We’re talking invasive planets, fish, insects, birds, and mammals establishing themselves in the River Thames. We caught up with Michelle Jackson, an aquatic ecologist who last year studied the species of the Thames. The good news is that the river has a rich diversity of life. The bad news is that many of those species aren’t supposed to be here.

Over the past two centuries, nearly a hundred species have been introduced into the Thames, either up stream or directly within the London city limits. The vast majority are fish and plants—species like the fathead minnow that was discovered in 2002 and has spread a bacterial disease to the river’s trout and eels. Or floating pennywort, a plant first seen in the early 90′s that can grow over the entire river channel and suffocate the ecosystem. The common guppy was even spotted in the Thames in 1963.

The fathead minnow (right), one of the Thames’ invaders, first seen in 2002. Photo courtesy GBNNSS

A good chunk of the species—40 percent to be exact—came from North America. What’s surprising about them, though, is that many of the introductions were intentional, brought over for river stocking or ornamental purposes. Jackson said that London being a main shipping port hasn’t helped. In fact human activity has made it worse. “It’s definitely accelerated,” Jackson told us. “From 1800 to 1820, you get one new species every decade. Now you see a new one every year.”

Of course ecosystems change over time and new species are often introduced into new environments. But what makes invasives more concerning is the impact they have on the broader ecosystem that’s already established. In the U.S., we’ve heard lots about Asian Carp that have spread between rivers in the Midwest and threaten to disrupt the entire food chain in the Great Lakes. The Thames in London appears to be facing a much broader problem, not just from a single offender, but compounded by how invasives interact with each other.

So what can be done? Environmentalists in London have tried to get serious, removing some of the swimming species before they breed and uprooting the plants before they reach too deep. In the past few years, the rate of introduction of invasives has started to slow. One reason why: The economy matters a lot in England (and everywhere, of course, but certainly in the land of pounds and pence). One study last year showed that every year, invasive species end up costing the £1.7 billion ($2.6 billion). So much for just small fish and plants.

How do you test water’s age? Not easily, it turns out. Generally you need a large amount of water, and a laboratory to do complex chemical analysis. There are a few ways to date water, but the most common is by testing isotopes of hydrogen and helium. Both are found in large supply in the universe, and fortunately for chemists, both also decay at certain known intervals. Measuring those intervals essentially gives you a rough estimate of how long the water has been stagnant, without the introduction of new hydrogen or helium.

In this case, the isotopes were quite old. The scientists put the number at 1.5 billion years, but it could be older—by a magnitude of another billion, said geochemist Greg Holland. It was likely a remnant of ancient oceans before it was covered by today’s landmasses. Yet it’s not the water that really interests sceintists. Locked with that ancient water may be single-celled microbes that have pretty much been living on a different planet for nearly half of Earth’s existence. That’s longer than humans have lived on Earth. They’d pre-date the dinosaurs by more than 750 million years.

The polar caps of Mars have been closely studied for evidence that the Red Planet once held water. New Earth research suggests that planets like Mars might contain life under the surface. Photo by NASA

Why does it matter? That’s a question we often ask in science, sometimes with less-than-satisfying answers. This time, however, the purpose might be nothing short of helping explain the arc of evolution. These microbes may turn out to be some of the first aliens humans have discovered, and on our own planet to boot. They’ve evolved on different timeline in their own closed ecosystem, giving us a parallel track of Earth’s natural history. Understanding them could offer an alternate track to study evolution—and get us closer to knowing just how much life there could be locked underground on other planets.

This time, we’re hopping across the pond. Aside from being a historic and iconic city that has very recently been on the world’s stage, London is also an epicenter of some big environmental themes: wildlife conservation, sustainable design, urban agriculture. The island nation is facing some unique challenges, too. Its centuries-old sewers have spurred a massive water infrastructure project. England’s coastline is eroding in ways that are bringing massive rock slides. The barriers that prevent the Thames River from flooding London proper are facing higher demands than ever.

