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Blue Crab Science at the Smithsonian
Poziom:
Temat: Środowisko
My name is Eric Johnson and I'm a fisheries ecologist
here at the Smithsonian Environmental Research Center (SERC)
SERC is located on the shores of the Rhode River
in Edgewater, Maryland
The Rhode River is a sub-estuary
of Chesapeake bay, about 2/3 of the way
from the bay mouth
to the Susquehanna River
SERC conduct research mainly on the land-
water interface and coastal ecosystems
It's one of the nation's leaders in that, and
much of our research focuses on
transitioning that information to the policy
makers and managers.
We've been tagging adult female and male crabs for approximately
a decade in systems throughout the Chesapeake Bay
with the with the goal of understanding
how females move, how females migrate in the
system and also how of the fishery impacts
the stock of blue crabs in the bay
One of the interesting parts of this research
is that we work directly with the watermen
to collect our animals so we actually
hire and work directly with the a local
fisher in one of the regions, in this case
the Rhode River,
to actually collect our animals.
Once the animals are collected, using the standard
commercial gear,
they're transferred from the commercial
boats to our research boat
where we have a an army of technicians that are
there to tag,
take the data on the crabs. Things like
their size, their sex and the condition of
those animals, before we release them back
out into the bay in the same areas in which
they were caught. The whole process probably
takes about of 30 minutes from when a crab
is captured to when a crab is tagged and returned
to the water.
"129...male...
...B...
...white, intact"
Each of the tags has the Smithsonian phone
number for the blue crab hotline which
directs the recapturers of the crab--
which can be recreational or commercial watermen--
to call in the information about that crab.
"130..."
Most of our recoveries do come from areas
is within the Chesapeake Bay however we have gotten
quite a few interesting recoveries. Our farthest
recapture that we think actually swam there
or walked there was from Florida. We
get new numerous recoveries from North Carolina
and we actually get quite a few from fish
houses. We got a call from California
from a person who had
a steamed crab sitting on their
plate with one of our pink tags and actually
called it in!
Crab are very important
in the Chesapeake Bay ecosystem. They form
a link between
the productivity that's occurring on the bottom--
things like worms and clams--
and the things that are of importance to us
like red drums
and some of a larger fish species which use
crabs as food essentially.
So they're very important link in that
food chain.
Crabs are obviously very important for the
economics of the bay, both for
the commercial fishery, which is the the
largest the fishery in the Chesapeake,
as well as from a recreational standpoint--
those fathers and
and daughters and sons who go out on the water
to catch those crabs and have that experience.
The overall goal of our research is to better
understand not only the migratory pattern,
but to translate that information
into sound management policy.
If we know when and where crabs are being
captured and by whom, managers can base
their policies on sound science.
Much of the research the we've been doing
here at the Smithsonian Environmental Research Center
and in our lab is focused on long-term studies
for some upwards of 30 years.
It's critical to have that long-term data
as a function of seeing how communities
change over time, over decades, to look at
how things are responding to, say, things like
climate change or to El Nino years and
those sorts of things. And this is an important
link to
on some of the
some the fishery things that are going on.
We're working our way towards ecosystem-
based fishery management,
a more holistic and comprehensive approach
that takes into account
these issues such as habitat and crabs' links to the
food web.
