Presentation for Biology 405W; Kate Stoutenburgh, Old Dominion University, 2013

1. A REVIEW OF THE PAST,
PRESENT, AND FUTURE
CONSERVATION STATUS
OF THE CHESAPEAKE
BAY BLUE CRAB
By: Kate Stoutenburgh
Faculty Sponsor: Dr. Kent Carpenter

2. Talk Outline
 Blue Crab Background
 Importance
 Threats
 Current Conservation Efforts
 Need for More Conservation Action
 Discussion and Questions

3. Background
 Callinectes sapidus
 Habitat Range
 Major Commercial
Fishery
 Stock suffered a
collapse in 1990s
http://commons.wikimedia.org/wiki/File:The_Childrens_Museum
_of_Indianapolis_-_Atlantic_blue_crab.jpg

4. Economical Importance
 Single most commercially exploited species
in Chesapeake Bay
 In 2011, the commercial landing of blue
crab in the Chesapeake Bay was 39,453
metric tons worth $82,509,522 (NOAA,
2011)
 Many Chesapeake Bay watermen rely
heavily on the blue crab for income

5. Ecological Importance
 Keystone predator
 Important prey of striped bass and other
commercial species
 Trophic link between benthic and pelagic
systems

6. Life History
http://classic.sidwell.edu/us/science/21bio/new/Crab_Poster_2005/Crab_Life_Cycle_files/image002.jpg

7. The Crash
This graph shows the collapse of the blue crab fishery in the 1990s, followed by an
increase in abundance after stricter fishing limits were put into effect in the early
2000s (Miller et al., 2011)

8. Current Status
 Recovering slowly from stock crash in 1990s
 Stock is currently above target abundance
 Abundance in 2012 lower than 2010 and 2011
 Juvenile recruitment estimate highest ever
recorded
 Still threatened by human actions

9. Fishing Exploitation
 What is juvenile recruitment?
 Blue crab population in the bay is recruitment
limited
 Recruitment is highly variable
 Stock is being fished at Maximum Sustainable
Yield (MSY)
 Fishing at MSY leaves stock vulnerable when
variations in recruitment occur

10. Current Overfishing Guidelines
This graph shows the current guidelines used to define overfishing of the crab
stock in Chesapeake Bay (Miller et al. 2011)

11. Climate Change and Habitat Loss
 Climate change may both help and hurt blue
crabs
 Rising temperatures decrease overwintering
mortality
 Rising sea levels destroy coastal marsh habitat
 Marsh habitat also lost due to human activity
and coastal development

12. Reduction in Fishing Effort
 The most recent stock assessment of the blue
crab in the Chesapeake Bay has
recommended a reduction in fishing
exploitation
 It has also been recommended that females
be used as a measure of population
abundance

13. New Overfishing Guidelines
This graph shows the new overfishing definition recommendations of the most
recent blue crab stock assessment (Miller et al., 2011)

14. Marine Protected Area and
Corridor
 What is an MPAC?
 VSSC established in lower bay in 2000 to
protect migrating females
 Increasing area of MPAC could help protect
even more females on their way to mate and
spawn
 Highly effective and low cost to implement

15. Hatcheries
 Involves releasing hatchery raised juveniles
into the wild
 Has great success, but is costly
 From 2002-2006, over 290,000 hatchery
raised blue crabs were released into the wild.
 The addition of these individuals into the wild
increased local populations around areas of
release by 50-250% (Zohar et al. 2008)

16. Why More Needs to be Done
 High variability in juvenile recruitment can
cause another stock crash
 Fishing at MSY can devastate a population if
recruitment drops suddenly
 Climate change is an unpredictable factor

17. Discussion
 Blue crabs are important economically and
ecologically in the Chesapeake Bay
 The population has crashed in the past and is
currently vulnerable to threats from climate
change and human exploitation
 More extensive conservation efforts are
needed to ensure a healthy population in the
face of these threats

18. Thank You!
Questions?