903R95007 CBP/TRS 132/95
February 1995
Chesapeake Bay
Striped Bass
Fishery Management Plan
A J Lippson
Annual Progress Report
1994
Chesapeake Bay Program
Printed on Recycled Paper •
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Chesapeake Bay
Striped Bass
Fishery Management Plan
Annual Progress Report 1994
A Commitment Progress Report
from the Living Resources Subcommittee
Printed by the United States Environmental Protection Agency for the Chesapeake Bay Program
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TABLE OF CONTENTS
List of Tables and Figures i
Introduction : 1
Background • 1
Stock Status 3
Fishery Dependent Monitoring ..... 4
Maryland ; •••••• 4
Virginia 7
Potomac River 10
District of Columbia 11
Stock Monitoring 12
Maryland 12
Virginia . 16
District of Columbia 18
Cooperative Baywide Tagging Mortality Study 19
Enforcement Program 19
Maryland 19
Potomac River 20
District of Columbia 20
Water Quality and Habitat Issues 20
Conclusion * 21
References 30
Implementation Plan . . 32
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LIST OF TABLES AND FIGURES
Tables
1. Harvest of striped bass from Maryland by fishing year
and fishery (pounds) 22
2. Harvest of striped bass from Virginia by fishing year
and fishery (pounds) 22
3. Harvest of striped bass from the Potomac River by
fishing year and fishery (pounds) 22
4. Summary of the estimated striped bass losses from the
Maryland fisheries during the 1993/1994 season due to
illegal fishing, hook and release mortality, and
bycatch 23
5. Annual striped bass juvenile indices from Maryland and
Virginia, 1980-1994..... 24
6. Summary of hatchery striped bass recovered during
Maryland's Chesapeake Bay Stock Assessment surveys and
the coastal tagging survey, September - May 1993 25
Figures
1. Coastwide female striped bass spawning stock biomass
(SSB) 26
2. Length-frequency distributions of commercial pound net
catches from Fall 1970, Fall 1992, and Fall 1993 27
3. Age-frequency distributions of commercial drift gill
net catches, Winter 1981-82, Winter 1992-93, and Winter
1993-94 28
4. Length-frequency distributions of Maryland's
recreational harvest in 1979-1980, 1992, and 1993 29
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INTRODUCTION
Protection of the striped bass (Morone saxatilisl resource has
been guided by mandatory coastwide management under the auspices of
the Atlantic States Marine Fisheries Commission (ASMFC) since 1984.
A Chesapeake Bay fishery management plan (FMP) for striped bass was
developed and adopted in 1989 as part of the 1987 Chesapeake Bay
Agreement to address specific Chesapeake Bay issues and implement
ASMFC recommendations. As a result of coordinated,
interjurisdictional management efforts, the coastal striped bass
stock has been declared restored to historic levels as of January
1, 1995. This assessment is based on a projected spawning stock
biomass of mature Chesapeake Bay females exceeding the historical
high average (calculated for 1960-1972, ASMFC 1994). In addition,
estimated fishing mortality rates have been below current target
levels (F=0.25); juvenile recruitment has been excellent; and.
catch-per-unit-of-effort (CPUE) has been steadily increasing.
Since management plans need to be adaptive and flexible to
respond to the changing status of a particular resource, each FMP
is reviewed annually. The review provides a format for evaluating
the progress of a plan, updating management measures, and
incorporating new research information. The Striped Bass FMP has
been reviewed in reports in 1991, 1992, and 1993. The Striped Bass
FMP was also reviewed by an independent fisheries management plan
re-assessment task force during 1993 (Report to the Living
Resources Subcommittee, July, 1993). The Task Force concluded that
the Bay jurisdictions were in compliance with the FMP and
recommended that several actions be reevaluated. The FMP is
scheduled for a substantive review and revision in August 1995.
Another Chesapeake Bay committee, the Fisheries Target Setting Task
Force, will be developing specific targets for the striped bass
resource. The targets will follow ASMFC guidelines and compliance
requirements and will be included in either a revised FMP or an
amendment to the plan.
The following report is an overview of the background, fishery
dependent and independent monitoring of the fisheries, research,
regulations, and enforcement of the 1989 Striped Bass FMP during
1993/1994. .For specific information on the plan, refer to the 1989
Chesapeake Bay Striped Bass Management Plan.
BACKGROUND
Striped bass are one of the most sought after commercial and
recreational finfish in the Chesapeake Bay. Beginning in the mid-'
1970's, their abundance, especially in the Chesapeake Bay began to
decline, primarily due to overfishing. In 1981, the ASMFC
developed a coastwide management plan for striped bass. Although
the ASMFC recommended management strategies, they lacked regulatory
authority. As a result, states were at their own discretion to
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implement recommendations. Stock abundance and recruitment
continued to decline. Amendments were developed recommending more
stringent controls on the harvest of striped bass. Management
measures were aimed at protecting the 1982 and following year-
classes until females could spawn at least once. States along the
Atlantic coast from Maine to Virginia began implementing
restrictions on the harvest of striped bass. In 1984, Congress
passed legislation providing federal authority to close striped
bass fisheries in those states which did not comply with ASMFC
recommendations. In the Chesapeake Bay region, Maryland enacted a
moratorium on striped bass fishing on January 1, 1985 and Virginia
enacted size limits and seasonal restrictions. Four years later the
Potomac River and Virginia fisheries were closed.
As states along the coast began implementing harvest
restrictions, striped bass abundance began to improve. The criteria
for managing a fishery under a transitional regime were developed
in ASMFC Amendment #3. The Maryland juvenile index was selected for
monitoring recruitment and as a trigger for beginning a
transitional fishery. The transitional management regime specified
a target fishing rate (F) of 0.25 or approximately 20% of the legal
size fish being harvested. The Striped Bass Scientific and
Statistics Committee agreed that an F=0.25 would provide a low
level of harvest while allowing the stock to rebuild. In 1989, the
Maryland juvenile index was the highest value since 1970 and
triggered the beginning of a transitional management regime. The
ASMFC established measures to control fishing along the coast
through combinations of size limits, seasons and creel limits.
Monitoring fishing levels and implementing research . were
accomplished through state programs approved by ASMFC. In the
Chesapeake region, limited recreational and commercial fisheries
were reopened for the 1990/1991 season.
In October 1989, ASMFC adopted Amendment #4 which provided for
changes in management regulations and monitoring programs based on
stock status.. Amendment #4 addressed the following issues:
procedures for making changes to state regulations; requirements of
state monitoring programs; calculation of juvenile indices (change
to geometric mean instead of the arithmetic mean to reduce index
variability and increase the reliability of estimating annual
harvest quotas); mandatory minimum sizes; and, the Delaware River
as a producer area. During 1992, ASMFC concluded that the states
had implemented management measures which kept fishing mortality at
the level specified in Amendment #4. Additional changes to
Amendment #4 were adopted in May 1993. It provided for a year-round
coastal recreational fishery at a minimum length of 34" or larger,
and scaled seasonal closures for minimum lengths between 28" and
34". Language was also added to ensure that producer areas maintain
a fishing mortality rate at or below F=0.25.
With the striped bass resource declared recovered, Amendment
#5 is being developed to consolidate the procedures and programs of
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Amendment #4 and eliminate the management measures no longer
considered appropriate. The goal of Amendment #5 is to provide
management guidelines for the long-term maintenance of a self-
sustaining spawning stock and provide for the restoration and
maintenance of critical habitats. It will include a model for
estimating spawning stock biomass (SSB) in the Chesapeake Bay which
has been used to define stock recovery and evaluate management
regimes. Amendment #5 will be considered an interim strategy
between the transitional fishing guidelines at F=0.25 and a fully
restored fishery at F=0.50.
STOCK STATUS
In Nay, 1994, the ASMFC striped bass board declared the
striped bass stock restored to historic levels as of January 1,
1995. This declaration was based on the results of a stock
simulation model of coastal female SSB (Rugolo et al. 1994). The
average historical spawning stock biomass calculated for 1960-1972
has been adopted as a reference level and used as a definition of
recovery (Figure l) . An index of stock biomass developed from the
Maryland spring spawning stock CPUE data is strongly correlated
with the SSB model (Hornick et al. 1994) . In the last several
years, there has been approximately a five-fold increase in the
abundance of spawning female striped bass in the Maryland portion
of the Chesapeake Bay. Maryland studies have also indicated a
progressive increase in overall stock size with the number of year-
classes reaching levels comparable to the mid- 1970s.
