25 March 2003
PCB's Save the Stripers? A Fish Story
By James Gorman
dredging of the Hudson River for PCB's will be starting a year later
than expected (in 2006 instead of 2005), but the striped bass season
in the river opened this month, right on time.
is no direct connection between the two events. The Environmental
Protection Agency needs more time to plan the dredging. And the
fishing for stripers has been going on for years with PCB's in the
river. In fact, there are more stripers in the river now than there
have been in decades. They migrate up the river in the millions
to spawn. It is almost as if PCB's are good for them.
is not the case, of course, not directly. No one can be sure exactly
why fish populations rise and fall, but one obvious and important
ingredient is fishing pressure. Greatly restricted fishing has reduced
that pressure on Hudson River stripers. Changes in regulations were
prompted partly by the health risk to people of the PCB's that accumulate
in the fat of fish, and partly by a general decline in striper populations.
is now no commercial striped bass fishing on the Hudson above the
George Washington Bridge and there has not been for quite a few
anglers can keep one striper a day in the river above the bridge,
but health recommendations suggest eating no more than one a month,
and none for children and women of childbearing age. Many anglers
could care less, since they like to catch the fish and let them
go. So the stripers, from a fisherman's point of view, are doing
rivers have improved as sport fisheries after problems with PCB's
were uncovered. The Housatonic in Connecticut is one of them. It
has catch and release stretches for trout that provide some of the
best freshwater fly-fishing in the Northeast.
have fished both rivers and had started to think of PCB's in stripers
as something like the cardiac glucosides in milkweed that monarch
butterflies ingest. The glucosides are not bad for the butterflies,
but they make birds that eat the butterflies sick, so birds do not
eat them. PCB's can make people sick, causing cancer or interfering
with embryonic development, so people — at least people who
worry about what they eat — do not eat the stripers. Although
the consequences of pollution are all unintended, surely protective
inedibility of game fish would be among the least expected.
was left out of this equation was the effect of PCB's on the fish
themselves. I called Dr. Adria Elskus, an assistant professor of
environmental toxicology at the University of Kentucky, who has
done research on the effects of various pollutants on fish.
PCB's bad for fish? I asked. Unequivocally yes, she said. They are
not at all the equivalent of glucosides. Monarchs are well adapted
to ingesting those chemicals and do not suffer from them. But, Dr.
Elskus said, PCB's and other chlorinated substances like dioxin
can hurt the ability of fish to reproduce, affect hormones, decrease
the chances of survival for the offspring and cause skeletal deformities
and devastating defects in heart development.
studies that showed these effects, Dr. Elskus said, were mostly
done not on striped bass, but "on the lab rats of the fish
world" — species that are easy to study in the lab, like
rainbow trout, zebra fish and Japanese medaka. It is, however, quite
sensible to expect stripers to experience similar effects. The reason
is that when it comes to these chemical effects "Fish Is Fish,"
as the children's author Leo Lionni so presciently announced in
his story with that title.
actual effect of PCB's on Hudson River fish has not been clearly
established, said Dr. Emily Monosson, an independent toxicologist
who did a study of just this subject for the National Oceanic and
Atmospheric Administration that was published in 1999. But PCB's
are present in the river at levels that should be causing some damage
then, are the fish doing so well? The answer is that the effects
of unrestrained fishing — mass fishicide — are much
worse than the effects of current levels of PCB's.
that people were in the position of striped bass. Aliens —
to whom we were the equivalent of striped bass, in both intelligence
and taste — came to Earth to harvest us by the hundreds of
millions. This went on for many generations until the human population
was really dwindling, at which point the aliens realized that the
exhaust from their spaceships included a chemical that accumulated
in our tissues and posed a danger to them. What would they do? Turn
to catch and release, probably. Oddly this is an exact description
of alien abductions, which makes you wonder: do fish have trouble
making other fish believe that they have been hooked, reeled in,
photographed, and then, inexplicably, released?
is a very limited analogy, of course, because fish cannot talk.
In addition, and more important, PCB's affect all sorts of life,
not just fish. Mammals suffer and birds and reptiles. PCB's are
only one nasty pollutant among many. And we are looking at the effects
after they are no longer being dumped and after decades of struggle
to clean up the Hudson of a variety of pollutants. Thirty years
ago, sections of the river were dead. It is a tribute to environmental
activism that from the stripers' point of view, fishing is now more
frightening than the remaining pollutants.
are fish, Dr. Elskus said, that have found a way to cope with devastating
pollution. In Newark Bay, some populations of the little baitfish
known as mummichogs or killifish have become resistant to a variety
of pollutants, including mercury and PCB's. Exposed to the same
poisons, they do not show the developmental problems that nonresistant
how the fish resist the effects of these poisons is not known. "We're
trying to figure that out," Dr. Elskus said, referring to the
small network of scientists who do similar research. The resistance
seems to have to do with the activity of an enzyme that breaks down
pollutants, releasing damaging toxins.
killifish do not migrate, however. Striped bass move around, from
the Hudson to the sea, from the sea to the Hudson. The killifish
were pretty much stuck in Newark Bay. And so, they were not able
to wait for cleanup and dredging. They had to survive the truly
old fashioned way, by evolution.
them, Dr. Elskus said, it was "die or adapt."