Resource value:
Sea urchins and sand dollars prefer different habitat types.
Both Echinoderms
are used in research in embryology, but the urchins are an important
marine resource and their eggs (roe) are harvested for food and
export to the Orient. Prior to 1971 urchins were considered a
pest on kelp beds (Their preferred food) and quick lime (Calcium
Oxide) and divers with hammers were used to kill them. |
Native Americans harvested urchins for thousands of years, but
there was little commercial harvest until 1972. Between 1971
and 1981 the catch climbed from a few hundred pounds to 25 million
pounds, and peaked at 52 million pounds in 1988 when urchins
became one of California's
most valuable "fisheries." Urchins are also harvested
by divers in Maine, Massachusetts and New Hampshire. |
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The Del Monte Shale Beds at Monterey Bay are highlighted by the
red arrow.These shallow areas are at the edge of the Monterey
Canyon which is larger than the Grand Canyon.
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The "Lone Cypress" on 17-mile Drive is one
of the most photographed trees in the world. Note the kelp beds
in the background (Good sea urchin habitat!) and a red-shouldered
hawk searching for prey
from a dead branch (Right). |
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"Swiss cheese" rocks exhibit high "rugosity."
These indentations are from the relentless burrowing of generations
of urchins, chitons and boring clams
and snails. This
is excellent habitat for urchins and creatures like the "top
shell" in the middle. |
Urchin habitat |
Research has shown that urchins may live 100-200 years, making
them one of the oldest known animals. If correct, some living
urchins
on the West Coast were alive in 1805 when Lewis and Clark
arrived in Oregon! |
Sand dollars
prefer bottoms deeper than about
13-meters and flat slopes with sandy bottoms. (Right)
Sand
Dollars are used primarily as ornamental curiosities collected
by beachcombers.. |
Sand Dollar habitat (Depth) |
Sand Dollar habitat (Slope and bottom) |
The great dunes of Sand City as seen from the wheelhouse of our
survey boat the Cypress Seas. |
(Right) Image from the depth finder confirms
the presence of a ledge in
65-feet of water. This soft shale erodes quickly and may represent
an ancient shoreline during the glacial period when sea-level
was lower. The interference may
be from kelp, schools of fishes or other marinlife.
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Chief scientist Tami demonstrates how the side-scan sonar will
"fly" through the water behind the vessel imaging the
bottom contours to our port and starboard. The data gathered
in a few minutes would take a diver months to document. |
The vessel "mows the lawn" following a predetermined
route across the study area with the sonar in tow. The image
shows sandy and rocky areas are distributed equally at 65-feet.. |
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"Shadows"
on the images help give us a 3-D view of the bottom
features.
A side-scan sonar image of a sunken and partially buried barge
in about 80-feet of water.
The bottom here is smooth and probably silt or fine sand.
Excellent for sand dollars. |
Otters also harvest urchins for food, controlling the over-grazing
of the kelp beds.
Many creatures are affected when urchin or otter populations
change. They are important members of the kelp forest. |
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Sea Lions posing for photographers in Monterey harbor. |
A California gull waits for fishermen to unload their catch. |
A hopeful pelican and an unusual dark-colored gull, the Heerman's
(Right), circle the vessel as we head for the dock after a successful
voyage.
For more information on the project, click here.
For more information on ROV's
and submersibles, click here. |
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