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Cordell Bank is a submerged island with the highest pinnacles are about a hundred
and twenty feet below the surface of the water.
The upper pinnacles are
totally covered with sponges and little
strawberry anemones,
ascidians which is another invertebrate encrusts on the rock, that cover
on the upper pinnacles and and shalower reef areas on the bank
is over a hundred percent.
Animals growing on top of animals.
One of the projects that we're doing out at Cordell bank right now is trying to
characterize the habitats
and get some quantitative estimates of
fish abundance, identify the invertebrates
that live on the bank and describe the distribution of those invertebrates on
the bank.
We've gone to using a manned submersible
and an observer, a biologist, sits in the front of the sub identifying areas on
the bank that we want to monitor,
go down to as deep as twelve hundred feet,
will count and identify fishes
We have a video camera mounted on the outside of the submersible that's
filming everything that we're seeing,
but then we'll also bring those tapes back to the lab after the cruise,
somebody
reviews the tapes and identifies the fish. We have lasers that tell us how large
the fish are.
Then we come back through the tape a second time
and characterize the the different substrate types like boulder,
reef,
bedrock, mud, sand.
And then what we hope to do is to start to get an idea not only how many fish we
have,
of what kind, and where they are, but then if we can associate them with a
particular kind of habitat,
then we can start to get a feel for
how much of that habitat we have
and we can make some guesses about how many fish might be where on the bank.
The bank is about four-and-a-half miles wide by about nine-and-a-half miles long.
Up on the northwest edge of the bank, the relief is extreme. We'll hit granitic walls that
are
fifty to sixty feet high and then it'll run along a ridge and then it'll just drop
straight off. The relief on Cordell Bank is is absolutely spectacular.
We want to be able to describe how things change over time.
How the fish abundance or species composition
changes over time.
We have a second major effort that is looking at
the water column and those animals that live above the water such as sea birds.
We also will drop a
instrument that measures
temperature, salinity, light penetration,
it also measures chlorophyll which gives us an idea of of, um, how many
phytoplankton are in the water,
and if we do this year after year we start to get a feel for
productivity
and how that varies from one year to the next.
There's only four eastern boundary currents
and there's only four these areas in the world,
the West Coast of North America being one.
An oceanographic phenomenon that's associated with these eastern boundary
current is upwelling.
Upwelling really is responsible for bringing nutrients up into the near-shore
area,
and Cordell Bank just happens to be in the center
of the California Current upwelling system,
Point Reyes being one of the major features
in the California Current upwelling system
and you'll see in satellite images, pictures of ocean temperature
color-coded
and so you get these deep blues and purples which represent
cold,
nutrient rich
water that's upwelled right next to the coast sitting right on the edge of the
continental shelf
and so you'll get a lot of
oceanic species
such as the albatross and the shearwaters
and
these birds that never visit land except when they're nesting
are common inhabitants around Cordell Bank
as well as the blue whales and the humpback whales that are, these are oceanic
species but you'll get them
in close proximity
to really subtidal species that typically you see right near shore like
the anemones
and the sponges.
And so the biological diversity at the bank is is just fabulous because you get
the offshore component and the nearshore component right in the same area.
So really in terms of diversity out there it's one of the most biologically
diverse places along our coast.
In the eighteen fifties George Davidson was returning from a survey trip up
the
North Coast of California
when he was enveloped in a thick
layer of fog and knowing that he was getting near Point Reyes he dropped the
lead line overboard and expecting to find three hundred to four hundred feet on
the continental shelf,
he actually, the lead line stopped at about a hundred and twenty feet.
In eighteen sixty-nine or after the civil war, they started getting reports
again of this high spot or shoal
off of Point Reyes and George Davidson sent Edward Cordell out
to try and relocate to bank.
And it took Cordell a while and finally he was drawn to this area by an
abundance of wildlife.
Cordell Bank is a destination feeding ground for blue whales and humpback whales
in the summer and fall
and the reason that these whales migrate to Cordell Bank from
Central America and Mexico is to feed on the krill.
Krill are really one of the keystone species out there at Cordell Bank. Everything feeds
on krill.
The threats to Cordell Bank could be environmental or they could be human
induced. The environmental threats such as El NiƱos, global warming
we don't have any control over.
The human threats we may have some control over.
Cordell Bank was designated as a National Marine Sanctuary in nineteen eighty-nine.
Until the early seventies, the oceans were seen as limitless. The resources were
limitless. We couldn't possibly
affect the conditions of the oceans by getting rid of our
garbage and our trash. In the middle sixties and early seventies
people started to understand we could harm the oceans, and we were. The sanctuary
program
was created to try and protect
some of these national treasures that have
significant biological or cultural resources.