Archive for the ‘California’ tag
More Gills or Eyes? The Purported Increase of Sevengill Shark Populations off the Coast of San Diego
Emerging technologies have a profound effect on how citizen scientists conduct their work. An underwater creature of ancient lineage helps to tell this modern story of technology’s importance to citizen science. Notorynchus cepedianus, the sevengill shark, of the ancient Hexanchidae family (cow sharks), features seven gill slits and a single dorsal fin, giving a prehistoric visage to this predator. Despite its uncanny appearance, this shark is one that has demonstrated little aggression toward humans, with fewer than five wild attacks accounted for since the 16th century.
In fact, divers have been increasingly encountering these creatures off the coast of San Diego. Harmless as these encounters are, they are spectacular and haunting, as Michael Bear, founder of the Sevengill Shark Tracking Project, would tell you. In the summer of 2009 he experienced the sevengill himself, after hearing rumors of its increased presence in the San Diego coastal area, when a giant seven-foot long (2.1 meters) sevengill glided between him and a dive-buddy. Describing that moment, Bear says that, “it is a humbling experience being in the presence of one of these large, apex predators––they have a grace and a majesty about them that is unforgettable.” But are these encounters an indicator of increasing sevengill populations or a product of increased numbers of divers––or perhaps divers with attentive eyes?
For many years few sightings were reported, but more anecdotal reports began to trickle in, and, Bear tells us, the “period that we really began hearing a significant increase in reports was 2009-2010.” Bear wanted to know more (and for good reason). The sevengill is a high-order or apex marine predator and therefore may be important to ecological structure, interactions, and ecosystem management (Williams et al., 2011 and 2012). In 2010 Bear’s project began to take shape.
The Sevengill Shark Tracking Project is a citizen science effort to collect baseline population data on the sevengill. Though it started out small, the project has grown, partnering with the Shark Observation Network. Now a single global database aggregates data on sightings to help determine baseline population information. Though a study of this kind can take many years, Bear’s project already has important insights for citizen science projects, especially in the use of new technologies.
Bear has developed the Sevengill Shark Tracking project’s smartphone app, called “Shark Observers.” It’s available for Android devices and allows divers to log sightings once they’ve surfaced and, presumably, dried off. While this particularly benefits sevengill tracking, the application actually allows users to submit logs for any kind of shark encounter to the Shark Observation Network database. This application can be downloaded through Google Play.
In addition to the app and database cataloguing the date, time, water temperature, and sightings––with separate databases for photographic and video recordings—the project has also started to use pattern recognition technology to identify individual sharks. This is an inexpensive alternative to costly and labor-intensive shark tagging.
With the I3S pattern recognition algorithm, which is also used for mapping star patterns on Whale Sharks, the sevengill project uses collected high definition photos to track individual sharks by their “freckling” pattern. Using the algorithm, Bear is able to identify the unique patterning on individual sevengill sharks. Eight individuals have been identified and tracked using this method, allowing Bear and other researchers to track the return of these sharks each year. What is crucial for this approach, Bear tells us, “is to have high resolution photographs where the freckling pattern is visible.” While crucial, this technological demand is not a significant barrier for most of the diver-citizen scientists, says Bear, since “most divers these days are using hi def cameras anyway.”
Since the motivation for Bear’s project was to determine baseline populations, knowing more about the number of sharks that are present and returning to the area becomes crucial. Tracking individuals helps to sort out the matter of whether the population of sharks or the population of divers (and therefore reported sightings) is increasing. Securing more data is essential to draw reasonable conclusions about these populations and so the Sevengill Shark Sightings project continues to collect sightings, including those with video and photographic data, submitted by divers in the San Diego area. Specifically, Bear’s project is interested in the population data over a 5- to 10-year period, asking whether the population density appears to stay relatively static or if there are notable changes.
In addition to these research interests, science education is built into this citizen science model. Bear hopes to train local divers in identification techniques for the sevengill shark. The Sevengill Shark Sighting project provides an interesting example of how technology can help citizen scientist organize anecdotal data into important scientific datasets.
Ashley Rose Kelly is a Ph.D. candidate in the Communication, Rhetoric, & Digital Media program at North Carolina State University. Ashley studies how emerging technologies may be changing science communication. She also teaches scientific and technical writing courses as well as an introductory course on science, technology, and society. You can find Ashley on Twitter as: @ashleyrkelly”
(1) Michael Bear is Science Diving Editor for California Diver Magazine and Contributor to Marine Science Today. He lives and works in San Diego, California.
