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Recent Changes in Blue CrabRecent Changes in Blue CrabManagementManagement
Brenda DavisBrenda DavisBlue Crab Program ManagerBlue Crab Program Manager
Maryland Department of Natural ResourcesMaryland Department of Natural Resources
How Many Crabs Should Be in the Bay – How Many Crabs Should Be in the Bay – the abundance of spawning adults.the abundance of spawning adults.
(2008 winter dredge survey)(2008 winter dredge survey)
0
50
100
150
200
250
300
350
400
450
500
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008Year
Nu
mb
er o
f C
rab
s (m
illi
on
s) adult abundance
minimum safe abundance = 86 million crabs
target abundance = 200 million crabs
Dangerously low
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1990 1992 1994 1996 1998 2000 2002 2004 2006
Year
Per
cen
tag
e R
emo
ved
Percentage of Crabs Removed
Target Percentage = 46%
Threshold Percentage = 53%
We can remove 46% of the crab population each We can remove 46% of the crab population each year. If more than 53% of the population is year. If more than 53% of the population is
removed, the population will begin to decrease.removed, the population will begin to decrease.
overfishingoverfishing
The Chesapeake Bay Stock The Chesapeake Bay Stock Assessment Committee’s Assessment Committee’s
(CBSAC) recommendation was (CBSAC) recommendation was to reduce bay wide harvest.to reduce bay wide harvest.
The biggest benefit would be The biggest benefit would be achieved if reductions were in achieved if reductions were in
female harvest.female harvest.
Following CBSAC recommendation -
“extending protection to female crabs will create the best odds of increasing the abundance of age 0
crabs.”
Females are more heavily fished than males – this needs to be corrected.
Increasing female abundance is the best bet for rebuilding the population as a whole.
Why Females?Why Females?
Maryland Proposes Regulations to Rebuild
Blue Crab PopulationAnnapolis MD – Today, the Maryland Department of Natural Resources proposed new recreational and commercial harvest regulations to help rebuilding the Chesapeake Bay blue crab population and fishery. The proposed regulations are designed to reduce female blue crab harvest by 34% in 2008.
.
THE DAILY NEWSwww.dailynews.com Chesapeake Bay Area Newspaper - April 22, 2008
The commercial industry initially The commercial industry initially suggested a harvest history based suggested a harvest history based
allocation and that system was used to allocation and that system was used to set bushel limits for the fall of 2008.set bushel limits for the fall of 2008.
Bushel limits in September and Bushel limits in September and October of 2008 were based on October of 2008 were based on
reported female harvest in September reported female harvest in September and October 2004 to 2007.and October 2004 to 2007.
0
50
100
150
200
250
300
350
400
450
500
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
Year
Nu
mb
er o
f C
rab
s (m
illi
on
s) adult abundance
minimum safe abundance = 86 million crabs
target abundance = 200 million crabs
Spawning-age (Age 1+) crabs in Chesapeake Bay Spawning-age (Age 1+) crabs in Chesapeake Bay from the 2009 Winter Dredge Surveyfrom the 2009 Winter Dredge Survey
0
10
20
30
40
50
60
70
80
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
Year
Per
cen
tag
e R
emo
ved
Percentage of Crabs Removed
Target Percentage = 46%
Threshold Percentage = 53%
The percentage of crabs removed from the population each The percentage of crabs removed from the population each year by fishing relative to target and threshold levelsyear by fishing relative to target and threshold levels
through 2008.through 2008.
0
100
200
300
400
500
600
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008
Year
Nu
mb
er o
f C
rab
s (m
illio
ns) Age 0 Abundance Average
Young-of-the-year (Age 0) crabs in Chesapeake Bay Young-of-the-year (Age 0) crabs in Chesapeake Bay from the 2009 Winter Dredge Surveyfrom the 2009 Winter Dredge Survey
DNR worked with members of the DNR worked with members of the industry and developed a system industry and developed a system where female bushel limits are in where female bushel limits are in
effect for the entire season, not just effect for the entire season, not just the fall, and are based on license the fall, and are based on license
typetype.
Changes for 2009 Crabbing Changes for 2009 Crabbing SeasonSeason
0
50
100
150
200
250
300
350
400
450
500
1990 1992 1994 1996 1998 2000 2002 2004 2006 2008 2010
Year
Nu
mb
er
of
Cra
bs
(m
illio
ns
)
adult abundance
minimum safe abundance = 86 million crabs
target abundance = 200 million crabs
Spawning-age (Age 1+) crabs in Chesapeake BaySpawning-age (Age 1+) crabs in Chesapeake Bayfrom the 2010 Winter Dredge Surveyfrom the 2010 Winter Dredge Survey
Spawning-age (Age 1+) crabs in Chesapeake BaySpawning-age (Age 1+) crabs in Chesapeake Bayfrom the 2010 Winter Dredge Surveyfrom the 2010 Winter Dredge Survey
The percentage of crabs removed from the population The percentage of crabs removed from the population each year by fishing relative to target and threshold levels each year by fishing relative to target and threshold levels
through 2009.through 2009.
0
10
20
30
40
50
60
70
80
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09
Year
Per
cen
tag
e R
emo
ved
Percentage of Crabs Removed Target Percentage = 46%
Threshold Percentage = 53%
Young-of-the-year (Age 0) crabs in Chesapeake Young-of-the-year (Age 0) crabs in Chesapeake Bay from the 2009 Winter Dredge SurveyBay from the 2009 Winter Dredge Survey.
0
100
200
300
400
500
600
90 91 92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07 08 09 10
Year
Nu
mb
er o
f A
ge
0 C
rab
s (m
illi
on
s)
age 0 - new recruits age 0 mean
Governor Martin O’Malley Announces Chesapeake BayBlue CrabPopulation Is At Its Highest Level Since 1997
Winter Dredge Survey Results Indicate 60%
Increase;
658 Million Crabs Show Bi-State
Management Actions Continue to Improve
Abundance
THE DAILY NEWSwww.dailynews.com THE WORLD’S FAVOURITE NEWSPAPER - April 15, 2010
Is the blue crab population
Is the blue crab population
in a pinch?
in a pinch?
Is the blue crab population
Is the blue crab population
in a pinch?
in a pinch?
Brenda DavisBrenda DavisBlue Crab Program ManagerBlue Crab Program Manager
October 20, 2009October 20, 2009
Chesapeake Bay Crabs Are Back
Give ‘em a Whack!It’s a great time to enjoy some Chesapeake Bay
crabs!Bay wide harvest restrictions for female blue crabs were put in place in 2008.
Those restrictions combined with favorable environmental conditions haveresulted in a significant increase in the number of crabs in the Bay.
The harvest restrictions protecting female crabs are still in placeto ensure a healthy population and a sustainable fishery.
Does this meanDoes this meanwe’re done?we’re done?
Absolutely Not!Absolutely Not!
We need to continue We need to continue limiting the amount of limiting the amount of
females harvestedfemales harvestedto have any hope ofto have any hope of
obtaining a sustainableobtaining a sustainablepopulation.population.
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