Erin Dillon is a PhD student at UC Santa Barbara studying how shark communities on coral reefs have changed over time. She graduated from Stanford University in 2014 with a B.S. in Biology and Honors in Marine Biology. Erin spent the following two years working with Dr. Aaron O’Dea as a fellow at the Smithsonian Tropical Research Institute in Panama, where she started exploring dermal denticles preserved in sediments as a paleoecological tool to reconstruct shark communities. She aims to develop this technique further as part of her dissertation to establish quantitative shark baselines and investigate spatial and temporal variation in shark assemblages on reefs. To do so, she has now set her sights on Curaçao, which is located in the southern Caribbean. There, she will work on validating the tool, explore differences in denticle assemblages between reef habitats, and provide estimates of relative shark abundance in data-limited parts of the island. Sharks are notoriously difficult to census, and it can be difficult to protect something that we rarely see. Therefore, the information provided by denticle assemblages extracted from reef sediments has critical implications for shark conservation, both in the Caribbean and worldwide. Erin is raising funds until September 22nd as part of Experiment’s Coral Reef Grant Challenge to unravel a pre-historical baseline of Caribbean sharks.
Sharks are important players on coral reefs. However, understanding the temporal and spatial dynamics of shark communities and how they are affected by human activities is challenging. Surveys and fisheries catch statistics reveal that shark populations worldwide have suffered significant declines over the past several decades due to overfishing and habitat degradation. But how many sharks should there be in a healthy coral reef ecosystem? The answer to this question is locked in the past. To address this issue, we turn to the recent fossil record to uncover clues about the sharks that used to roam the reefs of lore and paint a picture of how their communities have changed over time.
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.
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.
Matt Kolmann is a PhD candidate whose research program is at the interface of evolution, comparative anatomy, and biomechanics. He completed his Master’s degree at Florida State University with Dr. Dean Grubbs on the feeding biomechanics and fisheries ecology of cownose rays, a purported pest on commercial shellfish. During this process he developed a love of field work, and since then has collected rays and other fishes on expeditions across South and Central America with the Royal Ontario Museum. His PhD research investigates the evolution of biodiversity using South American freshwater stingrays as a model system. The number of different feeding niches these stingrays occupy is astounding, and Matt is using gene-sequencing, comparative phylogenetic methods, and biomechanical modeling to characterize the evolutionary processes underlying this biodiversity. From June 8th through the end of Shark Week, he will be raising funds to delve more deeply into the evolution of feeding behavior in freshwater rays – specifically investigating whether freshwater rays ‘chew’ tough prey like insects in a manner comparable to mammals. Follow him on twitter!
What role does our food have in explaining where we live, what we look like, and how we behave? I study how properties of prey – material, structural, and ecological – shape the evolution of predators. Specifically, I am interested in how animals adapt to novel foods and diets that pose unique challenges: prey that are tough, stiff, hard, or just generally robust. I approach these questions at the macroevolutionary (how species are related) level; biodiversity lends insight into engineering and synthetic design based on an understanding of how animals evolve using similar organic principles.