Science – Page 42 – Southern Fried Science

This Week in the Deep

January 26, 2013January 25, 2013 Andrew Thaler

Science

New and noteworthy publications in deep-sea science for the week of January 21, 2013.

Geobiology: Did life originate from a global chemical reactor?

Many decades of experimental and theoretical research on the origin of life have yielded important discoveries regarding the chemical and physical conditions under which organic compounds can be synthesized and polymerized. However, such conditions often seem mutually exclusive, because they are rarely encountered in a single environmental setting. As such, no convincing models explain how living cells formed from abiotic constituents. Here, we propose a new approach that considers the origin of life within the global context of the Hadean Earth. We review previous ideas and synthesize them in four central hypotheses: (i) Multiple microenvironments contributed to the building blocks of life, and these niches were not necessarily inhabitable by the first organisms; (ii) Mineral catalysts were the backbone of prebiotic reaction networks that led to modern metabolism; (iii) Multiple local and global transport processes were essential for linking reactions occurring in separate locations; (iv) Global diversity and local selection of reactants and products provided mechanisms for the generation of most of the diverse building blocks necessary for life. We conclude that no single environmental setting can offer enough chemical and physical diversity for life to originate. Instead, any plausible model for the origin of life must acknowledge the geological complexity and diversity of the Hadean Earth. Future research may therefore benefit from identifying further linkages between organic precursors, minerals, and fluids in various environmental contexts.

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How to tell if a “shark in flooded city streets after a storm” photo is a fake in 5 easy steps

January 23, 2013August 28, 2017 David Shiffman 3 Comments

Popular Culture, Science

The combination of increasing extreme weather and social media has created, if you’ll pardon the pun, a perfect storm for sharing photos that show post-hurricane devastation (both real and fake). Many of them take the form of of a shark swimming through flooded city streets. For better or for worse, I’m known as “the shark guy” among my friends and family, which means that every time one of these pictures pops up, I get it e-mailed to me on the order of 50-100 times.

With the hopes of lightening my inbox and edu-ma-cating our loyal readers, presented below is a simple guide to determine if any given “shark after the storm” photo is fake.

1) Use your vast knowledge of shark biology to determine if a shark that size of that species could possibly be in water that deep.

The image above was one of the first “shark after a storm” pictures to go viral. It claimed to show a great white shark swimming through the flooded streets of Puerto Rico after Hurricane Irene in 2011. Take a look at how high the car’s side view mirror is above the water. That means the water level, while more than high enough to be destructive to cars and buildings, is not nearly high enough for a shark of that size to be comfortably swimming in. Also, great white sharks are not typically found in the Caribbean in August.

This Week in the Deep

January 20, 2013January 28, 2013 Andrew Thaler

Science

New and noteworthy publications in deep-sea science for the week of January 14, 2013.

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Bring the trench to the bench or bring the bench to the trench? The future of deep-sea exploration

January 15, 2013January 15, 2013 Andrew Thaler

Science

AndrewThumb Newsweek, in is new and impressive digital format, released a series of articles this week on deep-sea exploration, the challenges of human occupied and remotely-operated vehicles, and the decline in funding for ocean science, particularly in the deep sea. The main article, The Last Dive? Funding for Human Expeditions in the Ocean May Have Run Aground, is a deep, detailed look at the state of deep-sea science, seen through the eyes of Dr. Sylvia Earle and Dr. Robert Ballard, two giants in the ocean community. The follow-up, James Cameron Responds to Robert Ballard on Deep-Sea Exploration, provides insight into the mind of James Cameron, who last year successfully dove the Challenger Deep in his own deep-sea submersible.

Both the articles continue to perpetrate the canard that there is a deep chasm between the human-occupied submersible (HOV) and remotely-operated vehicle (ROV) communities. The reality is that deep-sea scientists use a variety of tools, from mechanical samplers to autonomous robots, to study and understand the deep. The choice comes down to which tool is most efficient, least expensive, and currently available. Absent a sea change, ROV’s will continue to be the workhorses of deep-sea research. And that is a good thing. I sang the praise of my robot underlings the last time this debate breached the public consciousness. I also discussed why basic deep-sea research and training highly skilled ROV pilots is a matter of national security.

This Week in the Deep

January 12, 2013January 25, 2013 Andrew Thaler

Science

New and noteworthy publications in deep-sea science for the week of January 7, 2013.

