Some SCUBA diving operators use bait or chum to attract sharks so that their customers can get an up close and personal encounter. A new bill that would make this practice illegal in all U.S. waters has just been introduced into Congress. Section 3 of S. 3099, the “Access for Sportfishing Act of 2016,” contains the following provision:
Photo by Zoe Gillam
Sammy Andrzejaczek grew up ocean obsessed in Western Australia and knew from an early age she wanted to be a marine biologist. She completed her Bachelor of Science Degree in Queensland and developed a fascination with all things shark. Her Honours thesis on whale sharks fed that fascination and she has now moved onto a PhD where she is looking at the vertical movements of sharks and other pelagic predatory fishes. She hopes her project on tiger sharks will become the cornerstone of her thesis and enable her to compare findings with other species of shark around the world. In her (limited) spare time she can be found outside – surfing, diving, camping and hiking. She also loves martial arts and is a black belt in Zen Do Kai.
We live in the age of computers and information. While technology advances, the devices we use are getting smaller and more compact, and we are able to carry a world of information in our pockets. The same can be said for animal-borne tagging devices. Tags no longer just record where an animal is going; rather they are capable of telling us how an animal is moving, measure the physical environment that the animal passes through and record the physiological state of the animal as it undergoes movement. Some tags even have embedded video cameras that effectively carry us along for the ride as animals go about their daily behaviours. These advances in tagging technology offer a huge potential for researchers to gain an understanding of drivers behind movement patterns, i.e. not just where an animal goes, but how it moves and why it moves to get to a particular destination. For sharks – my study species – most movement research to date has largely focused on horizontal scales i.e. movements across ocean basins or along coastlines. However, marine animals live in a three dimensional environment, moving up and down through the water column as well as across it. It is fair to say that unless we understand how and why animals move in these three dimensions, then we have little chance of getting a real insight into their ecology.
Mareike Dornhege is currently finishing up her PhD on shark fisheries in Japan. She is based in Tokyo at Sophia University and after seeing no sharks many times were there should be sharks on reefs all around the world she wanted to dig deeper and find out when we lost them, why and where. She is trying to reconstruct baselines by looking at the history of sharks and humans, talking to old fishermen and of course modern data as well. And she really loves going on that shark-feeding dive about 90 minutes south of Tokyo!
The latest shark thriller The Shallows just hit theaters—coincidentally with Shark Week around the corner – and is latest in a long line of shark thrillers. In the grand, yet predictable fashion of movies like Deep Blue Sea, The Reef or Open Water, it fuels our fear of the sleek ocean predators that was first awakened by the mother of all shark movies, Jaws, in 1975. Or, was it? It is only since the Jaws theme that got stuck in our heads, even if we are just paddling around in a swimming pool at dusk, and images of dangling legs under water, that we got so irrationally scared and obsessed with the well-designed teeth of these fish after all, right?
Actually no. During my research on the history of shark and men I came across some hair-raising anecdotes of monster sharks from the Caribbean and man-hunting mantas that are just a bit older. A few centuries that is. This fishermen’s yarn must be the pre-digital equivalent of this youtube video of a megalodon shark caught on tape, real mermaids, and dragon footage. Let’s look at what they say and then at what the real science behind these stories is.
A member of the American Society of Ichthyologists and Herpetologists (ASIH) and the American Elasmobranch Society (AES), Joshua Moyer is an ichthyologist specializing in the evolution, biodiversity, and morphology of sharks and their relatives. Joshua has co-authored multiple scientific articles about shark teeth and routinely lectures in courses on marine biology, vertebrate biology, and evolution. He earned his Masters of Science in Ecology and Evolutionary Biology at Cornell University and is an instructor in the massively open online course (MOOC) in shark biology offered by Cornell and the University of Queensland through edX.org. Follow him on twitter!
What is a shark without its teeth? For that matter, what is any animal without the ability to process and ingest its food? So important are teeth to the way many jawed vertebrates survive, that you can tell a great deal about an animal just by looking at its teeth, or in some cases, lack thereof. Sharks are no different. By asking a series of questions, you can look at shark teeth and begin to piece together a more complete picture of the shark whose teeth you’re studying.
