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                    DRAFT
                Chesapeake Bay
              Blue  Crab
           Management  Plan
            Chesapeake Bay Program
                DRAFT
             Agreement Commitment Report

               Produced under contract to the
            U.S. Environmental Protection Agency


       Printed by the U.S. Environmental Protection Agency
             for the Chesapeake Bay Program
CB 00616

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SECTION 1. BACKGROUND                                                           N-^

General Information

The blue crab, Callinectes sapidus, is a dominant epibenthic predator in estuaries, lagoons
and coastal habitats of the Western Atlantic, Caribbean and Gulf of Mexico (Williams,
1984).  It is economically important throughout its range and has supported the largest
single-species crab fishery worldwide over the past decade (FAO, 1990).  The blue crab
harvest from Chesapeake Bay alone accounted for over 50 % of the national total during the
past two decades (Orth and van Montfrans, 1990), and it consistently outranks harvests from
other shellfish specjes in Chesapeake Bay by weight and total dollar value. The recreational
fishery, which is estimated at about 25 %  of the total commercial and recreational catch in
Chesapeake Bay, also contributes greatly to the economy of the region.  Thus, the blue crab
is an important natural resource requiring sound management to protect its long-term health,
ecological and economic benefits.

Recently, substantial increases in fishing pressure, a corresponding decrease in catch per unit
effort (Fig.  1), and concurrent declines in  other major exploitable fishery species (e.g.,
oysters and various finfish) have raised concerns over the potential for a major decline in the
blue crab stock and emphasize the need for fishery management based on a sound ecological
foundation.  This is particularly important given the substantial interannual fluctuations in
stock abundance (Fig. 2) which places the species at risk of overexploitation.

Causes of population fluctuations are poorly understood.  A spawning stock-recruitment
model developed from a 20-year data base can only account for 20-60 % of the variance in
the Virginia commercial dredge fishery (Lipcius and Van Engel, 1990).  Development of
population models applicable to the blue crab and its fisheries requires an  understanding of
processes associated with postlarval and early juvenile stages.  In particular, processes
affecting transport (i.e., dominant wind patterns  during the recruitment season and runoff),
settlement, metamorphosis (physiological state, behavior, nursery  habitat availability and
salinity effects) and post-settlement survival (mortality via fishery harvest and natural
predation including cannibalism) that influence juvenile survival appear critical to
understanding blue crab population fluctuations.
Life History

Larval and Postlarval Phases

The life history of the blue crab (Fig. 3) is similar to that of other marine species with
complex life cycles and open populations.  In Chesapeake Bay, larvae (zoeae) are released by
mature females in high salinity water near the mouth of the Bay (Van Engel, 1958).  Zoeae
are transported to the continental shelf where development proceeds for about 30-45 days
through 7 or 8 developmental stages (reviewed in Millikin and Williams, 1984; McConaugha

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et al., 1983; McConaugha,  1988).  Larvae feed on zooplankton and plant material (Truitt,
1939) High salinities in excess of 30 parts-per-thousand (ppt) are required for optimal
development (Costlow,  1967) and larvae are poorly adapted physiologically to undergo
proper development at salinities much below 26 ppt., emphasizing the need for an oceanic
environment for larval development.

Metamorphosis to the postlarva (megalopa) stage occurs on the nearshore Atlantic shelf
(Epifanio et al., 1984).   A retention mechanism has been postulated for blue crabs involving
the along-shore southerly flow of water entraining early zoeal stages,  coupled  with a mid-
shelf countercurrent and wind-generated flow of surface water to  the north in which later-
stage larvae and postlarvae return near the Bay mouth.
Settlement and Recruitment

In many marine species, larval or postlarval abundance and settlement set the limits within
which population size is determined, since these individuals represent the survivors of early
life-history phases (Fritz et al., 1990).   Blue crab postlarval abundance, though highly
variable (Fig. 3), generally follows a neap-spring tidal cycle,  with brief periods of high
abundance following spring  tides by several days.  This suggests that entry into the
Chesapeake Bay is facilitated by increased tidal excursion.  Superimposed on this fortnightly
pattern  are peaks of abundance related to  wind events that transport megalopae towards the
coast and into Chesapeake Bay via non-tidal volume exchange (Goodrich et al., 1990). Once
within Chesapeake Bay,  megalopae migrate vertically in response to  light and tide, utilizing
nocturnal flood tides to augment their transport up the estuary to shallow estuarine nursery
habitas  (Olmi, 1993).

Settlement of blue crab postlarve has been assessed in Chesapeake Bay using artificial
settlement substrates, and occurs  primarily between July and mid-November each year.
Settlement is characterized by episodic pulses during periods surrounding full and new  moon
(Orth and van Montfrans, 1987; van Montfrans et al., 1990; Fig. 3). The same fluctuating
pattern  of settlement has been observed annually, with substantial variation in timing and
magnitude.  The potential exists that episodic settlement peaks, which account for more than
half the annual total, may be the  major determinants of adult population size, similar to that
observed for tropical reef fishes (Doherty, 1987) and the Western Australian rock lobster
(Caputi and Brown, 1986).  Artificial settlement substrates may provide a measure of
postlarval settlement which reflects both planktonic abundance and natural settlement which
may serve as an indicator of future harvests in the fishery.

Early Juvenile Stages

Late premolt postlarvae settle  in the lower estuary and utilize submerged seagrass beds as
nursery areas until approximately the fifth juvenile instar (Orth and van Montfrans, 1987;
Pile, 1993).  Large juveniles migrate out of grass beds and are found in greatest abundance

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                                                                                      *
at upriver stations in lower bay tributaries and begin appearing in the upper-Bay Maryland
waters.  This evidence suggests the importance of lower salinity areas for larger juvenile
crabs which ultimately grow and segregate by habitat with large males generally occupying
the upper reaches of tributaries and females migrating towards higher salinity (Hines et al.,
1987).
Adults and Reproduction

Blue crabs mature at approximately 12 to 18 months of age (Van Engel, 1958) with an
expected average lifetime of two to three years under heavy fishing pressure. The
male:female sex ratio of the blue crab varies with salinity.  Males are usually more abundant
in lower salinities than  females, and most mating occurs from May  through October in
lower- and mid-Bay habitats where salinity preferences overlap.  Female crabs initiate their
final molt at approximately 115 mm (Knotts, 1989) and males "cradle" the females beneath
them during stages of molting.  Mating takes place while the female is in the soft-shell stage
of her final molt. After this final interval of growth, the average size of adult females is 155
mm (Knotts,  1989; Hines et ah, 1987).  The pairs separate and, after the shell hardens,
females migrate to higher salinities of the lower Bay. Early arrivals will spawn prior to the
coming winter while latecomers spawn the following spring after winter hibernation.  Males
and juveniles remain in lower salinities of the upper Bay and tributaries throughout winter
and hibernate in the sediment.

Females carry their egg mass beneath their aprons and open to the water to expose an
orange, round sponge containing 750,000 to 8,000,000 eggs, depending on crab size (Prager
et al.,  1990).  Blue crabs are serial spawners and spawn from May  to September up to three
times in a season, with a minor peak in June and a major peak July and August
(McConaugha et al., 1983; Jones et al.,  1990).
Predator-prey Relationships

Blue crabs serve as both predator and prey in the benthic and planktonic food webs of
Chesapeake Bay.  Movement through the water column by postlarvae (Olmi, 1993) make
them a food source for plankton feeders such as menhaden, as well as other finfish that
forage in the water column.  Settled postlarvae and young juveniles become prey for
numerous predators including eel, drum, spot, croaker, striped bass,  trout, catfish, some
sharks and cownose rays.  Endangered  Atlantic Ridley sea turtles migrate to the Bay every
summer for their preferred food, blue crab.  Recent concern has been raised over the
recovery efforts of the striped bass population where the resurgence of such a predator may
deplete the blue crab resource.  Goshorn and Casey (1993) and Mosca et al. (in prep.)
examined the relationship between striped bass abundance and blue crab landings in
Chesapeake Bay and found no significant relationship.  Instances where blue crabs are

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plentiful in the stomachs of striped bass are likely the result of opportunistic feeding (Booth
and Gary, 1993).

Prey of the blue crab include bivalves, crustaceans, fish, annelids, plants and detritus
(Darnell, 1958; Tagatz, 1986; Alexander, 1986). Although the blue crab is an opportunistic
predator that feeds on commonly occurring benthic prey (Laughlin,  1982; Mansour, 1992),
recent research on feeding  habits of blue crabs indicates that soft-shelled bivalves (e.g.,
Macoma spp. and Mya arenaria) are preferred food.  When these resources become depleted,
cannibalism on juvenile crabs increases in intensity (Mansour, 1992).  The incidence of
cannibalism in blue crabs from the York and Rappahannock Rivers averaged about 25-30 %
over a two year period (1988-1989).  Blue crabs may control some bivalve populations
(Lipcius and Hines, 1986; Eggleston, 1990; Mansour and Lipcius, 1993; Eggleston et  al.,
1993), and cannibalism may serve as  a self-regulating control on crab populations,
particularly during periods  of high crab abundance or low alternative prey abundance
(Mansour and Lipcius, 1993).
Habitat Requirements

Regionally, vegetated habitat area and commercial harvests of the blue crab are significantly
correlated (Orth and van Montfrans, 1990).  Lower Chesapeake Bay vegetated habitats are
most important for juvenile crabs on a bay-wide basis (Heck and Thoman, 1981; Penry,
1982; Heck and Thoman, 1984; Heck and Wilson, 1987; Wilson et al., 1987; Orth and van
Montfrans, 1987; Montane et al., 1993), and thus their availability and functional ecology in
concert with recruitment processes may  influence blue crab population size.  Beds of
submerged vegetation such as eel grass (Zostera marina) and Widgeon grass (Ruppia
maritima) fall within the salinity range of invading postlarvae and provide developing
juveniles with protection from predators during initial growth (Pile, 1993) and sub-adults
with molting  refugia (Ryer et al., 1990). In addition, juvenile crabs grow more rapidly in
seagrass beds than in adjacent unvegetated areas (Perkins,  1993).  As juveniles grow larger
than about 25 mm in carapace width they migrate out of grass beds and disperse  throughout
other shallow-water habitats.  Tidal guts of small creeks and rivers in and around salt
marshes provide additional shallow-water habitats for juvenile and male crabs to feed and
take refuge during molting.

