Chinese scientists have discovered how a plant tricks wasps into carrying its seeds great distances. Photo Credit: adapted from Chen et al. 2017 Figure S1; used with permission from Gao Chen
Stemona tuberosa is well known for its use in Chinese traditional medicine, but it’s got a much more intriguing claim to fame. It’s one of less than a handful of plants known to science that engages in vespicochory—that is, it gets predatory wasps to disperse its seeds. It was a strange enough discovery that Gao Chen and his colleagues at the Chinese Academy of Sciences in Beijing wondered how the plants manage to convince the hornets to haul their offspring around. All it takes is the right scent, the team discovered: parts of the plant smell and taste like the insects the hornets normally hunt. Continue reading “Chinese Medicinal Plant Tricks Predatory Wasps Into Dispersing Its Seeds By Smelling Like Prey”
Scientists are trying to solve the mystery of these big crabs’ colorful differences. Photo Credit: John Tann
Coconut crabs (Birgus latro) are gigantic land-dwelling crabs found on islands throughout the Indo-Pacific. They can live for decades, and can grow to be more than 3 feet wide (legs outstretched) and weigh in at more than 6 pounds. So that name isn’t because they’re the size of a coconut—it’s because they can actually tear open coconuts to eat their tender meat.
“If a coconut falls out of a tree, they’ll clamp onto it on the top and then drag it back to their husking ground,” explained Victoria Morgan, a PhD Candidate in the Department of Evolution and Ecology at University of California, Davis. You can always tell where a crab hides out by the piles of coconut husks lying around.
And it just so happens that out these massive, tree-climbing crabs come in multiple colors. They start out white as juveniles, when they act like other hermit crabs and don a protective shell. Then, as they mature and grow, they turn either red or blue. Really, really red, and really, really blue. “It’s weird that the colors are so distinctive,” Morgan explained. Stark color differences within a species, or color polymorphisms as scientists call them, are found in other crab species, but they’re generally in young animals. Continue reading “Red, White and Blue Crabs: These Tree-Climbing, Bird-Killing Crabs Come in Multiple Colors and No One Knows Why”
A kelp gull waits for an unfortunate pup to die. Photo by Naude Dreyer
I think it’s fairly safe to say that gulls are among the least-loved birds in the world. These loud and annoying seabirds have a disturbing lack of fear of large mammals — including us — and a seemingly insatiable appetite, as any beach picnicker can attest. It’s no wonder that the creators of Finding Nemo portrayed them as mindless feeding machines, the only species in the movie to lack intellect and personality. But they were wrong in at least one respect: while seagulls might be feeding machines, they are far from mindless. Continue reading “Kelp Gulls Tear Out Baby Seal Eyes So They Can Feast On Their Remains When They Die”
Lionfish I helped catch off the coast of Beaufort, NC in 2013. Photo by Christie Wilcox
As I’ve described before, the Indo-Pacific lionfish in the Atlantic and Caribbean are quite possibly the worst marine invasion ever. These toxic predators have been eating their way around for the past few decades, driving down populations of native species and threatening already-struggling habitats. Now, a pair of papers released this month have more bad news: the lionfish are continuing to spread, and they may be eating the very last of critically endangered species.
You would always be smiling, too, if you were high as a kite. Photo by Flickr user jeffk42
The BBC will be airing a cool new underwater documentary on Thursday called Dolphins: Spy in the Pod, where carefully disguised cameras were used to film the daily lives of everyone’s favorite marine mammals. But the most interesting detail seems to have been leaked on Sunday: during the documentary, some of the dolphins reportedly used a pufferfish to get stoned.
“Even the brightest humans have succumbed to the lure of drugs and, it seems, dolphins are no different,” said The Sunday Times. The article goes on to describe how the team got footage of dolphins gently harassing a pufferfish, which led to the dolphins entering “a trance-like state after apparently getting “high” on the toxin.”
