Wednesday, October 30, 2013

Marine Debris, Estrogen Mimics, and the Never-ending Story

This story and video at Collective Evolution prompted me to re-blog this post from a year ago on marine debris and the Great Garbage Patch in the Pacific.


From Surfrider Foundation. For more, go to
It's hard to maintain a positive attitude when you're a marine scientist, particularly if you study anthropogenic impacts to marine and coastal environments. There are so many, and some of the impacts are so completely devastating, avoidable, and ignored that it's easy to get frustrated. Marine debris is one of those persistently studied and talked about, and continuously shrugged off problems. The world's marine science community has been talking about it for decades. Environmental groups have been delivering marine debris education and outreach programs, including beach cleanups, for as long.


I participated in my first "clean up" in about 1970, with the Boy Scout's annual cleanup of the creek by my grandmother's house (my dad was the Scout master in the neighborhood--I did more Boy Scout than Girl Scout things.) At the time and far from the ocean in upstate NY, I didn't know about the route that litter would have taken down Choconut Creek to the Susquehanna River, south through Pennsylvania, eventually dumping into the Chesapeake Bay, and ultimately the ocean.

In my senior year of college in 1986, the CVI Dive Club (we named ourselves the Reefers, but the school wouldn't let us keep the name!) organized a "Trash-ure Hunt" complete with prizes. The group that began coordinating nationwide "Beach Sweeps" (Clean Ocean Action) was in its infancy and we'd never heard of them, but divers knew there was a litter problem on land that was affecting the reefs around the islands.

Five years later, I was organizing the annual Virgin Islands' Beach Sweeps on St. Thomas as the Sea Grant Marine Extension Agent at VIMAS (Virgin Islands Marine Advisory Service). Marine debris research, outreach, and education were a huge part of that job. I participated in local, regional, and international conferences where we talked about the problem, bemoaned the slow progress in addressing it, patted ourselves on the back for our efforts, and supported each other with assurances things would get better. How could they not? Look at all the work being done around the world? Look at the vast numbers of committed people, professionals and volunteers, who were getting the word out, pushing for better legislation, better waste disposal practices, and greater awareness. We WOULD succeed.
Yours truly at one of the many marine debris conferences
I attended over the years. I think this is the 3rd or 4th International
Marine Debris Confernce in Miami, 1994

We saw a number of victories. Recycling and bottle bills reduced the number of aluminum cans and glass bottles in the annual cleanups. Instead, cigarette butts became the number one beach cleanup item by number. Plastic bottles and bags were tops by volume. But plastic is light. It readily blows off the beach and into the water, where it floats away, out of sight, out of reach, killing marine life.

Six-pack plastic ring manufacturers began making break-away rings. Whoo-hoo! Animals would no longer get trapped in the rings and cut in half as they grew but the ring didn't. Plastic grocery bags, however, still floated in the sea like jellyfish, still were eaten by turtles, dolphins, seabirds, sharks, fish, and still killed them just as dead by filling their stomachs or blogging their intestines.

International regulations and increased enforcement led to many changes in the cruise ship and commercial fishing industries. Rewarding whistle blowers was a major victory. Everyone had cameras and video recorders on their cruise, and everyone knew if they caught any illegal dumping on film, they'd get a big chunk of money from whatever fines were imposed on the violator. It only took a few high profile cases and high fines before serious changes took place. As became apparent in a short time, many of those changes were superficial, resulting in sneakier, rather than better practices.


By the late-90s, many of us who'd been seeing, saying, and doing the same things over and over and seeing few results were burning out. Did annual beach cleanups help by drawing attention to the problem or hurt by rewarding those who were going to litter anyway? An out-of-sight, out-of-mind attitude seemed to be winning the marine debris war.

In 1997, a sailor came upon an enormous stretch of floating debris in the Pacific. The sailor, Charles Moore, alerted oceanographers. The phenomenon had been predicted a decade earlier, and now here it was, just as the models had shown. Rather than seeing a reduction in marine debris from all those efforts, we saw the Great Pacific Garbage Patch, the culmination of decades of plastics being discharged into the ocean, sometimes by accident, sometimes intentionally. Since then, a similar patch has been found in the North Atlantic.


The Garbage Patch is an area in the central North Pacific Ocean where circling currents "trap" debris. Estimates of its size vary from "twice the size of Texas" to "as large as the continental US." There is no finite border where, on one side there is plastic and on the other there is not, instead there's a gradient of decreasing plastic concentration, making the boundary difficult to judge.

You'd think that having a big floating garbage dump in the ocean would be a serious wake up call to the world that this is (still) a serious problem. But, out-of-sight, out-of-mind wins again. While plastics are forever, that garbage bag and plastic bottle that blew off the beach probably aren't floating in the gyre. What's there, are microscopic suspended particles--tiny pieces of those plastics. Sunlight and water work together to break down the plastics into ever smaller pieces. Plastics never go away, but they do get brittle and break up. Rather than one bottle or one bag, those pieces of litter now contribute hundreds of thousands of smaller polymers (still plastic, but itty-bitty pieces) floating in the sea. The particles are so small that even the tiniest plankton (small animals that feed bigger animals, like all the seafood we eat) can ingest it. And they do.

"So what?" you might ask.  Why should we care what little animals in the ocean eat? We haven't seen any real consequences to people from the Great Pacific Garbage Patch. Maybe this is a non-issue.

Well, hold on a second. Aren't we experiencing the consequences of plastics in the environment?

Besides the particles' danger to wildlife, on the microscopic level the floating debris can adsorb organic pollutants from seawater, including PCBs, DDT, and PAHs.  Aside from toxic effects, when ingested, some of these are mistaken by the endocrine system as estradiol, causing hormone disruption in the affected animal. Many of these fish are then consumed by humans, resulting in their ingestion of toxic chemicals. THAT is one of the really good reasons why we should care.


Estradiol is a sex hormone--it has a critical impact on reproductive and sexual functioning. Estrogen mimics, like those released from the photodegradation of plastics and magnified up the food chain into our seafood. In our bodies, they attach themselves to estrogen receptors in cells and mimic the action of the body's natural estrogen, or they may block the action of natural estrogen and are thus called estrogen antagonists.

The rise in estrogen mimics in the environment since the 40s (when widespread production and use of plastics really took off) coincides with decreased sperm counts in men during the same time. They have also been tied to the increase in cases of endometriosis in women in the same time period. A series of unrelated studies over that same time period, from around the developed world, show physiological problems involving abnormal reproductive development, unusual sexual behavior, and neurological problems exhibited by a diverse group of animal species including fish, reptiles, amphibians, birds, and marine mammals. All these problems are indicative of the action of estrogen mimics accumulating up the food chain and impacting living organisms, including humans.


While plastics are far from the only synthetic products releasing estrogen mimics and other chemicals into the environment, they are a concern, not only from the aesthetic standpoint of litter being ugly, but also from an environmental and human health position.

I have to remind my Human Biology classes each semester that the reason we study the environment during the class, as well as human physiology, is because we are part of the environment. What goes around comes back around. Usually, if we sent it around, it comes around and bites us in the ass.

The real problem isn't marine debris. The real problem, the one that beach cleanups and education can't solve, is that we care more about our own convenience today than the bite on our children's asses 30, 40, or 50 years from now. That's a problem that nature may fix for us if we keep ignoring the warning signs.

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