Grass beds also serve as the preferred overwintering habitat for juvenile crabs in  the lower
bay. Where seagrass beds are sparse in  northern parts of Chesapeake Bay, juveniles and
mature males bury in unvegetated creek and river channels, as well as the bay mainstem
(Hines et al., 1987).

Calculations of the total areal coverage of seagrass and unvegetated habitats < 2 m in depth
combined with estimates of juvenile abundance for the York and Rappahannock Rivers
demonstrate the relative importance of vegetated habitats to young juvenile blue crabs.  Total
areal coverage of unvegetated bottom is  approximately an order of magnitude greater than

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seagrass beds (Fig. 4).  In contrast, juvenile blue crab densities are nearly an order of
magnitude greater in seagrass (Fig. 4). Despite the significantly higher coverage of
unvegetated bottom, there are more juvenile blue crabs in lower bay seagrass beds (an
estimated  14 billion crabs) than in unvegetated habitats (approximately 11 billion,  Fig. 4),
indicating the importance of seagrass beds to newly settled and young juvenile blue crabs.
Chesapeake Bay Blue Crab Fisheries

Management of the baywide blue crab stock across geographic regions and state boundaries
is a dynamic and complicated process.  Principal commercial fishery techniques for hard
crabs include trotlines, crab pots and dredges, whereas scrapes and peeler pots are mainly
used for the capture of peeler crabs (i.e., crabs  about to molt or shed their exoskeleton) to be
used in  the soft-shell and bait industries.  Trotlines are utilized in Maryland where
commercial crab pots are prohibited in tributaries, but are not commonly used in Virginia.
The crab pot is the most widely used gear throughout Chesapeake Bay.

Blue crabs are currently the most valuable commercial fishery, as well as a highly valued
recreational species in Chesapeake  Bay.  The blue crab supports the largest crab fishery
worldwide in terms of landings (FAO, 1991).  An eleven year average (1982-1992) indicates
annual commercial landings in Maryland of 45.4 million pounds (MDNR data). The
reported 1993  commercial harvest of over 57 million pounds in Maryland was worth
approximately 35 million dollars at dockside. In 1993, there were 6,740 commercial crab
licenses in Maryland (MDNR data).  The largest proportion of commercial catch is landed by
crabbers licensed to fish more than 50 crab pots (34% in 1992), followed by tidal fish license
holders (31% in 1992) and unlimited crab  catcher licensees (23% in  1992).  These three
license types represent crabbers who previously have not been limited in the amounts of gear
they can fish.  In 1992, limited crab catcher licensees (up to 50 pots, trotlines, etc.) landed
only 12%  of the total commercial catch.  Licensed noncommercial crabbers in  1993 (15,378)
were  more than double the number of licensed commercial crabbers, with 54% of all license
types combined issued as noncommercial residents.  Harvest by noncommercial crabbers for
1993  was  more than 6 million pounds, almost 10% of the  total combined harvest
(commercial and noncommercial).

The preliminary estimate of commercial landings in Virginia in  1993 is 50.6 million pounds
(VMRC data,  mandatory reporting initiated in 1993,  1993 landings not comparible to
landings from  previous years).  In  1993, Virginia had 4,568 licensed commercial crabbers.
Issuance of crab licenses in Virginia has not stabilized, and sales of licenses for crab potting
and dredging have continued to increase over recent years.  Crab dredging is limited to a the
lower portion of the Bay mouth (prohibited in tributaries) and license breached 300 in  1989,
with a high of 315 in 1993.  Licensing structure for crab potters changed in 1993, but from
1980  to 1992,  the number of crab pot licenses increased steadily from 1,738 to 2,614.

In 1990, 500,000 recreational crabbers in Maryland made  2.5 million trips, harvesting 11

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million pounds of crabs (Stagg, et al.,  1992).  The 1990 recreational survey interviewed both
licensed and unlicensed crabbers in Maryland, and their catch was estimated to be 19% of
the total combined harvest (commercial and recreational) for 1990.  In 1993, 15,378 licenses
were issued in Maryland for recreational crabbing, composing 11%  of total reported landings
for that year.  Although there are no quantitative estimates of the recreational fishery for
Virginia, annual reporting by all licensed recreational fishermen is required as of 1993.
Improvements in data reporting should reveal the impact of the recreational catch on the blue
crab stock.
Abundance, Catch Per Unit Effort and Exploitation

Catch statistics for the Virginia commercial dredge fishery show a significant decline in
winter harvests from 1956 to 1992 (Fig. 2), and this decline is also reflected in the fishery
independent trawl survey conducted by VIMS/W&M which shows a decline in adult female
abundance for the same time period (Fig. 1).  The increase in commercial landings in
Maryland after 1981 coincides with a change  in the  reporting system, however, it is believed
that the increase in landings was real and a result of an increased crab population.  Maryland
DNR summer trawl survey data, which has been collected annually since 1977, indicates that
blue crab abundance was relatively high in 1977, low from 1978-1980, and has been
relatively high through 1986.  Since then (1987-1993), considerable fluctuation has been
observed.  Virginia Institute of Marine Science (VIMS) trawl survey data from 1972-1988
indicates major interannual fluctuations in blue crab  abundance, often asynchronous with
abundance patterns of crabs in Maryland.  Lipcius and Van Engel (1990) note that population
abundance remains high or low for two or more years before significant fluctuation is
observed, and suggest some internal feedback mechanism within the population.  However,
this has not been  the case in recent years.  Winter dredge survey data from MD DNR,
University of Maryland, and VIMS  show fluctuations between single years with high
population estimates in 1991 and 1993 and a very low estimate in 1992 (Volstad Łt al.,
1994).  This  recent and rapid fluctuation may be cause for concern and should be
investigated to understand the cause(s).  Catch and effort data for Maryland commercial
trotlines and crab pots indicates a trend of increasing effort with concurrent declines in catch
and CPUE, and suggests fishing pressure is becoming a  significant factor affecting blue crab
abundance in the  Chesapeake Bay.

The population of blue crab in Chesapeake Bay  was  estimated by Volstad gt aJL (1993) to be
653,3 million crabs, of which 366.7 million were 50 mm or greater.  While these estimates
are thought to be conservative  when compared to total Baywide landings, they are the only
estimates currently available. Little is known about  the growth of crabs in the wild, and it is
uncertain if crabs in the winter, less than 50 mm, will  enter the fishery until the following
year (Casey,  pers. comm., Montane el aL, 1993). Assuming that they do, the exploitation
rate of crabs  50 mm and greater in 1992 was  50% (Volstad el aL, 1994).  This figure does
not include harvest of soft and peeler crabs or harvest by recreational fishermen which would
increase the exploitation rate.  Recent analysis show  that indices of abundance, such as those

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generated by the VIMS/W&M trawl survey, are useful in projecting commercial landings
(Fig. 5).
Problems and Concerns

Fishing Pressure

The blue crab fishery is diverse and targets juvenile and adult segments of the population.
Peeler crabs are harvested throughout spring and summer and are consumed as soft crabs or
sold as bait.  With the exception of a small percentage of larger males, most crabs caught by
this segment of the fishery are harvested prior to reaching maturity and are therefore
removed before reproducing. Economically, however, the peeler crab fishery constitutes the
highest rate of economic return per pound of harvest and therefore maximizes financial gain
from the resource. The impact of this fishery  on the blue crab population is difficult to
assess  due to inadequate mandatory reporting regulations in the past.

The hard crab fishery represents the largest component on a bay-wide basis both in terms of
total dollar value and landings.  Larger crabs are harvested in their hard shell condition
throughout the bay in the pot (Virginia and Maryland) and trot line (Maryland) fishery.   The
pot fishery targets both males and  females; males represent an increasing proportion of the
harvest in the upper bay and tributaries whereas females are more common  with  increasing
proximity to higher salinity water associated with the lower tributaries and bay mouth.  The
Maryland trotline fishery targets primarily larger males in low salinity tributaries of the
upper bay. Egg-bearing females represent a large proportion of the harvest in the lower bay
during the spring in Virginia waters,  but make up a very small percentage of the population
in Maryland and are illegal to harvest.  Another segment of the fishery,  the winter dredge
fishery, occurs exclusively in Virginia and targets hard crabs that hibernate  and overwinter  in
deeper water of the bay mainstem. This component is estimated to consist of between 85%
and 98% mature, inseminated female crabs (Van Engle,  1962; Schaffner and Diaz, 1988)
waiting to spawn the following spring.  Because there exists a relationship between the
number of spawners  and the number  of young  (stock-recruit relationship) in this  species
(Lipcius and Van Engel,  1990), conservation of the blue crab at any stage of the fishery
should enhance subsequent harvests and maintain adequate population levels (Holmes,  1994).
Although the potential size of blue crab stocks are initially controlled by entry and settlement
of blue crab postlarvae (i.e., the survivors of the larval phase sensu, Fritz et ah, 1990) in
nursery habitats , subsequent natural mortality and fishery harvest are likely the major factors
affecting the size of the reproductive population.  There has been growing concern in recent
years that declines in  other important Chesapeake Bay fishery stocks (in particular, oysters)
have increased fishing pressure on the blue crab.  During years of relatively high levels of
abundance, fishing effort is rewarded with exceptional harvest.  Because blue crab abundance
fluctuates annually the potential exists that excessive fishing pressure on the resource during

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periods of low population levels could seriously affect the future of the resource as has
occurred in  many other exploited species (Holmes, 1994).

