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.
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.
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.
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
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.
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).
Despite their small size and plain appearance, menhaden have been called “the most important fish in the sea” because numerous coastal fish species rely on them for food. Although they aren’t typically eaten by humans, there is still a huge fishery for them for bait, aquaculture food, and oil. That fishery has been essentially unregulated, allowing fishermen to take as many as they want. Recently, there’s been a campaign among certain environmental groups to fix this problem and put catch limits in place for menhaden.
I was surprised to see PolitiFact, a non-partisan political fact-checking website, address this issue. I’ve checked PolitiFact pretty regularly for years, and I’ve never seen them cover a topic like this before. They focused on a claim by the Pew Environment Group that “In recent years, menhaden numbers along our coast have plummeted by 90 percent.” While I admit I am not familiar with specific details of menhaden population trends, anyone who has paid any attention at all to the ocean knows that we’re overfishing at alarming rates. According to the UN Food and Agriculture Organization, approximately 1/3 of all global fisheries are depleted or overexploited, many by more than the 90% referenced for menhaden. Shockingly, PolitiFact called the claim by Pew “mostly false”. Their reasoning for this ruling is even more ridiculous than the ruling itself:
Technology in water? That seems a bit counter-intuitive doesn’t it? Well, Dr. Kersey Sturdivant, during his undergraduate and graduate years, denied the golden rule of electronics and submerged a video camera under water. But this is not your typical Canon Powershot D10.
As much as I love thumbing through magazines and flipping page after page of vibrant underwater pictures of colorful flora and fauna, WormCam skips the excess and gets right to the bottom. Literally.
The video camera, modified from your average security camera, is set at certain time intervals and takes still pictures, as opposed to recording a video, for technical reasons. WormCam unveils the under-sediment realm. The images are not of mystical jellyfish and elegant fish nor the teeming micro and macro-zooplankton; rather the camera captures worms, crabs, snails and all things benthic.
WormCam, a dense yet delicate technology, is encased within a waterproof, blade-shaped prism, which is attached to the side of a larger platform. The lead battery, also in a waterproof case, sits on top of the rectangular prism. Linking the two components together with a waterproof wire, WormCam is complete and ready to be deployed.
Back view of deployed WormCam. Photo by Lucy Ma
Depending on the depth of the water, WormCam can either be deployed by hand in shallow waters or by rope in deeper waters. When held horizontally, the prism, where the camera is housed, protrudes below the bottom of the platform. Strategically designed, WormCam inserts itself within the sediment like a spoon sinking into yogurt. The camera is then peeking halfway beneath and halfway above the sediment. Through the clear, plexi-glass window, the camera snaps images of the water-sediment interface.
Now, Dr. Sturdivant, other scientists and aspiring undergraduates can observe the happenings at the sediment-water interface for extended periods of time. You can too! Watch a movie from a WormCam deployed in the York River (if you look closely, the grooves in the sediments are worms wiggling around!).
But the seafloor is stereotypically dark and unattractive. Why is this important and why should we care?
Having the ability to observe sediment changes and sediment-organism interactions over time offers marine scientists an enormous advantage. For example, during eutrophication, the phytoplankton bloom is incredibly obvious, thanks to the single-celled organisms’ conspicuous chlorophyll. Studies have confirmed that fish and other organisms die because of the lack of oxygen, but what about the worms and other sea-dwelling creatures that live beneath our scope of vision? WormCam widens this limited scope. With WormCam, scientists can then begin to understand these silent creatures and their roles in the aquatic ecosystem. Bioturbation in a Declining Oxygen Environment, in situ Observations from WormCam offers more technical information on the application of WormCam.
Thus far, WormCam has been deployed off of the Chesapeake Bay, Gulf of Mexico and Pivers Island. Each location has offered a benthic perspective on what is happening on and beneath the seafloor in the least intrusive way as possible. For example, the deployed WormCam off of the Gulf of Mexico has facilitated scientists’ understanding of the effects of Deepwater Horizon oil spill on sediment and benthic organisms.
Currently, Dr. Sturdivant and I, one of the aspiring undergraduates, have deployed a WormCam off of Pivers Island. We want to understand how chemical cues from gastropods affect crustacean behavior as well as how the attracted crustaceans impact other species residing in the sediment. Some very interesting observations have been made, but there is more to come. It’s a good thing that WormCam has its very own twitter page. Follow @wormcam.
Lucy Ma is an undergraduate who participated in a blog writing workshop led by Andrew Thaler. She works with Dr. Sturdivant on WormCam.
Dr. Kara Yopak, an elasmobranch nervous system expert who served as the editor of this special issue, explains why increased knowledge about the brain function of one of the most basal groups of vertebrates is fascinating and important:
“Although is a common misconception that sharks are small-brained and operating from a limited set of behaviors, they actually have relative brain sizes that are comparable to birds and mammals, a battery of highly developed sensory systems, and an extremely sophisticated suite of complex behavioral and social repertoires. Research in this area allows us to combat these preconceived notions about the shark brain and develop a better understanding of how the shark nervous system has evolved, how these animals receive and process information from their environment, and the implications these variations have for evolutionary adaptations in the brain across all vertebrates, including humans.”
The research featured in the special edition includes methods as diverse as histology, MRI, electrophysiology, and behavioral ecology. The implications of this research are vast, including the potential for species-specific bycatch reduction in fisheries which accidentally catch sharks, the development of more effective shark repellents, and an increased understanding of the evolution of the vertebrate brain. I encourage any scientists or shark enthusiasts interested in fisheries, evolution, or neuroscience to check it out.