“After chewing the puffer and gently passing it round, they began acting most peculiarly, hanging around with their noses at the surface as if fascinated by their own reflection,” said Rob Pilley, zoologist and one of the producers of the documentary. “This was a case of young dolphins purposefully experimenting with something we know to be intoxicating.” And so it would seem that we can add drug use to the long list of dolphin bad behaviors, (a list which includes bullying, rape and murder, for the record; illicit drug use seems a minor offense in comparison).
I imagine that adjusting to life around humans, with all our buildings and fast-moving transport mechanisms, is tough for a bird. It’s estimated that some 80 million birds are killed in motor vehicle collisions every year, and with an ever-growing population of people driving around and paving roads in more remote areas, things must be getting harder and harder for the animals we share our world with. But, the American Cliff Swallow (Petrochelidon pyrrhonota) isn’t one to let people ruin the neighborhood. More and more, their huge nesting populations can be found in man-made structures like bridges and overpasses, and have even become cultural fixtures in areas like California. Their new nesting sites allow them to survive even as their former habitat disappears, but it comes at a cost: by living near roadways, the birds are more at risk than ever of being on the wrong end of an oncoming vehicle.
Sharks are incredible animals. They’re some of the world’s most well known creatures, popular enough to get entire weeks of television dedicated to them. They hold a special place in our hearts and minds. Whether you fear them or love them, or a bit of both, they’ve dominated our oceans for hundreds of millions of years, and still manage to evoke powerful emotions from us.
But, as amazing as they are, they are not going to cure cancer.
First off, there will never be a “cure for cancer”. Not now, not in 50 years, no matter how much we know about how cancers form and spread. And no, it won’t be because there is some big conspiracy, where doctors and pharmaceutical companies are keeping some miracle drug from hitting the market.
You see, there can’t be a cure for cancer, because cancer isn’t a single disease. Cancer is a category of diseases, like rock is a category of music. While rock music is characterized by being song-based, usually with a 4/4 beat and a verse-chorus form, cancer is characterized by cell growth gone terribly wrong, allowing a group of cells to grow uncontrollably. You wouldn’t say that Korn and Elvis sound the same, would you? Well not all cancers are the same, either. Some cancers are slow growing, some are fast. Some are always fatal, others go away on their own.
The thing is, there is no universal trait to all cancers that can be attacked with one treatment, except for the fact that they are cells that grow out of control. Thus a universal cure for cancer would have to be something that prevented and reversed cell growth, which will never, ever be safe to take over an extended period of time. You need cells to grow and replicate in your body – just not when and where they shouldn’t be.
The treatment for a given cancer is heavily dependent on where it is and what it’s doing. There may eventually be a million cures – a cure for Acute Lymphoblastic Leukemia, a cure for Basal Cell Carcinoma, a cure for Craniopharyngioma, and so on and so forth from A to Z – but there will never, ever be a cure for cancer.
But I digress.
The notion that sharks may hold they key to curing cancer rests on the idea that sharks don’t get cancer. Out of all they myths in the world, there are few that have been more ecologically damaging and pervasive despite unequivocal scientific evidence to the contrary. This simply untrue statement has led to the slaughter of millions of sharks via the industry for shark cartilage pills, which are sold to desperate cancer patients under the false pretense that they can help reduce or cure their illness.
The myth started way back in the 1970s when Henry Brem and Judah Folkman from the Johns Hopkins School of Medicine first noted that cartilage prevented the growth of new blood vessels into tissues. This creation of a blood supply, called angiogenesis, is one of the key characteristics of malignant tumors, as the rapidly dividing cells need lots of nutrients to continue growing. It’s not shocking, then, that angiogenesis is a common target for those seeking potential cancer therapies.
