2017 was… yeah. Of all the years I’ve lived through, 2017 was definitely one of them. Anyway, some interesting things happened in the world of shark research. Here, in no particular order, are 17 amazing and important things that scientists discovered about sharks and rays over the last year.
1 Sharks can switch between sexual and asexual reproduction. We’ve known that several shark species can reproduce asexually for over a decade now, but this year, Dudgeon and friends showed an individual shark switching between sexual and asexual reproduction for the first time!
Noteworthy media coverage: CNN, National Geographic, Gizmodo
Photo credit: Jessica King, Marine Photobank
The United States Congress is considering a nationwide ban on buying, selling, or trading shark fins. While several of my posts and tweets have briefly discussed my stance on such policies, I’ve never laid out my full argument in one post. Here is why I, as a shark conservation biologist, oppose banning the shark fin trade within the United States. The short answer is that the US represents a tiny percentage of overall consumers of shark fin, but provide some of the most sustainably caught sharks on Earth, as well as important examples of successful management, to the world. This means that banning the US shark fin trade won’t reduce total shark mortality by very much, but will remove an important example of fins coming from a well-managed fishery while also hurting American fishermen who follow the rules. Also, a focus on these policies promotes the incorrect belief that shark fin soup is the only significant threat to sharks, and that addressing the tiny part of that problem locally represents the end of all threats. For the longer answer, read on. And for the case for shark fin bans, please see this guest post from Oceana scientist Mariah Pfleger.
In June of 2014, almost 400 of the world’s top shark researchers gathered in Durban, South Africa for the 2nd Sharks International conference. The four keynote presentations have just been put online.
Beyond Jaws: Rediscovering the “lost sharks” of South Africa
Dave Ebert, Moss Landing Marine Laboratory
Biography:Dave Ebert earned his Masters Degree at Moss Landing Marine Labs and his Ph.D. at Rhodes University, Grahamstown, South Africa. He is currently the Program Director for the Pacific Shark Research Center, a research faculty member at Moss Landing Marine Laboratories, and an honorary research associate for the South African Institute for Aquatic Biodiversity and the California Academy of Sciences Department of Ichthyology. He has been researching chondrichthyans around the world for nearly three decades, focusing his research on the biology, ecology and systematics of this enigmatic fish group. He has authored 13 books, including a popular field guide to the sharks of the world and most recently he revised the Food and Agriculture Organization’s Catalogue of Sharks of the World. He has published over 300 scientific papers and book chapters, and contributed approximately 100 IUCN Shark Specialist Group Red List species assessments. Dave is regional co-Chair of the IUCN Northeast Pacific Regional Shark Specialist Group, Vice Chair for taxonomy, and a member of the American Elasmobranch Society and Oceania Chondrichthyan Society. He has supervised more than 30 graduate students, and enjoys mentoring and helping develop aspiring marine biologists.
In 1999, government officials from all over the world gathered in Rome for a meeting of the United Nations Food and Agricultural Organization’s Committee on Fisheries. The Committee meets every two years, but one of the numerous outputs of this meeting was particularly significant, at least for sharks. Based on years of consultation and discussion by experts, the group agreed on a formal set of general principles that should make up sustainable and well-managed shark fisheries.
These 10 principles, part of a larger International Plan of Action for Sharks (IPOA-Sharks) , have helped shape more than a decade of scientific research and management priorities for the chondrichthyan fishes. When properly implemented and enforced, they allow people to use sharks (and rays and skates and chimeras, included in the IPOA-Sharks definition of “sharks”) as a natural resource while keeping populations healthy and allowing depleted stocks to recover.
According to the IPOA-Sharks, a national shark plan should aim to:
Photo Credit: Jessica King, Marine Photobank
I’ve written in the past about why shark fin bans might not be the best tool for the conservation and management of sharks. Though specific details vary, these so-called “blanket bans” typically make it illegal for anyone to buy, sell, or possess shark fins regardless of the source *. Additionally, to date most of these fin bans have taken place in a few U.S. states and Canadian towns. If the goal of these state-level fin bans is to reduce the supply of fins to the global market, proponents should consider that according to TRAFFIC, more than 95% of the supply of shark products comes from countries outside of the U.S. and Canada. Even if every U.S. state passed a fin ban, it would have a negligible direct impact on global supply. Additionally, the United States has some of the most sustainably managed shark fisheries in the world (hammerhead sharks and a few others are an exception). We want other countries to emulate out management practices, not to remove our management practices from the global marketplace.
If the goal of these local fin bans is to reduce global demand, proponents should consider that the overwhelming majority of the demand for shark fin soup is in China and Southeast Asia, where passing such bans will pose a significant challenge. Some proponents of fin bans say (after the negligible impact on supply and demand is pointed out) that fin bans help with “raising awareness of the problem of overfishing of sharks”. While these fin bans do result in (relatively) positive media coverage for shark conservation, “raising awareness” is not the publicly stated goal of these bans. If your goal is to educate people about a problem, educate people about the problem.
Instead of inflexible and ineffective fin bans that penalize fishermen who have adopted best practices * without impacting the global market, I’ve advocated for a science-based approach to sustainable shark management following the 10 basic principles in line with what has been laid out in the United Nations Fisheries and Aquaculture Organization’s International Plan of Action for Sharks and IUCN Shark Specialist Group guidance. These principles include banning finning of sharks by requiring that carcasses be landed whole (recall that finning is a specific fishing practice not synonymous with the fin trade), using science-based quotas to manage the fisheries of sharks whose populations can support a fishery, and restricting the harvest of species whose populations cannot.
Recently, the United States National Marine Fisheries Service (which, once again, manages some of the most sustainable shark fisheries on Earth) has started to officially speak out against state level fin bans.
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).