Since the Hudson and Chesapeake stocks contribute
significantly to the coastal migratory stock, their status has
traditionally been used to indicate the status of the Atlantic
coast stock. More recently, contributions from the Delaware and
Albemarle/Roanoke areas have been acknowledged. Tag-recapture
studies from the Maryland Chesapeake stock indicate that mortality
rates have been at or below the transitional target of F=0.25. The
most recent estimate of fishing mortality from the Chesapeake Bay
(MD and VA, combined) was F=0.09 (ASMFC 1994) . Data from the Hudson
River indicates that fishing mortality is below the target rate of
0.25. Preliminary data from Delaware also suggest that mortality
rates are below target levels.
Overall recruitment and CPUE data indicate that Atlantic
striped bass stocks continued to grow during 1993 and 1994.
Recruitment levels for striped bass were excellent all along the
Atlantic coast during 1993, with record or near-record juvenile
indices from all major producer areas. The Maryland juvenile
striped bass survey, conducted since 1954, has been used
intensively as an indicator of stock status not only for the
Chesapeake Bay but for the Atlantic coast. In 1993, the Maryland
juvenile index arithmetic mean was 39.8 (13.9 geometric mean), a
value significantly higher than 30 of 36 previous years. In
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Virginia, an adjusted overall geometric mean is calculated to
measure relative juvenile abundance. The Virginia juvenile index in
1993 was 18.1, the highest value over a 21 year sampling period and
was three and half times the overall average index of 5.3 (Austin
et al. 1993a). The 1989 supplement to the ASMFC Striped Bass plan
recommended the development of a baywide juvenile index. Year-to-
year variability within each river system make it difficult to
determine a baywide index. There is also a problem with the lack of
a baywide data set to statistically validate a juvenile index. In
a few more years, the Maryland experimental gill net and Virginia
pound net monitoring data may provide a data set of sufficient time
duration to use for validation. A baywide juvenile index should be
pursued since Virginia waters account for approximately 30% of the
Chesapeake Bay stock (Austin et al. 1993b).
The CPUE data from different areas along the Atlantic coast
suggest that there has been an increase in relative abundance, a
trend that has been occurring over the last five years. The mean
CPUE from the Marine Recreational Fishery Statistics Survey (MRFSS)
has been increasing, since 1989. During 1993, approximately 5.6
million fish were caught by recreational anglers, the highest
recorded value since the survey started in 1979.
FISHERY DEPENDENT MONITORING
Monitoring the commercial and recreational harvest of striped
bass and sampling the catch for age, size and sex composition are
essential to meeting management needs. Data from commercial and
recreational landings are important for assessing harvest
distribution among user groups, identifying and/or revising
existing management recommendations, and substantiating fishing
mortality rates derived from fishery independent monitoring
programs for each jurisdiction during 1993-1994. A comparison of
striped bass harvested by fishing year, type of fishery, and
jurisdiction-can be found in Tables 1-3.
MARYLAND
Maryland Department of Natural Resources (MDNR) developed a
harvest control model (Rugolo and Jones 1989) to manage a limited
striped bass fishery and control fishing mortality at 18% to 20% of
the stock. The quota based system has been in effect since 1990.
The total fall 1993 to winter 1994 quota for resident premigratory
striped bass for all user groups combined was 2,097,715 pounds.
This was an increase from the 1992-93 quota of 1,636,000 pounds.
The quota was allocated as follows: recreational fishery, 891,529
pounds (42.5%); commercial fishery, 891,529 pounds (42.5%); and
charterboat fishery, 314,657 pounds (15%). The Atlantic Coast
commercial quota remained at 25,000 pounds. Quotas remained the
same for the 1994/1995 fishing year.
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Spring Recreational Fishery
The spring recreational striped bass fishery was open from May
1 through May 31, 1993 and limited to 3,000 fish. Recreational
anglers wishing to participate in this fishery were required to
possess a valid striped bass fishing permit unless fishing from a
charterboat. During this time period the following restrictions
were in effect: a 36 inch minimum size limit; a 1
fish/angler/season creel limit; area closures to protect fish on
spawning grounds; mandatory tagging and reporting of kept striped
bass at designated check-in stations; prohibition of gaffs and
natural bait; and prohibition of possession of striped bass while
on the water between 8 p.m. and 5 a.m. MDNR monitored harvest,
biological characteristics of the landings, and fishing effort
through telephone surveys, check-in station reports, and
charterboat logbooks. The total estimated harvest of 2,719 fish
(61,640 pounds) was based on estimates from the recreational (2,116
fish) and charterboat (603 fish) fisheries. A total of 34,910
permits were issued by May 31, 1993 compared to 31,937 in 1992.
Check station results indicate that 661 fish were checked in during
the 1993 spring season. These ranged from 36 to 55 inches TL and
15 to 52 pounds. The average length and weight were 39 inches TL
and 23 pounds, respectively. Based on length-at-age calculations,
it appears that the spring 1993 harvest was primarily 8-10 year-old
fish with 7 to 21+ year-old fish present.
The 1994 spring trophy fishery followed 1993 restrictions with
only minor changes. The cap for 1994 increased to 5,000 fish and
the creel limit was set at 1 fish/angler/day and 3
fish/angler/season for private boat fishermen. Charterboat
fishermen were allowed to catch 1 fish/day throughout the season.
Mandatory tagging, reporting and charterboat logbooks continued to
be required in 1994. Fishing effort continued to increase in 1994
with 42,773 permits being sold. Total estimated harvest is not yet
available for the 1994 spring season.
Fall Recreational Fishery
The fall 1993 recreational season in the Bay was open from
October 1 through November 21, 1993. Restrictions included: a
minimum size of 18 inches, a one fish/angler/day creel limit; a
special striped bass fishing permit; fishing during daylight hours
only; and a gaff prohibition. Maryland's Atlantic coast
recreational season was open from July 15 through November 30, 1993
and was not included in the Bay quota but had the following
restrictions: a creel limit of 1 fish/angler/day with a minimum
size of 28 inches TL. A total of 146,821 fishing permits were
issued prior to closure of the season. This was an increase from
the 136,182 permits issued in 1992, indicating that fishing effort
increased. Recreational harvest estimates were based on access-
intercept and telephone surveys. A total estimate of 649,018
pounds (113,810 fish) or 73% of the recreational Bay quota was
harvested in 1993. Catches from private boats averaged 24.8 inches
TL and 5.8 pounds. The catch was comprised primarily of 4-7 year-
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old fish with fish 3-11 years old being represented. The total
number of legal and sublegal striped bass released was 56,182 and
396,385 fish, respectively.
Seven days were added to the Chesapeake Bay recreational
season in 1994 extending it from September 24 through November 22.
Fishing effort continued to increase in 1994. Preliminary results
indicate 166,471 permits were sold when the fishery closed.
Preliminary harvest estimates range from 631,739 to 650,699 pounds
for the Chesapeake Bay recreational season (MDNR data). These
estimates are based on new methods using tag return data. MRFSS
estimates for the Chesapeake Bay and Atlantic Coast will be
available early 1995.
Charterboat Fishery
Regulations for the 1993 charterboat fishery were the same as
the recreational fishery except that the creel limit was 2
fish/angler/day, and charterboat anglers were not required to
obtain a striped bass fishing permit. Charterboat captains wishing
to participate in the charterboat fishery were required to declare
their intent. Mandatory logbooks were issued to each captain and
were used to determine harvest. The total estimated 1993 harvest
was 349,531 pounds (57,960 fish) which was 11% over the charterboat
quota. Average weight was 5.9 pounds. The total number of striped
bass released from charterboats was 34,093.
The 1994 charterboat fishery followed regulations for the 1993
fishery. Preliminary logbook estimates for 1994, indicate 57,965
fish (296,201 pounds) were harvested. Average weight was 5.1
pounds. Logbooks also reported 91,288 striped bass were released.
Final logbook estimates will be available in 1995. Preliminary
estimates for the 1994 charterboat fishery, based on tag return
data, indicate 482,098 pounds were harvested (MDNR data).
Commercial Fishery
The Chesapeake Bay and Atlantic coast 1993-1994 commercial
fishery were regulated under a•quota'system. License holders were
required to declare their intent to fish and state which gear type
they would use. The Chesapeake Bay commercial quota was allocated
according to gear type with drift gill nets being assigned 73%
(650,817 Ibs.), pound net and haul seine, 25% (222,882 Ibs.), and
hook and line, 2% (17,850 Ibs.). The pound net/haul seine season
was September 15 through November 12, 1993, and hook and line
season was November 15 through December 7, 1993. The drift gill
net fishery was split into three components: 1) December 1 through
December 17, 1993; 2) January 3 through January 17, 1994 and
January 24 through January 26, 1994; and 3) February 1 through
February 14, 1994 and February 21, 1994. Daily quotas were
determined and used to distribute harvest. The Atlantic coast
quota was not allocated according to gear type but was available to
both drift gill netters and otter trawlers between December 1, 1993
and February 28, 1994 until individual quotas were met. The
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minimum size was 18 and 28 inches for the Chesapeake Bay and
Atlantic coast, respectively and each landed striped bass had to
have been tagged and checked-in at a designated check station.