Brem and Folkman began studying cartilage to search for anti-angiogenic compounds. They reasoned that since all cartilage lacks blood vessels, it must contain some signaling molecules or enzymes that prevent capillaries from forming. They found that inserting cartilage from baby rabbits alongside tumors in experimental animals completely prevented the tumors from growing1. Further research showed calf cartilage, too, had anti-angiogenic properties2. A young researcher by the name of Robert Langer decided to repeat the initial rabbit cartilage experiments, except this time using shark cartilage. Since sharks’ skeletons are entirely composed of cartilage, Langer reasoned that they would be a far more accessible source for potential therapeutics. And indeed, shark cartilage, like calf and rabbit cartilage, inhibited blood vessels from growing toward tumors 3.
Around the same time, a scientist by the name of Carl Luer at Mote Marine Laboratories in Sarasota, FL was looking into sharks and cancer, too. He’d noticed that sharks seem to have relatively low rates of disease, especially cancer, and wanted to test their susceptibility experimentally. So he exposed nurse sharks to high levels of aflatoxin B1, a known carcinogen, and found no evidence that they developed tumors4.
That’s when Dr. I William Lane stepped in. He’d heard about the studies done by Langer and Luer, and become immediately entrenched in the idea that oral shark cartilage could be a treatment for cancer. In 1992 he published the book Sharks Don’t Get Cancer: How Shark Cartilage Could Save Your Life. The book was a best-seller, popular enough to draw in the media from 60 Minutes who did a special on Lane and his new cancer cure. The segment featured Lane and Cuban physicians and patients who had participated in a non-randomized and shoddily done ‘clinical trial’ in Mexico which heralded spectacular results. He then co-authored a second book, Sharks Still Don’t Get Cancer, in 1996.
Of course, Lane started up his own shark fishing and cartilage pill making business called LaneLabs (which still made and sold cartilage pills until recently). But Lane was not alone – many companies began selling shark cartilage pills and powders as alternative therapies or nutritional supplements. The world market for shark cartilage products was estimated to have exceeded $30 million in 1995, prompting more and more harvesting of sharks for their cartilage.
The results have been devastating. North American populations of sharks have decreased by up to 80% in the past decade, as cartilage companies harvest up to 200,000 sharks every month in US waters to create their products. One American-owned shark cartilage plant in Costa Rica is estimated to destroy 2.8 million sharks per year5. Sharks are slow growing species, and simply cannot reproduce fast enough to survive such sustained, intense fishing pressure. Unless fishing is dramatically decreased worldwide, a number of species of sharks will go extinct before we even notice.
It’s bad enough that all this ecological devastation is for a pill that doesn’t even work. Shark cartilage does not cure or treat cancer in any way, even in mouse models6. These are also the results of at least three randomized, FDA-approved clinical trials – one in 19987, another in 20058, and a final one presented in 2007 (published in 2010)9. Ingestion of shark cartilage powders or extracts had absolutely no positive effects on cancers that varied in type and severity. To paraphrase Dr. Andrew Vickers, shark cartilage as a cancer cure isn’t untested or unproven, it’s disproven10. Indeed, the Federal Trade Commission stepped in by 2000, fining Lane $1 million as well as banning him from claiming that his supplements, or any shark cartilage derivatives, could prevent, treat or cure cancer.
But what’s worse is that this entire fraudulent enterprise that steals the money of those desperate for any kind of hope is based on a myth. No matter what a money-grubbing man with a PhD in Agricultural Biochemistry and Nutrition tries to tell you, sharks do get cancer.
L: Kidney Tumor, R: Cartilage Tumor
In 2004, Dr Gary Ostrander and his colleagues from the University of Hawaii published a survey of the Registry for Tumors in Lower Animals11. Already in collection, they found 42 tumors in Chondrichthyes species (the class of cartilaginous fish that includes sharks, skates and rays). These included at least 12 malignant tumors and tumors throughout the body. Two sharks had multiple tumors, suggesting they were genetically susceptible or exposed to extremely high levels of carcinogens. There were even tumors found in shark cartilage! Ostrander hoped that this information would finally put to rest the myth that sharks are somehow magically cancer-free.
