Tuesday, June 03, 2008

Sick Lobsters: A Message in a Plastic Bottle

You know how when you buy a lobster, sometimes part of the shell is black, as if it has been singed in a fire? That's called shell rot, and it affects a big proportion of the lobster population in the northeast, including in Long Island Sound.

Hans Laufer, a professor at the University of Connecticut, has been studying the problem and thinks he might have found a cause: plastic bottles. There's a good story about it in the New Brunswick Telegraph Journal. Here's an excerpt:

Hans Laufer, a professor at the University of Connecticut, has spent the last four years investigating the link between the plastic byproducts, called alkyphenols, and shell rot.

In recent years, the disease has become an epidemic in Long Island Sound (located between Connecticut and Long Island, N.Y.) affecting up to 70 per cent of some lobster populations at its peak.

"There seems to be a direct relationship between plastic compound breakdown and shell disease," Laufer said.

The alkyphenols are absorbed into the lobster's bloodstream and inhibit the chemicals that keep the shell hard, which makes them more susceptible to bacteria and other infections that eat away at the shell.

"The lobsters try to molt out of the old shell," Laufer said.

"If it's just mild enough, they recover. If it's serious, of course, it kills them."

Although plastics can eventually disintegrate in water, they aren't biodegradable.

The chemicals remain in the water and are eaten or absorbed by marine species.

Laufer adds that lobster aren't the only creatures harmed by the compounds.

"There is evidence that some of these compounds get into fish, and they will reverse the sex of the fish. You can sometimes find fish populations that are maybe five per cent male," Laufer said. "I think it's kind of scary."

The shell rot problem is not the same as the lobster die off that happened in 1999 and is apparently happening again this year. Since 1999, the industry has fallen on hard times. There were 746 licensed lobstermen in New York then, compared to 442 now; in Connecticut, it’s gone from 440 to 252.



Blogger j-m said...

Hi, great blog! I just found you. I'm a teacher on L.I. and looking forward to reading your, "This Fine Piece of Water."

We just had a conversation about lobster. My daughter, a waitress at a seafood restaurant in the Hamptons, said most of their lobster came from Canada. We were wondering why the shortage of LI lobsters, since it's not brown tide or other issues. Now, I know why. Thanks.

10:18 PM  
Blogger Nan Patience said...

I'm no professor, but I don't think that's it at all. It's the slight increase in water temperature and the pollution caused by runoff, sewage, and other sources.

9:27 AM  
Blogger Sam said...

As usual it is a"a multitude of sins" that cause such problems. It certainly could be that phenol could be a bad actor along with temperature, parasitic bacteria, resuspended silts that contain toxics, and a whole host of possible causes including simple old fishing pressure and contamination from human hands (as many "shorts" are thrown back overboard).

But it's a heck of a find. Some oceanographers from Italy recently linked dying reefs to a trace compound used in ... you're not going to believe this ... sunscreen! -sam

12:53 PM  
Anonymous Africa Jen said...

I heard that the lobster population was devastated when they began to spray for West Nile virus, and the populations never came back. Something about it's such a political hot potato this is not discussed or analyzed openly. I have no idea if this has any validity or not.

8:56 AM  
Anonymous Tom Andersen said...

My post was needlessly vague. There are at least two problems that lobsters in the Sound are having: shell-rot and whatever it is that's causing the die off.

The plastic bottles and their compounds are implicated in the shell rot.

As for the die-off, here's what the report of the scientists who looked into it said:

"Sixty-five scientists at 30 institutions and agencies nationwide participated in the research initiative, investigating the effects of environmental factors, mosquito control pesticides, and disease on the physiology and health of American lobsters. The results indicate that the physiology of the lobsters was severely stressed by sustained, hostile environmental conditions, driven by above- average water temperatures. A new lobster disease, paramoebiasis, was identified as the proximate cause of death for the majority of lobsters examined by pathologists. Laboratory studies demonstrated that the pesticides used for mosquito control have sub-lethal or lethal effects on lobsters, based on concentration and time of exposure; however, modeling exercises indicate it is unlikely that the concentrations of individual pesticides in western Long Island Sound were high enough to cause the mortality event."

The consensus is that pesticides played no role, although lobstermen and others continue to think they did. You can find more by searching for lobstermen + pesticides in the search box in the upper left corner of this blog. -- Tom

10:04 AM  
Blogger Sam said...

Good catch Tom, although in my mind the shell disease and die-off are probably related events, more related than some want to admit.

Anything that causes stress on lobsters is suspect, including warmer temperatures to PCB's from Milford and West Nile spraying in New York. The pathogen you identified was simply one that could flourish in such nasty waters, much to the detriment of the lobsters.

Then I consider that the shell rot or disease showed up at about the same time as the die-offs. That doesn't mean they're causally linked but something makes me think twice.

Whatever the explanation is it probably doesn't matter. All species of lobster are plummeting around the globe. Even the good days of Maine lobsters are coming to a close.

Most likely we did it somehow. For as smart as us humans think we are, ultimately we will never know WHY.

5:46 PM  
Anonymous Brian said...

Hi, I'm a high school student researching the effects of pollution on Long Island Sound, and I found this thread particularly interesting. Thanks for all this information.

8:38 PM  

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