Starting this weekend, we hope you’ll join us as we explore the UK. And we’d love some suggestions on what deserves attention. If there are themes or people we shouldn’t miss, please leave them in the comments below, or tweet me at @NatGeoDan.

Speaking of which, we’ll be writing this blog regularly, but tweeting much more. Join us on Twitter and Instagram (I’m @NatGeoDan on both) to follow the entire journey, and to be in touch with us every step.

Oh and lastly, lest you think I’ve begun to prematurely employ the Royal We, the “we” I keep mentioning is myself and ace National Geographic photographer and video producer Spencer Millsap. He’s one of the best we’ve got, and an excellent travel partner. Just think of us as two guys, as eager to report some incredible geographic stories as we are to find the UK’s best fish and chips. We’re glad to have you along.

On Beacon Hill, just south of central Seattle, landscape developers and a few affordable-food advocates are building an edible food forest. Everything grown in the area, from the tree canopies to the roots, will be edible. And it’ll be open around the clock to anyone who wants to come and pick some fresh blueberries or pears. In its first phase, the farm will be 1.5 acres. But if it’s successful, the public land it’ll sit on—currently owned by Seattle Public Utilities—will be able to accommodate 5.5 more acres of growth.

Photo by Beacon Food Forest

One thing that’s striking about the idea (other than the idea in itself to have essentially a public farm that anyone can use—or abuse) is how the selection came together. Organizers shared with National Geographic a list of the crop offerings. Many are expected: apples, berries, row vegetables like lettuce or tomatoes. But others are pretty far out. A large Asian community in the area suggested things like Asian pears and honeyberries. A European influence led to the planting of medlar trees.

The concept is modeled on permaculture, a design system and school of thought aimed at returning some land to its own devices. Offering people free, fresh food is one motivation, but making the land useful and ecologically enriched is the larger goal.

That all said, some potential problems come to mind. What if all of one fruit is gone the first weekend its ripe? What if people pick things too early and spoil the potential for everyone? Or even worse: what if a colony of squirrels moves in and gorges while the rest of us are sleeping?

Organizers aren’t concerned about those first two questions (the third is a problem, of course, anywhere organic food is grown). ”We’ve had many discussions about what would happen if someone comes and picks all the blueberries?” says Margarett Harrison, the landscape architect designing the project. “But that’s been perceived as a good thing. We’ll just plant more.”

As with anything related to agriculture and good food—in large quantities—take time. Most of the trees won’t be mature enough for a few more years. But a few decades could turn the area impressively productive.

Idealistic? Perhaps. But it’s the kind of idealism that anyone who likes to eat fresh things from time to time can get behind. And that’s the type of motivation that organizers hope will keep it going. After it’s finished, organizers will offer classes on things like canning fruit or pruning trees. All they’ll ask for in exchange are a few hours volunteering at the farm.

As you can tell from the song title, the celebrities are not in favor of fracking.

The song makes a number of claims about the dangers of fracking … but are they true?

Let’s look at the lyrics (in bold italics)  and the on-screen messages (in bold), and see.

Lyric: Now gather round and listen to my song

It’s easy to see both sides of the argument. Centuries of human civilization have taken a serious toll on  wildlife, driving many species toward extinction at a faster pace than at any point in the planet’s history. What better way to apologize than to give them new life? To, essentially, render them un-extinct?

Our April cover.

On the other hand, having the power to bring back species we’ve driven off the planet means that efforts to protect species that are currently imperiled like the polar bear or rare amphibians ring hollow. “Save the Leatherback sea turtle or we’ll never have another one!” doesn’t mean anything if we can, in fact, create another one.

It’s a fascinating story. But don’t take my word for it. The April edition will be on newsstands next week. Or check back here tomorrow for the link. (A third option, of course, would be to subscribe.)

In the meantime, we’ve got more planned. Tomorrow at Nat Geo headquarters, some top scientists, ethicists and activists will be hosting a TEDx conference on de-extinction. They’ll be speaking about the science, plus the implications. No one has all the answers, but they’re hoping to start a broader conversation about scientific innovation and its role in conservation.