But it hasn’t. I still see all kinds of shark cartilage pills for sale at the local GNC. But furthermore, the myth that sharks are cancer-free is still believed by many intelligent people. I read a tweet from The National Aquarium a while ago that said “It must be something in the water. Sharks are the only known species to never suffer from cancer.” The National Aquarium has over 9,000 twitter followers, and this inaccurate tweet was passed on by a number of them, including The Smithsonian Marine Station in Fort Pierce, FL. How can such a large non-profit, dedicated to “extending the knowledge and resources gained through daily operations toward the betterment of the natural environment” perpetuate such an erroneous and ecologically damaging myth?
Then there’s the BBC, whose division called BBC Earth decided to run a “trick or treat” campaign for Halloween last year featuring truths or falsehoods about different animals. Among them?
When I called them out on their egregious error, they didn’t even admit they were wrong. Instead they simply said that “the science behind their immune systems is still an area of fascination which we know little about, and thankfully people are still studying.”
Maybe I haven’t been clear. Maybe we don’t know everything about shark immune systems, but there is one thing that we do know with 100% certainty.
SHARKS DO GET CANCER.
We can’t even really say they get cancer less often than other species. It’s true that the number of sharks that we have observed with cancer is low. However, only a couple studies have even attempted to look at disease rates in shark species. Furthermore, these studies are hampered by the fact that sharks tend to be wide-ranging, open ocean fish. They live in some of the least contaminated areas on earth. This means that, odds are, they have low levels of exposure to the chemicals that cause cancer in so many land and near-shore species. Furthermore, the odds that a really sick shark would make it into a researcher’s hands to study are slim. A shark whose function is compromised by tumors would likely end up the meal of other, hungry sharks long before they’d end up on a hook cast by scientists. So even the idea that sharks have low rates of cancer or disease is hard to scientifically support.
Perhaps the most disappointing part is that the shark immune system is incredibly fascinating and worth study whether or not it can squash out cancer. Sharks are the earliest evolutionary lineage to have developed an adaptive immune system complete with immunoglobin, T-cell receptors, MHCs and RAG proteins12, and they do it without bone marrow, the source of almost all of our immune system cells. Instead, they have two completely unique immune organs, the Leydig’s and Epigonal organs, that are barely understood. Studying the shark immune system is essential to understanding the evolution of adaptive immunity that is present in all higher vertebrates. And if, indeed, they are resistant to cancer, then that makes the study of their immune system all that much more important.
Carcasses of sharks fished for their fins
Instead, we mindlessly kill millions of them a year to make Asian delicacies and ineffective cancer treatments, and we perpetuate the myth that sharks don’t get cancer. Be assured that whenever I see someone say that sharks don’t get cancer, I will call them out, especially if they should know better. It’s time that this myth is busted once and for all.
Brem H, & Folkman J. (1975). Inhibition of tumor angiogenesis mediated by cartilage. J Exp Med (141), 427-439 DOI: 10.1084/jem.141.2.427
Langer R, & et al (1976). Isolations of a cartilage factor that inhibits tumor neovascularization. Science (193), 70-72 DOI: 10.1126/science.935859
Lee A, & Langer R. (1983). Shark cartilage contains inhibitors of tumor angiogenesis. Science (221), 1185-1187 DOI: 10.1126/science.6193581
Luer CA, & Luer WH (1982). Acute and chronic exposure of nurse sharks to aflatoxin B1 Federal Proceedings, 41
Camhi M. Costa Rica’s Shark Fishery and Cartilage Industry. http://www.flmnh.ufl.edu/fish/Organizations/SSG/sharknews/sn8/shark8news9.htm (1996).
