ecology | Southern Fried Science

“Sharks create oxygen”: A scientific perspective

Posted on February 10, 2012 by David Shiffman

I want to apologize to our regular readers for stating something that should be incredibly obvious. Sharks in in no way connected to the global supply of atmospheric oxygen. If every single species of shark went extinct, there would be a variety of negative ecological effects, but a reduction in the global supply of atmospheric oxygen would not be among them. There is not a shred of scientific evidence supporting the idea that the loss of sharks would affect our oxygen supply- not a single scientific paper, not a single technical report. I’ve attended a dozen scientific conferences focusing on marine ecology or shark biology (including three international conferences) and I’ve never seen or heard of anyone presenting or even discussing this. To the best of my knowledge, not a single person who has authored a scientific paper or technical report supports this idea. Despite the complete lack of any kind of credible evidence, and despite many recent blog posts thoroughly debunking it (see here here here here here here and here ), this pseudoscience just won’t die.

The premise of the sharks and oxygen claim is as follows:

Updates from the Deep: New and Noteworthy in Hydrothermal Vent Research

Posted on January 10, 2012 by Andrew Thaler

From hairy-chested yeti crabs to the deepest known fields, hydrothermal vents have been enjoying a bit of science celebrity in the last few weeks. Beneath the headlines, there has been an eruption of vent-related research published in the scientific literature and some exciting new expeditions just left port.

The Discovery of New Deep-Sea Hydrothermal Vent Communities in the Southern Ocean and Implications for Biogeography

'Hoff' crabs in paradise. Image from ChEss Southern Ocean Consortium

The exhaustive author list on this paper reads like a who’s who in hydrothermal vent biogeography. This is the paper that introduced “the Hoff” crab to the world, but the findings are far more significant. Hydrothermal vent systems are sorted into biogeographic provinces, with different regions supporting different communities. The iconic giant tube worms dominate the eastern Pacific, while the western Pacific (prominently featured in Deep Fried Sea) plays host to fist sized snails, and the Atlantic features shrimp as its dominant species. There are several missing gaps in our understanding of how these qualitatively different communities are connected – the Southern Ocean, the south Atlantic, the Indian Ocean, and the Cayman Trough, among others. Filling in these gaps in our knowledge can help us understand the history and evolution of hydrothermal vent ecosystems.

That sinking feeling: Hog lagoons, superbugs, and the proliferation of antibiotics in livestock

Posted on January 2, 2012 by Andrew Thaler

From here, it looks like such a lovely pond. Photo by Andrew David Thaler

The murky brown water was still, reflecting, perfectly, the drifting clouds above. Had I not known what it was, an acre-wide manmade pond almost a dozen feet deep filled to the brim with hog feces, I might be tempted to describe it as “beautiful”. Hog lagoons like this are a common sight in North Carolina, though their use is in decline. My lab group arrived at this particular lagoon to take microbial samples, fungi in this case, from the steaming cauldron of organic waste: an ideal culture medium. Carefully, we loaded a small skiff and rowed out into the stink. Near the center, we gingerly dipped our sampling vials, affixed to the end of an old fishing pole, into the dense fluid. It was then that we noticed the rising waterline, the slow trickle at the stern, the shift in balance. We locked the oars and rowed, frantically, towards shore. Our labmates on shore had, thankfully, tied a line to the bow before we departed. The skiff’s gunwales were creeping closer and closer to the water. We were sinking. We were sinking in a lake of pig shit.

Better Conservation through Cloning: this cock doesn’t crow

Posted on December 7, 2011 by Andrew Thaler

Poor Vindaloo never learned to crow. Photo by Andrew David Thaler.

I awoke one morning early last spring to a noise I has been dreading for weeks, the first crow of a chicken that was not supposed to be a rooster. It took me several minutes to fully register what I was hearing. Rather that the classic cock-a-doodle-do we often associate with the rooster’s crow, the sound emanating from my hen house was an awkward, unstable noise not unlike a turkey squawking through a vat of molasses while being vigorously shaken. Over the next several months, two more cocks arrived crowing, in my flock. All three roosters, different breeds from different parents, made noises resembling nothing like a rooster’s crow. There was no pattern; some mornings they would crow off-and-on for a few hours, other mornings they would, for lack of a better word, gargle for half-an-hour straight.

I raise my chickens from day-old hatchlings. Those three roosters, from my very first flock, had never met an adult chicken. They imprinted on Amy and me and looked to us for guidance. When we introduced them to new food, new water dispensers, even small changes to their habitat (like a particularly terrifying log), we had to teach them. Instinctively, they would scratch for food, and if left to their own devices, they would attempt to eat everything, but for the most part, we had to show them how to eat, how to drink, how to roost. But we could not teach them how to crow.

Which is why Casey B. Mulligan’s Economix article in the New York Times – Species Protection and Technology – which argues that cloning could be an effective tool to restore extinct species (a topic I’ve been thinking about quite a bit in terms of population dynamics), is fatally flawed.

Bluefin Tuna, Big Game Hunters, and the Conservation Vortex

Posted on November 29, 2011 by Andrew Thaler

Bluefin Tuna. Public Domain NOAA

Why are we still killing Bluefin Tuna? This question has resonated through the ocean blogosphere recently, as various experts weigh the issues surrounding overfishing and wonder why, when we know how limited the Bluefin Tuna populations are, and how precipitously they’ve declined in the last decade, do they demand record-breaking prices able to support an industry that must range further afield to chase that last, lonely fish? Other conservation writers discuss the recent extinction of not one, but two, rhinoceros species and ponder the fate of large terrestrial mammals. Knowing how rare these rhinoceroses were, why did they continue to be poached? Where does this demand come from?

