PAID ADVERTISEMENT
You’re invited to the 2011 Watershed Walk
From Your Backyard Shed
To Our Watershed…
Explore the Eastern Shore’s
NATURAL RESOURCES with over
20 family-oriented, hands-on exhibits
at Town Park during Onancock’s
Harborfest on September 10.
This event is sponsored by the
Eastern Shore Environmental Education
Council with support from the Eastern
Shore Soil and Water Conservation
District, Eastern Shore Master
Naturalists, Accomack-Northampton
Planning District Commission, the
Chesapeake Bay Foundation and the
National Fish and Wildlife Foundation.
The Eastern Shore
Environmental Education Council is
an informal network of individuals,
agencies, and organizations interested in
promoting conservation and protection
of our area’s natural and cultural
resources. Membership is free and
open to everyone. Benefits include
information sharing on conservation
programs and volunteer opportunities in
our community. For more information,
contact the Eastern Shore Soil and
Water Conservation District at 757-7870918.
Exhibitors include: Eastern Shore
Master Naturalists, Chincoteague
National Wildlife Refuge, Eastern
Shore National Wildlife Refuge,
Marine Science Consortium, Virginia
Department of Environmental Quality,
Chesapeake Bay Foundation, USDANRCS, Virginia Tech, Eastern Shore
Soil and Water Conservation District,
Virginia Department of Conservation
and Recreation -Kiptopeke State Park,
Onancock Tree Board, Waste Watchers,
University of Virginia, Citizens for a
Better Eastern Shore, ESCC SPARK
Program, Virginia Wesleyan College,
Eastern Shore Resource Conservation
and Development Council. Also a
reptile and amphibian display and
entertainment by the popular local
band, Three Sheets.
Enter to WIN
Plan to enter the free raffle
at the Watershed Walk to win these
prizes: Gift Certificate from Southeast
Expeditions -Kayak Ecotour for Two;
SYSTERN© Rain Barrel or EARTH
MACHINE© Composter donated by the
Eastern Shore Resource Conservation
and Development Council; landscape
plant donated by Maplewood Gardens.
FEATURED CREATURE
The Blue Crab – Symbol of the Chesapeake Bay
By Tamsey Ellis, Education Director,
Eastern Shore Soil and Water
Conservation District
organisms. They help prevent over
population of any one species (including
their own).
The blue crab gets its name
from the brilliant sapphire blue color
of its claws. It is one of the most
recognized animals in the Chesapeake
Bay and serves as the symbol of the
Bay. You may think “Why the crusty
old crab? It is not a cute animal like the
harbor seal. It is not gorgeous or regal
looking, as the great blue heron. And
it is not as fascinating as the seahorse.”
However, since it is a keystone
species it is a great symbol for the
Bay. Keystone species are organisms
(plants or animals) that affect many
other organisms in their environment.
The blue crab certainly does that. It
is a favorite meal for many animals,
including bony fish as striped bass (rock
fish), catfish, red drum and Atlantic
croakers along with eels, cownose rays,
herons, humans and even some sharks.
The almost microscopic blue crab
larvae are even eaten by filter feeders
as oysters, clams and menhaden. When
crabs are abundant then many other
animals in the Bay have plenty of food
and their numbers increase. When crabs
are scarce then the populations of these
other animals decrease.
Although many animals,
including humans, love to dine on blue
crabs, this predator/prey relationship
works both ways. Crabs are very
opportunistic and will eat anything
they can get their claws on, including
dead plants and animals. They are the
sanitation managers of the Bay. They
feed on marine snails, seaweeds, fish,
clams, detritus and almost anything they
can find as they walk sideways (that
is just the way their legs bend) across
the bottom of the Bay. They even help
salt marshes by feeding on periwinkles.
Blue crabs will even eat other blue
crabs that are still soft after a molt.
Some scientists claim that cannibalism
provides 25% of its food supply. In fact,
crabs are a major factor in regulating
population growth among many
The scientific name for the blue
crab is Callinectes sapidus. The blue
crab’s first name (Callinectes), when
translated, means “beautiful swimmer”
and its last name (sapidus) means
“savory”. If you have ever dined on a
hard or soft shell crab you will probably
agree that it certainly is delicious. The
blue crab swims sideways using its back
pair of paddle shaped legs which rotate
20 to 40 times per minute. It hardly
makes a ripple in the water even when
it darts away from a predator and its
graceful movements in the water may
remind you of a ballet dancer,
Few blue crabs live longer
than 3 years. Males molt and grow
their entire life. The largest male found
in the Bay had a width of 9 inches.
Females, after reaching sexual maturity,
never molt again so they stop growing.
Therefore males will grow larger than
the female.
Crabs mate from
May to October in brackish, or slightly
salty, waters of the Chesapeake. The
female mates only once in her life while
the male mates more often. Mating
can only occur when the female is in
the soft shell stage. After mating, the
female heads towards saltier waters at
the mouth of the Bay to spawn while
the male stays in less salty water and
searches for other females.
