A post from my directed studies student at Boston University last semester.

*The 4th installment of "At MBL," Joseph Caputo's experience as a science
writing intern at the Marine Biological Laboratory <> in
Woods Hole, Massachusetts. The following **story originally appeared, along
with more photos, on the MBL

The search for what causes a debilitating shell disease affecting lobsters
from Long Island Sound to Maine has led one Marine Biological Laboratory
(MBL) visiting scientist to suspect environmental alkylphenols, formed
primarily by the breakdown of hard transparent plastics.

Preliminary evidence from the lab of Hans Laufer suggests that certain
concentrations of alkylphenols may be interfering with the ability of
lobsters to develop tough shells. Instead, the shells are weakened, leaving
affected lobsters susceptible to the microbial invasions characteristic of
the illness.

"Lobsters 'know' when their shell is damaged, and that's probably the reason
when they have shell disease, why they molt more quickly," says Laufer, a
visiting investigator at the MBL for over 20 years and professor emeritus of
molecular and cell biology at the University of Connecticut. "But
ultimately, they still come down with the disease. And we think the presence
of alkylphenols contributes to that."

Like any crustacean, lobsters shed their shells multiple times in one
lifetime. After molting, the outer skin of the soft and exposed lobster will
begin to harden. It is here that Laufer thinks the alkylphenols are doing
their damage. At this point, a derivative of the amino acid tyrosine, whose
function is to harden the developing shell, is incorporated. It is known
that alkylphenols and tyrosine are similarly shaped and Laufer suspects that
the toxin may be blocking tyrosine from its normal functions. He is at MBL
this summer to measure the amount of competition between the two molecules.
Alkyphenols are also known to act as endocrine disruptors.

Laufer discovered the presence of alkylphenols in lobsters serendipitously
while investigating a tremendous lobster die off at Long Island Sound in
1999, when shell disease, first observed in the mid-1990s, was noted to be
on the rise. Although an unusually hot summer, it was also the first time
New York City sprayed mosquito populations to prevent the spread of West
Nile virus. Laufer, who began his career as an insect endocrinologist,
suspected the toxins from the sprayings may have contributed to the lobster
die off. In 2001, while searching for the mosquito toxins in lobsters, he
instead found alkylphenols.

"It's a real problem," Laufer says. "Plastics last a long time, but
breakdown products last even longer. Perhaps shell disease is only the tip
of the iceberg of a more basic problem of endocrine disrupting chemicals in
marine environments."

Michael Balter
Contributing Correspondent, Science
Adjunct Professor of Journalism,
Boston University

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