Manuel Dureuil is a Ph.D. candidate whose research focuses on the conservation ecology of sharks. He did both, his Bachelor and Master thesis, in the field of shark conservation at the University of Marburg and Kiel in Germany. His main interest are spatial ecology and data-limited assessment approaches to form a scientific basis for a more comprehensive protection of sharks. A species with particular focus of his research is the Atlantic weasel shark, which is only found in West Africa. Sharks in this area are among the least researched yet most threatened by illegal and unregulated fishing. The weasel shark fulfills all criteria to be considered data-limited: there is no population assessment, no information on its spatial ecology and almost no information on its biology. Manuel is raising funds till the 9th of July as part of The Experiment’s Sharks Grant Challenge, to start a weasel shark project in Cabo Verde, West Africa. Using the weasel shark as an umbrella species the researchers also hope to create awareness for sharks in this region in general, on a national and international level.
The remote island nation of Cabo Verde holds one of the last remaining hotspots for sharks in the entire North Atlantic Ocean and therefore could offer some degree of protection from the ongoing decline in shark populations. This is particularly important for locally endemic species which only occur in this area, such as the Atlantic weasel shark. We know almost nothing about this species and accordingly it is listed as ‘data deficient’ on the IUCN Red List. However, the little we know suggest that this shark is vulnerable to overfishing, making the protection of important habitats (such as nursery grounds) crucial for healthy populations and preventing extinction.
David Ebert has been researching sharks and their relatives (the rays, skates, and ghost sharks) around the world for more than three decades focusing his research on the biology, ecology and systematics of this enigmatic fish group. His current research efforts are focused on finding, documenting, and bring awareness to the world’s “lost sharks”. If you would like to learn more please see our crowd funding project “Looking for Lost Sharks: An Exploration of Discovery through the Western Indian Ocean” and consider making a donation. The more we raise, the more sharks we can name and the more schools we will be able to reach.
Jaws, the mere mention of the movie conjures up images of a large triangular fin cutting through the water, beneath it a large fearsome-looking toothy shark swimming with a sense of authority, a purpose. One of the movie’s trailers at the time hyped the fact that this was a mindless eating machine!
I recall seeing the movie Jaws in the theater for the first time during my high school days in the summer of 1975. It was the first big summer blockbuster film, it was something new to audiences, and certainly new to me. Prior to the film’s release people generally did not anticipate such great summertime entertainment from movies like Jaws and subsequently Star Wars (released in 1977). These were fun movies to see with your friends and spend an afternoon or evening afterwards talking about certain scenes or dialog from the movie, “You’re gonna need a bigger boat”; remember this was back in the pre-iPhone, Facebook, Twitter, social media era when kids actually spent time together talking with each other, without the aid of electronic devices and no texting!
The movie as an ancillary and an unintended consequence brought a lot of attention to sharks, both good and not so good. Shark attacks that were of minimal media attention became big news stories, catching big sharks became a sport and shark diving became popular; all of this after the movie’s release. A few high profile shark attacks, one in particular in Monterey that made international news, only further fueled the public’s fascination and fear of sharks. Just going into the water suddenly became an adventure, with the prospects (however unlikely) that one may see a shark. It certainly put the public’s awareness of sharks in their conscience.
Dr. Glenn R. Parsons is a 30 year veteran in the battle against University Administrators, bean-counting bureaucrats, and disinterested students (i.e. he is a Professor at Ole Miss). In his spare time he conducts research work on fish physiology and ecology and has published many papers on shark biology, primarily Gulf of Mexico species. He is author of the seminal book on sharks of the Gulf of Mexico entitled “Sharks, Skates and Rays of the Gulf of Mexico” and a popular novel entitled “Cherokee Summer” that could have been on the New York Times best seller list (if only it was better written and was backed by a high-powered agent like John Grisham’s). He received his PhD from the University of South Florida, School of Marine Science, MS from the University of South Alabama and BS from the University of Alabama. He was a DISL Marine Research Fellow, a Gulf Research Council Research Fellow, and a winner of a World Wildlife Fund, Smartgear Competition (for his bycatch research).
Folks, The world has witnessed an unparalleled decline in sharks that began about 30 years ago and has continued to the present. While the explanations for this decline are varied, scientists are in agreement that “bycatch” during fishing is one of the problems. Bycatch is the un-intended capture of non-target species during fishing. For example, commercial fishing for tuna and swordfish results in the capture of many sharks. The World Wildlife Fund estimates that 50,000,000 sharks are taken as bycatch during commercial fishing. Unfortunately, many of these sharks do not survive the stress of capture (a topic that my lab has researched for many years). Fishers do not want these sharks (they are dangerous to handle and they damage fishing gear) and they would welcome new developments that would reduce or eliminate shark capture.