Horsman MR, Alsner J, & Overgaard J (1998). The effect of shark cartilage extracts on the growth and metastatic spread of the SCCVII carcinoma. Acta oncologica (Stockholm, Sweden), 37 (5), 441-5 PMID: 9831372
Miller DR, Anderson GT, Stark JJ, Granick JL, & Richardson D (1998). Phase I/II trial of the safety and efficacy of shark cartilage in the treatment of advanced cancer. Journal of clinical oncology : official journal of the American Society of Clinical Oncology, 16 (11), 3649-55 PMID: 9817287
Loprinzi CL, Levitt R, Barton DL, Sloan JA, Atherton PJ, Smith DJ, Dakhil SR, Moore DF Jr, Krook JE, Rowland KM Jr, Mazurczak MA, Berg AR, Kim GP, & North Central Cancer Treatment Group (2005). Evaluation of shark cartilage in patients with advanced cancer: a North Central Cancer Treatment Group trial. Cancer, 104 (1), 176-82 PMID: 15912493
Lu C, Lee JJ, Komaki R, Herbst RS, Feng L, Evans WK, Choy H, Desjardins P, Esparaz BT, Truong MT, Saxman S, Kelaghan J, Bleyer A, & Fisch MJ (2010). Chemoradiotherapy with or without AE-941 in stage III non-small cell lung cancer: a randomized phase III trial. Journal of the National Cancer Institute, 102 (12), 859-65 PMID: 20505152
Vickers, A (2004). Alternative cancer cures: “unproven” or “disproven”? CA: A Cancer Journal For Clinicians, 54, 110-118 DOI: 10.3322/canjclin.54.2.110
Ostrander GK, Cheng KC, Wolf JC, & Wolfe MJ (2004). Shark cartilage, cancer and the growing threat of pseudoscience. Cancer research, 64 (23), 8485-91 PMID: 15574750
Flajnik MF, & Rumfelt LL (2000). The immune system of cartilaginous fish. Curr Top Microbiol Immunol (249), 249-270
Every once in a while, you write something you really, really like. You write something you like so much, you wish you could write it again, over and over. Well, I happen to have a few of these posts that I have written previous to my move here, and I want to share them with you. They’ll be labelled as “Observations,” indicating they were originally posted on my old blog, Observations of a Nerd. Enjoy!
Mouse, my adorable cousin, showing off a bubble
“Christie! Christie!” My four-year old cousin tugs eagerly on my jacket. “I wanna see the fishes.”
“Ok, Tuna, we can go see the fish.”
My little cousin loves the word ‘tuna’. She says it all the time. Tuna, tuna, tuna. Everything is a tuna-face or a tuna-head. She doesn’t even like tuna (she doesn’t eat it), but she loves the sound of the word rolling off her tongue. Finally, her nanny threatened that if she kept saying ‘tuna,’ we’d have to start calling her it. My ever so adorable cousin’s response was, of course, “TUNA!” So now that’s her nickname. She’s Tuna.
I’m waiting in line with her and her sister at the Rainforest Cafe in the Burlington Mall. They love the Rainforest Cafe. There’s a giant mechanical alligator out front that they can’t seem to get enough of. Mouse (as I now call Tuna’s older sister) is convinced that it’s real. Who am I to burst her bubble?
But now, in line, their eyes are instead drawn to the entrance arch of fish tanks. As a marine biologist, I feel obligated to tell them about the fish.
“You see that one? That’s a butterflyfish. And that one — that’s a grouper. Oh! And that little colorful one there — that’s the Hawaii State Fish. It’s name in Hawaiian is Humuhumunukunukuapua’a. Can you say Humuhumunukunukuapua’a?”
My two cousins look at me like I’m insane. I guess they’re a little young to try and learn Hawaiian fish names.
“Christie! Christie!” Tuna grabs my jacket again. “Are there any tuna?”
“Tuna. Tuna. TUNA!” Mouse grins at her sister, and the two burst into giggles.
Their attention quickly drifts to shooting back and forth funny words like Tuna and Pizza, and instead I am left with my little cousin’s innocent question derailing my thoughts.
Tuna. One of my favorite fish. Large, majestic creatures built for speed and strength. Even a rudimentary understanding of how perfectly suited they are as open ocean predators leaves one in awe of evolution’s handiwork. A sleek, streamlined design, with specialized circulation and muscles to provide warmth and power even in cold water — they are truly incredible fish.