When the female is ready
is ready to spawn she deposits about
2 million fertilized eggs into a large
“sponge” she forms on her abdomen. It
takes about 14 days for the embryos to
When rain falls on the Earth, that water
flows across or under the ground and
begins its way to a stream or river, and
then on to a larger body of water such as
an ocean. The land that the water flows
across on its way is called a watershed.
Not all watersheds are the
same. A watershed can be in the
mountains or where the land is nearly
flat. Cities, farms, and forests may be
in a watershed. How we use the land
in a watershed affects the water that
flows through it. What we do in our
backyard impacts our waterways. We
Credit: Dorothy Perucci
develop and hatch. Only about 1 egg
per million will survive to maturity.
The newly hatched baby
blue crab, called a zoeae, is almost
microscopic at about a quarter of a
millimeter in width (think 1/100th of
an inch). You would never recognize it
as a crab since it looks like a question
mark-shaped worm. The zoeae float in
the water and are carried by wind and
currents in and out to sea. Many of
them die because they are not carried
back into the Bay. Zoeae will molt four
to seven times over the next 31 to 49
days and grow to 1mm in width. With
its last molt it changes significantly to
its 2nd life stage, called a megalops. A
megalops is free swimming with biting
claws and pointed joints at the ends of
the legs and appears more like a baby
lobster than a baby crab. It likes to stay
near the bottom and close to the shore
at the mouth of the Bay. The megalops
stage lasts 6 to 20 days with only one
molt that results in a juvenile (or “first
crab”) stage. .By this time the crab is
about 2.5 mm (1/10th of an inch) wide.
This small crab migrates to shallower,
less salty waters in the upper estuaries
and rivers. By the following spring or
summer after the year of their hatching,
the Chesapeake blue crabs reach sexual
maturity at the age of 1 to 1.5 years old.
They live only about one more year.
The past decade has resulted
in a large decline of the blue crab. The
reasons for this are three fold: pollution,
loss of habitat, and over fishing.
Pollution coming off of the
land (especially of sediments, nitrogen
and phosphates) creates “dead zones”
in the Bay. These are areas where the
oxygen levels in the water are so low
that aquatic life can not exist. Most
aquatic animals cannot leave the Bay.
There have been times when crabs
have been seen crawling ashore in huge
numbers in search of oxygen. These
events are “crab jubilees” resulting in
the loss of numerous lives and are a
strong message to us that the Bay is in
trouble.
Loss of habitat is mainly
caused by the loss of submerged aquatic
vegetation (SAVs – see the seagrass
article in this supplement). SAVs
provide nurseries for juvenile crabs and
protect them from predators. They also
provide a hiding place for molting crabs
helping them to evade predators during
this dangerous time. Without seagrass
and other SAVs it would be difficult for
the blue crab to survive.
Over fishing is the third
reason for the decline. In the 2007- the
Chesapeake blue crab harvest was 44.2
million pounds and was one of the
lowest since 1945. This is almost half
of the normal amount. Maryland and
Virginia placed a ban on dredging for
crabs in the Bay in 2008. About 90 %
of the crabs picked up through dredging
were mature females ready to produce
young in the spring. Mature female
crabs are more vulnerable to dredging
because they like saltier, deeper waters.
They will bury in the mud of the lower
part of the Bay for the winter. Males
and immature females like less salty
waters and migrate to Bay tributaries
or the mid-Bay muddy bottom for
hibernation. In 2009 the harvest was
53.9 million pounds. In July 2011 the
harvest report for 2010 revealed that 89
million pounds of blue crab had been
harvested. It appears that the ban on
dredging plus other methods to help
clean up the Bay are working. This
increase in crab population is good
economic news since about one third of
the nation’s blue crab catch is from the
Bay.
The next time you see this
iconic symbol on the Chesapeake Bay
License Tags do not think of it as a
crusty old crab. Instead, think of it as a
survivor, a valuable waste management
system, a beneficial population control
regulator plus it makes a tasty crab
cake. Besides, maybe it is cute - in its
own way. Maybe we should give this
“beautiful swimmer that is savory” a
little more respect.
What is a watershed?
all live in a watershed – even plants and
animals – so it’s important to protect our
waterways. We all need clean water for
drinking, swimming, fishing, recreation
and producing goods.
MD-0000569013
PROOF O.K. BY: __________________________________________________
O.K. WITH CORRECTIONS BY:_________________________________________
PLEASE READ CAREFULLY • SUBMIT CORRECTIONS ONLINE
ADVERTISER: EASTERN SHORE SOIL & WAT PROOF CREATED AT: 8/30/2011 6:33 PM
SALES PERSON: MEGAN LEWIS
PROOF DUE: NEXT RUN DATE: 09/07/11
PUBLICATION: MD-VA WEEKLY PUBLICATIONS
SIZE: 6 col X 20.5 in
MD-0000569013.INDD