Daily and weekly check station reports were the basis for
determining the commercial harvest. The total 1993-94 Chesapeake
Bay commercial harvest was 858,622 pounds or 96% of the total
Chesapeake Bay quota. Harvest by gear type included: pound net
(181,215 Ibs,); haul seine, (22,156 Ibs.); hook and line, (8,188
Ibs.); and drift gill net, (647,063 Ibs.). The total Atlantic
coast harvest was 4,065 pounds or 16.3% of the Atlantic coast
quota. The total Maryland commercial harvest was 862,687 pounds or
94% of the state-wide quota of 917,500 pounds. In addition to
monitoring landings, the commercial fishery was randomly sampled to
obtain biological data. A total of 3,746 fish were sampled during
the pound net season. The mean total length for this sampling
period was 20.7 inches. During the Chesapeake Bay gill net season,.
the commercial catch was subsampled at randomly selected check
stations. The mean total length for this sampling period was
approximately 22.0 inches and age 5 (1989 year-class) fish were
most abundant in all areas sampled. Biological monitoring of the
commercial hook and line fishery was not conducted due to the
patchy nature of fishing activity, and the small individual quotas.
Restrictions for the 1994/1995 commercial striped bass season
are identical to the 1993/1994 season except for minor season
changes. The pound net/haul seine season was August 29 through
November 11, 1994; and hook and line season was November 23 through
November 30, 1994. Preliminary harvest results from the 1994
commercial season include: 237,308 pounds (95% of quota), pound
net/haul seine fishery; and 46,954 pounds (263% of quota), hook and
line fishery.
Non-directed Mortality
Striped bass losses due to bycatch and illegal harvest were
calculated in order to estimate sources of non-directed mortality.
Specifically, MDNR estimated losses from 1) the recreational and
charterboat fisheries; .2) the commercial striped bass fisheries;
and 3) the commercial white perch and American shad fisheries.
Overall, estimated losses due to bycatch and poaching activities in
Maryland's 1993-94 fishing season ranged between 97,217 and 240,734
striped bass (Table 4) . A complete description of the assumptions
and calculations for each fishery can be found in the Maryland DNR
monitoring report (MDNR 1994). Estimates of non-directed striped
bass losses during the 1994/1995 fishing season are not yet
available.
VIRGINIA
Recreational Fishery
For the first time since 1990, Virginia's recreational fishery
was strictly a weekend fishery (Thursday - Sunday). The
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recreational fishing season, including charterboats, was October 28
through December 19, 1993. No quota was established for the
recreational fishery. Daily creel limits were 2 fish/angler.
Minimum size limits were 18 inches and 28 inches for the Chesapeake
Bay and Atlantic Coast, respectively. A maximum size limit of 36
inches was in effect for all areas but recreational fishermen were
allowed to keep one fish 48 inches or larger as part of their two
fish creel limit.
Virginia relied exclusively on the National Marine Fisheries
Service (NMFS) MRFSS for recreational catch estimates. Estimates
are calculated using access-intercept (catch estimates) and
telephone surveys (trip estimates). In 1993, the MRFSS instituted
new procedures for estimating trips. Because trend data is
important in fishery management, 1993 catch estimates were
calculated using both the "old" and "new" method, however, the
"new" estimates are more accurate. The MRFSS hopes to provide
"new" estimates for 1990-1993 by the end of 1994.
"Old" and "new" methods produced recreational harvest
estimates of 76,540 and 67,127 striped bass, respectively. An
average fish weight of 6.5 pounds was calculated using the "old"
method. An estimated 495,450 pounds were harvested during the 1993
recreational fishery.
Restrictions for Virginia's 1994 fishery were similar to 1993
except: 1) no maximum size limits; 2) the season was adjusted to
October 27 through December 18, 1994, to fit the Thursday - Sunday
schedule; and 3) the Atlantic Coast season was extended, December
19, 1994 through March 31, 1995, with a 1 fish/day/person creel and
28 inch minimum size limit. MRFSS estimates for the 1994
recreational fishery will not be available until early 1995.
Charterboat Fishery
A total of 167 permits were issued to charterboat captains in
1993. Of these, only 54.5% actually fished. The estimated 1993
charterboat harvest, from captain's reports, was 4,663 striped
bass. A total o'f 1,773 striped bass were measured and a length-
frequency distribution was estimated for the entire recreational
fishery harvest. Striped bass 20 to 25 inches TL accounted for 42%
of the recreational harvest.
Virginia's 1994 charterboat fishery followed recreational
fishery restrictions. Harvest estimates for 1994 will not be
available until 1995.
Commercial Fishery
Virginia's 1993 commercial striped bass season was split into
two fishing periods to accommodate fishermen and the temporal and
spatial distribution of striped bass and gear type used in
harvesting. The first period was open March 1 through March 31,
1993, for fyke nets only. The second period was open to all other
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gear types (gill net, pound net and haul seine), September 15
through December 31, 1993.
A commercial harvest quota of 211,000 pounds, which has been
in effect since 1990, was set for 1993. During each fishing period
a limited entry system, in combination with the mandatory fish-
tagging program, allowed the quota to be distributed by gear type
as follows: gill net (147,700 pounds); pound net (52,750 pounds);
haul seine (6,330 pounds); and fyke net (4,220 pounds). Fishermen
were allowed to fish one gear type, except during the second
fishing period when hook and line could be used to supplement their
primary gear harvest. Size limits were the same as the
recreational fishery except commercial fishermen were not allowed
to harvest striped bass larger than 36 inches.
All commercial fishermen and striped bass buyers (first sale
from harvester) were required to obtain permits from the VMRC.
First sale buyers were required to submit a final report of daily
purchases to the VMRC one week after the spring and fall seasons
closed. Daily catch records were due one week after the spring
season and on a monthly basis for fall fishermen. The commercial
harvest for 1993 was derived from written reports submitted from
harvesters and buyers and totaled 2,274 and 207,709 pounds for the
spring and fall fishery, respectively.
No biological data were collected during the spring fyke net
fishery. During the fall fishery, VMRC staff collected data on
length, weight, age, and sex composition. The average length and
weight was 24.7 inches TL and 5.7 pounds, respectively. Length and
weight were similar to 1992 but slightly larger than fish measured
in 1990 and 1991. Fish aged 7+ comprised 15% of the 1992 and 1993
samples but only 2.5% in 1990 and 1991. This increase in size and
age could be a result of fishermen selecting larger fish for market
or an increase in number of older fish. Males accounted for 70% of
the fish sampled in 1990 through 1993.
Virginia's 1994/1995 commercial fishery had minor changes.
The fall season did not open until October 1 but the closure date
remained December 31, 1994. The spring 1995 fishery will again be
open in March. Seasonal quotas for each gear type were identical
to those in 1993. However, individual tag allocations decreased
slightly due to an increase in the number of fishermen and slightly
larger fish being harvested. Harvest estimates and catch
characteristics for the 1994/1995 fishery are currently
unavailable.
Non-directed Mortality
Data to estimate non-directed mortality in Virginia's
commercial fisheries are limited. The estimated illegal harvest
for 1993 is 225 striped bass weighing 1,220 pounds. This is based
on the number of striped bass that the Virginia Marine Police
confiscated in 1993, and is a minimum estimate. Striped bass
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bycatch occurs in other commercial fisheries but is primarily
restricted to the winter and spring shad, white perch and herring
gill net fisheries. An estimate of bycatch mortality in 1993 was
limited to Virginia's shad fishery with a total of 55,294 striped
bass weighing 237,738 pounds. Non-directed striped bass mortality
estimates for 1994 are unavailable.
POTOMAC RIVER
Recreational Fishery
The 1993 Potomac River recreational striped bass season was
scheduled for 29 days, October 1 through 19 and November 5 through
14 with a 1 fish/person/day creel limit, a 18 inch minimum, and a
36 inch maximum size limit. Due to very low harvest estimates, the
fishery was extended 7 days to November 24. The Potomac River
Fisheries Commission (PRFC) has regulated the recreational fishery
since 1990 through a mandatory free fishing permit system. A total
of 7,097 permits were issued in 1993 which is an increase from
6,644 in 1992. Efforts by the PRFC to increase permit return rates
continued in 1993 and appears to be somewhat successful. Although
the overall return rate was slightly less than last year, return
rates for renewal permittees was 63.5% compared with a 44% rate for
first-time permittees. The 1993 estimated recreational harvest of
striped bass from the Potomac River was 120,899 pounds (21,385
fish). This estimate was based upon fisheries data collected from
returned 1993 permits as well as non-respondent data gathered from
a 1991 study.