There are many kinds of tuna: Albacore, Bigeye, Blackfin, Bluefin, Karasick, Longtail Skipjack and Yellowtail. Even within a ‘kind’ like Bluefin there is Northern Bluefin, Southern Bluefin, and Pacific Bluefin.
They’re all similar in that they’re unbelievably delicious.
I remember the last time I ate tuna. I would love to say it was a long time ago, but it wasn’t. I slipped into the take-out sushi place as quietly as possible, but the little bells attached to the door handle announced my entrance.
“Wat can get fo you?” the nice man behind the counter asked.
“I’ll have the Spicy Ahi Maki, please.” Once my treat was handed over, I made quick work of the bright red fish smothered in my favorite chili mayo. The soft, tender flesh melted in my mouth, tasting of decadence. Within a matter of minutes it was all over.
As soon as I walked out the door, though, it hit me. The guilt. You should know better, I chided myself. The tuna fisheries, by and large, are a disgrace. Many are overfished and on the verge of collapse. Take the Mediterranean Bluefin tuna fishery, the largest fishery for Bluefin in the world, for example. Tuna are caught young in massive numbers and corralled in cages offshore where they’re fattened for the sushi and sashimi market. If the Mediterranean Bluefin tuna fishery is not closed now, some scientists project that the tuna in that part of the world will be functionally extinct in just two years.
Of course, I know that the tuna I ate wasn’t likely to be Bluefin. It wasn’t Albacore, either, as Albacore is the tuna you get in cans, not the kind served in sushi bars (though it can be found under the name “Shiromaguro” if they have it). While the Japanese are much pickier about their labeling, giving each species a different name, in the states, Ahi or Maguro can refer to just about any tuna species, though most often it refers to Bigeye, Yellowfin or sometimes Skipjack. It’s only if you get Toro, the fatty tuna that will cost you an arm and a leg, that you’re likely to be eating Bluefin.
But ordering tuna in a restaurant is a bit like playing ecological Russian Roulette. Rarely do restaurants know or care where their fish comes from, only that they got it at a decent price. Even if they think they know and think they care, they’re often wrong. A recent study which genetically tested ordered tuna in restaurants found you may be served anything from the critically endangered Southern Bluefin to Escolar, a disgusting fish known to cause illness when eaten. Most (79%) of the menus did not say what species was served, and when asked, almost a third said the wrong species while another 9% had no idea.
The problem, of course, is that it matters which species you eat. All Bluefin fisheries are unsustainable, and eating them ensures their doom. Meanwhile, Yellowtail and Bigeye, though better off, are approaching the same fate — though if caught with pole and line (the slower and more expensive way to fish), they could be sustainable. Only Albacore and Skipjack have healthy and well managed stocks right now, though if we lean more on them to make up for losses in the other three major fisheries, it’s likely they, too, will be in trouble. Despite warning after warning, government agencies all over continue to keep quotas for most species well above sustainable levels.
As if that’s not bad enough, members at the recent CITES meeting rejected legislation that would have limited the trade of tuna between countries. It seems that the politicians just don’t care enough, and it’s up to the public to make it clear that driving these species to extinction is not something we’re willing to stand for. To do that, we have to stop supporting the market… to stop going out to little take out sushi places and getting the Spicy Ahi Maki.
I tried to console myself that, living in Hawaii, it’s possible that the tuna I just ate was Skipjack, pole-caught locally… but I know better. Pole-caught fish are more expensive, and it’s not likely the cheap take-out sushi place is splurging for the local variety just for kicks, especially if they aren’t advertising the fact. No, that delicious meat was likely Yellowfin or Bigeye purse-seined or long-lined in some foreign country and shipped, frozen, to Honolulu to be eaten by cheap people like me.
The feeling that washed over me in that instant was not unlike the feeling you get when you drunkenly sleep with your ex a month or so after the breakup. Sure, it seems like a good idea at the time, and for a brief moment you feel pure pleasure. But you wake up the next morning coated with filth and regret. The truth is, you’ve only made things worse. You glare at yourself in the mirror, pissed that you were so stupid. But the worst part is the unshakeable feeling that lingers for days. You feel… well, there’s really no nice word for it. You feel like a slut.
