Italian Sea Snails Go Macho

Most of the stories we see in the news about “sex change chemicals” in the environment focus on male animals turning into females, with the blame often being placed on the use of contraceptives by human women. But all sorts of things can happen in the weird and wonderful world of biology. Here is a story to redress the balance.

Murex is a genus of carnivorous sea snails with impressively spiny shells. Different species are found in many places in the world, but the Mediterranean varieties are particularly famous for being the source of Tyrian Purple, the expensive dye that was beloved of Roman emperors and other potentates of ancient times. While the snails are no longer harvested to make dye, they are still eaten by people around the Mediterranean. Sicily was noted for its fisheries, until now.

According to a study by Italy’s Institute for Environmental Protection and Research (ISPRA in Italian), populations of Murex around the Sicilian coast face extinction because all of the female snails have turned into males. The culprit is apparently a chemical called TBT which used to be used in anti-fouling paints. It was banned in 2001, but has yet to be totally phased out. A report in an Italian newspaper explains:

The exact mechanism behind the transexual molluscs is still being studied. A handful of Italian researchers are at the cutting edge. One of them, Antonio Terlizzi of Lecce University, explained that TBT boosts the production of testosterone in the female murexes, making them sterile and eventually turning them into males.

”It’s a little bit like all those women shot-putters with moustaches you used to see a few years ago,” he said.

Um, quite. So eating Sicilian sea snails might not be a good idea right now.

Politics and Pollution

I’ve written before about the effect of complex chemical pollutants on the environment, in particular the “feminization” of animals such as fish and amphibians. There is little doubt that significant changes are being seen in many animal populations, and there is no credible explanation other than chemical pollution. However, the exact mechanism is unclear, as is the level of danger to more complex animals such as humans.

Up until now the favorite explanation for this effect has been estrogen. We know that there is a lot more of it going into the water than there used to be, and it is a popular villain chemical in a number of ways. For male journalists, estrogen is a physical embodiment of girl cooties. It allows them to write about how our environment is being polluted by “girl stuff” that is “turning our sons into sissys”. Puritans of various stripes have put the blame on vain women. If people didn’t use hormone replacement therapy, the argument goes, we wouldn’t have this problem. And the Catholic church has leaped at the chance to identify contraceptive pills as a major pollutant.

What does the science say? As usual, it is complicated. But a new study by some UK scientists suggests another potential cause. Estrogen isn’t the only hormone pollutant around, and the new study looked at what are called “anti-androgens” – that is chemicals that block the effects of testosterone. These chemicals are used in the treatment of prostate cancer, and also in fertilizer. They have also been shown in lab work to be important in producing the sorts of feminizing effects seen in nature.

The new study is statistical. That is, it doesn’t demonstrate actual causality, it simply shows that there is a strong correlation between high levels of anti-androgen pollution and high numbers of feminized fish. Nor does it exonerate estrogen – there could well be some complex effect requiring more than one chemical going on here. But the correlation between estrogen pollution alone and feminized fish is a lot lower.

As ever, there is more work to be done. But if there is a lesson here it is that we shouldn’t jump to conclusions simply because they happen to fit our particular prejudices.

I can’t find the original paper online, but you can read the abstract here.

It’s a Global Economy

Remember all those people celebrating the “death of capitalism” and saying how the world would be a much better place because of the economic troubles? Well, one of the effects of those troubles has been a massive collapse in the prices paid for recycled materials. As a result the recycling industry in the USA is being pretty much wiped out. This, I suggest, is probably not a good thing.

Risks of Geoengineering

It appears that terraforming is now known as geoengineering. Whether this is because you can only terraform worlds that are not actually dear old Terra, or whether someone decided that they needed a word that was not tainted by association with science fiction, or indeed whether whoever coined geoengineering had never heard of terraforming, I do not know. However:

Planet Earth

After many evening of happy viewing I have finally come to the end of the BBC’s Planet Earth series (thank you, Kevin!). I’ve seen a fair amount of nature programming in my time, and I have to admit that this series really does have some awesomely spectacular photography. Scenes like the surfing dolphins, the chimp war, the great white shark and snow leopard hunting, the vampire squid and so on will stay with me for a long time. If you have an interest in the natural world, the series is definitely worth buying.

If I have a complaint at all it is that the series is still very much bogged down in the traditional male naturalist view of what a nature program should be about: sex and death. Animals do exhibit a wide range of different behaviors, but put a man behind a camera with some animals and what he’ll want to film is them either fucking or killing each other. With mammals in particular an essential part of behavior is raising their young, but this is much less often shown, and even when we do get shots of mother leopards and bears the narrative is all about how she catches food for the cubs, not how she trains them to hunt, which she surely must do.

Still, given the quality of the shots, and the efforts that the camera crews went through to get them (the “diary” sections at the end of each program are very revealing), I can hardly complain.

What is more, some of the best stuff was added at the end. The final DVD contains three 1-hour programs that are illustrated with shots from the series, but are primarily talking head debates about the current state of the conservation debate. I have to admit that the BBC did a superb job in finding the most oily and unconvincing people to put the Rethuglican case (not that this really mattered – their position was fatally caricatured long ago by Shea and Wilson in the form of the guy in Illuminatus! whose ambition was to be the person who killed the last ever bald eagle in America). On the other hand, some of the environmentalists, particularly James Lovelock, are equally scary. In the end what matters is that we save the planet, not that someone with a rigorous and narrow ethical standpoint forces everyone to do what he says.

