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“I TRY TO EAT SOMETHING THAT IF I DO GET
sick, I wouldn’t mind it coming back up,” she says.
Once past the odor, it’s easy to get excited by what she
finds. Much of it is too small to easily identify but the
discovery of three quarter-sized crabs is pay dirt. Going into
the project, Grey expected the rays’ diet to consist of bigger,
high-caloric prey such as clams and crabs. After examining
20 or so stomachs, that’s not what she is finding.
Cownose rays are those sleek kite-shaped, long-tailed
fishes you often see swimming around in aquaria “touch
tanks.” Seems odd, then, that life in the Chesapeake Bay is
considerably more hostile for the stingrays.
“I have seen these beautiful rays shot with guns and shot
with arrows and had large stones and cinder blocks dropped
on their heads, all because everyone assumes that they are a
direct competitor that needs to die,” says Grey’s advisor John
Morrissey, a marine biologist at Sweet Briar.
e rays have been accused of a host of atrocities from
wiping out the softshell clam fishery and plundering
commercial oyster beds to destroying delicate grasses that
conservationists have been at pains to re-establish in the
environmentally troubled Chesapeake.
e problem is they migrate into the Bay every summer
by the millions. ere they both reproduce and feast —
leaving behind telltale feeding craters in the sediment where
they’ve searched for prey. In such numbers, and with each
adult weighing 25 to 35 pounds, they do eat a lot. But what
exactly are they eating?
“Well, everyone in the area simply assumes that they are
eating whatever is important to that person,” Morrissey says.
“So commercial clammers are ‘certain’ that the rays are eating
clams, and recreational crabbers are ‘certain’ that they are
eating crabs, and the oystermen are ‘certain’ that they are
eating oysters.
“Bottom line? Everyone hates them and a grassroots
campaign to exterminate them is vigorously under way.”
Worse, there’s a movement afoot to establish a
commercial fishery to control their numbers in the Bay—
something scientists fear would endanger the migratory
species and have ecological repercussions. ey reproduce
slowly, there’s no reliable estimate of their actual numbers
and no one knows where they go when they leave the
Chesapeake in September.
To take some of the heat off the beleaguered fish, Grey
and Morrissey are collaborating with Doreen McVeigh ’09
and her master’s thesis advisor Drew Ferrier at Hood College,
to determine what it really does eat. Previous studies
produced conflicting data, but one in the late 1970s
concluded they eat softshell clams exclusively. It was later
supported by a 1985 study. at fishery, however, no longer
exists in the Bay.
In the summer of 2010 Grey interned with McVeigh
at St. George Island, Md. ey, along with McKenzie
Grundy ’13 and Morrissey, spent several weeks trying to
catch rays.
Several fruitless fishing trips led them to befriend
commercial fishermen, who are happy to hand over the rays
that wander into their pound nets. e fieldwork taught Grey
to expect things to not go as planned and to work with what’s
at hand. “at’s continued on with the research I am doing
now,” she says.
Actually, the unpredictability in the field and lab appeals
to her and she has decided to apply to marine biology
graduate programs. “I was pre-vet for a while,” she said,
stopping herself. “at’s a lie, I was pre-vet since I was five.”
Under Morrissey’s guidance in the lab, Grey is working
with frozen specimens this semester and she will report on
her findings in late November. ey may not be ready to
draw conclusions by then; much depends on how many
samples Grey is able to process. So far, however, the diversity
of worms, fishes and nearly microscopic bivalves contradicts
earlier studies suggesting their diet is highly specialized. at
could go either way for the cownose ray.
“Frankly, I would be shocked if they don’t eat something
that is of commercial value,” Morrissey says. “But if we can
show that they are still very narrow in their prey selection,
then maybe we can cause, for example, oystermen to
continue to despise them while everyone else leaves them
alone.
“Would the rays get to swim around with fewer arrows
in their backs after that?”
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