That’s what you are, you know my conscience spits at me. You’re a tuna slut.
“Christie! Christie!” My cousin’s pleas snap me back.
“What is it Tuna?”
“You’re a toushie-face!” They erupt into laughter. The two are completely out of control. With the artful skill only an older cousin can have, I draw their attention back to the fish, explaining the different types and little facts about how they live. They’re mesmerized. Soon enough we’ve been seated, ordered our food, and had a nice lunch surrounded by the chaotic jungle of the Rainforest Cafe.
Later that evening, the girls kiss and hug me goodnight. “Goodnight Mouse, Goodnight Tuna,” I whisper to each. As they head upstairs with their parents to bed, I sip a glass of my uncle’s homemade red wine and can’t help but think about the plight of tuna.
A fish so beloved by so many like myself, yet its very survival is threatened by that adoration. The trouble is that it’s just hard to give up something we love so much. If I — a marine biologist armed to the teeth with the knowledge of exactly how bad the problem is — still cannot restrain myself from indulging, it seems hopeless to expect that the world will. If we continue to fish for bluefin and other tuna like we do now, there is no ambiguity about the result. They will disappear. Probably within my lifetime, maybe even sooner. And before they disappear, they’ll become so hard to find that a slice of sashimi will be as expensive as Beluga caviar is now.
It’s possible that regulating agencies will come to their senses and limit the catch, thus allowing tuna species to rebound before they’re completely gone — but they sure as all hell don’t seem inclined to. Some have had the idea of rolling moratoriums, where certain fishing locations are banned for several years, then others the next few years, to allow wild populations time to recover. Or maybe they could instate tuna credits, allowing fish-hungry nations like Japan to eat their fill while others abstain. There are a lot of ways politicians could help prevent overfishing — none of which, of course, they seem to want to do.
It’s also possible that we’ll find a way to farm tuna, taking the pressure off of falling wild stocks. As it stands now, many species of tuna are caught young and kept in pens until they’re big and fat enough to be slaughtered. But this isn’t really farming in the truest sense because they still have to be wild-caught first. Tuna species, particularly the plummeting Bluefin, have proven to be extremely difficult to aquaculture. They take 12 years to mature, and apparently, don’t find large aquariums or offshore corrals very romantic, so they don’t produce the next generation in captivity. Some have had luck using drugs to trick them into producing eggs, but the method was expensive and labor intensive, and it has yet to be seen if the young produced are healthy. While this does produce hope, it’s limited, and it’s hard to see commercial aquaculture technology rising fast enough to the occasion to save these species.
I can’t help but wonder if, in fifteen or twenty years, I’ll even be able to order maguro if I take my cousin out to a nice sushi restaurant so she can try the fish she’s nicknamed after.
Even if I can, I hope that when I suggest it, she glares, then sighs like she’s sick of explaining this kind of thing to ignorant people like me. Her generation will have learned from our mistakes. They will do better. She will remind me that tuna are rare and beautiful fish; that they’re aren’t that many left, and if we keep ordering tuna and continuing the demand for their meat, they will disappear altogether.
And, she’ll likely say, I’m a grown woman now — so stop calling me Tuna.
For more information about sustainable seafood choices, take a look at the Monterrey Bay Aquarium’s Seafood Watch List for your area. In particular, you can help protect the wild tuna by ordering other, more sustainable sushi. For examples, check out SustainableSushi.Net.
Learn more about the plight of the tuna and what you can do to help at SaveTheBluefinTuna.Com.
Not everyone adjusts well to living in a city. Having spent a few days in Manhattan earlier this year, I can say quite unequivocally that I’m one of those people. The size of the buildings, the speed and energy with which people move – it’s fascinating, beautiful, and would overwhelm me in a matter of weeks. I’m impressed by anyone who fits in to that kind of intense culture, but I’m even more impressed by the animals that do.
