Students explore oceanography
aboard Texas A&M's research ship
by Amy Warren
Going to sea during an ocean research cruise brings
classroom oceanography to life. Texas A&M University's research vessel,
the Gyre, is a floating laboratory and learning environment, and the phrase
"all hands on deck" well-describes the teamwork necessary for
a successful cruise.
Recently, Dr. Doug Biggs and Dr. Norman Guinasso directed
a team of graduate and undergraduate students and research scientists on
a two-week cruise in the northeast Gulf of Mexico, sponsored by the Minerals
Management Service. (Read Cruise News in the Spring 1998 Quarterdeck for
more details about the Northeast Gulf of Mexico expeditions.)
"It was valuable to get some sea time under my
belt and experience what it's like to be on a ship with the same people
for an extended period of time in a relatively small area," said Lori
Muller, senior marine sciences major at Texas A&M University-Galveston.
"It teaches you something about how well you work as a member of a
team, which is how most scientific endeavors are performed."
The R/V Gyre
can carry up to 23 scientists, plus technicians, deck engineers and the
ship's crew. (File photo)
In a lab aboard the R/V Gyre, Lori Muller learns from Dr. Doug Biggs the process of filtering surface sea water for measurement of chlorophyll. (Amy Warren)
The students and scientists collected water samples
at 99 locations, or stations, in the gulf in order to study temporal and
spatial properties of waters over the U.S. continental shelf and slope.
The water collection continued night and day, so the student researchers
divided into two teams, each team working a 12-hour shift from noon to midnight
or midnight to noon.
"Twelve hours doesn't seem very long, especially
in the daytime and when the sea is calm," said graduate student Ou
Wang. "It's really fun work." Gaston Gonzales, a graduate student
who has participated in more than 14 cruises, disagreed a little: "I
worked the night shift, and the night hours seemed longer," Gonzales
said.
The students, with supervision, are responsible for
the centerpiece of the water-sampling effort: a cylinder-shaped metal frame
carrying conductivity-temperature-depth sensors (CTD), twelve 10-liter Niskin
water collection bottles and several other oceanographic instruments.
When the ship approaches a sampling station, the team
"on watch" dons floatable work vests for safety and heads to the
main deck to prepare for sampling. Team members open all the bottles and
make sure the instruments are ready to descend. They also check for kinks
in the hydrographic cable that provides electrical power to the instruments
and allows data transmission to the ship.
When the ship is stationary, the team scoots the 350-kilogram
instrument package to the edge of the ship where the railing is cut away
for easy launch and retrieval of instruments. Several people guide the frame
as the crane operator lowers it into the water.
Once the instrument package is submerged, the students
can visit the computer lab to observe real-time CTD data-temperature, salinity,
light transmission and fluorescence-as the package descends to the seafloor.
Depending on the depth of the sampling station, ranging from 10 meters to
1,000 meters, the descent and ascent can take from five minutes to more
than an hour.
While the packgage is underwater, the team is busy preparing
to collect and analyze the water being collected in the Niskin bottles.
Graduate student Gaston Gonzales filters water for pigments. (Amy Warren)
Students guide the frame of twelve 10-liter water collection bottles and oceanographic instruments over the edge of the ship at a sampling station. (Amy Warren)
When the instrument package emerges, the team members
guide it safely onto the deck, and the ship steams to the next station.
The team swarms around the package and systematically draw water samples.
"It was satisfying to actually get my hands on
the equipment and experience the data retrieval first hand," Lori Muller
said.
Next, the student researchers and research assistants
perform a variety of tests and filtrations in the ship's labs. They measure
nutrients and oxygen concentrations and the amount of phytoplankton pigments,
particulate organic carbon, suspended particulate matter, and salinity.
The research scientists always are available to direct
and assist the students. "Part of the job of our research scientists
is to supervise the students and train them in excellent sampling techniques
and habits," said Dr. Ann Jochens, deputy program manager for the Northeast
Gulf of Mexico program.
When the filtering is finished and the next station
is an hour or two away, the team members disperse. Some go to the lounge
to browse the ship's paperback collection or to watch one of 200 (or more)
videotapes; others visit the galley for a cup of Blue Bell ice cream; still
others climb a ladder to the flying bridge to help watch for whales and
dolphins.
But all are alert for the signal that the ship is approaching
the next station ... when the sampling will start again.
After the cruise, the students and researchers process
the data and then analyze and interpret the results.
During this cruise, NEGOM scientists noted an extensive
region of low-salinity water in the western part of the study area. This
fresh water "tongue" was most likely influenced by river discharge
from Mobile Bay and/or the Mississippi River. The scientists are investigating
the effects of this fresh water on the northeast gulf.
Get the inside scoop from
graduate students and faculty
about preparing to study oceanography.
Dawn Hart,
senior geology major, draws ocean water from the collection bottles for
later analysis. "I feel very fortunate to have been able to go,"
Hart said, "and I'm looking forward to my next voyage on the Gyre."
(Amy Warren)
Projects bring scientific diversity to cruiseIn addition to helping with water collection activities for the NEGOM project, several students and scientists used their spare time to work on other oceanography projects. More ... |