Wasteful Harvesting Practices

Fostering the survival of juvenile crabs benefits future recruitment to the brood stock.  Small
crabs contain less meat, and harvesting small crabs as soft shells before they recruit to the
hard crab fishery and the larger soft shell fishery may not maximize yeild from the resource.
The preference for larger crabs shipped into Maryland from out-of-state demonstrates a
market demand for larger softshell crabs (Uphoff et aL, 1993).  Size limits for the soft and
peeler fishery in Maryland are 3" and  3.5" respectively.  Virginia has no size limit, and the
Potomac River Fisheries Commission has a 3"  limit on peelers.  Increased size limits for soft
and peeler crabs would reduce juvenile mortality in the fishery (Rothschild et al.. 1992) and
make Chesapeake Bay's product more  competitive in  the market (Uphoff et aL, 1993).

Blue crabs are notorious cannibalistic predators, and sub-legal crabs retained in crab pots
with larger crabs have high mortality rates (Eldridge gt aL, 1979).  Cull rings worked in the
mesh of a crab pot create a circular opening that allows undersized crabs to escape.  In a
study by Raynie and Casey (1992), the use of cull rings 2.25" in diameter in crab pots in the
Chesapeake  Bay were tested for practical use in the crab fishery. The number of legal crabs
caught in pots was the same with or without cull rings. However, pots with three cull rings
retained 89% less sublegal  crabs, and pots with only one cull ring  retained 83% less sublegal
crabs than pots without cull rings. Thus,  cull rings are an effective measure in reducing the
capture of sublegal crabs in crab pots with no negative effect on the fishery, although,
commercial  watermen have expressed concern for the potential loss of small peeler crabs and
mature females that are legal to harvest.  Virginia is currently investigating the loss of small,
mature female from cull rings. (Summarize findings here?)  Self culling  crab pots also save
time culling crabs by hand  and reduce  injury to sublegal crabs during handling. Some
watermen have developed their own techniques and began to use cull rings voluntarily.
However, cull ring use in Maryland and Virginia is now mandatory and widespread
participation and standardized methods will further reduce sublegal  crab  catch and
subsequent mortality.

Crab pots lost to storms or left abandoned at the end of the fishing season are attractive
refuge sites  for blue  crabs.  Crabs and fish trapped  inside abandoned pots die and act as an
attractant for other animals that feed on the carcasses  (Guillory,  1993).  This process of self-
baiting is cited as a cause for concern in many  other pot fisheries including lobster,  king
crab,  snow crab and  black  cod.  As a cannibalistic species, blue crabs are attracted by the
weak and dead of their own species impounded in abandoned traps (Guillory,  1993).

A study of abandoned pots in Chincoteague Bay found 88% of crabs retained were sublegal
(Casey and Daugherty,  1989). A similar study by Casey and Wesche (1981) in Sinepuxent
Bay from July through December examined 40  un-baited pots on a weekly basis.  A total of
1,033 crabs  were impounded,  and crabs were tagged and returned to their respective pots.

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The results found 33% of the impounded crabs were unable to escape and subsequently died.
Although abandoned pots during winter months in Chincoteague Bay caught less crabs,
mortality increased to 100% due to decreased water temperature and crabs' inability to
hibernate.  A study in Louisiana found 55% mortality of impounded crabs (Guillory, 1993).

When interviewed, watermen in Chesapeake Bay cited estimates of a 10 to 30 percent rate of
pot loss annually (Casey, 1990). Management of the lobster fishery has called for action
regarding ghost pots in New England (American  Lobster Fishery Management Plan) by
developing biodegradable escape panels.  Casey (1990, 1992) studied materials for their
degradibility in Chesapeake Bay.  Escape panels  made of jute decayed within two months.
This may not be accepted by watermen who would have to replace them frequently
throughout a season.  Cotton twine was unreliable and decay rates were varied.  Materials
that degraded in six to nine months also proved impractical, and fouling tended  to clog
escape vents as panels degraded.  Other options are non-galvanized  wire mesh over a portion
of the pot or burning off galvanizing with a torch in a section chosen for escape.  Variability
of pots and the degradation of escape vent materials under different environmental conditions
needs to be examined more thoroughly before a recommendation can be made.

Habitat

Habitat protection is necessary to preserve both juvenile and adult crabs.
Drastic declines in submerged  aquatic vegetation (SAV) in the 1970's induced research to
determine the cause. Shoreline development, channel dredging, heavy boat traffic, crab
scraping and clam dredging have all been identified as causes of local destruction  (Hurley,
1991).  Crab scrapes are toothless  dredges that are dragged through grass beds to collect soft
and peeler crabs that take refuge there.  Heavy crab scrapes hauled  with power  winders may
cause significant damage to habitats that are important nursery grounds for young crabs and
other species.  Submerged grasses  sliced at the base offers no refuge until the grass is able to
recover. Areas of high frequency  scraping may be scarified the same way high frequency
propellor contact scars grass beds,  often resulting in permanent removal of the habitat
(Fonesca et aL, 1992).  Larger boats are being utilized more by crab scrapers, and the crab
scrape fishery is expanding as  more watermen drop out of the oyster fishery and outfit their
boats and power rigging for the crab fishery. Virginia prohibits mechanized hauling of crab
scrapes which must be pulled in by hand, and, consequently,  limits  the weight of scrapes that
can be hauled.

Shallow water habitats are necessary for blue crab  survival, particularly during development
after megalopea settle and metamorphose into tiny crabs. Shallow waters of creeks and
marsh guts are areas of high productivity and provide an abundance of food for young crabs.
Beds of submerged aquatic vegetation that grow in shallow water offer refuge from
predators.  Shoreline structures such as bulkheads,  revetment and breakwaters alter habitat
and reduce the area of shallow water available.  Dredging  for marinas and boat navigation
also reduce shallow water habitat.  Population on Bay's coastline, projected growth...number
of coastline permits issued last year...

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Sediment, from shoreline erosion and land erosion, and nutrient influx have been identified
as the main causes for Baywide declines. Land vegetation lowers the impact energy of rain,
and soil runoff is greatly increased in deforested areas (Schlesinger, 1991) such as
agricultural lands, developing areas and road construction.  Sediments suspended in the water
reduce the amount of light that reaches SAVs.  These sediments also settle out on leaves and
stems, further blocking photosynthesis.

Nitrogen and phosphorus from  agricultural and urban landscape fertilizers find their way to
the Bay in runoff after rains or as dissolved ions percolated through the soil.  Loss of
wetlands and forests to development and agriculture allows eroded  soil and nutrients that
were  once trapped and utilized  by terrestrial and wetland plants to enter water bodies
directly.   Automobiles and power plants that burn fossil fuel emit nitrogen oxide to the
atmosphere that is then deposited to bodies of water either as acid rain or dry particulates
(Schlesinger, 1991).  High levels of nitrogen and phosphorous  in waters and tributaries feed
algae that coat leaves and stems of SAVs and create favorable conditions for explosive algae
blooms.  Phytoplankton in the water column are so abundant during such blooms that they
block sunlight to bottom  dwelling grass beds.  Phytoplankton deeper in the water column are
blocked out by those crowded at the surface, and subsequently  die, fall to the bottom, and
decompose. Massive decomposition uses up oxygen at an accelerated rate and inhibits SAV
respiratation.

During the months of May to September, deeper waters of the  mid-Bay mainstem from
Baltimore to the mouth of the Potomac River become anoxic.  Oxygen is depleted and those
areas  are inaccessable to  blue crabs and benthic food organisms are killed. Cross-current
winds and low pressure storms  push anoxic water  into shallow  areas, causing further
destruction to  the benthos.

The anoxic portion of the Bay has been steadily increasing in size and duration over recent
history.  First documentations of oxygen depletion were mainly hypoxic areas,  or areas of
reduced oxygen content,  which over recent years have worsened to anoxic conditions (Officer
et al.. 1984).  Historically, the  affected area was limited to a narrow strip of the deep
channeled area of the Bay but it now covers a much wider area with fringes of hypoxia
stretching across almost the width of the Bay and down to the Bay mouth during some years
(Officer et aL_, 1984).

Heavy loads of nutrients  and  organic matter into the Bay are believed to be the cause for the
historical increase of anoxia throughout the Bay.  In May, when waters begin to warm,
accumulated organics from the  previous summer and fall beneath the halocline begin to
decompose and anoxic conditions continue in deep waters through September (Officer ej aL_,
1984; Taft gt aL, 1980).  As  winter approaches, decomposition slows to a halt and oxygen
supplies are replenished with  the diminished halocline until the  following spring.

The depletion  of filter feeders in the Bay, particularly oysters, may have had some added
effect. Oysters overwinter, unlike other phytoplankton feeders, and spring warming


                                          10

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stimulate feeding early in the season. Today a large portion of the spring phytoplankton
bloom goes ungrazed (Newell, 1988), adding to organic accumulations later in the season and
potentially further contributing to anoxia.  Oyster repletion efforts in the Bay are underway
with a revised management plan with progressive new strategies.  Disease and parasites will
effect the recovery rate and it will be many years before any recovery occurs.