The 1994 Potomac River recreational fishery was September 30
through October 23, 1994 and November 4 through November 15, 1994.
Creel and size limits were unchanged from 1993, but the maximum
size limit was removed. The number of permits issued in 1994
dropped slightly to 6,813. The preliminary harvest estimate, with
53%% permits returned, is 50,000 pounds.
charterboat Fishery
The chartefboat season began on October 8 in 1993 and was
scheduled to run until November 7 or until the 22,860 pound cap was
reached. Low catch estimates and numbers of charterboats operating
in the Potomac prompted the PRFC to extend the season by one week.
Monitoring efforts remained unchanged from 1992 and consisted of
mandatory catch reports. Logbooks indicated 9,857 pounds (1,925
fish) were harvested by the charterboat fishery, which was 43% of
their quota.
The only change for the 1994 charterboat fishery was the
season, October 1 through November 6, 1994. Preliminary harvest
was 6,000 pounds, as of December.
Commercial Fishery
The 1993-1994 Potomac River commercial fishery was identical
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to the 1992 cap of 155,000 pounds. Fishing seasons and quota
allocations were delineated according to gear type. The commercial
seasons and quotas were: hook and line, Wednesdays and Thursdays,
August 4 though September 3, 1993 (10,000 Ibs); pound net, Monday
through Friday, August 23 through September 3, 1993 and October 4
through November 19, 1993 (35,000 Ibs); and gill net, November 29
through December 23, 1993 and February 1 through March 5, 1994
(110,000 Ibs). Fishermen were required to tag individual striped
bass prior to landing. Reporting requirements remained unchanged
from 1992 and was the basis for monitoring harvest. Estimates for
the commercial harvest are: hook and line, 7,380 pounds; pound net,
43,967 pounds; and gill net, 91,395 pounds for a total of 142,742
pounds (24,451 fish), 92% of the quota.
Seasons for 1994-1995 fishing year included: hook and line,
August 8 through September 29, 1994 and November 28 through.
December 23, 1994; pound net, August 22 through August 26, 1994 and
October 3 through November 18, 1994; and gill net, November 23
through December 23, 1994 and February 6 through March 10, 1995.
Estimates for the 1994 fishery are preliminary: hook and line,
6,250 pounds; pound net, 28,861 pounds; and gill net, 47,149
pounds.
Non—directed Mortality
Additional striped bass losses due to poaching and hook and
release mortality were calculated according to ASMFC
recommendations. A 15% rate was used to calculate illegal harvest
and an 8% rate was used to calculate hook and release mortality.
During the 1993 fishing season, 47,364 pounds (9,629 fish) of
striped bass were lost due to poaching and hook and release
mortality (PRFC 1994). Non-directed mortality estimates for
striped bass during 1994 are unavailable.
DISTRICT OF COLUMBIA
Recreational Fishery
The recreational season extended from June 7 to November, 1993
with a minimum size limit of 18 inches, maximum size limit of 36
inches, and creel limit of 1 fish/angler/day. The sale of
recreational catch was strictly prohibited.
In 1993, a total of 11,916 licenses were sold to anglers
fishing in the District of Columbia. Of these, 4,150 were sold to
District of Columbia residents and 7,113 were sold to non-
residents. In addition, there were 653 short-term licenses sold
for 14 day angling.
Commercial Fishery
There is no commercial season in the District of Columbia.
11
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STOCK MONITORING
In addition to monitoring the commercial and recreational
harvest of striped bass, fishery independent monitoring is required
to evaluate stock status. The essential elements of a long-term
monitoring program include: the annual assessment of juvenile
abundance; spawning stock assessment; stock characterization (age
distribution, catch per unit effort (CPUE), size distribution, and
sex ratios); stock identification, and tagging.
MARYLAND
The objectives of Maryland's stock assessment studies include
characterizing and monitoring the spawning and
resident/premigratory stocks, assessing the relative abundance of
juvenile striped bass, determining the contribution of hatchery
striped bass to the population, and participating in baywide and
coastal striped bass tagging studies. The following is a summary
of the Striped Bass Stock Assessment Program (SBSA) during
1992/1993, the fall 1993 mortality study and preliminary results
from 1994. Except for work completed in 1994, details can be found
in Hornick et al. (1993).
Spawning Stock Survey
Excessive fishing mortality on Chesapeake Bay spawning stocks
during the 1970's and early 1980's reduced the number of spawners
and diversity in age and size of spawners which resulted in
decreased reproductive potential. Management actions were set in
the 1989 Chesapeake Bay Striped Bass FMP (i.e. size limits and
fishing mortality rates) to allow a limited fishery and provide
growth in the spawning stock.
Maryland has monitored the striped bass spawning stock since
1982. This survey enables biologists to examine how actions set in
the ASFMC FMP and the Chesapeake Bay Striped Bass FMP have impacted
the Chesapeake Bay spawning stock. In 1993 and 1994, data was
collected from experimental drift gill nets and commercial pound
nets on age, size, sex composition and relative abundance from the
Choptank River, Potomac River, and upper Bay. Results indicate
that the Chesapeake Bay spawning stock continues to diversify in
age and size, and increase in abundance.
The number of year-classes representing the male spawning
stock increased to ten in 1993. In 1988, when the survey expanded
to include the Potomac River only five year-classes were present.
The upper Bay male spawning stock was predominately composed of age
3, 4, and 5 year-old striped bass. The age composition of the
Choptank River and Potomac River male spawning stock was more
evenly distributed between 2 and 8 year-old fish. Age 4 males were
the most abundant cohort in all sampling areas, indicating good
recruitment by the strong 1989 year-class.
12
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The number of year-classes present in the female spawning
stock has more than doubled since 1988. In 1993, striped bass 3 to
18 years of age were present. The majority of these'fish were
between 6 and 11 years old.
The female component of the 1993 spawning stock was comprised
of more than 60% age 8+ striped bass. When pooled with male
striped bass, the Baywide percentage of fish age 8+ was 15% in
1993. In 1993, the ASMFC decided to use a spawning stock biomass
index (SSB) of 56.22 as a target for a recovered fishery instead of
a percentage of age 8+ fish. The SSB model calculated that this
level would be surpassed in 1995 (Figure 1).
Data for the 1994 spawning stock survey are being analyzed,
however, some results are available. Note that sampling was not
conducted in the Potomac River in 1994. The number of year-classes
in the male spawning stock increased to twelve in 1994. Age
distributions among sampling areas remained similar to 1993 and the
1989 year-class was again the most abundant.
Striped bass 3 to 16 years-old represented the 1994 female
spawning stock. The majority of fish were between 5 and 11 years
of age. Females from the 1986 and 1988 year-classes were most
abundant in the upper Bay. The 1985 year-class was most abundant
in the Choptank River.
The percentage of age 8+ fish continued to show improvement in
1994. Females age 8+ comprised over 70% of the female component
and total baywide percentage of age 8+ fish increased to 19%.
Egg Presence-Absence Survey
A field trial of presence-absence egg sampling was conducted
during 1994 in the Choptank and Nanticoke Rivers. These results
were contrasted with historic data to investigate baywide spawning
biomass trends, develop criteria for assessing whether spawning
stock was at a self-sustaining level, and evaluate spawning
population recovery. The successful 1994 field trial indicated
that egg present-absence sampling has a place in Maryland's
monitoring of striped bass spawning stock. The ease of
interpretating egg presence-absence in the field allowed for a
preliminary assessment of spawning stock, available to managers
within the same timeframe that recruitment is assessed by the
juvenile survey. Detailed information .can be found in Uphoff Jr.
1994.
Juvenile Survey
Maryland's 1993 striped bass juvenile survey produced a bay-
wide arithmetic mean (AM) of 39.8 and geometric mean (GM) of 14.1.
This was a record value, significantly higher than all years since
1970, except for 1989, and significantly greater than the AM target
period average (TPA) of 12.0. The TPA is the average of indices
from 1959 through 1972 and has been suggested as a period of
13
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general stock health (ASHFC 1989). Of the four major spawning and
nursery areas sampled each produced record or near record values in
1993 (Table 5). Sampling from auxiliary sites also produced record
results in 1993.
Maryland's 1994 striped bass juvenile survey produced a bay-
wide AM of 16.1 and GM of 6.4 (Table 5). Of the four major
spawning areas sampled, each produced values well above the TPA,
except for the Potomac River. Auxiliary sampling in 1994 continued
in the upper Bay and Patuxent River, and produced above average
values. Additional auxiliary sites were sampled in the Wye and
Miles Rivers in 1994. It appears these sites had good production
but their values still need to be compared to past data.
