16 THE SCIENTIST | the-scientist.com
discovered wooden wrecks—one around
500 meters deep and the other nearly
1,800 meters down—in the Gulf of Mex-
ico, says Hamdan, who presented the
data at the Ocean Sciences Meeting in
San Diego in February.
Hamdan joins Field as one of the
few microbiologists to focus on ship-
wrecks. In her first such project, Ham-
dan and colleagues navigated a remotely
operated vehicle to six Gulf of Mexico
wrecks, all located between 140 meters
and 2,000 meters deep, to collect sam-
ples that could help them understand
the effects of the 2010 Deepwater Hori-
zon oil spill on the microbes in andaround the wrecks. She’s also studied
how the shipwrecks themselves affect
the microbial communities surrounding
them. Most recently, she and her team
placed pieces of wood near wrecks in the
deep sea that they later retrieved, using
an acoustic signal to trigger a flotation
device to bring them to a research vessel
at the surface, to see what microbes had
grown on them.
The results support the idea that the
composition of microbial communities
changes with distance from wrecks, she
says. “We’ ve seen a... definitive sig-
nature of increased biodiversity in a
ring around the shipwreck Anona,” ayacht that sank in the Gulf of Mexico in
1944, “and we’re also seeing this pattern
emerge around one of the two wooden
shipwrecks that we studied last sum-
mer.” Hamdan says these results will be
published soon.
“Looking at microbial communities
on shipwrecks is definitely something
n e w,” says Kirstin Meyer-Kaiser, a marine
biologist at Woods Hole Oceanographic
Institution who studies invertebrate com-
munities that live on shipwrecks. She
suspects that, with more research on the
microbial communities in and around
shipwrecks, scientists will learn about
how those communities interact with
invertebrates, too. Just as the material of
the ship appears to affect which bacteria
settle where, she speculates, perhaps the
biofilms those bacteria form affect which
invertebrates take up residence.
Hamdan says it’s very likely microbes
are playing a role in shaping macrofaunal
communities at shipwrecks. “For you to
be able to see any corals and tube worms
and all of this gorgeous stuff that grows
on shipwrecks, the microbes have to get
there first.”
—Jef AkstSpidershot
Leg over leg, a furry brownish-black spi-
der tugs on a single silk thread, tightening
the frame of its web. It pulls and pulls, as if
removing slack from a slingshot, and then
it waits. Minutes pass, sometimes hours.
Then, when an unsuspecting insect flies
by , the spider releases the thread, spring-
ing itself and its satellite dish–shaped web
toward its prey. All of this happens in the
blink of an eye, with the spider and its
web hurtling through the air at more than
4 meters per second (9 miles per hour)
with accelerations exceeding 130 g. That’s
130 times the acceleration experienced inNOTEBOOKUNDERWATER ACTION: Maritime
archaeologist Nathan Richards drills a core
from the hull of the Pappy Lane shipwreck.JOHN MCCORD, UNC COASTA LSTUDIES INSTITUTE