A REVIEW OF THE PAST, PRESENT, AND FUTURE CONSERVATION STATUS OF THE CHESAPEAKE BAY BLUE CRAB

By: Kate Stoutenburgh

Faculty Sponsor: Dr. Kent Carpenter

Talk Outline

Blue Crab Background Importance Threats Current Conservation Efforts Need for More Conservation Action Discussion and Questions

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

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

Ecological Importance

Keystone predator Important prey of striped bass and other

commercial species Trophic link between benthic and pelagic

systems

Life History

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

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)

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

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

Current Overfishing Guidelines

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

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

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

New Overfishing Guidelines

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

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

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)

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

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

Thank You!

Questions?