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March 15, 2003: Leg 3, Day #4
On our way to Guaymas Basin
Today's update has been provided by George
Matsumoto.
We
have left La Paz and are steaming back toward the Farallon Basin. We
recovered the vehicle last night, and then we set off toward La Paz after
hearing that our ships agent had located a regulator for our oxygen
cylinder and managed to secure our net out of Guadalajara. The R/V
Western Flyer launched the "Spare RHIB" (Rigid Hull
Inflatable Boat) when we were just off of the dock. The Spare RHIB went to
shore to collect the net and the regulator (see image within the map). We
then turned around and headed back to yesterday's position. We expect to
be onsite and ready to dive around 1400 or 1500 hours. This will be a
short and shallow dive as we will be using Dr.
Edie Widder's special bioluminescence camera to conduct transects in
the upper 1000 meters. Check back here tomorrow to see how the dive went
from Dr. Widder's perspective. You can also see daily updates from Dr.
Widder on the Harbor Branch Oceanographic Institution website at http://www.at-sea.org/missions/cortez/preview.html.
More
later...
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It's 1:15 p.m., and we have just launched the ROV Tiburon
in the Farallon Basin. We're
at 25 27.0071N and 109 50.0021 W diving in the midst of a huge red tide.
We stopped on station, and we were surrounded by a
wide layer of dinoflagellates. Don't know if they
are toxic or not, but the water is pretty empty and there
are lots of moribund jellies floating at the surface. Kim
Reisenbichler, Steve
Haddock, and Karen Osborn are
taking off for a blue water dive. Kim has a detritus
sampler from the ROV. He is also going to be a "human
detritus sampler" and will attempt to collect a
larvacean and a house for Dr.William
Hamner (UCLA). We are hoping to be able to watch
the larvacean build a house in the lab. It's so unusual to see them in
shallow water— it is just amazing to be able to SCUBA
dive and look at something in person that we have only seen on video
screens for over ten years! Since they are at
ambient seawater temperature, we don't have to try and study them in
chilled seawater. The animals collected will be placed into a plankton
kreisel (designed by Dr. Hamner several years ago) and hopefully will
build a house.
Late update from the blue-water SCUBA divers—the
dinoflagellate layer is wide but v ery thin. It
starts right at the thermocline and is only a few
centimeters thick. The oxygen regulator arrived, and
Brad Seibel has gotten his equipment set up and working—just waiting for some animals to put into the
chambers. Brad will be able to collect blood oxygen binding data
for a range of cephalopod species. Each animal is
run through 10 different oxygen levels for several minutes,
which
means Brad
will be working late into the night after many of us
have gone to bed. The trawl net (above) has also arrived. Kim
Reisenbichler and Jeff
Drazen worked all morning getting the rigging
ready so that we can tow. Here's an image of Jeff (see left) with
the Precision Depth Recorder. This ancient instrument
will record the depth that the net is fishing.
Today's
ROV dive will be short as we lost some time with our transit into
La Paz last night. Because of that, Edie
Widder will be doing her
bioluminescent transects, which can only go down to
1000 meters. Otherwise her special camera housing
will leak. It was designed for Harbor
Branch's Johnson Sea
Link subs, which only go down to 1000 meters. We did
have some problems hooking up the acoustic current meter (ACM)
as the 12- volt power on the ROV was
not behaving. So the pilots
(Dave
French and Jim
Cohen in this picture) opened up
one of the waterproof housings to get to the 24-
volt power and send that to the ACM which will take 24- volt power.
Even with the short ROV dive, we managed to collect a few
jellies, spiders, and some cephalopods. As we work
up these specimens, we will try and provide you with
more information about them. One thing is clear,
life in the Gulf of California is diverse, rich, and
extremely interesting. The research that we are
starting here will keep us busy for many months to
come. We are learning an awful lot, but I already know that I would
like to come back and spend even more time in this
area.
Once we finish up here, we're going to be heading further
north into the Guaymas Basin for a couple of days
of ROV operations,
SCUBA, and trawling. A typical
day there will consist of 12 hours of ROV operations
(6 a.m. to 6 p.m.), a SCUBA dive (around 10 am), and
then trawling from 6 pm to midnight. Then, we can
start to process the animals and information that
we've collected. We won't do any trawling tonight because
we wouldn't get on station tomorrow until later in
the day. So come back and check out the updates over the next week
to see and read about what we've collected with the
trawl.
We were visited by a small plane this afternoon that
buzzed the boat fairly low a few times and then it
went away. Just as we were finishing up the last of
the biolum transects (50 meter depth), the recovery
process was interrupted by the bridge informing us
that we were being boarded by the Mexican Navy. The Jacobs
Ladder went over the side, and two Mexican Navy
personnel came aboard. They were greeted by our collaborator, Rebeca
Gasca Serrano, and were taken up to the bridge.
It seems that they didn't know we were in the area, but once
they saw our permits, everything was okay. Rebeca
and Darryl
Palmer gave them a tour of the boat, which included an impromtu
session on siphonophores by Steve Haddock in the
wet lab. The Lt. used to be a marine biologist and was
very interested in what we were doing. Although his
English was excellent, it was comforting to have Rebeca helping
to interpret. The Lt. said that he would pass on the
word that MBARI and the R/V Western Flyer were operating with permission
in the Gulf of California.
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