The continued importance of the JI survey is reflected in its
many uses. The JI is related to adult relative abundance, used as
a projection tool in the SSB model to determine stock size and
health, and used in establishing quotas by the Harvest Control
Model.
Resident/Premigratory Stock Survey
Maryland continued its fall and winter stock assessment and
commercial fishery monitoring during the 1992-1993 fishing year.
Commercial pound nets were sampled in September and October, 1992
and commercial and experimental drift gill nets were sampled from
December, 1992 through February, 1993. The objective of this
survey is to characterize the age, size and relative abundance of
the resident/premigratory striped bass stock.
Striped bass from the 1988 (age 5) and 1989 (age 4) year-
classes dominated both the pound net and gill net fisheries. The
1990 (age 3) and 1984 through 1987 (ages 6-9) year-classes
comprised the remainder of the harvest. Striped bass older than
age 10 were not encountered during sampling and were presumed to be
fully recruited to the coastal migratory stock. Ages 4 through 7
have been the predominate age-classes targeted in the fall pound
net and winter drift gill net fishery for the past three years.
Mean lengths of the total catch from pound nets increased from
upper to lower Bay sampling areas. This trend was also evident
during fall 1991 pound net sampling and coincides with the age
differences observed between sampling areas. Younger striped bass
were more abundant in upper and middle Bay samples.
Since the re-opening of the striped bass fishery in 1990, the
commercial gill net fishery has been sampled onboard commercial
watermen's boats. This allowed Maryland biologists to obtain
estimates of abundance. However, these abundance estimates are
dependent upon a number of factors, including individual fishermen,
mesh sizes, and area fished, which resulted in inconsistencies from
year to year. Abundance estimates, therefore, characterize
commercial catch and not the resident striped bass population.
14
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Because of these problems, CPUE estimates will no longer be
obtained from the fishery and characterization of the 1993-1994
commercial gill net catch will occur by sampling catches at check-
in stations.
Only some of the results for the 1993-1994 fishing year are
available. Striped bass aged 2 (1992) to 10 (1984) were
represented in the fall 1993 pound net samples. The 1989 year-
class was most abundant and the majority of fish were between 3 and
8 years of age. Average weights for the upper, middle, and lower
Bay are 3.9, 5.8 and 4.2 pounds, respectively.
A total of 9 age classes (ages 3-11) were represented in
winter 1993-1994 gill net samples. Age 5 (1989 year-class) fish
were most abundant followed by age 6 (1988 year-class) fish.
Check-in station sampling was divided into Northern (above Bay
Bridge), Eastern (Eastern shore below Bay Bridge), and Western
(Western shore below Bay Bridge) areas. Mean lengths were: 22.0
inches TL, Northern; 22.8 inches TL, Eastern; and 21.5 inches TL,
Western. Average weights for the Eastern and Northern areas were
4.9 and 4.0 pounds, respectively.
The effects of intensive management on striped bass stocks
over the last 14 years are evident from Maryland's Chesapeake Bay
resident population. Length-frequencies and the number of age
classes present in Maryland's resident population has increased
substantially (Figure 2 & 3) . Management measures have also
dramatically altered Maryland's recreational harvest. The presence
of a wide range of sizes and age-classes has allowed selective
harvest of larger striped bass not previously available in
Maryland's resident population (Figure 4).
Tagging
Maryland participated in the Cooperative Coastal Striped Bass
Tagging Program during the 1992/1993 and 1993/1994 sampling
seasons. Fish were tagged from the resident/premigratory and
spawning stock in the Bay, and Maryland biologists also
participated in a tagging cruise off the coast of Virginia and
North Carolina. These tagging studies provide valuable information
on stock movements and fishing mortality rates.
During the 1992/1993 sampling season a total of 2,998 (412
resident/premigratory and 2,586 spawning) striped bass were tagged
in the Chesapeake Bay and 530 were tagged in the territorial sea
south of Cape Henry, VA.
During the 1993/1994 sampling season, in the Chesapeake Bay,
4,899 resident/premigratory fish were tagged as part of a directed
mortality study and 2,035 fish were tagged during the spring
spawning survey. During the 1994 North Carolina tagging cruise
4,632 fish were tagged.
15
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gatcherv Fish Sampling
Maryland continued hatchery production in 1993 to enhance
striped bass spawning stocks. Hatchery fish are implanted with a
small magnetically detectable coded wire tag (CWT). A major
component of Maryland's sampling involved scanning fish for the
presence of hatchery implanted CWT's to determine hatchery
contribution to the population.
A total of 11,206 striped bass were scanned during 1992/1993
sampling and 298 tested CWT positive (2.6%). Separation by
sampling mode included: 4.3%, pound nets; 2.8%, main bay gill nets;
1.0%, Choptank River gill nets; 2.0%, spring spawning stock survey;
and 0.1%, juvenile survey (Table 6). During the 1993 coastal
tagging operation, 577 fish were scanned and 34 (5.9%) tested CWT
positive.
During the fall 1993 pound net sampling survey, 2,033 fish
were scanned and 74 (3.6%) were positive. A total of 4,235 fish
were scanned during 1993-1994 winter gill net sampling and 6.0%
were positive. At the time of Maryland's 1994 juvenile survey,
hatchery fish had only been stocked in the Nanticoke River. The
juvenile survey crew scanned 2,619 juveniles throughout the
Chesapeake Bay, 517 from the Nanticoke River, but all scanned
negative. Reduced stocking efforts and abundant 1993 and 1994
year-classes have overwhelmed contributions from hatchery fish. In
the 1994 spring spawning survey approximately 3,300 fish were
scanned and 106 (3.2%) tested positive. Coastal tagging results in
1994 are preliminary. Approximately 1,500 fish were scanned and 59
(3.9%) tested positive.
Annual trends in hatchery contribution are difficult to detect
because no statistical analyses have been conducted. It appears
that a increased percentage of Chesapeake Bay hatchery fish have
migrated from the resident stock to the coastal stock.
VIRGINIA
The following is a review of Virginia's 1993 striped bass
monitoring programs for 1993. Details can be found in Virginia
Marine Resources Commission (VMRC) Striped Bass Report (1994).
Ichthvoplankton Monitoring Survey
Management actions were implemented within the Chesapeake Bay
in early 1985 in order to reduce fishing mortality rates and
protect and enhance the spawning stock. Olney et al (1991),
recorded substantial increases in egg production and spawning stock
size in the latter part of the 1980's. In 1989, the Virginia
Department of Game and Inland Fish (VDGIF) initiated a spring
electroshocking survey of the York River system. An area of
overlap existed in the Pamunkey River where ichthyoplankton and
electroshocking data collection occurred. Ideally, observations of
16
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increased egg production in the Pamunkey should parallel adult
catch rates. However, electrofishing CPUE during 1989-1993 found
an increase in male but not female abundance on the' spawning
grounds. Mean annual CPUE of females have not corresponded to
biomass estimates based on the VIMS egg production model. Because
an increase in female abundance was expected due to harvest
restrictions, concerns about the validity of the data generated in
these surveys has mounted. Whether assessment techniques have
accurately reflected trends in female abundance is unknown. All
resources and effort in 1994 were directed towards a critical
analysis of historical data resulting from these two surveys in the
York River system during the five year period 1989-1993.
Spawning Stock Monitoring Survey
VIMS Anadromous Fish Program has been monitoring the striped
bass spawning stock using experimental gill nets and pound nets on
the Rappahannock River since the early 1980's. In 1993, gill net
and pound net CPUE was greatest for males from the 1988 year-class
and females from the 1987 year-class.
Since 1988, the VDGIF, USFWS, VIMS, and VMRC have attempted to
enhance the Chesapeake Bay spawning stock by stocking hatchery-
reared fingerlings in the York River system. Personnel from the
VDGIF and United States Fish and Wildlife Service (USFWS) collected
spawning stock data while electrofishing for broodfish from
February to June of 1989-1992. In 1993, female CPUE was
substantially higher than those from 1989-1991. Despite problems
in locating large (age 8 and older) females, the CPUE for older
females remained close to the 1992 record high value. Most of the
observed decrease in female CPUE occurred in younger age-classes.
This is probably related to the fact that young females are always
abundant in the upper rivers. Sampling efforts were concentrated
downstream because large females were concentrated further
downstream in 1993 where the majority of sampling occurred.
Juvenile Survey
The striped bass juvenile index from the Virginia Chesapeake
Bay nursery areas in 1993 was 18.1 and was the highest on record
(Table 5) . Recruitment success in the York River drainage was the
highest for the entire time series with fish being abundant in both
the Pamunkey and Mattaponi Rivers. In 1993, both the Chickahominy
and main stem of the James and produced record values. The
Rappahannock River produced its third highest year-class and
contributed to the record 1993 index.
