Sam Bowser [U Albany Alumnus; B.S.'79, Ph.D.'84] spends three months a
year diving in the frigid ocean waters of Antarctica to study what he
calls "giants of the deep." By giants, though, Bowser isn't
referring to whales or sharks or huge squid or luminescent fish swimming
the seas. Bowser's giants, instead, are large, single-celled creatures
known as Foraminifera. Sometimes the size of a fingernail, these important,
one-celled protozoans inhabit the ooze at the bottom of the ocean. One
of the most abundant organisms on Earth, Foraminifera are fascinating
and mysterious creatures with capabilities that would seem far too complex
for their size. For one thing, each Foraminifera builds itself a tiny
but sophisticated shell out of grains of sand glued together with a highly
effective underwater adhesive. In addition, the one-celled creature is
able to capture and eat ocean organisms many times larger than itself.
Bowser, a professor of biomedical sciences in the University's School
of Public Health and a scientist at the New York State Department of Health's
Wadsworth Center, has spent the last ten years investigating these and
other mysteries. In the short term, Bowser says the goal of his National
Science Foundation-supported work is to provide basic information on the
Foraminifera's habitat, life cycle, reproductive patterns. ecological
niche, eating habits, evolutionary history and the role the creature plays
in recycling organic nutrients in the oceans.
Considering how widespread Foraminifera are in the ocean, Bowser says
it is astounding to him that the organisms, and their role in recycling
carbon in the ecosystem, haven't been studied more thoroughly. "These
protozoa are clearly one of the most dominant life forms on the planet,"
he says, "and amazingly, we don't know much about them at all."
In the long term, Bowser also believes that important health and medical
applications could come out of his basic research. If scientists can unlock
the chemical secrets of the underwater adhesive that Foraminifera use
to glue sand grains together to make their shells, it may be possible
to manufacture that adhesive for use in a variety of watery environments.
Bowser suggests that such adhesives would prove highly useful in sutureless
surgery, dentistry, pharmacology, nerve repair and in the construction
of artificial organs and limbs.
It is September
in Albany, a gorgeous Indian summer day, but Sam Bowser is heading to
the forbidding white wasteland of Antarctica, where the temperature routinely
dips to 30 degrees below zero. After a 36-hour commercial flight with
five separate connections, he and his team of researchers land at a U.S.-operated
facility at Christchurch, New Zealand. There, Bowser and his team and
all their cold-weather gear are deployed to Antarctica aboard a huge Air
Force C 141 transport plane.
The plane lands on the ice runway at McMurdo Station, a research outpost
built into a desolate volcanic island. McMurdo houses from 200 to more
than 1,000 people at a time in dormitory complexes, but Bowser and his
crew don't live in the relative comfort of these dorms. Instead, they
take helicopters another 60 kilometers into the wilderness to a site known
as Explorer's Cove. There, nailed into the Antarctic tundra, is Bowser's
campsite, a small gathering of Korean War-era wood and canvas tents that
look like giant oil drums lying on their sides.
Why do the University at Albany researchers travel to Antarctica to study
this common ocean protozoan'? The reason is simple: Foraminifera live
deep on the ocean bottom, which means the organism ordinarily can only
be recovered out of muddy sediments that are one to two miles straight
down. It would be highly inefficient and expensive to arrange for submersibles
to collect the protozoa from these deep ocean sites.
In Antarctica, however, the relatively shallow ice shelf mimics the dark,
cold and nutrient-poor conditions of the deep ocean floor in other parts
of the world. Bowser and his colleagues have only to dive about 100 feet
to "vacuum" up the protozoa from the ooze.
Before they can dive to collect samples of the Foraminifera, however,
the scientists must first punch holes through a 15-foot layer of ice.
Diving for ocean creatures in Antarctica is tough, grueling and dangerous
work. The scientists routinely have to slip out of their clothes and into
their diving suits in temperatures that are well below zero. Bowser, energetic
with something of a cowboy's attitude toward his adventurous work, says
the seawater is so cold that after about a half hour, a diver is usually
too numb to work. (His own record underwater is 65 minutes, but more often
his dives last 35 to 40 minutes.)