I’ll be live-tweeting much of the conference. So as always with issues of environmental technology, come on back to Change Reaction. Or follow me at @NatGeoDan.

At the annual meeting for the Convention on International Trade in Endangered Species (CITES) in Bangkok this week, a coalition of global governments voted to protect five species of sharks and two species of manta rays. By restricting the international trade of the animals’ fins, regulators hope to add legal and social stigma to killing overfished marine wildlife, several species of which have been declining at rates faster than some scientists believe the animals can reasonably rebuild their populations.

A manta ray and snorkeler. Photo: Violeta Jahnel, MyShot

The species deemed imperiled that will receive the new protections are oceanic white tip sharks, three species of hammerhead sharks (scalloped hammerheads, great hammerheads, and smooth hammerhead) and porbeagle sharks. The main drive was led by Colombia, Brazil, and the United States. Only about two-third of the countries agreed to many of the changes in international law. Forty two countries opposed the proposal.

Bryan Arroyo, lead negotiator for the U.S., said his delegation was “extremely pleased” at the vote, an agreement not nearly as well received among some Asian countries. Both China and Japan voted no, arguing that shark population management should fall to regional fishery managers, rather than international bodies.

Most sharks are desired for their fins, the primary ingredient in shark fin soup in China and other parts of Asia. While global quotas on shark takes have long existed, high demand for fins has led many fisherman to bypass quotas by simply cutting the fins off of live sharks and throwing their bodies back into the water, where they eventually suffocate.

Some fin trade will be able to continue under the agreement, but at a reduced level that regulators, working with scientists, will agree is sustainable. Left unknown is whether shark fins becoming more scarce might result in driving the price of shark fin soup—and the bounty on fins—up even higher.

Update: CITES members also voted by consensus to approve Australia’s proposal to list freshwater sawfish on Appendix I, meaning most commercial trade would be banned. (The ruling still needs to be finalized at the plenary on Thursday.)

“The sawfishes are among the oceans’ most threatened species and urgently need the strongest protections possible,” Sonja Fordham, president of Shark Advocates International, said in a statement.

The statistical report, compiled by researchers at Dalhousie University in Halifax, Canada, crunched numbers of reported shark catches globally and used data from nearly 100 former papers to estimate the number of unreported shark deaths every year. In a moving range, the researchers were able to calculate that between 6.4% and 7.9% of sharks of all species are killed annually.

Hammerhead sharks are particularly at risk. Photo by Jim Abernaty / Pew Environment Group

To put that range in perspective, researchers analyzed life data from 62 shark species and found that only 4.9% of sharks can be killed each year to maintain population stability. Anything more than that threatens long term survival of species like the oceanic white tip, porbeagle and several kinds of hammerheads. What’s worse, sharks are considered uniquely vulnerable because they take long periods to mature and generally produce few young over their lifetimes.

Photo by Shawn Heinrichs / Pew Environment Group

The culprit is the proliferation of illegal shark finning that spiked in the 1990s to feed appetites for shark fin soup, a delicacy in parts of Asia on par with fine truffles or expensive caviar. According to some reports, a bowl of shark fin soup can sell for as much as $100.

While some sharks are allowed to be caught, illegal shark finning occurs when fisherman cut fins off live sharks and dump their bodies into the open ocean to avoid declaring the full animal at port and surpassing fishing quotas.

“There’s a staggering number of sharks being caught every year and the number is way too high considering the biology of species,” says Dalhousie biologist Boris Worm, the study’s lead researcher. The 100 million sharks was actually a conservative estimate. Worm’s team found the number could be as high as 273 million sharks killed each year.

To combat such numbers, most countries have authority to regulate around their own coastlines and the catches brought into their ports. But pressure has grown over the past few years for the Conference on International Trade of Endangered Species (CITES) to regulate international trade of the most imperiled species. As recently as 2010, CITES officials denied meaningful protections to sharks. But after a United Nations panel recommended earlier this year that governments get serious, CITES officials will meet this week in Bangkok to consider finally phasing in protections.