VIMS continued to sample auxiliary index stations in 1993 to
account for the annual variability in the center of young-of-the-
year abundance. This annual variability makes it difficult to
provide an accurate state-wide index of annual juvenile
recruitment. This issue was addressed with support from the
Chesapeake Bay Stock Assessment Committee (CBSAC) and in 1993 a
baywide index was developed from scaled, geometric means, weighted
17
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by area of spawning ground in each producing river but has not yet
been approved by the ASMFC.
VIMS also validated the Virginia's juvenile index with CPUE
from a fishery-independent monitoring program. The juvenile index
is related to subsequent year abundance of age l to age 3+ cohorts
in fall Rappahannock River pound net catches.
Tagging
A total of 42,165 wild striped bass have been tagged and
released in the James (17,730) and Rappahannock Rivers (24,435)
since 1987. The USFWS has reported over 11,000 returns for both
rivers, combined.
In fall 1992, VIMS tagged and released 491 striped bass in.the
James River. The size of the fish ranged between 15.4 and 26.2
inches fork length (FL) with 50% between 15.8 and 19.7 inches FL.
The 1989 and 1990 year-rdasses accounted for 75% of the total
tagged fish.
In spring 1993, VIMS tagged and released 621 striped bass in
the Rappahannock River. Tagged fish ranged between 22.2 and 44.1
inches FL. Male striped bass between 21.7-23.6 inches FL and
females 24.0-25.6 inches FL were most abundant. Catch-per-unit-
effort (CPUE) data was also collected during spring tagging
operations. Results were similar to data collected by the
Anadromous Fish Program with females from the 1987 and males from
the 1988 year-classes dominating the age composition.
DISTRICT OF COLUMBIA
During 1993, the District of Columbia sampled for striped bass
with gill nets, a bagless seine, and an electroshocking boat on a
monthly basis at seven fixed sites (Potomac River, 4; Anacostia
River, 2; and Washington Channel, 1). In addition, ichthyoplankton
surveys were conducted at these sites. The study period extended
from the last week of February to the last week of December.
Catch rates indicate the maximum number of fish were caught in
July. The catch consisted primarily young-of-year fish. Striped
bass were not found in the District waters earlier than April or
later than November.
Age analysis of the adult population shows fish age 1 to 8
were present. Age 1 fish were most abundant and the frequency of
older fish (age 2-8) gradually reduced.
The 1993 young-of-year index for striped bass set a new record
for that area of the Chesapeake Bay. The index was 7.02 with all
sites combined. However, if only sites where young-of-year were
actually collected are taken into consideration, the index rises to
18
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30.64.
A total of eight striped bass were tagged with USFWS anchor
tags. No recaptures were reported.
COOPERATIVE BAYWIDE TAGGING MORTALITY STUDY
The VMRC, PRFC, and MDNR implemented a baywide mark-recapture
program to estimate the rate of exploitation in the Bay arid the
abundance of the resident, premigratory stock over 18 inches. The
study was conducted prior to the fall 1993 recreational,
charterboat, and commercial striped bass season. Reporting rate,
exploitation rate, population abundance, and directed fishing
mortality rate were estimated. There was a high degree of
variability associated with the reporting rate (75%) due to the
number of tags issued in each region of the Bay and the number of
associated recoveries. The rate of exploitation (the fraction of
the total population taken as catch) by the recreational and
charterboat fisheries for the entire Bay was 0.05. The estimated
fishing mortality rate due to the recreational, charterboat, and
commercial fisheries was 0.09. These rates are well below the F =
0.25 recommended by the ASMFC. The estimated number of fish in the
baywide, resident premigratory striped bass stock, 18 inches and
larger, was 6.6 million. The baywide estimate of stock abundance
was 7.7 million (Rugolo et al. 1994).
ENFORCEMENT PROGRAM
MARYLAND
Natural Resource Police (NRP) officers concentrated aggressive
enforcement efforts on areas of heavy fishing activity, using
highly visible operations (patrol vessels, cars, and aircrafts) as
a deterrent during 1993 and 1994. NRP officers also continued
soliciting active participation of the public, including fishermen,
to report fishing violations by calling a toll free "Catch a
Poacher" line.
In 1993, NRP police spent an average of 2,914 hours per month
enforcing striped bass regulations. A total of 85,497 striped bass
checks were conducted resulting in 48.4 arrests and 118 written
warnings. Arrests and warnings were most frequently for untagged
fish, possession during the closed season, and fishing without a
license.
Preliminary results for 1994 indicate NRP officers spent an
average of 2,255 hours per month enforcing striped bass regulations
through November. To date, 86,748 striped bass checks have been
conducted resulting in 1,960 arrests and 149 written warnings.
Possession of striped bass during the closed season continues to be
19
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a problem throughout the year, accounting for 1,650 arrests in
August. Other enforcement problems frequently encountered are
untagged fish, undersized fish, and fishing without a license.
POTOMAC RIVER
Law enforcement in the Potomac is done by the cooperative
efforts of Maryland NRP and Virginia Marine Patrol officers.
Defendants are tried through the Maryland or Virginia District
Court systems and statistics on inspections, arrests, etc. are
maintained by the respective agencies.
Each boat fishing during the striped bass season is required
to have in possession a valid permit. Officers are requested to
initial the log sheet on each permit at each boarding. A sport
fishing flyer is given with each recreational striped bass permit.
It includes information on season, size, and creel limits for all
species in the Potomac River in addition to striped bass.
DISTRICT OF COLUMBIA
The enforcement of fishing regulations is entrusted with the
District of Columbia Harbor Police who monitor angling activities
on a daily basis. No infractions were reported in 1993.
WATER QUALITY AND HABITAT ISSUES
Restoring and improving habitat and water quality for living
resources have been priorities of the Chesapeake Bay Program.
Actions towards fish passage, wetlands, monitoring,, toxics, exotic
species, submerged aquatic vegetation (SAV), nutrient reduction,
and atmospheric deposition are being implemented. The water
quality and habitat requirements for striped bass have been defined
and reported by Setzler-Hamilton and Hall in the document entitled:
Habitat Requirements for Chesapeake Bay Living Resources
(Funderburk et al. 1991). To date, habitat sections within each
Chesapeake Bay FMP have been generic and similar from plan to plan.
Both the Fisheries Management Plan Reassessment Task Force and the
Chesapeake Bay Foundation have recommended strengthening the FMP
habitat actions and utilizing them for managing habitat. There are
some inherent problems in moving from water quality and habitat
improvements to enhanced fish production. The effects of habitat
alteration and water quality on fish populations are generally
indirect, gradual and unquantifiable (Burns 1991). Fish habitat
consists of a wide range of physical, chemical and biological
factors. Modifications of fish habitat can vary along a geographic
range or across a temporal spectrum and present a very complex
situation. To add another level of complication, fish can also
respond to their environment by changes in their behavior, growth,
20
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reproduction, and physiology. The FMP Workgroup will begin a
comprehensive review of habitat issues and how they relate to fish
production during 1995. The ultimate goal of this project will be
to develop habitat sections in the FMPs that can be utilized as a
vehicle for encouraging and justifying resource conservation by
those agencies with regulatory authority over modifications to
terrestrial and aquatic ecosystems (Carter, in prep).
One of the goals of the ASMFC Amendment #5, to the interstate
plan, is to provide for the restoration and maintenance of critical
habitats for striped bass. In order to accomplish this task,
critical habitats and environmental factors that limit long-term
maintenance and productivity must be identified and standards of
environmental quality adopted and promoted. Amendment #5 will
include a description of striped bass spawning, nursery, and adult
resident habitats; narratives on the present status of habitats and
impacts on the fisheries; and the identification and distribution
of essential habitats. The status of habitats will include current
threats and effects on the ability to harvest and market. Once
these parameters are described by ASMFC, they can be applied to the
Chesapeake Bay region. Each state will be required to implement
management measures that protect striped bass habitat so that
existing habitat is preserved; incompatible activities between
state and federal fishery management agencies are avoided; and
historical habitat is restored, improved or enhanced.
CONCLUSION
Coordinated, interjurisdictional management efforts have
restored coastal striped bass stocks to historic levels (as of
January l, 1995). This assessment is based on a projected spawning
stock biomass of mature Chesapeake Bay females exceeding the
historical high average (calculated for 1960-1972, ASMFC 1994). In
addition, estimated fishing mortality rates have been below current
target levels (F=0.25); juvenile recruitment has been excellent;
and CPUE has been steadily increasing. The ASMFC is developing
Amendment #5 to provide management guidelines for the long-term
maintenance of a self-sustaining spawning stock and provide the
restoration and maintenance of critical habitats. During 1995,
areas that should be emphasized to improve striped bass management
are:
1) Adopt Amendment #5 to the ASMFC Fishery Management Plan.
