Dr. Will White is an assistant professor of marine biology at the University of North Carolina Wilmington. He uses a combination of lab experiments, field studies, and mathematical models to study fish behavior and population dynamics, in particular how fish populations respond to protection in no-take marine reserves.
My adventure with the news media began on a Friday morning in early October, when I received an unexpected email from Melanie Hunter, a senior editor at CNSNews.com. The terse email mentioned my recent grant on sex-changing fishes, and asked why this was “an effective use of taxpayer funds.” She gave me a deadline of 4 pm that day. Now, usually it’s great when reporters want to cover scientific research, but generally once someone starts asking about “taxpayer funds” it’s because they don’t think those funds are being used wisely. What ended up happening with CNS News (“Federal Govt’ Spends $728K to Study Sex-changing Fish”) bore out my suspicions.
I should back up to explain that I do have a federal grant from the National Science Foundation (NSF) to study sex-changing fish. For anyone who has ever applied for an NSF grant, the idea that they are just handing out taxpayer dollars willy-nilly is pretty laughable: the grant selection process is notoriously grueling. For the division of NSF that funds research in marine biology, only 5-10% of proposals are funded. Proposals are reviewed by multiple anonymous peer referees, and then a panel comprised of multiple experts in the field convenes to evaluate the proposals based on the peer reviews and identify the best ones for funding. In fact this was my first successful NSF grant after about five previous proposals were declined.
When Dr. Gavin Naylor and his team started a genetic survey of existing shark and ray species, they didn’t expect the results of their project to make international news. Their recent paper (which, at over 250 pages and complete with more than 100 figures, is nothing short of epic), however, is too striking to ignore. The results indicate that there may be as many as 79 previously unrecognized cryptic species of sharks and rays.
A cryptic species is defined as a group that looks almost exactly like another, and may even live in the same region, but is genetically distinct. We’ve known that cryptic species of sharks and rays exist for some time, such as manta rays and scalloped hammerhead sharks, but 79 is a lot; as of the paper’s publication, only 1,221 species of sharks and rays were recognized.
According to Dr. Naylor,
“Organisms become genetically differentiated over time through the cumulative effects of mutation and recombination mediated via drift and selection. When they differentiate in isolation they eventually become so different from the parental stock from which they were derived that they can no longer produce fertile offspring when crossed with them. Some biologists use the point of reproductive inviability as the point at which new species should be recognized….. For practical purposes we recognize “new species” as being genetically or morphologically distinctive from previously recognized forms.”
The study’s methods, though enormous in scope, were relatively basic. According to Dr. Naylor, the study utilized a technique very familiar to geneticists: “standard DNA extraction, PCR, Sanger sequencing, alignment and analysis of a protein coding mitochondrial gene”. To achieve the goals of understanding both evolutionary relationships of sharks and rays and parasite host specificity ( where certain parasites associated only with one species), Dr. Naylor and his team obtained and analyzed samples from as many species as they could. The numbers are impressive- 56 of 57 known families of elasmobranchs were represented among the 4,283 samples from 305 species of sharks and 269 species of batoids. In other words, this study included approximately half of all known elasmobranch species, including many that had never been analyzed genetically before. Since 1986, when the project began, samples have been obtained in more than 50 countries, mostly through the team’s own field work!
“There are known knowns; there are things we know we know. We also know there are known unknowns, that is to say we know there are some things we do not know. But there are also unknown unknowns – the ones we don’t know we don’t know.” – Former U.S. Secretary of Defense Donald Rumsfeld.
As nature documentary viewers often hear, there is a lot about sharks and rays that scientists don’t know… but what are the most important things that we need to know? A new paper written by Colin Simpfendorfer, Will White, and former Shark Science Monday interview subjects Michelle Heupel and Nick Dulvy attempts to identify these “known unknowns” of shark and ray conservation. “The importance of research and public opinion to conservation management of sharks and rays: a synthesis”, which arose out of the 2010 Sharks International conference, is the most complete record ever created of the research questions that we need to answer in order to better conserve and manage these animals. For young shark researchers eager to work on projects with practical conservation importance, this paper is a great place to start looking for ideas. Additionally, future published work that claims to be important for conservation and management would do well to cite it, and anyone interested in this subject should read it.