Enter 3-D printing, the old technique that’s recently gotten lots of buzz for its application to manufacturing, medicine, and now, food. The basic idea behind 3-D printing is that with the right core ingredients, you can literally produce anything. Isolating those ingredients down to a molecular level means that they can be melded and organized at will, essentially stacked in layers until you have, voila, a homemade steak.

I’m exaggerating a little. You can’t actually produce anything the same way it would appear in nature or at the supermarket—especially not a full t-bone ready for the barbecue. But creating protein is well within the realm of possibility. In fact, it’s currently being done. Back in 2011, Jeff Bartholet (a National Geographic contributor) wrote a story for Scientific American that looked at ongoing research pursuing a future full of meat grown in petri dishes rather than on farms.

Less that two years later, the prospect is scaling. A company named Organovo Holdings that developed a way to manufacture human tissue is working with a software developing company to make a 3-D printer of muscle. You can apply that muscle toward helping people regrow muscle mass. Or you can grow muscle—or in other words, meat—from animals like cows and chickens and pigs. The product is a sort of synthetic meat. Modern Meadow, a leading meat research company is trying to come up with “novel biomaterials” to create meet much easier and simpler.

In an “Ask Me Anything” chat on the website Reddit this week, Modern Meadow’s CEO Andras Forgacs explained that the inputs are mostly animal cells taken from an animal through a biopsy mixed into a soupy cell culture liquid with the nutrients to allow the cells to grow. Then energy is added to get the cells to mature and, after it “matures” with time, it’s formed into meat products. The process is scientifically rigorous, but not that complex. As the company is refining the culture liquid to maximize rate of cell growth, it’s not hard to see several years from now a similar process you can complete in your kitchen.

None of that speaks to the biggest question determining its success: how it tastes. Modern Meadow’s scientists have already tasted some. The ratio of fat to protein that gives most conventional meat its flavor, they’ve said, could use some refining. The obvious final step might be a PR campaign. Few things sound less appetizing than synthetic lumps of cells you build in your garage. Pack some compelling statistics on population growth and global hunger with a few smart marketing of celebrities loving their synthetic meat, and you just might have a product people are willing to not immediately rule out.

Social media might be the answer. A new study from the University of Vermont realized that analyzing tweets might offer clues about aggregate happiness in a given U.S. state. The results are bemusing. America’s happiest state is, unsurprisingly, Hawaii, followed by Maine, Nevada, Utah and Vermont. Bringing up the caboose as the saddest states are Delaware, Maryland, Mississippi, and, dead last, Louisiana.

The researchers geo-tagged 10 million tweets from 373 urban areas in America during 2011. Then they gave each word a value of positiveness on a scale from one (mopey) to nine (elated). ‘Rainbow,’ for instance, had the happiest score at 8.1. ‘Earthquake’ was the lowest at 1.8. Words like “the” or “thereof” without inherent sentiment score somewhere in the middle. For statistical buffs, the calculation is complex. You can find it in the study, here.

Sentiment measuring isn’t terribly new. Odewire, a project of Intelligent Optimist Magazine, developed a news screening search engine for people who only want good news. The analytics company General Sentiment has refined software for measuring favorability mentions of TV shows, sports stars and political candidates.

The begging question: is it actually accurate? Algorithms can do a lot of things these days like forecast your travel preferences and automate your Christmas gift list. But measuring the happiness of specific words takes a leap that seems to ignore context. Anyone can use the word rainbow, but does that mean they’re happy (“This weather is terrible, I wish I could see a rainbow,” might, for instance be considered pretty joyful; “Barack Obama hates gun violence,” packs a lot of negative-sounding words). Then there’s the drawback of just testing social media, users of which skew younger and more susceptible to self doubt, insecurity and melodrama. Getting a computer to give a mosaic can be helpful and interesting. Still, in a world full of nuance, context is often something a computer—and sometimes even a human—can simply find much harder to pick up.