Of final concern for the health of the blue crab is water quality.  Blue crabs that overwinter
in sediments are externally exposed to accumulations of toxins, and their preference for
benthic bottom feeders, such  as filter feeding bivalves, make them likely candidates for
internal contamination  as well.  Blue crabs examined in the two most polluted tributaries of
the Chesapeake Bay, the Elizabeth River (Norfolk, VA) and Patapsco River's Baltimore
Harbor (MD), found blue crab to be highly tolerant of toxic environments (ref.).  Very little
contaminants were found in their muscle tissue, however, toxins were accumulated in the
hepatopancreas.  Blue crabs'  migratory nature and short life history may make them less
sucsceptible to accumulations of toxins. Blue crab larvae, on the other hand, may be highly
sensitive to water quality, and sublethal doses of toxins have been found to slow larval
development (Epifanio, 1984).  Van Heukelem (1991) summarized literature on contaminants
to blue crabs including petroleum hydrocarbons, polynuclear aromatic hydrocarbons,
polychlorinated biphenyls, kepone,  mirex, malathion, halogenated compounds, chlorine and
chlorine produced oxidants, and  heavy metals including cadmium, chromium and mercury.
No literature was found for arsenic, copper, lead, mercury, nickel or zinc.
Conclusion

The following section will address concerns identified in the previous section and will
describe accomplishments thus far and specific actions to be taken in coming years by each
jurisdiction.  These actions are based on the best biological and ecological data available, as
well as historical examinations of crab abundance from commercial landings and fishery
independent surveys.  Biological and ecological studies identify environmental requirements
for blue crab survival, such as habitat and water quality, and compromises needed in the
fishery and by people living all around the Bay and the watershed.   Continued monitoring of
abundance, habitat and fishing pressure allow scientists and managers to identify trends and
take action before the damage is irreparable.  Early action is important, as the people of
Chesapeake Bay have already seen with other species that are now struggling to recover.
                                           11

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                                                            JO
    60 r
                                                   — 13.06
    1955 1960 1965  1970 1975  1980 1985 1990  1995
                            Year
Figure x.  Adult female crab abundance from VIMS/W&M trawl
survey by year for 1956-1992.  Note the relatively low level of
abundance during the past decade. Dotted lines indicate means
for each period shown.

-------
 UO/-L-" JH  1O.OJ
                                VIMb/'jt-ULLUjY
                                                            did
                                    Chesapeake Bay
Figure 3.  Life history of the blue crab in Chesapeake Bay. Large open
arrows indicate dominant summer water flow.

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                              VIMS/GEOLOGY
PAGE 87
                                                    -10.8 million


                                                     -7.2 million
      1960  1965  1970  1975  1980  1985  1990

                         Year
Figure x. Landings from Virginia commercial dredge fishery,
1956-1992 (VMRC data). Dashed lines represent means for the
periods  indicated.

-------
                     250
                   S200
                   o
  150


  100


jE 50
                   o
                   M
                   T>
                   o
                        a.) total area in lower bay
                       b.) juvenile crab density
                       c.) juvenile crab abundance
                         seagrass  unvegetated
Figure x;  Estimates of the total number of blue crabs in the
Lower Chesapeake Bay.  Figure a denotes the total area of
submersed bottom  in the lower bay which is less than 2 m in
depth.  Figure b represents the mean density of juvenile crabs in
vegetated and unvegetated areas of the lower bay.  Figure c
shows the resulting estimate of juvenile crab abundance in
vegetated and unvegetated lower bay habitats occurring in less
than 2 m water depth.

-------
       HARD CRAB LANDINGS
                VIRGINIA
    Million
 20-
               1960    1970

                   Year
     1980
I I I I Til I
 1990
        Landings (Ibs.)
Dockside Value ($)
1993 reflects new reporting method
       tf

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                  12.0
                   9.0
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                0)


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                I
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                XI
                S.
                a
                  6.0
                  3.0
                      * Dredge -^Sept-Nov VIMS/W&M Indx
                  0.0
                                                        5.0
                                                        4.0
                                                          c
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                      81  82 83  84 85 86 87 88 60 80 91  92 03 04

                                    Year
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-------
   SOFT AND  PEELER  LANDINGS

                VIRGINIA
   Millions
  1940
1950
1960
1970
1980
1990
        Landings (Ibs.)
1993 reflects new reporting
               Dockside Value ($)
      1
    d

-------
CO
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O
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   3.5



    3H

"In


|  2.5-

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    2-




   1.5-
          MARYLAND SOFT AND PEELER LANDINGS

               AND AVERAGE PRICE PER POUND
1981
             i   I
1984
                           1987

                          YEAR
                               i   i   i    r
                                 1990
                                                 -2.6


                                                 -2.4
   -2.2 co
       DC
                                            i   r
                                                 -2.8
1993
   H.8


    1.6


    1.4


    1.2
       o
       COMMERCIAL LANDINGS
                           PRICE PER LB.

-------
Alexander, S.  1986.  Diet of the blue crab, Callinectes sapidus Rathbun,  from nearshore
habitats of Galveston Island, Texas. Texas J.  Sci. 38:85-89.

Austin,  H.  1993.  The striped bass as a predator on the Chesapeake Bay blue crab.  Virginia
Sea Grant Program, Virginia Mar. Res. Bull.  25(l-2):8-9.

Booth, K. and M.  Gary.   1993.  Striped bass  feeding behavior and the potential effect on the
blue crab population in the Chesapeake Bay.   MD DNR.  Fish. Tech. Memo.  Ser. No. 2.
Jan., 1993.

Casey, J.  1990.  A study of biodegradable escape panels in crab pots.  Maryland DNR Tidal
Fisheries Division.

Casey, J.  1992.  A continuation of the study  of biodegradable escape panels in crab pots.
Maryland DNR Tidal Fisheries Division.

Casey, J. and A. Wesche.  1981. A study of derelict crab pots in Maryland's coastal bays.
Maryland DNR Marine Fisheries Unit.

Darnell, R.   1958.  Food habits of fishes and  larger invertebrates of Lake Pontchartrain,
Louisiana, an estuarine community. Texas University Inst. of Mar. Sci. Publ. 5:353-416.

Davis, C.  1942.   A study of the crab pot as a fishing gear.  Dept. of Res. and Ed.
Chesapeake Biol.  Lab. Publ.  No. 53.

Eggleston, D.  1990.  Foraging behavior of the blue crab, Callinectes sapidus. on juvenile
oysters, Crassostrea virginica: effects of prey  density  and size.  Bull. Mar. Sci. 46:62-82.

Eldridge, P., V. Burrell, Jr., and G. Steele.   1979. Development of a self-culling blue crab
pot.  Mar. Fish. Rev.  Dec. 1979:21-27.

Fonesca, M., J. Kenworthy and G. Thayer.  1992. Seagrass beds: nursery for coastal
species. In:  R.  Stroud, editor. Stemming the  Tide of Coastal Fish Habitat Loss.  Mar.  Rec.
Fish. 14.  Ntl.  Coalition for Marine Conservation, Inc.  Savannah, Georgia.

Goodrich, D, J. van Montfrans and R. Orth.  1989. Blue crab megalopae influx to
Chesapeake Bay:   evidence for a wind-driven  mechanism.  Estuarine;  Coastal and Shelf
Science. 29:247-260.

Goshorn, D., J. Casey. 1993.  An examination of the relationship between striped bass and
blue crabs.  Maryland Department of Natural  Resources.  Fish. Tech. Mem. Ser. 3, Jan.
1993.

Guillory, V. 1993.  Ghost fishing by blue crab traps.  N. Amer. J. Fish.  Mgt.  13:459-466.


                                           12

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Hines, A., R. Lipcius and A. Haddon.  1987.  Population dynamics and habitat paartitioning
by size, sex, and molt stage of blue crabs Callinectes sapidus in a subestuary of central
Chesapeake Bay. Mar.  Ecol. Prog. Ser. 36:55-64.

Hurley, L.  1991. Submerged aquatic vegetation.  In:  Funderbunk, S., J. Mihursky, S.
Jordan and D. Riley (eds.).  Habitat Requirements for Chesapeake Bay Living Resources.
Ches. Res. Consor., Inc.  Solomons, MD.  pp. 2.1-2.19.

Knotts, K.  1989. Preliminary Stock  Assessment of the Chesapeake Bay Blue Crab
Population.  Thesis submitted to  University of Maryland.  206 pp.

Kunishi, H.  1988.  Sources of nitrogen and phosphorus in an estuary of the Chesapeake
Bay.  J. Envir. Qual. 17:185-188.

Laughlin, R.  1982.  Feeding habits of the blue crab, Callinectes sapidus Rathbun,  in the
Apalachicoa Estuary, Florida.  Bull. Mar.  Sci. 32:807-822.

Lipcius, R. and W. Van Engel.  1990.  Blue crab population dynamics in Chesapeake Bay:
variation in abundance (York River, 1972-1988) and stock-recruit functions.  Bull.  Mar. Sci.
46:180-194.

Mansour, R. and R.  Lipcius.  1993.  The feeding ecology of blue crabs in the lower
Chesapeake Bay.  Virginia Sea Grant Program, Virginia Mar. Res. Bull. 25(l-2):8-9.

Montane, M.  1993.

Montane, M.  1994. A  field study of the population dynamics of the blue crab, Callinectes
sapidus. in the Chesapeake Bay.  Report submitted to Virginia Marine Resources
Commission, Chesapeake Bay Stock Assessment Committee, and National Oceanographic
and Atmospheric  Adiministration. Feb.  21,  1994.

Mosca, T. and P. Rudershausen.

Newell, R.  1988. Ecological changes in Chesapeake Bay: Are they the result of
overharvesting the American oyster, Crassostrea virginica?  In:  Lynch, M. and E.  Krome,
eds.  Understanding the Estuary:  Advances in Chesapeake Bay Research.  Proceedings of a
Conference.  Baltimore,  MD. Ches. Res. Consort. Pub. 129.

Officer, C., R. Biggs, J. Taft, L. Cronin, M. Tyler and W. Boynton.  1984.  Chesapeake
Bay anoxia: Origin, Development, and Significance. Science 223:22-27.