Because Climate is Complex

There’s an interesting article over at Nature on the effect of aircraft contrails on climate. As you may remember, the lack of air travel in the days immediately following 9/11 coincided with a significant rise in average temperatures in the US. This led one group of scientists to speculate that perhaps contrails had a significant effect. No one should have concluded that this proved anything either way, because coincidence does not prove causality, and to be fair to the scientists involved they never said that it did. The media, however, latched onto the story with its customary enthusiasm and lack of rigor.

The right thing to do is, of course, to investigate possible mechanisms, and so another group of scientists has looked at the effect of clouds on climate to try to see if the type of clouds created by aircraft have significant effects. Their conclusion, as Nature reports, is that they don’t.

Note that this does not prove that air travel has no effect on climate. It simply casts doubt on one possible mechanism. But I can see where this will go. Sections of the environmental movement are already convinced that contrails are “Destroying the Planet!!!” and will assume that any evidence to the contrary is simply lies paid for by the airline industry. Meanwhile the PR flacks in that industry will be preparing material explaining how the effect of aircraft on climate has been “proven to be false”. And the people who will suffer most will be the scientists trying to make sense of all this.

An Endangered Gender

Today’s Independent contains a classic science scare story. It alleges that, because of certain types of chemicals that have been commonly used in recent times, the male gender is under threat, throughout the animal kingdom. Some of this is doubtless traditional journalistic scaremongering, but some of the studies on animals are quite startling, for example:

Research at the University of Florida earlier this year found that 40 per cent of the male cane toads – a species so indestructible that it has become a plague in Australia – had become hermaphrodites in a heavily farmed part of the state, with another 20 per cent undergoing lesser feminisation.

Fish are apparently the worst affected types of animals, but the effects have been noted all through the animal kingdom, including in otters, deer, antelope and polar bears. The report on which the story is based concludes:

Feminisation of the males of numerous vertebrate species is now a widespread occurrence. All vertebrates have similar sex hormone receptors, which have been conserved in evolution. Therefore, observations in one species may serve to highlight pollution issues of concern for other vertebrates, including humans.

Hard line feminists will doubtless continue to suggest that there is no biological component whatsoever to gender identity, and I’m not qualified to pronounce one way or another. However, here is an article by a qualified doctor who also happens to be a male-to-female transsexual and who was exposed to one of these “gender bending” chemicals in the womb.

I should note, by the way, that exposure to chemical pollutants is by no means the only possible cause of gender confusion. However, if it happens then it provides firm proof that biological mechanisms can be a contributory factor. And if that is the case then it is further reason to give short shift to those who prefer to believe that all gender variance is a form of sexual perversion.

We Have Turtles!

In amongst all of the doom and gloom, here’s an environmental feel-good story: leatherback turtles are visiting California again. Apparently they have been attracted by larger than usual swarms of jellyfish, which are a favorite delicacy:

Hungry as they are, leatherbacks don’t eat the jellyfish’s transparent globular bells – it’s the viciously stinging tentacles they love, and Benson and his colleagues found themselves “covered with stinging jellyfish slime” whenever they hauled any of the turtles aboard, he said.

I’m all in favor of other creatures that want to help in the fight against tentacles beings from beyond the stars. Especially if they happen to find the slimy bits tasty.

The Recycling Business

One of the things that always depresses me about coming back to the UK is the ridiculous level of bureaucracy surrounding recycling. I know it is different in different parts of the country, but here in Darkest Somerset there are all sorts of complex rules about what you can and cannot recycle, what has to be separated from what, and so on. According to my mother if you get any of this wrong the council will simply refuse to collect your recycling. And they are now talking about fining people for not recycling properly.

Back in California all of our recycling goes into a single bin (together with that of our neighbors, so there’s no possibility of fining individual households). It ll gets collected. But that’s nothing compared to what goes on in San Francisco. According to the Chronicle, not only is everything collected, but there is a thriving business in theft of recycled materials. The stuff is now so valuable that there are organized gangs who go around at night stealing it before the council can pick it up. Here’s why:

Prices for aluminum run more than $3,700 per ton, glass $210, plastic $180 and cardboard $130, according to Sunset Scavenger, a division of giant Norcal Waste Systems Inc.

Prices for metal in particular are only going to go up. So why is recycling still such a problem here? (I have some ideas, but I’m interested in hearing yours.)

Earth Hour Tomorrow (and some economics)

Yes, this is another one of those international “everyone do something” events. Tomorrow the World Wildlife Fund is asking everyone to turn off their lights (and hopefully most other energy-using appliances as well) for an hour. It will be 8:00pm in California when Earth Hour starts, so there will probably still be some daylight, but our apartment gets so little natural light that we’ll be in the dark anyway. I have no idea how they are planning to monitor the success of this, though electricity output numbers will be interesting, but there is an event for it on Facebook so you can register your intention to participate there. It currently has just short of 800,000 members, which is a drop in the ocean for the world population but not bad for Facebook. More details from the official web site.

Kevin has just commented that various people are blogging about what a sham the whole thing is because it won’t actually do much to reduce energy consumption. Here’s an example. Power station economics is, of course, one of my areas of expertise, so here’s my take.
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Saving the World by Eating

Suppose you were an absolute whiz at genetic engineering, what would you set your sights upon making? Unicorns? Domestic cats with tiger markings? Broccoli that tastes like chocolate? Beer that doesn’t give you a hangover? All sorts of ideas come to mind, but if you really wanted to do something good for the world, and you were happy to play with nice, simple little animals, how about this: bacteria that eat CO2 and shit gasoline.

Of course if you are Michael Crichton you’ll be immediately starting work on a book about how evil, genetically-engineered bacteria escape from a lab and almost destroy the world by eating the entire atmosphere until it turns out that they can be killed by spraying them with underarm deodorant (exact brand to be left to the product placement guys). But for the rest of us, hey, it isn’t such a bad idea, especially if it works.