Then, of course, there are the challenges of living in the Antarctic.
The scientists are routinely blasted by wicked winds which whip sand across
the desert-like tundra at more than 120 miles per hour.
To bathe and to wash dishes, the scientists have to use melted ice water.
Most food is freeze-dried. And there is hardly what you would call regular
entertainment out there on the tundra. Occasionally, the researchers are
whisked back to McMurdo Station by helicopter for a hot shower and a VCR
movie. And the scientists do have solar-powered cellular phones and computers
to help ease the feeling of isolation out on the unending ice.
Bowser thinks the Antarctic research is well worth every bit of discomfort
and trouble. (In fact, he recently applied for a federal research grant
that would expand his ocean explorations and his studies of Foraminifera
into the waters off the coast of Greenland. Polar bears are his only concern,
Each trip to the Antarctic lasts two to three months, during which time
Bowser collects between 20,000 and 30,000 samples of Foraminifera. (The
organism's scientific name is Astrammina rara.) One of the first
set of experiments Bowser conducted in his Albany laboratory was aimed
at investigating what the organism ate. The scientists assumed that the
one-celled Astrammina would eat organisms smaller than itself,
so they fed the creature bacteria, algae and fecal matter. Astrammina
ate all of the above, as expected. But then, something amazing happened.
In an experiment aimed at seeing what creatures would feed on Astrammina,
Bowser introduced into a plate of Astrammina a crustacean that
he assumed would be a predator on the smaller one-celled protozoa. Lo
and behold, Bowser found that instead of eating the one-celled Astrammina,
the crustacean was actually eaten by the smaller organism!
"This was completely unexpected," he says. "It was completely
backward, actually reversing the food chain." After further study,
Bowser concluded that in order to eat the larger crustacean Astrammina
relies on the many long filaments (called pseudopods) that it pokes
out of holes in its sand-encased shell. The pseudopods (which at their
largest are about the size of a human hair) secrete strong extracellular
fibers that, netted together, can trap larger organisms.
"These single-celled creatures, we have decided, act like the spiders
of the sea," Bowser says, "sending across the ocean floor a
carpet of pseudopods that act like webs." While he has no direct
proof, Bowser hypothesizes that Foraminifera probably feed on the young
of many larger ocean organisms, including starfish and sea cucumbers,
thereby regulating the population size of these larger creatures.
"We believe that this tiny one-celled creature may in fact be a major
player in terms of regulating marine life on the planet," Bowser
says. "In any case, we believe that we as humans should learn more
about these organisms and certainly we should be careful not to dispose
of toxins in the ocean which could hurt them."
Probably the most fascinating feature of' Astrammina, though, is
the fact that it is able to build its own shell. "How does a single-celled
creature pick up a grain of sand and say, 'O.K., this is the right size,
shape and color, I think I'll glue it in place here'? How is a single
cell able to do this'? For 150 years, nobody has been able to figure it
Foraminifera's remarkable shell-building capability was first described
by a scientist named W. B. Carpenter in the mid1800s. Later, Carpenter
wrote to Charles Darwin to share his observations on this phenomenon.
Darwin wrote back to Carpenter, expressing his amazement and saying he,
too, was puzzled about how the creature was able to assemble its own shell.
Curiously, in certain species, the youngest Foraminifera build shells
that are triangular in shape. As the organism matures, the creature constructs
a more and more complex geometrical shape, becoming a square, and then
adding more sides to its "house."
In the laboratory, Bowser focuses on finding out how Astrammina secretes
the adhesive for its shell. Barnacles and other large sea creatures rely
on several glands and physical agents to secrete adhesives. But Foraminifera
have none of these features. So Bowser, a cell biologist by training,
is now busy looking for "organelle equivalents" that might explain
the Foraminifera's ability to produce adhesives.
In the long run, his search for the adhesive may yield some vitally important
health and medical applications. "Here we have a simple creature
that can secrete a remarkable glue that works underwater," Bowser
says. "Maybe, in the future, it will help us solve a whole host of
binding problems in watery environments."