Olmi, E.  Immigration of Blue Crab (Callinectes  sapidus) Megalopae in the York River,
Virginia:  Patterns and Processes. Dissertation presented to the College of William and
Mary, Virginia Institute of Marine Science.


                                          13

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Orth, R. and J. van Montfrans.  1987. Utilization of a seagrass meadow and tidal marsh
creek by blue crabs Callinectes sapidus. I. Seasonal and annual variations in abundance with
emphasis on post-settlement juveniles.  Mar. Ecol. Prog. Ser. 41:283-294.

Prager, M., J. McConaugha, C. Jones, P. Geer.  1990.  Fecundity of blue crab, Callinectes
sapidus. in Chesapeake Bay: biological, statisical, and management considerations. Bull.
Mar. Sci.  46(1): 170-179.

Raynie, R. and J. Casey.  1992.  Results of the 1991 Cull Ring Study.  Maryland
Department of Natural Resources.  15pp.

Rothschild, B., C. Stagg, K. Knotts, G. Dinardo and A. Chai.  1988.  Blue crab stock
dynamics in Chesapeake Bay. Report submitted to MD Dept. Nat. Res. and Ches. Bay
Stock Asses. Comm.  163  pp.

Rothschild, B., J. Ault, E. Patrick, S. Smith, H. Li,  T. Maurer, B. Daugherty, G. Davis, C.
Zhang, and R. McGarvey.  1992.  Assessment of the Chesapeake  Bay Blue Crab Stock.
Univ. of Maryland, Chesapeake Bay Biological  Lab.  CB92-003-036, CEES 07-4-30307,
Solomons, Maryland.

Ryer, C.,  J. van Montfrans and R. Orth.   1990. Utilization of a seagrass meadow and tidal
marsh creek by blue crabs Callinectes sapidus.  II. Spatial  and temporal patterns of molting.
Bull. Mar. Sci. 46:95-104.

Schaffner, L. and R. Diaz. 1988. Distribution and Abundance of overwintering blue crabs,
Callinectes sapidus. in the  lower Chesapeake Bay.  Estuaries.  ll(l):68-72.

Schlesinger, W.  1991.  Biogeochemistry, An Analyisis of Global  Change. Academic Press.
443p.

Stagg, C., M. Holloway, L. Rugolo, K. Knotts, L. Kline and D. Logan.  1992. Evaluation
of the 1990 recreational, charter boat, and commercial striped bass fishing surveys, and
design of a recreational blue crab survey.  Chesapeake Bay Res. and Monitoring Div.
CBRM-FR-94-1.

Taft, J., E. Hartwig and R. Loftus.  1980. Seasonal oxygen depletion in Chesapeake  Bay.
Estuaries.   3(4):242-247.

Tagatz, M.  1969.  Biology of the blue crab, Callinectes sapidus Rathbun, in the St. Johns
River, Florida. Fish. Bull. 67:17-33.

Thomas, J., R. Zimmerman and T. Minello.  1990.  Abundance patterns of juvenile blue
crabs Callinectes sapidus in nursery habitats of two Texas bays.  Bull. Mar. Sci. 46:115-125.
                                          14

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Truitt, R.  1939.  Our water resources and their conservation.  Ches. Biol. Lab.
Contribution 27:1-103.

Uphoff, J., J.  Casey,  B. Daugherty and G. Davis.  1993. Maryland's blue crab peeler and
soft crab fishery;  problems, concerns, and solutions.  Maryland Dept. Nat. Res. Tidal
Fisheries Tech. Report Ser. 9.

Van Heukelem.  1991. Blue Crab, Callinectes sapidus.  In:  Funderbunk, S., J. Mihursky,
S. Jordan and  D.  Riley (eds.). Habitat Requirements for Chesapeake Bay Living Resources.
Chesapeake Res. Consortium, Inc.  Solomons, MD.

Volstad, J., B. Rothschild and T. Maurer. 1994.  Abundance estimation and population
dynamics of the blue crab in the Chesapeake Bay.   Report submitted to Maryland
Department of Natural Resources, Fisheries Department. Annapolis, MD.  53pp.

Wolcott, T. and A.  Hines.  1989. Ultrasonic biotelemetry of muscle activity from free-
ranging marine animals: a new method for studying foraging by blue crabs, Callinectes
sapidus.  Biol. Bull. 1976:50-56.
                                          15

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  SECTION 2.  BLUE CRAB MANAGEMENT IN CHESAPEAKE BAY
Background
       In 1989, the first Chesapeake Bay Blue Crab Fishery Management Plan (BCFMP)
was developed under the auspices of the Chesapeake Bay Agreement and encompassed the
jurisdictions of Maryland, Virginia, Potomac River Fisheries Commission, District of
Columbia and Pennsylvania.  The Background Section of the 1989 BCFMP included crab
biology, fishery and economic datas, status of the resource, habitat,  laws and regulations,
management approaches, and data and information needs.  The Management Section
addressed problems and presented management solutions.  Five "Problem  Areas" were
identified: 1. Increased Fishing Effort, 2. Wasteful  Harvesting Practices, 3. Lack of Stock
Assessment Information, 4. Regulatory Issues, 5. Habitat Degradation.

       In the four full years since the adoption of the original plan,  much has  changed. More
extensive data that  provides increased understanding have become available. Beginning in
1990, the Annual Progress Reports chronicle each year's activities for all adopted Fishery
Management Plans. Significant regulatory changes  as a result of the 1989  Plan have
occurred and social, economic, and fisheries conditions have changed. The 1994 Plan retains
some of the original goals of the 1989 Plan, such as the action to  contain the commercial
harvest, and also outlines a new direction based  on  current information and current social,
economic, and fisheries conditions.
    The year 1992 produced one of the lowest crab harvests on record and generated great
public concern. By the fall of 1992, after extensive public discussion, both states introduced
regulations to curtail the increasing fishing pressure from commercial and recreational
crabbers.  Despite the low harvests and public outcry that something must be done, the
Maryland proposals were withdrawn due to lack of public support. Virginia was able to pass
some legislation and regulatory measures in 1992 which took effect in 1993.  To address the
continuing concerns over harvest rates and increased effort, Maryland established the Blue
Crab  Advisory Board in November of 1992, similar to Virginia's Blue Crab Advisory
Committee formed in 1987. After six months of deliberations, the Maryland Board's
discussions produced the basis for  the Maryland Crab Action Plan.
    During this same time period the Living Resources Subcommittee (LRSC) established an
independent body to review all Chesapeake Bay Fishery Management Plans.  The Fisheries
Management Plan Re-Assessment Task Force (FMP RAT) evaluated the 37 prescribed
actions of the BCFMP and produced its findings in 1993.  The Task Force judged  that there
was measurable progress on twenty-eight of the 37 actions, 13 of the 28 actions were delayed
beyond the scheduled date, four  actions were considered partially or minimally implemented
and five have not been implemented.  Action items identified by the FMP RAT Force which
were  not fully implemented include:
                                         16

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       Action 1.1.1  Contain the commercial harvest at present levels;

       Action 1.2   Establish Bay-wide regulations concerning harvests and size limits;

       Action 11.3.2       Resolve conflicts between user groups;

       Action 2.3.C Investigate extent of mortality on mature female crabs  used as bait in
                    the eel fishery;

       Action 3.2   Collect Bay-wide recreational catch and effort data and evaluate impact
                    of recreational harvest.

       The FMP RAT Force review was thorough but many of the actions listed as delayed
or partially implemented or not implemented have now been accomplished by regulation and
legislation effective in 1994. The FMP RAT Force also produced recommendations for
improving the effectiveness of the Fishery Management Plans, one of which  is to conduct a
substantive review at three to four year intervals to update, amend or revise  the Plan.

       One year after 1992 produced the worst crab harvest in years, the 1993 commercial
catch in Maryland was the largest on record. Increased effort and/or participation in the
Maryland fishery could account for some of the increased landings.  Commercial hard crab
landings for 1993 in Virginia were double the 1992 landings.  Virginia implemented
mandatory reporting by all commercial harvesters  in 1993 and the large increase in landings
for that year may be, in part, an artifact of  the new reporting system. Anecdotal
observations from the industry indicate 1993 was not an exceptional year for the fishery, and
may even be on scale with 1992 landings.

       One of the management strategies shared by Maryland and Virginia is to limit fishing
effort. Implementing a combination of effort control management strategies, i.e. gear, time,
and license reductions or stabilization may be effective at containing harvest.  Maryland's
Crab  Action Plan (CAP) and respective legislation and regulations in Virginia responded to
the strategy of effort stabilization with commercial and recreational restrictions.  Many of the
measures proposed in Maryland's CAP and  adopted as regulations or legislation in 1994, and
as Virginia law and regulations in 1992 and 1993, meet, and even exceed, the expectations
of some problem areas in the 1989 BCFMP. The following section outlines  recent
management measures that resulted from commitments in the 1989 Plan.


Management Measures,  1992 - 1994

Virginia Regulations and Legislation, 1992 - 1994:

       The 1992 session of the General Assembly passed a law which requires that all
commercial fishermen obtain a registration license and a two-year delay process is in effect

                                          17

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for new entrants.  VMRC was given authority to limit entry and establish a maximum             4
number of license holders and to require catch reports.  A mandatory reporting program was
established which requires that all commercial fishermen report their catch.

       In 1992, the VMRC established a regulation describing the procedures for the
registration of commercial fishermen and the manner and forms of mandatory harvest
reports.  Another regulation described the procedures  that must be followed to cull harvested
crabs to the legal limits.

       The 1993 session  of the General Assembly passed a law which authorized VMRC to
establish recreational licenses. In other action, the commercial license structure was
revamped. New licenses were established including a license for shedding crabs on a
commercial scale and a peeler pot license.