America’s lust for gigantic breasts leads to impotence: the population genetics of captive-reared turkeys

Posted on November 23, 2011 by Andrew Thaler

Gobble? image from http://www.public-domain-image.com

The noble turkey, a centerpiece of the American Thanksgiving supper. It looms large from its prominent position on the dining room table. The master of ceremonies – or, in my case, the guy who keeps slicing himself open with various sharp objects yet is inexplicably the one people call on when there’s knife-work needs doing – draws a set of fine, honed knives, set aside for this particular task, and carves, delicately yet firmly, into the hefty white meat of the turkey’s breast. Sure, some favor the dark, rich meat around the legs, but this white meat, soaked in gravy and topped with cranberry sauce or stuffing, that is what we crave.

“We give thanks,” the benediction may begin, “to Charles Darwin, for determining the underlying mechanism by which a theropod may, over the course of 65 million years, through a process of gradual change by means of the retention of beneficial traits through successive generations, evolve into this delicious, delicious bird.” And then, perhaps, that surly teenager, the one determined to point out the social inequalities inherent in the holiday and the colonialist attitudes which led to the wholesale extermination of America’s native peoples – every family has at least one – will chime in to quip “you know, evolution didn’t shape the turkey. The modern Thanksgiving turkey is the product of an extensive selective breeding program that began in the 1940’s. Commercial turkeys can’t even reproduce naturally, they have to be artificially inseminated.” At which point the older members of your family may blush and/or faint at such an unseemly turn of phrase.

Salmon, aquaculture, and the spread of Infectious Salmon Anemia

Posted on October 27, 2011 by Andrew Thaler

Coho salmon - public domain image

In 2008, a deadly virus decimated Chilean aquaculture facilities, causing $2 billion in damage and crippling an industry. This week, preliminary reports suggest that this same disease may have infected wild salmon in the north Pacific. The internet has been blowing up with news reports of Infectious Salmon Anemia (ISA) detected in wild salmon populations. Reports range from balanced – Deadly Fish Farm Virus Found in Wild Pacific Salmon – to hyperbolic – B.C.’s salmon feedlots need to be closed – but all hinge on the fact that ISA, a lethal salmon-infecting virus previously resigned to aquaculture facilities, has been detected in wild salmon populations in British Columbia. This has the potential to be a very big deal. ISA is 90% lethal and mortality occurs in 10 days or less. The virus is waterborn, but can also be transmitted through handling with contaminated equipment. There is no treatment once a fish is infected.

Before I go on, a couple points need to be clarified:

ISA does not infect humans, though as it threatens a fishery and a major agricultural industry, it most certainly affects humans.
ISA was isolated from 2 wild sockeye salmon. It has not been confirmed from independent test yet, although one statement indicates that the current infection is from a non-infectious strain of ISA (which raises some interesting questions about who currently knows what about this outbreak).

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A slimehead by any other name should never be on your plate

Posted on October 26, 2011 by Andrew Thaler

Orange Roughy - image by FishBase artist Robbie Cada

Slimehead is not a word you would expect to find on the menu of a fancy restaurant. Like dolphin*, toothfish*, goosefish*, mudbug*, hog*, and gizzard fish*, slimeheads have undergone a bit re-branding over the last few decades to make their name as palatable as their fillets. Enter the Orange Roughy, a dull, uninspired name that captures nothing of the grandeur of Hoplostethus atlanticus and ignores the defining characteristic of these deep-sea fishes.

What does Orange Roughy mean to you? Well, it’s probably orange, and I guess roughy means it might be rough, or something. The name is pretty uninformative. But slimehead! Slimehead tells you quite a bit about this creature, and leads to some interesting ecological questions. Why is it’s head covered in slime? What does the slime do? How is the slime contained in its head?

I heart cryptozoology

Posted on October 6, 2011 by Andrew Thaler

Cryptozoology, the study of animals whose existence is unproven, lies just south of the boundary between science and pseudoscience. Unlike most psuedoscientific movements, which require adherents to suspend disbelief and ignore the realities of physics, chemistry, medicine, and, well, reality, the foundational principals of cryptozoology – that there are remnant populations of thought-to-be-extinct species and that there are still large, charismatic animals that have not yet been discovered – are grounded in ecology. In deep-sea biology, we discover new species all of the time, some of which are far more fantastical than humans can imagine. Some times, we even discover once extinct species. So it is not much of a leap to go from exploratory zoology to cryptozoology.

The post-oil spill Gulf of Mexico

Posted on October 4, 2011 by David Shiffman

As some of you probably remember, there was an oil spill in the Gulf of Mexico last year. You can be forgiven for not remembering it, as our news media hasn’t been talking about it very much lately. In fact, if your only source of oil spill news was the mainstream media, you probably think that the Gulf is doing great! A little over a year ago, CNN ran a story about how the BP oil well that caused the spill was “effectively dead” and was “no longer a threat to the Gulf”. CNBC (and many others) ran stories about how 75 percent of the oil from the spill was gone from the Gulf. Bloomberg reported that the Gulf would recovery completely by 2012. London’s Telegraph celebrated a dramatic recovery after only one year. Whew… things aren’t as bad as we feared, and the Gulf has almost totally recovered! Or has it?