2) Review and revise the Chesapeake Bay FMP to account for
changes in Amendment #5.
3) Continue to refine the spawning stock biomass (SSB) model.
4) Continue and improve efforts to monitor commercial and
recreational (including charterboat) harvests.
5) Review and improve the habitat section, focussing on how
habitat issues relate to striped bass production, so it can be
used to justify the protection and enhancement of critical
habitats.
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Table l. Harvest of striped bass from Maryland by fishing year and
fishery (pounds).
Fishing
Season
Commercial
(Bay)
Commercial
(Coast)
Recreational
Charter boat
Trophy
*1990/91
133,912
4,926
413,896
97,971
closed
*1991/92
326,986
14,454
460,866
159,218
7,973
*1992/93
791,210
17,770
844,973
229,259
22,834
1993/94
856,622
4 , 065
649,018
349,531
61,640
* Final totals for each fishery. Previously reported numbers were
preliminary.
Table 2. Harvest of striped bass from Virginia by fishing year and
fishery (pounds).
Fishing
Season
Commercial
Recreational
Charter boat
1990/91
264,250
180,000
* 8,000
1991/92
201,830
210,690
* 9,540
1992/93
205,192
214,455
*10,364
1993/94
209,983
495,450
436,326
* New estimates should be available in 1995.
Table 3. Harvest of striped bass from the Potomac River by fishing
year and fishery (pounds).
Fishing
Season
Commercial
Recreational
Charter boat
1990/91
168,479
63,186
18,204
1991/92
216,755
162,500
14,193
1992/93
127,398
193,738
28,378
1993/94
142,742
120,899
9,857
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Table 4. Summary of the estimated striped bass losses from the
Maryland fisheries during the 1993/1994 season due to
illegal fishing, hook and release mortality, .and bycatch
(MDNR 1994).
Fishery
Recreational
subtotal
Commercial
White Perch
American Shad
TOTAL
Gear
pound net
gill net
hook & line
ocean trawl
gill net
ocean gill
net
Losses
(# of fish)
Hist. 192,461
New 89,673
385
poaching- 1,500
sublegal
bycatch- 4,894
410
69
150 - 40,879
138
97,217 - 240,736
Losses
(Ibs)
*
*
1,001
3,375
• *
820
324
150 - 40,879
846
*
* Data not available,
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Table 5. Annual striped bass juvenile indices from Maryland and
Virginia, 1980-1994.
YEAR
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
MARYLAND
(Arithmetic Mean)
2.0
1.2
8.4
1.4
4.2
2.9
4.1
4.8
2.7
25.2
2.1
4.4
9.0
39.8
16.1
MARYLAND
(Geometric Mean)
1.0
0.6
3.5
0.6
1.6
0.9
1.3
1.5
0.7
4.9
1.0
1.5
2-3
14.0
6.4
VIRGINIA
2.5
1.6
2.7
3.5
4.4
2,4
4.8
15.8
7.6
11.2
7.3
3.8
7.3
18.1
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Table 6. Summary of hatchery striped bass recovered
during Maryland's Chesapeake Bay Stock'
Assessment surveys and the coastal tagging
survey, September 1992 - May 1993.
Fall Pound net (Sept. - Oct. 1992)
System
Upper Bay
Middle Bay
Lower Bay
TOTAL
Total
Caught
1524
2306
1225
5055
Number
Scanned
806
1245
537
2588
Number
Positive
17
71
24
112
Percent
Positive
2.1
5.7
4.5
4.3
Winter Gill Net (Jan. - Feb. 1993)
System
Choptank R.
Main Bay
Total
Total
Caught
98
1989
2087
Number
Scanned
97
1939
2036
Number
Positive
1
55
56
Percent
Positive
1.0
2.8
2.8
Spring Spawning Stock (April - May 1993)
System
Choptank R.
Potomac R.
Upper Bay
TOTAL
Total
Caught
3287
1803
3062
8152
Number
Scanned
2812
1784
1986
6582
Number
Positive
93
13
24
130
Percent
Positive
3.3
0.7
1.2
2.0
Coastal Tagging Survey (Feb. 1993)
System
TOTAL
Total
Caught
577
Number
Scanned
577
Number
Positive
34
Percent
Positive
5.9
25
-------
CO
CO
CO
_0
CC
0)
LL
Figure 1. Coastwide female striped bass
spawning stock biomass (SSB).
YEAR
Source: Rugolo et a!., 1994
26
-------
LJJ
o
CC
LU
Q_
Figure 2. Length-frequency distributions of
commercial pound net catches from Fall 1970, Fall
1992, and Fall 1993.
25
20 -
15 -
10 -
20
25
30
LENGTH (inches TL)
MONR Striped Bass Stock Assessment Data
-------
to
CD
LU
O
DC
LU
Q_
Figure 3. Age-frequency distributions of commercial drift
gill net catches, Winter 1981-82, Winter 1992-93, and
Winter 1993-94.
50
40
30
20
10 -
0 4
1981 -82
1992-93
* 1993-94
AGE CLASS
MDNR Striped Bass Stock Assessment Data
-------
LJJ
o
DC
LJJ
O.
Figure 4. Length-frequency distributions of
Maryland's recreational harvest in 1979 -1980,1992,
and 1993.
20
15
10
11979,1980
11992
1993
r
25
30
35
LENGTH (inches TL)
MDNR Striped Bass Stock Assessment Data
-------
References
ASMFC 1994. Atlantic States Marine Fisheries Commission 1994 Annual
Review of Interstate Fishery Management Plans: Atlantic
Striped Bass (Morone saxatilis). John Field, ed. October,
1994. p. 33-39.
Austin, H.M., A.D. Estes and D.M. Seaver. 1993a. Estimation of
juvenile, striped bass relative abundance in the Virginia
portion of the Chesapeake Bay. Annual Progress Report 1993.
Virginia Institute of Marine Science, Gloucester Point,
Virginia.
Austin, H.M., J.A. Colvocoresses, and T.C. Mosca, III. 1993b.
Develop a Chesapeake baywide young-of-the-year striped bass
index. Final Report to the Chesapeake Bay Stock Assessment
Committee, Cooperative Agreement No. NA16FUO393-01.
Hornick, H.T., R.K. Schaefer, D.T. Cosden, K.J. Booth, D.M.
Goshorn, J.L. Markham, M.L. Gary, C.B. McCullough, and W.S.
Harbour. 1993. Investigation of striped bass in Chesapeake
Bay. USFWS Federal Aid Performance Report. Project No. F-42-
R-6. Maryland Department of Natural Resources, Annapolis,
Maryland.
Maryland Department of Natural Resources. 1994. Maryland's spring
and fall 1993, and winter 1994 striped bass harvest and
background fishing losses. Maryland Department of Natural
Resources, Annapolis, Maryland.
Olney, J.E., J.D. Field, and J.C. McGovern. 1991. Striped bass
egg mortality, production, and female biomass in Virginia
Rivers, 1980-1989. American Fisheries Society. 120:354-367.
Potomac River Fisheries Commission. 1994. The 1993 striped bass
harvest report. A special report to ASMFC, March 1994.
. Potomac River Fisheries Commission, Colonial Beach, Virginia.
Rugolo, L.J., P.W. Jones. 1989. A recruitment-based interseason
harvest control model for Chesapeake Bay striped bass.
Maryland Dept. of Natural Resources, Annapolis, Maryland.
Rugolo, L.J., P.W. Jones, R.K. Schaefer, K.S. Knotts, H.T. Hornick
and J.L. Markham. 1994. Estimation of Chesapeake baywide
exploitation rate and population abundance for the 1993
striped bass stock. Maryland Dept. of Natural Resources,
• • Annapolis, Maryland.
Rugolo, L.J., V.A. Crecco, and M.R. Gibson. 1994. Modeling stock
status and the effectiveness of alternative management
strategies for Atlantic coast striped bass. Summary Report to
the Striped Bass Management Board, ASMFC. May, 1994. p. 1-30
30
-------
Uphoff Jr., J. H. 1994. Spawning stock status of striped bass in
Maryland's Chesapeake Bay, 1955-1994 determined by egg
presence-absence. Fisheries Division, Technical Report 12.
Maryland Dept. of Natural Resources, Annapolis, Maryland.
Virginia Marine Resources Commission (VMRC). 1994. Review of
Virginia's 1993 striped bass fisheries and monitoring
programs. A Report to the ASMFC Striped Bass Technical
Committee. VMRC, Newport News, Virginia.