       In June  1993, VMRC established licenses for the recreational and personal use of
crab pots, crab traps, and ordinary crab trot lines.  This regulation limits the amount of gear
and the catch, and sets gear identification and reporting requirements. The Commission also
passed regulation which requires at least one unobstructed cull ring (2-5/16 inch diameter) in
all hard crab pots as of January 1,  1994.

       In November 1993, VMRC reduced the crab dredge daily catch limit from 25 to 20
barrels.  Conditions to which the Commission would consider granting exceptions to the two
year delay for a commercial registration license were added.  The Commission  also adopted
regulation limiting entry in the crab dredge fishery. The sale of crab dredge licenses is
limited to those persons who held licenses and were actively engaged in the fishery as of
March 31, 1994, and caps the number of participants at 225.

       In 1994, the General Assembly authorized the VMRC to promulgate regulations
limiting the size of dredges.
Maryland 1994 Regulations and Legislation:

       Maryland's Limited  Entry  Bill,  recommended by the Maryland CAP and passed as
legislation in April, 1994, limits new entries into the commercial fishery. Maryland has had a
delayed entry program for five years, requiring that a person wait two years upon application
before they will recieve a license to fish. Any person whose name was on the two year waiting
list in Maryland prior to April 1, 1994, will receive a license two years after the date of
application.  The Limited Entry Bill gives the Department of Natural Resources authority to
establish a prescribed number of people to participate in any given fishery.  Once the two year
waiting list is exhausted,  no new licenses will be issued for that fishery until the number of
licenses drops below the prescribed number.  As licenses are lost voluntarily, by  revocation or
by death, the fishery will be capped at a maximum number of participants, and fishing effort will
be limited.
                                           18

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       Prior to 1994, there was no limit on the number of crab pots a commercial fishermen
could fish in Maryland. Each licensee is now limited to no  more than 300  pots, with an
additional allottment of 300 pots per crew member not to exceed 900 pots per boat.

       Times when  commercial and recreational crabbers can set and fish their gear  were
defined in regulation in 1994 (see Appendix ).  Time limits were defined as such to limit effort
in the number of man hours spent fishing, and were staggered  in such a way as to minimize
conflicts among user groups.

       The noncommercial crab license was eliminated through legislation. Maryland currently
has no  licensing  system for recreational  crabbers, which  now includes crabbers who  were
previously licensed as noncommercial crabbers.  Unlicensed recreational crabbers were limited
to 5 crab traps and/or rings per person while the licensed noncommercial crabber was allowed
up to 50 traps and/or rings. All recreational crabbers are now limited to 10 traps and/or  rings
per person,  not to exceed 25 traps and/or rings per boat.  Trotline, which was limited to 500
feet for recreational crabbers and unlimited for noncommercial crabbers, is now limited for all
recreational crabbers to 1000 feet per person, not to exceed 2000 feet per boat.

       Cull rings which enable undersized crabs to escape have been used on a voluntary basis
for several years.   Current Maryland regulations require one cull ring 2 5/16 inches in diameter
in all crab pots with mesh  size greater than  11/2 inches or less than 2 inches.  The cull ring
may be obstructed at any time of year for the purpose of catching peelers.

       The maximum number of crab pots which can be set from private property in Maryland
is two.  Some counties  prior to 1994 were  allowed four.  The proposal that pots be set or
constructed  so trapped  air-breathing animals could survive until released was rejected.   All
Maryland recreational crabbers are now limited to no more than one bushel per person and no
more than 2 bushels per boat.
Current Management Strategy

       Populations  of blue crabs in the Bay fluctuate from  year  to year.  Reproduction is
influenced by environmental conditions such as temperature, weather events, offshore winds and
currents.  There is evidence that a relationship between levels of spawning stock and levels of
reproduction exists when the spawning stock is fished below a certain threshold. Methods for
forecasting annual abundance of the blue crab  resource in the Chesapeake Bay are still being
refined and a conservative approach to its exploitation  is necessary.

       The harvest of a fluctuating resource such as  blue crab can be subject to a  "ratchet
effect." During relatively stable periods of high abundance as in the last decade, harvest rates
and effort stabilize at a level which is  excessive when abundance is average or below average.
When the population is less abundant,  the previously "normal" level of exploitation may result
in overharvest and a potential for collapse of the population.

                                          19

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       Managers  from both jurisdictions are careful not to assume recent regulations will be
completely effective in limiting effort and harvest of the fishery.  These  new restrictions and
their effectiveness at stabilizing fishing effort must be evaluated. If these actions prove successful
in limiting fishing effort on the blue crab stock in Chesapeake Bay, this management plan will
have succeeded in  the objective of being a "problem preventing"  tool  rather than  solely a
"problem solving" plan which many of the earlier management plans have been.  If these actions
prove successful, effort will stabilize,  catch per unit effort will increase, landings will stabilize
within  some range  over  time and  spawning stock will remain  at a level adequate for  stock
replenishment.

       Future management considerations could include daily individual harvest quotas, as are
required in the commercial striped bass fishery in Maryland, as an effective alternative if current
strategies prove inadequate. However, daily quotas are difficult to formulate and fishermen may
be unable to respond  to  market demands.  There  is some concern  that a quota system may
actually induce  more effort as those who did not normally land as  much would feel compelled
to fish  up  to the quota. As more data becomes available, a quota system could be investigated
as a method of  preventing overharvest in addition to or possibly instead of current regulations
that restrict effort.

       The 1994  BCFMP  is better adapted to the realities of fisheries management on an
interjurisdictional basis and is evolving to a "problem prevention/stock maintenance" strategy.
Future management decisions will depend on the effectiveness of current regulations.  Over the
course of the next several years intensive research and monitoring will be necessary to evaluate
whether the Bay states have insured the long term survival of the blue crab resource or whether
new solutions must be sought to preserve the resource.  The Blue Crab Bay-wide planning effort
has been a model cooperative program to date.
                          Goal Statement and Objectives


The goal of the 1994  Blue Crab Fishery Management Plan is  to manage blue crabs in
Chesapeake Bay in a manner which conserves the Baywide stock, protects its ecological value.
and optimizes the long-term use of the resource.

In order to achieve the Goal, the following objectives must be met:

1.     Maintain the spawning stock at a size which minimizes low reproductive potential (from
       harvest) as a cause of poor spawning success.

2.     Maintain a clear distinction between conservation goals and allocation issues.

3.     Minimize conflicts among user  groups and between jurisdictions by  coordinating

                                          20

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V.  '

               management efforts throughout Chesapeake Bay.

        4.     Promote a program of education and publicity to help the public understand the causes
               and nature of problems in the blue crab stock, its habitats and its fisheries and the
               rationale for management efforts to solve these problems.

        5.     Promote a baywide regulatory process which provides adequate resource protection,
               optimizes the commercial harvest, provides sufficient opportunity  for recreational
               crabbers, and considers the needs of other user groups.

        6.     Promote harvesting practices which minimize waste of the resource.

        7.     Determine and achieve environmental  quality and  habitat protection necessary  for the
               maximum growth, reproduction and survival of blue crabs.

        8.     Identify and promote  research to improve the understanding of blue crab biology and
               population dynamics.

        9.     Promote studies to collect necessary economic, social, and fisheries data to effectively
               monitor and manage the blue crab  fishery.
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                Problems, Issues, and Solutions for 1994 -1999
                           1.  Increased Fishing Effort
Problem 1.1:  Fishing Effort
The total amount of gear used and the number of participants in the crab fishery has increased
over time.  Research  indicates  there is a significant stock/recruitment  relationship  in  the
Chesapeake Bay blue crab population. The number of young produced (recruited) is influenced
by the number of adult spawners and by environmental factors.   Good recruitment requires
sufficient spawning stock and favorable environmental conditions.

Strategy:    In order to protect the reproductive potential of the blue crab stock, limits have
             been placed on fishing effort and on the number of participants.  The new laws
             and regulations adopted in 1994 in Maryland and  1993 in  Virginia to contain
             commercial  and recreational fishing effort and protect stocks must be evaluated
             to determine their effectiveness.  Both states will continue to monitor commercial
             catch, proceed with efforts to estimate effort by the recreational fishery, analyze
             the combined fisheries, determine safe levels of harvest,  and,  in  Maryland,
             determine the maximum number of commercial harvesters.

Actions:

1.1.1  Maryland, Virginia and Potomac  River Fisheries Commission have modified reporting
       methods to acquire more accurate and detailed data.  Maryland and Virginia's mandatory
       reporting system collects data on areas fished,  gear  types and amounts, hours fished,
       amounts harvested and biological  data.  This data will be analyzed  to determine actual
       harvest, biological composition of catch, and the effectiveness of current regulations for
       maintaining safe levels of harvest.

                    Implementation:   1994
1.1.2  Reliable and standardized crab landings are critical to evaluating the performance of the
       revised regulations and laws in Maryland and Virginia.  New reporting methods will be
       compared with previous methods to standardize catch data in the two periods.

                    Implementation:  Maryland,  1994
                                         Virginia, Indeterminate
1.1.3  Maryland  will determine a maximum number of commercial crabbing licenses and

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       licenses with crew allocations as required under new Limited Entry law (Sect. 4-210).
       Based on recommendations of the Tidal Fisheries Advisory Board, the Chesapeake Bay
       Program and any other appropriate management body.  The Department shall consider
       the number of people historically participating in the fishery,  annual harvest, mortality,
       total biomass, size, number, incidental catch, target species, and any other factors which
       are necessary and appropriate.

                    Implementation:  1994
1.1.4  The  impact of the  1993-1994 regulations  and law in Maryland and Virginia will be
       evaluated.  Evaluating the new limits on crabbing effort will take several years.

              A.     It will  take  several years before limited entry reduces  the  number of
                     licenses through attrition.