Williams, GD, Andrews, KS, Farrer, DA, Bargmann, GG, and Levin, PS. (2011). Occurrence and biological characteristics of broadnose sevengill sharks (Notorynchus cepedianus) in Pacific Northwest coastal estuaries. Environmental Biology of Fishes 91: 379–388. doi: 10.1007/s10641-011-9797-z.
Williams GD, Andrews KS, Katz SL, Moser ML, Tolimieri N, Farrer DA, Levin PS. (2012).
Scale and pattern of broadnose sevengill shark Notorynchus cepedianus movement in
estuarine embayments. Journal of Fish Biology 80(5): 1380–1400. doi:
Photo: Michael Bear; photo credit Kelli Shaw, 2011.
Remember those old diagrams in your grade school science text books? I used to flip through each chapter trying to find the coolest images, but was continually disappointed when I was forced to squint at tiny illustrations. As I continued through school, however, I found myself drawn to large illustrations that conveyed information effectively and in plain language. I read The Way Things Work every night before bed. The blend of science, art, design, and communication, was intriguing, and I suppose part of why I entered the field of GIS and mapping.
From subway maps to government information pamphlets and all across digital and print media, illustrations are an engaging way to convey information.
NASA’s Jet Propulsion Laboratory (JPL) agrees, and their new citizen science project, JPL Infographics, calls on you to be the scientist-artist in charge of communicating their cutting edge science. NASA provides a huge library of amazing high-resolution space images, 3-D models, and lists of interesting facts for you to piece together into your very own Infographic. You can browse other user submissions for inspiration and then upload your finished image easily online.
Head to the JPL Infographics project to learn more. It is free to join, and registration is easy! This is a really fun and challenging project, and your work will be used to educate and inform others about cutting-edge space exploration.
Fire up both sides of your brain and create some educational space art!
Photo: NASA JPL
For those of you who watched “Raiders of the Lost Ark” and wondered how you could go searching for ancient artifacts yourself, here is your chance to get in on some archaeology action. The Calico Early Man Site, located near Yermo, California, is starting its fall digging season this weekend (October 2 and 3) and they welcome volunteers to help with their unearthing efforts.
JK Mueller, the organizer of the dig, let us know what first-timers should expect. When you first arrive, she says, you’ll see on the ground “chips and artifacts scattered everywhere, mostly made of chalcedony, an orange glass-like material.” She assured us that diggers will learn on the job “how to sift for artifacts and how to distinguish an artifact (human made) from a geofact (nature made).”
Saturday night lectures cover a wide range of related topics, from geology, gemology, and tool manufacture to climate. Volunteer effort is central to keeping the site running, and helpers have made many significant finds. Just last season, says Mueller, “The Friends of Calico president found two projectile points in the piles of mined bentonite clay right outside the main building. One still had animal hair and leather string attached [and was] dated at 1500AD.”
This archeological site has delivered interesting finds—and scientific controversy—since digging began there in the 1940s. From the mid-1960s until his death in 1972, Dr. Louis S.B. Leakey, famous for his research in evolutionary anthropology, directed the excavation. Of particular debate are rocks found at the Calico site that look much like prehistoric tools, and that are thought to be around 200,000 years old. While the tool-like rocks may appear to have been made by people, other scientists have argued that they could have acquired their shape through typical geological processes. If these rocks are indeed human made—that is, artifacts—rather than a result of geologic pressures—geofacts—the finding could push back the traditionally accepted date of human entry into the Americas (about 11,000 years ago) nearly 20-fold.
To see for yourself, and to learn more about the science behind the dig, head down to southern California. There is no cost to volunteer, but if you wish, you may join the Friends of Calico, a non-profit organization that helps finance ongoing scientific projects. It’s also helpful, notes Mueller, to bring “gloves, scarves, jacket, hiking boots to travel the last few feet of rough ground, [as well as] magnifying glasses and knee pads.”
And be prepared to make friends. Mueller says, “Volunteers are loquacious, energetic, and personable, and love to talk about varied topics and to learn at all ages. New volunteers almost always feel right at home.”
To join the dig or find out more information, sign up here.