Deep Sea Research Part 1: Oceanographic Research Papers: Discovery of a new hydrothermal vent based on an underwater, high-resolution geophysical survey

A new hydrothermal vent site in the Southern Mariana Trough has been discovered using acoustic and magnetic surveys conducted by the Japan Agency for Marine–Earth Science and Technology’s (JAMSTEC) autonomous underwater vehicle (AUV) Urashima. The high-resolution magnetic survey, part of near-bottom geophysical mapping around a previously known hydrothermal vent site, the Pika site, during YK09-08 cruise in June-July 2009, found that a clear magnetization low extends ~500 m north from the Pika site. Acoustic signals, suggesting hydrothermal plumes, and 10 m-scale chimney-like topographic highs were detected within this low magnetization zone by a 120 kHz side-scan sonar and a 400 kHz multibeam echo sounder. In order to confirm the seafloor sources of the geophysical signals, seafloor observations were carried out using the deep-sea manned submersible Shinkai 6500 during the YK 10-10 cruise in August 2010. These discovered a new hydrothermal vent site (12°55.30′N, 143°38.89′E; at a depth of 2922 m), which we have named the Urashima site. This hydrothermal vent site covers an area of approximately 300 m x 300 m and consists of black and clear smoker chimneys, brownish-colored shimmering chimneys, and inactive chimneys. All of the fluids sampled from the Urashima and Pika sites have chlorinity greater than local ambient seawater, suggesting subseafloor phase separation or leaching from rocks in the hydrothermal reaction zone. End-member compositions of the Urashima and Pika fluids suggest that fluids from two different sources feed the two sites, even though are located on the same knoll and separated by only ~500 m. We demonstrate that investigations on hydrothermal vent sites located in close proximity to one another can provide important insights into subseafloor hydrothermal fluid flow, and also that, while such hydrothermal sites are difficult to detect by conventional plume survey methods, high-resolution underwater geophysical surveys provide an effective means.

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Surviving Grad School: A Practical Guide to an Impractical Lifestyle

January 10, 2013January 10, 2013 Andrew Thaler 1 Comment

Science

Ah, graduate school. For approximately 5 years you will live awash in the intellectual stimulation that comes with the pursuit of knowledge. You will learn more than you ever have before. Now at the forefront of the human data engine, you are not just being taught, but pushing the limits of human understanding imperceptibly, but significantly, … Read More “Surviving Grad School: A Practical Guide to an Impractical Lifestyle” »

This Week in the Deep

January 5, 2013January 25, 2013 Andrew Thaler

Science

New and noteworthy publications in deep-sea science for the week of December 31st, 2012.

PLoS One: How Deep-Sea Wood Falls Sustain Chemosynthetic Life

Large organic food falls to the deep sea – such as whale carcasses and wood logs – are known to serve as stepping stones for the dispersal of highly adapted chemosynthetic organisms inhabiting hot vents and cold seeps. Here we investigated the biogeochemical and microbiological processes leading to the development of sulfidic niches by deploying wood colonization experiments at a depth of 1690 m in the Eastern Mediterranean for one year. Wood-boring bivalves of the genus Xylophaga played a key role in the degradation of the wood logs, facilitating the development of anoxic zones and anaerobic microbial processes such as sulfate reduction. Fauna and bacteria associated with the wood included types reported from other deep-sea habitats including chemosynthetic ecosystems, confirming the potential role of large organic food falls as biodiversity hot spots and stepping stones for vent and seep communities. Specific bacterial communities developed on and around the wood falls within one year and were distinct from freshly submerged wood and background sediments. These included sulfate-reducing and cellulolytic bacterial taxa, which are likely to play an important role in the utilization of wood by chemosynthetic life and other deep-sea animals

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The ten best and worst events in shark fisheries management of 2012

January 4, 2013October 27, 2013 Guest Writer 1 Comment

Conservation, Science

Sonja FordhamPresident, Shark Advocates International — Sonja Fordham
President, Shark Advocates International

Sonja Fordham founded Shark Advocates International as a project of The Ocean Foundation in 2010 based on her two decades of shark conservation experience at Ocean Conservancy. She is Deputy Chair of the IUCN Shark Specialist Group and Conservation Committee Chair for the American Elasmobranch Society, has co-authored numerous publications on shark fisheries management, and serves on most of the U.S. federal and state government advisory panels relevant to sharks and rays. Her awards include the U.S. Department of Commerce Environmental Hero Award, the Peter Benchley Shark Conservation Award, and the IUCN Harry Messel Award for Conservation Leadership.

The last twelve months added up to another exciting year in shark and ray conservation policy. We certainly saw and should herald a lot of great progress in 2012. I think it’s also important to acknowledge what went wrong so we know where we stand and how best to move forward. I’ve taken a look back and compiled a top ten list of what I see as the best and worst events in shark fisheries management for 2012, based on my work at Shark Advocates International. I’m starting with the low points, but keep reading! It ends on a high note.

