Friday, August 22, 2008

Yet more evidence of plastic's poison effect

Man-made chemicals tied to sick lobsters
by Doug Fraser
from the Cape Cod Times August 22, 2008 6:00 AM

A Woods Hole scientist believes he may have found a key culprit behind a mysterious disease linked to a dramatic drop in lobster populations from Buzzards Bay to Long Island.

In research conducted this summer, Hans Laufer found that common man-made chemicals used in plastics, detergents and cosmetics had infiltrated the blood and tissue of lobsters, making them more vulnerable to a particularly virulent strain of shell disease.

"We need to use less plastic," warned Laufer, a molecular and cellular biology professor at the University of Connecticut who has been a researcher at the Woods Hole Marine Biological Laboratory for more than two decades.

In 2001, Laufer was one of many scientists investigating the mysterious die-off of lobsters in Long Island Sound, when he noticed high concentrations of man-made chemicals, known as alkyphenols, in the blood and tissues of lobsters afflicted with lobster shell disease.

The disease causes gross deformation of the lobster's protective shell, and it can interfere with growth and reproduction. In the worst cases, the shell is so badly pitted it prevents the lobster from molting, resulting in death.

"It looks like the shell has been eroded away by acid," said Robert Glenn, a state Division of Marine Fisheries senior biologist and director of the state's lobster program. Glenn said more research needs to be done to pinpoint the cause of the problem. "We don't have enough of a handle on the mechanism causing the disease," he said.

First seen in Long Island Sound in the mid-1990s, the shell disease quickly spread up the coast into Southern New England and corresponded with a steep drop-off in the lobster harvest.

New York's lobster catch plummeted from more than 7 million pounds in 1999 to less than 3 million pounds in 2000 and less than a million pounds by 2003. The trend continued up the coast to Connecticut, Rhode Island and Buzzards Bay, with lobster landings dropping off quickly over the next four years. The Southern New England and Long Island lobster stock is still at historic low levels, Glenn said.

In 2005, lobster was the single most valuable commercial fishing species in New England, worth nearly $12 million to 132 Cape lobstermen and about $56 million statewide.

Alkylphenols are found in a wide variety of products including many cosmetics, detergents and plastics.

The chemicals are classed as endocrine disrupters: agents that mimic or interfere with the work of hormones. In low-oxygen environments such as heavy sediments or underwater, alkylphenols degrade very slowly. The chemicals enter the ocean through wastewater and septic system effluent, as well as road run-off.

In his research at MBL, Laufer used radioactive alkylphenol molecules to track the chemicals in lobster tissue. He found alkylphenols were blocking a critical amino acid derivative that hardens lobster shell.

Scientists believe bacteria may be responsible for the shell disease. But the lobster can molt to shed a defective shell, and Laufer believes the alkyphenols inhibit a new shell from hardening, leaving affected lobsters vulnerable to bacteria and other opportunistic diseases and predators.

Glenn agrees that alkylphenols "have some relationship to the shell disease puzzle," but he is skeptical Laufer has found the main cause of the lobster disease. He questioned why Boston Harbor, for example, shows little incidence of shell disease, while the pristine Elizabeth Islands have a relatively high rate of the illness.

Glenn's research has found rising water temperatures in the waters south of the Cape could be a prime factor in the spread of the disease.

While lobster stocks in colder waters off the Outer Cape and to the north in the Gulf of Maine show a small occurrence of the disease, concern that the region's most valuable fishery was in jeopardy prompted Congress to appropriate $3 million to establish the New England Lobster Research Initiative. The research initiative has spent $2.3 million on Laufer's study and eight other research projects focused on determining how the disease is spread, how it attacks the shell, and the impact of environmental factors such as pollutants and temperature rise.


Alkylphenols have been shown to alter hormone activity, causing reproductive and growth problems in plants and animals. Studies have not shown any carcinogenic risk.

* Alkylphenols are found in face makeup, fragrances, hair bleach, hair conditioner, hair dye, shampoo, manicure products, skin moisturizers and cleansers, pesticides, and liquid laundry detergents. Sources of alkylphenols in the environment include beauty parlors, textile companies and pulp manufacturing, but the chemicals enter the ocean largely through discharge from wastewater treatment plants.
* Sediment in areas tested between Buzzards Bay and Long Island Sound show some highly elevated levels of alkylphenols. Although alkylphenols degrade quickly into less toxic elements when exposed to oxygen in the air, they do not break down in water or low oxygen sediment layers on the ocean bottom.
* Lobsters absorb alkylphenols either through their food or by walking through contaminated sediment.
* Scientists speculate that alkylphenols may inhibit lobster amino acids, which bind proteins to other proteins in building a hard shell.

Sources: Marine Biological Laboratory,

email Doug Fraser at


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