              B.     Evaluation of the effects of limited entry will require several years of
                     information from licensing data and the catch reporting system.

              C.     The effects  of  stabilized  fishing effort on  stocks will  be difficult to
                     evaluate and must be done through fishery independent studies.

              D.     Sport crabbing surveys in Maryland must be conducted consistently to
                     evaluate the effects of time and gear restrictions.  It will take several years
                     for Virginia  to accumulate a data base.

              If the performance of the new requirements is determined to be insufficient, new
              regulations defining harvest seasons, additional gear restrictions, catch limits,
              and/or size limits will be considered to stabilize harvest and effort at levels which
              protect the reproductive potential of the blue crab stock.

                     Implementation:  Indeterminate
1.1.5  Maryland will continue to develop a method of recording recreational catch and Virginia
       will continue to collect recreational data.  Both states will monitor this data to determine
       if further restrictions on the recreational fishery are necessary.
                    Implementation:  Indeterminate
                        2.  Wasteful Harvesting Practices
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Problem 2.1:  Economic Yield
Harvesting small crabs or crabs of poor quality  does not  maximize economic value of the
resource.  The economic yield of crabs is not always optimized if buckrams (recently shed crabs
whose shell is no longer soft, but is still in the process of hardening), which yield small amounts
of meat, and late winter dredge crabs, which can yield poor quality meat, are brought to market.
Other marginal  harvesting  practices  include  taking  egg-bearing  females which  decreases
reproductive potential and green crabs (any peeler crab without red or pink coloration in the
swim fin).

Strategy:    Optimum use of the blue crab resource  will be promoted by eliminating and/or
             minimizing wasteful harvest practices, and by informing the consumer of poor
             quality or poor value crabs and discourage their purchase.

Actions:

2.1.1 Maryland  and Virginia will continue  to  promote the release of buckrams  through
      brochures  and/or newsletters which identify buckrams  and demonstrate the  potential
      weight gain through time.

                    Implementation: Ongoing
2.1.2  Since buckrams weigh considerably less than hard crabs, i.e. 25 Ibs./bushel as compared
       to 36-40 Ibs./bushel for hard crabs, Maryland will investigate publicizing optimal bushel
       weight ranges for the various types of crabs and establishing minimum weight limits for
       each.

                    Implementation:
2.1.3  Maryland and Virginia will educate the consumer about wasteful harvesting practices and
       their effects on the resource so they may be better informed when purchasing crabs.

                    Implementation:
Problem 2.2:  Cull Apparatus
Small crabs retained in hard crab pots suffer high mortality rates due to predation by larger
crabs.  Cull rings, which allow small crabs to escape, have been instituted in all jurisdictions;
however, regulations allow cull rings in hard crab pots to be obstructed when fishing for peelers
in Maryland and  during times of economic hardship in Virginia.  Cull rings may allow the
escape of small, legal size peelers and mature females during certain seasons.


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Strategy:     The biological benefits and economic impact of cull rings in crab pots will be
              investigated to determine specific seasons when cull rings may be obstructed with
              minimal impact on the resource and the greatest economic benefit.  Cull rings
              may also be considered as an alternative to size limits on soft and peeler crabs
              which are easily damaged during handling.

Actions:

2.2.1  Maryland will define seasons for peeler fishing with hard crab pots (pots with mesh size
       1.5 inches or greater) for which cull rings may be obstructed to minimize the impact on
       the resource  and maximize economic benefits.   Outside  of the defined  season, the
       unobstructed cull ring requirement will be enforced.

                    Implementation:
2.2.2  Virginia will consider the mandatory use of cull rings  throughout the hard crab pot
       season.

                    Implementation:
2.2.3  Virginia has already initiated studies to determine the economic impact of the cull ring
       requirement and  will continue research to determine  the  significance of allowing
       obstructed cull rings for short periods of time.

                    Implementation: Ongoing
2.2.4  Virginia is investigating the use of cull rings in peeler pots to allow small crabs to escape
       and will consider mandatory cull rings in peeler pots and peeler pounds.  Maryland?

                    Implementation:  1994
Problem 2.3: Female Harvest Rates
The practice of harvesting sponge crabs and females at other life history stages results in a loss
of reproductive potential.

Strategy:    Landings and fishery independent data will be reviewed to determine if actions
             limiting  female harvest  are  needed.  Biological and economic data will  be
             reviewed to assess the effects of importing sponge crabs into Maryland.
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Actions:

2.3.1  Maryland will investigate the interstate trade of blue crabs for the purpose of quantifying
       the number of sponge crabs and other types of crabs (which may not be legally harvested
       in Maryland) coming into the state.

                    Implementation:
2.3.2  Maryland will investigate the effects of prohibiting the import of sponge crabs, or crabs
       from which the egg packet has been removed, into Maryland, and consider regulations
       if the action is deemed biologically necessary.

                    Implementation:
2.3.3  Virginia will consider the expansion (time and/or area) of the spawning sanctuary.

                    Implementation:


2.3.4  Maryland will evaluate the use of female crabs as eel bait in eel pots.

                    Implementation:
2.3.5  Virginia and Maryland will continue to collect data on female size at maturity, migration,
       distribution and harvest by sex to study the effect of female harvest on crab population
       dynamics.  This data can be used to  determine management  measures that protect the
       reproductive potential of blue crabs.

                    Implementation:
Problem 2.4: Abandoned Pots
Lost and abandoned crab pots are attractive refuge sites and often trap and eventually kill
significant  numbers  of crabs and finfish.   Weak  and dead  crabs  attract other crabs into
abandoned pots, and are self-baiting. Abandoned pots also trap and drown air breathing animals
such as terrapins that inhabit tributaries.  Biodegradable materials and escape panels have been
the subject of preliminary investigation  in Maryland.   Abandoned pots are also navigational
hazards for boats.  The abandonment of pots is illegal in Maryland, and is prohibited during the
month of January in  Virginia. Enforcement is difficult and fines are not significant enough to
discourage  deliberate abandonment.  Pots are also lost when boat propellors cut buoy lines,


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during storms, and  by sabotage.   Pots partially crushed by clam dredging  may also be a
significant source of abandoned pots.

Strategy:     Causes of abandoned pots will be investigated, the deliberate abandonment of crab
              pots will be discouraged, and escape mechanisms in pots will  continue to be
              researched.

Actions:

2.4.1  Virginia  and Maryland will continue to address regulation of abandoned crab  pots,
       including significant fines that  may discourage deliberate abandonment.

                     Implementation:
2.4.2  Virginia and Maryland will continue to investigate materials for biodegradable escape
       panels and latches in crab pots and escape mechanisms for air breathing animals.

                    Implementation:
2.4.3  Maryland and Virginia will investigate the feasibility of establishing used pot disposal
       sites in  Bay counties  and other incentives which would encourage proper disposal of
       damaged or spent crab pots.

                    Implementation:
2.4.4  Maryland and  Virginia  will  educate  commercial  crabbers  about the problems of
       abandoned  crab pots and educate property owners  about the effects of pots left
       unattended.

                    Implementation:

2.4.5  Maryland and Virginia will investigate placement of identification on crab pots so that
       lost pots  may be returned and purposeful abandonment will be discouraged.

                    Implementation:
2.4.6  The problem of clam dredge rigs destroying pots will be investigated.

                    Implementation:
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Problem 2.5: Shedding Mortality
The mortality rate of green crabs (a peeler crab without red or pink coloration in the swim fin)
held in shedding floats is high compared to peelers that are close to molting.  Mortality rates in
shedding floats  and poorly operated shedding systems  may  be  high.   Virginia allows one
shedding tank or float for personal use without a license.

Strategy:    Information  will  be  provide to shedders to minimize mortality in shedding
             operations.

Actions:

2.5.1   Maryland and Virginia  will continue to provide technical  information to shedding
       operations that promote reduction of peeler mortalities associated with holding practices.

                     Implementation:  Ongoing
2.5.2  Virginia established a commercial shedding license, effective January 1,  1994, and will
       monitor data reports.

                    Implementation:
2.5.3  Maryland will reintroduce the shedders license requirement for the purpose of identifying
       shedders and in order to provide technical assistance.

                    Implementation:
2.5.4  Virginia will continue to educate watermen on problems related to green crab mortality.

                    Implementation:  Ongoing
2.5.5  Maryland will investigate a joint venture with commercial watermen's associations to
       establish a state-of-the-art shedding facility for the purpose of research and to educate the
       shedding industry.

                    Implementation:
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                        3.   Stock Assessment Deficiencies
Problem 3.1: Commercial Reporting
Maryland introduced a new reporting system in  1994 which collects information on effort by
gear type and person, time spent fishing, and biological characteristics (hard females, #1 and #2
male hard crabs,  soft/peelers, culls) of the harvest.  Virginia instituted a mandatory reporting
system in January, 1993, to include information on harvest and effort levels and biological
characteristics of the harvest.  While the new Maryland and Virginia systems are comparable,
they are still not fully compatible.  Potomac River  has mandatory reporting by all fishermen
which collects data on effort, age and sex of blue crab harvest.

Strategy:     New reporting methods will be used with continued fishery independent surveys
              to  monitor trends in catch and effort,  produce reliable estimates of blue crab
              abundance, and understand the fishery and the relationships between harvest and
              stock.

Actions:

3.1.1  Maryland  and Virginia will monitor commercial  records  in order to evaluate the
       relationship between fishery dependent and fishery independent indications of abundance.

                    Implementation:  Ongoing
Problem 3.2: Recreational Harvest
There is a lack of information about the blue crab recreational catch and effort and the economic
impact of recreational crabbing in Chesapeake Bay.  Virginia has instituted mandatory reporting
for all licensed recreational  crabbers.   Maryland  was unsuccessful in attempts  to  require
recreational licenses during 1994.

