the
stock assessment. Total landings from the recreational striped bass fish-
ery are calculated using type A+B1 records from the MRFSS. In 2003,
these landings were estimated to be 2.4 million fish or 11,486 mt (25.3
million lb), with 80 percent accounted for by the private and rental mode
in the MRFSS. Type B2 catch was estimated at 14.6 million fish. Size-at-
age information on these discards indicate that it is the smaller fish that
are generally released (peak at age 3; age range is 113 years). An 8
percent hooking mortality rate is assumed for recreational discards,
resulting in an estimated loss of 1.2 million fish in 2003. Diodati and
Richards (1996) examined mortality of striped bass hooked and released
in saltwater. Predicted annual mortality averaged 9 percent and ranged
from 3 percent under ideal conditions to 26 percent for the worst set of
conditions. They found that surviving hooked fish had significantly
lower physical condition factors than fish that had not been hooked.
The 2004 Striped Bass Stock Assessment Technical Committee ex-
pressed concern that there was considerable error in the catch produced
by the MRFSS in 2003. The MRFSS estimated increases in some of the
waves even though fishing effort was reported to have decreased due to
hurricanes. On the other hand, there was also concern that the harvest
had been underestimated because the winter fisheries (wave 1) in North
Carolina and Virginia were not covered.
Estimates of commercial discards for striped bass rely on direct
measurements from fisheries in the Hudson River Estuary and Delaware
Bay and River and tagging information for the other areas. Since 1982,
estimates for the other areas have been based on the ratio of tags reported
from the discarded fish in the commercial fishery to tags reported from
discarded fish in the recreational fishery, scaled by total recreational
discards.
Demographics
Length and weight measurements usually are recorded by intercept
interviewers for type A fish catch records. These data have been used to
develop catch-at-length and catch-at-age estimates. Length frequencies
of recreational landings for striped bass were based on a combination of
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182 APPENDIX C
the MRFSS length samples and volunteer angler logbooks. The age
compositions of the recreational catch for each state were estimated
using state specific agelength keys. Lengths from the volunteer angler
logbooks and the American Littoral Society data were used to estimate
the age composition of the recreational discards.
For the striped bass assessment, mean weights-at-age in the 2003
catch were determined from Maine and New Hampshire recreational
harvest and discards; Massachusetts recreational and commercial catch;
Rhode Island recreational and commercial catch; Connecticut recre-
ational catch; New York recreational catch and commercial landings;
New Jersey recreational catch; and Delaware, Maryland, Virginia, and
North Carolina recreational and commercial catches.
Abundance Indices
Indices of abundance for striped bass represent both fishery-
independent and fishery-dependent sources. There are seven sets of
fishery-independent indices used for the adult population: the Maryland
gillnet survey of the spawning population (ages 213+), Virginia pound
net CPUE (ages 213+), New York ocean haul seine (ages 313+),
Northeast Fisheries Science Center spring inshore survey (ages 313+),
and three age-aggregated trawl indices from Connecticut (ages 26),
New Jersey (ages 2+), and Delaware (ages 27). Juvenile surveys
produce indices of young-of-year (age 0) in Maryland, Virginia, New
York, and New Jersey as well as age 1 indices for Maryland and Long
Island, New York.
The fishery-dependent indices represent a mix of commercial and
recreational fishing data, including the Massachusetts commercial catch
per trip (ages 713+) and the Connecticut volunteer angler catch per trip
(ages 213+). Altogether, these data sources represent 55 age-specific
indices that are used in the ADAPTVPA model.
The MRFSS estimates of catch rate are not used in the striped bass
assessment, although the time series of these catch rates have been
compared with trends from VPA by the technical committee and found
to be similar in recent years.
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APPENDIX C 183
Economic and Social Information
Amendment 6 of the Interstate Fisheries Management Plan for At-
lantic Striped Bass states that the Atlantic Coast Cooperative Statistics
Program will require the collection of baseline social and economic data
on all recreational fisheries through add-ons to existing recreational catch
and effort surveys (Atlantic States Marine Fisheries Commission, 2003).
This information is defined in the Atlantic Coast Cooperative Statistics
Program documents as follows:
Economic information includes information on market
conditions in commercial fisheries (price and value
information), as well as complementary information on
recreational fisheries. Social sciences information is
typically broader sources of information specific to
commercial and recreational fishermen, their families,
and the fishing community in general. For many man-
aged fisheries economic and social sciences information
is not available and is provided in an informal manner by
fishermen during public comment periods. At times, this
information is viewed as anecdotal and may be difficult
to use in the fishery management decision-making
process. (Atlantic States Marine Fisheries Com-mission,
2003)
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Representative terms from entire chapter:
nrc national