Five organisms with real super powers that rival their comic book counterparts

January 2, 2013September 19, 2013 Andrew Thaler 6 Comments

Popular Culture, Science

There is no force more creative than the painstakingly slow process of evolution. Ever wanted to walk through walls? Naked mole rats can physically bore through concrete. How about fly? There are a couple dozen different ways to accomplish that goal, even if you’re a squid. Incredible power of regeneration? Flatworms, roundworms, and echinoderms have us beat. Among the vertebrates, species like the axolotl can regrow limbs, organs, and parts of their brain. For practically every super power we can imagine, something on the tree of life has come up with a real-world analog.

Some real super power are more super than others:

1. The immortal rotifer that absorbs the abilities of anything it touches.

Bdelloid Rotifers. photo by Diego Fontaneto

Around 80 million years ago, a small, unassuming group of metazoa decided that sex just wasn’t for them. Instead of going through the effort of recombining their genetic material with a mate every generation to produce a viable offspring with a roughly 50% contribution from each parent, Bdelloid Rotifers started reproducing asexually. Males completely disappeared from class bdelloidea, leaving females to generate genetic duplicates through parthenogenesis. This is not their super power.

Bdelloid rotifers are incredibly tough. When environmental conditions are less than favorable, they can enter a dormant state. In this dormant state,they can survive the worst unscathed. Dehydrated, they can endure extreme temperatures, drought, even ionizing radiation. A bdelloid rotifer in its dormant state can even survive in space. If that isn’t enough, while dormant, these rotifers continue to produce offspring, which also remain dormant. This is not their super power.

Bdelloid rotifers’ super power appears when they recover from their dormant state. As they rehydrate and repair whatever damage their cells incurred, they incorporate DNA fragments from their environment. This includes partially digested food and any DNA in close proximity to them, even bacterial and archael DNA. It is this ability that allows bdelloid rotifers to overcome the limitations of asexual reproduction and survive for 80 million years without mates. They can literally absorb the attributes of those around them.

Their incredible toughness, celibate lifestyle, and ability to absorb the powers of anything they touch, put Bdelloid Rotifers firmly on par with X-Men perennial favorite: Rogue.

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13 wrong things about sharks that conservation advocates should stop saying in 2013 (and what they should say instead)

December 27, 2012December 27, 2012 David Shiffman 64 Comments

Conservation, Science

davesquare

While the rest of the scientific and management community and I are grateful for the passionate support of many shark conservation advocates, passion is no substitute for knowledge and accuracy. Some conservation issues are a matter of opinion and can (and should) be reasonably be discussed by people with different views, but many others are a matter of fact. Presented here, in no particular order, are 13 incorrect statements and arguments commonly made by well-intentioned but uninformed shark conservation advocates, along with the reality of the situation.

1) “Shark finning” is synonymous and interchangeable with “the global shark fin trade.” Shark finning is a specific fishing method. It is not the only way to catch sharks, and it is not the only way to provide shark fins for the global fin trade. Stopping shark finning is a worthy goal (that has largely been accomplished already *) because it is a wasteful and brutal fishing method that complicates management, but stopping shark finning does not stop the global shark fin trade. Many people calling for a ban on finning really seem to want no shark fishing and no fin trade of any kind (a viewpoint I disagree with, but regardless, proper terminology matters). For more on the difference between shark fishing and shark finning, see this post from June 2012.

2) 100 million sharks a year are killed for their fins. The origin of this number is still debated, but it was popularized by Sharkwater. While we will likely never know exactly how many sharks are “killed for their fins”, the best scientific estimate of the scope of the fin trade we have comes from a 2006 paper by Dr. Shelley Clarke. She found that the fins of between 26 and 73 million sharks end up in the fin trade each year, with a simulation average of 38 million. Dr. Clarke wrote an essay for SeaWeb on the misuse of her work, which is worth a read.

3) 1 in 3 species of sharks face extinction. This one is actually relatively close to accurate, and can be fixed with the addition of just two words. An IUCN Shark Specialist Group report found that 1 in 3 species of “open ocean” sharks are Threatened with extinction (Threatened means Vulnerable, Endangered or Critically Endangered according to IUCN Red List standards). 1 in 6 species of shark, skate, ray, or chimera are Threatened- while still a troubling number indicative of a very bad situation, it’s half as bad as claimed by many advocates. Also, please note that I included skates and rays, which are similarly threatened but often ignored by conservation advocates (with one notable exception from 2012).