Strategy:    There will be a Bay wide effort to collect recreational catch and effort data and
             to evaluate the economic impact of the recreational harvest.

Actions:

3.2.1  As of 1993, Virginia requires annual reporting by all licensed  recreational crabbers
       including weight harvested, location of harvest,  days fished, and amount of gear used.
       This data will be used to determine recreational  harvest and effort.

                    Implementation: Underway
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3.2.2  Maryland will seek a recreational crabbers license requirement in 1995. Maryland would
       require reporting for licensed recreational crabbers compatible with Virginia's reporting
       method.

                    Implementation:  1995
3.2.3  Maryland will continue to pursue a method of recording recreational catch as stated in
       Action 1.1.5, and propose a sport crabbing monitoring project to improve monitoring of
       the blue crab resource.

                    Implementation:
Problem 3.3:  Research Needs
The population dynamics of the blue crab  stock is not fully understood.  Our understanding
would be improved by obtaining additional information on natural and fishing mortality rates,
the stock-recruitment relationship, and the effects of environmental variables and anthropogenic
change on year class strength and availability.

Strategy:    The Baywide effort to collect population data on blue crabs  will continue, and
             current methods will be improved  to assure baywide uniformity of data sets and
             achieve reliable and more accurate catch estimates.

Actions:

3.3.1  Maryland and Virginia will continue to refine the analysis  of the winter dredge survey
       as a consistent annual assessment of the  abundance, distribution, and mortality of the
       crab resource.

                    Implementation:  Ongoing
3.3.2  Maryland  and Virginia will continue to encourage research on recruitment-stock and
       stock-recruitment relationships and how environmental parameters affect fluctuations in
       crab abundance.

                    Implementation:  Ongoing
                                4.  Regulatory Issues
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Problem 4.1:  Commercial/Recreational Conflict
The blue crab fishery consists of recreational and commercial fractions which provide economic,
social and recreational benefits to the community. Conflict between commercial crabbers and
recreational boaters has become a serious problem in some of the more densely populated areas
of Virginia  and Maryland.  From the recreational boater's point of view, crab pot floats are
interfering with recreational boating.  From the commercial waterman's perspective, recreational
boaters are interfering with crab potting because they inadvertently run over and cut off crab pot
floats. There is competition for trotline space in the tributaries.

Strategy:    Conflicts among user groups and the general boating public can be minimized by
             rational  application of time,  area, and  gear restrictions  to allocate  space  and
             harvest of the resource. Coordinated interstate management is necessary to insure
             optimal baywide usage.

Actions:

4.1.1  Maryland and  Virginia  will continue  to monitor conflicts between  crabbers  and
       recreational boaters and enforce existing  regulations on open and closed crabbing areas
       and buoy-free channels.

                    Implementation:  Ongoing
4.1.2  Maryland has staggered start and end times for recreational and commercial crabbing.
       The effectiveness of these time limits will be monitored.

                     Implementation: 1994
Problem 4.2: Interstate Trade
The interstate shipment  of  peelers and  soft crabs may  circumvent efforts to protect the
Chesapeake Bay stock from  illegal fishing activities.  A major problem in Maryland is that
undersized crabs are illegally harvested and then either marketed in state as out-of-state crabs
or shipped to states which have no minimum size limits.

Strategy:    Maryland and  Virginia will continue to investigate the biological and economic
             effects of size  limits on the soft crab fishery and the need to coordinate soft and
             peeler size  limits.

Actions:

4.2.1  Maryland  will consider a ban  on  the importation of crabs which do not meet State

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      requirements.

                    Implementation:
4.2.2 Maryland and Virginia will work to achieve consistent Baywide standards for minimum
      sizes of all crabs harvested in Chesapeake Bay.

                    Implementation:
                  5.  Public Health and Consumer Concerns
Problem 5.1:  Personal Consumption
Poor quality crabs yield less  meat and bring lower prices.   Quality crabs are reserved  for
preferred customers such as restaurants and seafood markets,  while the lesser quality crabs  are
often all that is available to the small consumer who buys whole crabs, usually by the bushel,
for personal consumption.

Strategy:    In order to  maintain  the quality of the supply of crabs available for public
             consumption, minimum weight standards and volume could be established for the
             various types of blue crabs.

Actions:

5.1.1   Maryland will evaluate the necessity of establishing a minimum bushel weight for various
       grades of crabs.

                   Implementation:
5.1.2  Maryland will define by regulation the minimum volume of a crab bushel, as well as
       potential substitutes,  such as the waxed cardboard seafood box.

                   Implementation:
Problem 5.2:  Foreign Import
Regulations limiting effort in the Chesapeake blue crab fishery have generated fear that foreign
markets will see reduced local harvest as an opportunity to move in on the market.  The present
regulations are not expected to reduce harvest, but rather limit excessive growth of the fishery

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and prevent any future openings in the market for foreign producers to fill.   Over the past
several  years there has been an increase in imports of crabmeat from warmwater areas that
compete with  processed Chesapeake Bay crabmeat.  This substitute product puts downward
pressure on the price of crabmeat, and may lower profits of crabmeat processors and the price
paid to  watermen.  The industry has made strong  efforts to differentiate the Chesapeake Bay
product as a higher-quality product than imported meat in order to maintain a higher price for
its product. Maryland passed legislation in 1994 that requires crab meat with foreign content
be labeled as  such.   Regulations  are  pending in  Virginia  concerning  the  repacking and
subsequent labeling of crabmeat.

Strategy:     Efforts will  be made to insure that consumers are aware of the origin of the crab
              products they  purchase.

Actions:

5.2.1 Imported crab meat shall be identified as such in Maryland as required by Section 21-339
      of Annotated Code of Maryland,  Health Article.

                    Implementation:
5.2.2  In  addition to foreign  crab  meat,  the interstate  shipment of crab products  shall be
       surveyed in Maryland.

                    Implementation:
                             6.  Habitat Degradation
Problem 6.1:  Anoxia
Loss of wetlands and forests to development and agriculture has reduced the percolation of
rainwater.   Excess nutrients entering the Bay from agricultural and  urban runoff, sewage
treatment plants and atmospheric deposition  from the burning of fossil fuels results in algal
blooms which produce anoxic conditions in the Bay. The anoxic portion of the Bay has been
steadily increasing in size and duration over time and is reducing the amount of habitat available
to crabs, increases intraspecies competition, compresses fishing effort and harms commercial
fishing due to the high mortality  of crabs retained in pots in anoxic and hypoxic areas.

Strategy:     Maryland,  Pennsylvania, and the District of Columbia have outlined a Tributary
             Strategy that will reduce the amount of nutrients from tributaries to the Bay 40%
             by the year 2000 to meet the Bay Program's nutrient reduction goal.
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Actions:
Major goals outlined by the jurisdictions include:

Maryland:
       * Upgrade 50 waste water treatment plants to
       phosphorus discharges.
       * Encourage farmers to implement nutrient
       and plant cover crops.

Pennsylvania:
       * Implement nutrient control efforts in state farm
       * Fence hundreds of miles of streams to keep
                                                                     control nitrogen and

                                                                       management plans
                                                                      lands.
                                                                       livestock out.
District of Columbia:
       *  Upgrade Blue Plains waste water plant, the
       nutrients from the district.
       *  Control combined sewer overflow to reduce the
       overloads.
       *  Control additional runoff at construction sites,    new development,
       public education, and habitat     restoration.
                                                                       greatest source of

                                                                            frequency of
              Virginia is in the process of formulating a tributary strategy which will reaffirm
              the 40%  nutrient reduction goal and is  expected to be adopted in late 1994.
              Virginia  also plans to continue tributary monitoring in  support of  tributary
              modeling.
Problem 6.2: Submerged Aquatic Vegetation and Intertidal Wetlands
Shoreline development that reduces shallow water habitat, channel dredging, heavy boat traffic,
crab scraping and clam dredging have all been identified as  sources of local  destruction of
submerged aquatic vegetation (SAV).  Crab scraping in Virginia is restricted to hauling by hand
and hard crab bycatch is illegal. In Maryland heavy scrapes with power winders are used during
the early season to catch hard crabs.  Nutrient influx, as discussed in problem 6. 1, and sediment
runoff are  responsible for widespread declines throughout the Bay.  The loss of SAV and
intertidal wetlands has resulted in the loss of blue crab habitat, particularly during the juvenile
and molting stages.

Strategy:     The Bay jurisdictions will maintain a priority status on protection of SAV and
              intertidal wetlands.

Actions:

6.2.1  Maryland and Virginia will prepare a report on blue crab habitat and biology and identify
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       critical habitat utilized by the species,  and will emphasize preservation of blue crab
       habitat for permitting agencies.

                    Implementation:

6.2.2  Maryland will consider limits on scraping for hard crabs in the early crabbing season.

                    Implementation:
Problem 6.3: Water Quality
The blue crab appears to be a resilient species.  Their migratory nature and short life span make
them  less susceptible to  bioaccumulation of contaminants.  Toxicology studies  in Baltimore
Harbor and the Elizabeth River, the two most heavily polluted areas of the Bay, found minimal
accumulation of toxins in tissues  of blue crabs.  Once toxics are allowed to accumulate their
effects are difficult to impossible to reverse, and blue crabs could be affected by the loss of
benthic foods and/or toxics may accumulate beyond some threshold which exceeds the crab's
level  of tolerance.  Blue crabs are most sensitive during their larval  stages.   Environmental
requirements of larval and juvenile crabs are not well known, and spawning grounds and major
nursery areas are not easily identified.

Strategy:
Actions:

6.3.1  Virginia will continue their long term monitoring program  which samples the water
       column, benthos,  and biological community in the bay mainstem and tributaries and
       continue fall line nutrient monitoring and chlorophyll analysis.

             Implementation:  Ongoing
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