31
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CHESAPEAKE BAY STRIPED BASS IMPLEMENTATION PLAN 1994
Problem Area
Action
Date
Comments/Notes
1.1 Overfishing.
1.1.1 The jurisdictions will utilize a
combination of harvest restrictions to
meet target fishing mortality rates.
Began 1990, continued
through 1994.
The striped bass stock has been
declared restored as of January 1,
1995. Jurisdictions will establish
strategies to meet transitional fishing
mortality targets,
1.1.2 The jurisdiction will cap
commercial harvest with a quota not to
exceed 20% of the average annuel
commercial catch from 1972-1979.
Began 1990, continued
through 1994.
The MD harvest is governed by a
harvest control model. During 1993
and 1994, the commercial quotas
were: 991,529 Ibs., MD; 211,000
Ibs., VA; 155,000 Ibs., PRFC; and no
commercial fishing in DC.
1.2 Reduced spawning stock.
1.2.1 The jurisdictions will establish a
minimum size limit of 18 inches in the
Bay.
Began 1990, continued
through 1994.
1.2.2 The jurisdictions will prohibit the
keeping and sale of sublegal striped
bass bycatch.
Begen 1990, continue
through 1994.
1.2.3 The jurisdictions will establish a
maximum size limit of 36 inches in the
Bay.
Begen 1990,
discontinued in 1994.
An 19 inch minimum size limit has
allowed the stock to increase in size •
and diversify in age and length. The
Atlantic coast minimum size limit is 29
Inches and Maryland's spring trophy
size limit is 36 inches. Size limits are
being reviewed for the transitional
fishery.
Harvest of sublegal fish has been
minimized with mesh size restrictions.
Regulations are in place that prohibit
the possession and sale of fish under
19 inches. Losses due to sublegal
bycatch have bean estimated.
Maximum size limits were set as a
conservative measure. Stocks have
recovered and jurisdictions are
eliminating maximum size limits.
32
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1.3 Reduced number of spawners.
1.3.1 During the trensition fishery, age
VIII and older females will be protected
until they comprise a certain
percentage of the female spawning
population.
1.3.2 During a recovered fishery,
females age VIII and older will be
protected at a certain percentage of the
spawning population.
1.3.3 Maryland and Virginia will
continue hatchery production to
enhance the striped bass spawning
stock.
1.3.4 Hybrid and non-native striped
bass stocking will be restricted
according to ASMFC guidelines.
Began 1990, continued
through 1994.
Open
Continue
Began 1991, continued
through 1994.
The ASMFC declared the striped bass
stock recovered based on the results
of a stock simulation model of coastal
female spawning stock biomass (SSB).
The SSB model was agreed upon as a
management tool in place of
protecting age 8 + females because it
reduces the amount of error strong
year-classes have on the population.
The SSB model will be used to monitor
and protect a sustainable spawning
population.
Stocking has been restricted but
efforts continue to enhance areas
where striped bass abundance remains
at tow levels.
2.1 Allocation issues.
2.1.1 Maryland quota will be allocated
as follows: 42.5% commercial; 42.5%
recreational; and 15% charter. Virginia
and Potomac River Fisheries
Commission will use various
restrictions to equitably allocate
harvest.
Began 1990, continued
through 1994.
Commercial quotas for each
jurisdiction were allocated by gear
type. The 1993/1994 and 1994/1995
recreational caps were: 891,529 Ibs.,
MD recreational; 314,657, MD
charterboat. The VA and PRFC
recreational fisheries had a creel limit
and seasonal restrictions.
2.1.2 Commercial fishing seasons will
be closed when harvest caps are
reeched, regardless of time during
season.
Began 1990, continued
through 1994.
Jurisdictions continue-to monitor the
commercial harvest of striped bass.
2.2 Gear restrictions.
2.2.1 The jurisdictions will establish
minimum mesh sizes for gill nets.
Began 1990, continued
through 1994.
Jurisdictions continue to enforce
minimum mesh sizes targeting striped
bass 18 inches and larger: 5 Inches,
MD and VA; and 5.25 inches. PRFC.
33
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2.2 Gear restrictions (continued).
2.2.2 Maryland and Virginia will require
drift gill net* to be marked, tended, and
recovered daily. Other Virginia gill nets
must be marked. Potomac River
Rsheries Commission will continue
fixed location for gill nets.
2.2.3 Maryland and Virginia will
establish a maximum length of gill net
allowed. Potomac River Fisheries
Commission will establish a maximum
number oY gill net licenses.
2.2.4 Maryland and Virginia will
establish annual quotas for their
commercial fisheries.
Began 1990, continued
through 1994.
Began 1990, continued
through 1994.
Began 1990, continued
through 1994.
Regulations vary between Jurisdictions.
Regulations have been enacted.
Commercial harvest caps were
enacted (see Action 1.1.2). Daily and
seasonal limits ware also established.
2.3 Selling and buying striped bass.
2.3.1
A) Maryland will establish check
stations;
B) Virginia dealers and watermen will
be required to have a special permit to
sell;
C) Sale by recreational and charter
fishermen will be prohibited.
Began 1990, continued
through 1994.
A) MD established check stations.
B) VA established a permit system for
harvesters and dealers.
C) Regulations ware established.
2.3.2 Jurisdictions will establish
reporting systems for buyers end
commercial watermen.
Began 1990, continued
through 1994.
MD watermen are required to maintain
daily logs and submit it at the end of
the season and dealers call in daily and
submit weekly submittals. VA
watermen and dealers must submit
weekly reports. PRFC watermen
report weekly.
2.4 Seasons, creel limits, and fishing
areas.
2.4.1 A-E Jurisdictions will establish
fishing seasons in the Bay with as
much consistency as possible.
Began 1990, continued
through 1994.
Seasons differed slightly because of
striped bass migratory patterns and
local practices. Refer to the annual
report for seasons. Season
restrictions are being reviewed.
34
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2.4 Seasons, craal limits, and fishing
areas (continued).
2.5 Monitoring
2.6 Management and enforcement
authority.
3.1 Stock assessment and research
needs.
2.4.2 Maryland will prohibit commercial
striped bass fishing on weekends and
at night.
2.4.3 Jurisdictions will maintain striped
bass fishing areas.
2.4.4.1 Jurisdictions will establish creel
limits of. up to 5 fish for the
recreational and charter fisheries.
2.4.4.2 Maryland may allow one trophy
fish per boot during a May trophy
season.
2.5.1 Jurisdictions will monitor striped
bass harvest using a variety of
method*.
2.5.2 District of Columbia will conduct
an angler survey to determine striped
bass catch and effort.
2.6.1 Jurisdictions will develop
appropriate mechanisms for timely
management of the striped bass
resource.
2.6.2 Jurisdictions will adopt
consistent enforcement policies.
3.1 Jurisdictions will continue their
efforts to collect stock information.
Began 1 990, continued
through 1994.
Began 1990, continued
through 1994.
Began 1992, continued
.through 1994.
Began 1992, continued
through 1994.
Began 1990, continued
through 1994.
Began 1991, continued
through 1994.
Began 1990, continued
through 1994.
Began 1990, continued
through 1994.
Continue
MD has established regulations
prohibiting commercial striped bass
fishing on weekends and at night. MD
also prohibits recreational fishing at •
night.
Striped bass area restrictions are being
reviewed.
MD fall creel limit*: 1 fish/person/day,
recreational; and 2 fish/person/day,
charterboats. VA: 2 fish/person/dey.
PRFC and DC: 1 fish/person/day.
Creel limits are being reviewed.
MD 1993: 1 fish/angler/season. MD
1994: 1 fish/angler/day and 3
fish/season.
Jurisdictions used a combination of
access/intercept and telephone
surveys, check stations and reports
from harvesters and dealera.
Jurisdictions have the authority to
regulate their fisheries. Regulations
permit the opening and closing of
seasons when quotas/caps are
reached.
Jurisdictions continued to maintain an
aggressive enforcement program.
These programs include assessment of
Juvenile and adult abundance,
monitoring the fisheries, tagging for
stock discrimination, migration and
mortality estimates.
35
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3.1 Stock assessment and research
needs (continued).
3.2 Jurisdictions will review, update,
and initiate studies as needed on
reproduction, early mortality, etc.
Variable
Jurisdictions are in the progress of
developing a bavwWe juvenile index.
4.1 Water quality.
4.1 Jurisdictions will continue to
support the commitments under the
1987 Chesapeake Bay Agreement.
Continue
Significant habitat Improvements have
been mads within the main*tern of the
Bay. Tributary and Basinwide Toxics
Reduction and Prevention Strategies
have been adopted and will further
enhance Bay habitat.
LEGEND
MD - Maryland
VA - Virginia
PRFC - Potomac River Fisheries Commission
DC • District of Columbia
36
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