Think about it – we, as human beings, have all this intellect and adaptability at our disposal. We built those cities – it seems only natural that we master them. But we are not the only creatures which have taken to our metropolitan masterpieces, and we’re not the only ones who flourish in them. Creatures you would never expect have moved in to our neighborhoods and made even our coldest cities welcome habitat. To do so, they have overcome the overpowering sights, sounds and smells that form the charm – and repulsion – of big cities.
There is more to your everyday park pigeon than meets the eye. Birds are common in all cities, from the frozen alleys of Moscow to the sizzling streets of Miami. What makes birds such good city dwellers? Urban birds tend to be smart and adaptable, much like the people they fly over. They’re omnivores in the truest sense, eating a wide variety of foods from restaurant scraps to stale bread tossed by park-goers. Moreover they take advantage of the benefits a city has to offer, including warm places to nest in the winter.
While we might be aware of the pigeons or sparrows, we often fail to see the complexity and diversity that characterizes the urban bird community. There are over 70 different bird species in residence in Tokyo. There are whole websites dedicated to birding in New York City. Did you know that New York and Berlin have the highest concentrations of peregrine falcons in the world? Or that one of the most successful urban birds in the 21st century is the parakeet?
Of course, birds aren’t the only group of animals that has taken well to cities. Perhaps some of the most impressive examples of city dwellers are mammals. There’s no question that rats and mice have been making our cities home for almost as long as we have. These vermin serve not only as examples, but as a tempting food source. As it turns out, the abundance of rodents has attracted other mammals to test their hand at city life.
In Illinois, red foxes have decided that humans make better neighbors than coyotes. The sly carnivores have been slowly moving into suburbs and cities ever since coyotes took back the fields where the foxes normally roam. Ecologists which study these urban foxes have determined that they live longer, healthier lives than their rural counterparts, with a diet that is almost 50% rodent. In the country, coyotes kill almost half of the young foxes and a quarter of the adults, making the cities seem like a safe and welcoming place for a fox to raise her young despite the risks. It’s not just cities in Illinois that are getting these new furry inhabitants – foxes have become common in cities around the world, including London and Zurich.
While the foxes have moved into cities more recently, their cousins, dogs, have made cities their homes for much longer. In Moscow, the stray dog population has become a cultural phenomenon. There are around 35,000 stray dogs in Russia’s capital city. They have been living with the people there for at least the past 200 years, and have evolved specialized behaviors which help them survive in their urban habitat. Though there are many different strategies employed by these urban canines, perhaps the most well known and the most impressive are the metro dogs, which have taken to using the subway.
The metro dogs don’t just haphazardly transit the underground system; they have complex territories with specific stops and routes. Becoming a savvy subway rider has changed how the dogs look and behave. Gone are the spots and floppy ears we associate with domesticated pups, for these are truly feral dogs. Yet instead of pack hierarchies led by the strongest brute, the metro dogs are led by the smartest. Because of the complex nature of their territories, they rely on brains, not brawn, for survival.
Cities bring out the ingenuity in animals large and small. Squirrels have been documented waiting for crosswalks to turn green, even in the absence of people walking. A peculiar cat used to ride the bus every morning. When animals are forced to deal with the chaos of our city life, they find a way to adapt, and then some.
All of this begs the question: what evolutionary impact are our cities having on animals long term? Selection for ingenuity could dramatically change the animals we know today. Riding subways might be a parlor trick compared to what the urban wildlife of the future will be capable of. One thing is for certain – the intelligence and adaptability of our streetwise species will never cease to amaze me.
The metro dogs don’t just haphazardly transit the underground system; they have complex territories with specific stops and routes. Becoming a savvy subway rider has changed how the dogs look and behave. Gone are the spots and floppy ears we associate with domesticated pups, for these are truly feral dogs. Yet instead of pack hierarchies led by the strongest brute, the metro dogs are led by the smartest. Because of the complex nature of their territories, they rely on brains, not brawn, for survival. 