Julia Wester is the Director of Program Development for Field School. She received her PhD from the Abess Center for Ecosystem Science and Policy at the University of Miami in 2016. Her dissertation studied the psychology of decision making about the environment, specifically with regard to limited water resources. She also received a Msc with Distinction in Biodiversity Conservation and Management from Oxford University and worked as a Legislative Aide in South Florida, focusing on environmental policy. She has consulted with nonprofit programs to evaluate their educational programs and assisted with training staff to conduct effective public outreach.
The folks at Southern Fried Science, as part of their commitment to research and education, have generously given us this platform to talk about our educational start-up, Field School. (Thanks, SFS!). They’ve also been kind enough to get excited about working with us to develop and test new research techniques, study awesome animals and ecosystems, and improve marine science field education—so stay tuned for some of those upcoming collaborations!
What is field school?
Field School is a hybrid company on a mission to support field research in marine and environmental science, and create high-quality educational and training opportunities for students and the public. We offer hands-on, research focused courses on a variety of topics, from corals to sharks, on our 55’ custom live-aboard research vessel.
Field School offers researchers and students opportunities to engage with and study tropical marine ecosystems. Photo credit: Kristine Stump
Part of what makes Field School special is the team we’ve brought together. Our captain and crew all have doctoral and/or masters degrees in marine or environmental science, have authored numerous scientific publications, and have a combined 25 years of experience in field education and outreach. We have developed short- and long-term training and mentoring opportunities for students, teach highly reviewed and award-winning university courses, and work with partner non-profits to create outreach programs for the public. We collaborate closely with our scientific advisory board and partner universities to develop the conservation and research projects our students work on, ensuring their time in our courses is professionally relevant and meaningful.
Once again, the internet is in a fervour over a rarely documented, but pretty common, animal interaction. The video below shows fishermen at a pier in L’Escala, Spain tossing small fish to a tuna. A nearby seagull went for the same fish and was ingested by the tuna, much to everyone’s surprise. Naturally, the tuna spat out the seagull, luckily uninjured, and it flew away to dive another day:
Seabirds are often ingested by marine megafauna since both groups forage in the same areas, often on the exact same prey. This video was an artificial overlap of foraging animals created by the people tossing fish from the pier, but in natural settings where two animals feed on the same prey and one of those animals is considerably larger than the other, the smaller animal faces a pretty high risk of being swallowed.
This is especially true for lunge-feeding whales that take in large mouthfuls of fish, water, and anything else at the surface. Haynes et al. identified three Glaucous-winged gulls in the fecal remains of foraging humpback whales in Glacier Bay, Alaska. The birds were mostly intact, suggesting that humpback whales aren’t capable of digesting birds well (we’ve all been there).
All of the examples above are accidental ingestion, but some marine animals deliberately target birds for food, too. Tiger sharks seasonally aggregate at the Hawaiian Islands of French Frigate Shoals to forage on albatross fledglings. Fledglings are fat, slow, and naïve, making them easy and profitable prey. This foraging strategy is common among sharks and is the same reason white sharks target seal colonies during South African winters.
The alien giant catfish of the river Tarn in southwestern France is an aquatic example. They have also acquired a taste for feathered food and learned to ambush aloof pigeons, with a success rate of 28%:
Although not mega- megafauna, the Hilaire’s Side-necked turtles of Brazil have been documented consuming pigeons in a scene that honestly rivals Jaws. Who’s slow now? (Edit: Thanks to @mattkeevil for the reference!)
Marine and aquatic animals do indeed eat birds, accidentally and deliberately. Exactly how regularly this happens is unknown, but this antipodean pairing is essentially the chocolate shake and fries of the natural world. The bottom line is, if you are in the same space where something bigger than you is foraging, you might get swallowed. Birds, and humans, alike:
William E Bemis is Professor of Ecology and Evolutionary Biology at Cornell and lead faculty member for the edX MOOC Sharks! Global Biodiversity, Biology, and Conservation. He studied at Cornell University, the University of Michigan, the University of California Berkeley, and the University of Chicago before serving 20 years as Professor of Biology at the University of Massachusetts Amherst. From 2005 to 2013, he served as Kingsbury Director of Shoals Marine Laboratory at Cornell. Bemis conducts research in comparative vertebrate anatomy, trains research students, and teaches courses in vertebrate anatomy and evolution.
How do you get thousands of people interested in basic biological concepts? By teaching a course on some of the most fascinating animals on Earth – sharks and their relatives.
This is a particularly exciting time to be a shark scientist. An explosion of new research methods and technologies are leading to a surprising world of discovery. Our new course, free and open to anyone in the world, explores discoveries in many areas, including: