5 things to know about sixgill shark teeth, this month’s 3D printed reward!

I recently unveiled a new tier of Patreon rewards: 3D printed shark and ray models!For $17 per month, you will get a monthly 3D printed educational model of different shark or ray parts in the mail, and you’ll be supporting my efforts to provide these models to schools for free.

This month’s reward is a tooth from Hexanchus griseus, the bluntnose sixgill shark, a member of the cowshark family!This particular specimen was scanned by Dr. Lisa Whitenack as part of her Ph.D. dissertation work on comparative evolution and biomechanics of shark teeth.

Figure from Whitenack et al. 2011, the sixgill tooth is the one in the lower right! This paper studied teeth of different shapes using Finite Element Analysis (FEA). When Lisa inputs the shape of the tooth, how elastic the tooth is, and how much force the tooth experiences into her computer program, FEA will map out stress on the entire tooth. High points of stress are where a tooth would be likely to break.

Learn more about the bluntnose sixgill shark and it’s unusual shaped teeth below!

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I asked 15 ocean plastic pollution experts about the Ocean Cleanup project, and they have concerns

The online ocean science community has been vocally skeptical about the Ocean Cleanup, a device that aims to physically remove plastic pollution from the ocean. Drs. Kim Martini and Miriam Goldstein published a technical review of its feasibility over at Deep Sea News, and Andrew asked some important questions that have yet to be answered. Also, be sure to read environmental journalist Chris Clarke’s thorough overview of these concerns.

Overall concerns include a lack of understanding of the problem (including but not limited to the fact that much of the harmful ocean plastic is small and well-dispersed), insufficient structural integrity for a large object that will be deployed in the open ocean (which would result in the object breaking and creating even more ocean garbage), and the fact that this device is designed to aggregate objects of a certain size to remove them from the water but cannot distinguish between plastic and living things.

Mainstream media coverage has been noticeably less critical of the Ocean Cleanup, often presenting the idea as revolutionary and it’s creator as a genius.

Artist’s conception of the Ocean Cleanup, from TheOceanCleanup.com

I am not an expert in ocean plastic pollution. However, the uncritical tone of most mainstream media coverage of the Ocean Cleanup does not seem to correspond with my impression of expert opinion on this matter from speaking with expert colleagues who study this.

Through professional contacts, I developed a list of 51 ocean plastic pollution experts who work in academia, government, and the environmental non-profit sector, and I sent them some questions about the Ocean Cleanup. 15 (4 in academia, 5 each in government and the non-profit sector, and 1 in industry) agreed to participate in an anonymous survey. While this is not (and not intended to be) an exhaustive survey of the entire field of ocean plastic pollution, the broad agreement among a diverse group of experts is telling. Below, please see what they had to say through some representative quotes. Some respondents chose to provide an on-the-record quote, while many chose to remain anonymous out of concerns about reprisal.

I also asked Lonneke Holierhoek, COO of the Ocean Cleanup, to respond to these concerns. Her comments are included in each section.

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5 things to know about stingray barbs, this month’s 3D printed reward!

I recently unveiled a new tier of Patreon rewards: 3D printed shark and ray models!For $17 per month, you will get a monthly 3D printed educational model of different shark or ray parts in the mail, and you’ll be supporting my efforts to provide these models to schools for free.

This month’s reward is the barb from a Pacific Cownose RayRhinoptera steindachneri. This particular specimen is a part of the Texas A&M University Biodiversity Research and Teaching Collection, and was scanned as part of the #ScanAllFishes project! 

I reached out to Heather Prestidge and Kevin Conway, curators of the Texas A&M collection. They told me that this particular specimen was collected in 1993 by John McEachran (author of the multi-volume “fishes of the Gulf of Mexico“) and Janine Caira (now a parasitologist at UConn). It was collected in Baja California, Mexico. Heather was pleased to learn that I was using their specimen for this project, and said “our specimens have an unlimited number of uses even after their primary project!”

Here’s a picture of another specimen of the same species from this collection, you can see why they’re sometimes called “Golden Cownose Rays”.

Photo courtesy Christian Jones, NOAA

Here’s a CT scan focusing on the barb, from the Virtual Natural History Museum.

Learn more about the Pacific cownose ray and the science behind stingray barbs below!

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Obama’s ocean monuments, deep diving seals, and sustainable US fisheries: Thursday Afternoon Dredging, May 24th, 2018

Cuttings (short and sweet): 

Spoils (long reads and deep dives):

Please add your own cuttings and spoils in the comments!

If you appreciate my shark research and conservation outreach, please consider supporting me on Patreon! Any amount is appreciated, and supporters get exclusive rewards!

Plastic Free Fish, Chainsaw Lobsters, and Artificial Horseshoe Crab Blood: Thursday Afternoon Dredging, May 17th 2018

Cuttings (short and sweet): 

Spoils (long reads and deep dives):

Please add your own cuttings and spoils in the comments!

If you appreciate my shark research and conservation outreach, please consider supporting me on Patreon! Any amount is appreciated, and supporters get exclusive rewards!

Seafaring neanderthals and switchblade fish: A mega Thursday Afternoon Dredging, May 10th, 2018


After two weeks off, we’re back and bigger than ever!

Cuttings (short and sweet): 

Spoils (long reads and deep dives):

Please add your own cuttings and spoils in the comments!

If you appreciate my shark research and conservation outreach, please consider supporting me on Patreon! Any amount is appreciated, and supporters get exclusive rewards!

Ocean apps and beluga migrations: Thursday Afternoon Dredging, April 19th, 2018

Cuttings (short and sweet): 

Spoils (long reads and deep dives):

Please add your own cuttings and spoils in the comments!

If you appreciate my shark research and conservation outreach, please consider supporting me on Patreon! Any amount is appreciated, and supporters get exclusive rewards!

This month’s 3D printed reward is a horn shark and horn shark egg case!

I recently unveiled a new tier of Patreon rewards: 3D printed shark and ray models! For $17 per month, you will get a monthly 3D printed educational model of different shark or ray parts in the mail, and you’ll be supporting my efforts to provide these models to schools for free.

This month’s reward is a model of a horn shark (Heterodontus francisci) and a horn shark egg case!

It comes from Alex Warneke, the Science Education Coordinator of Cabrillo National Monument! “”Using 3D printing technology has not only changed the way we educate the public, but it has broadened our perspective on what is possible in National Parks,” Alex told me. “We have been able to connect students to nature from an entirely different angle and provide them the tools and context they will need to succeed as scientists of the next generation.” This individual horn shark comes from the ichthyology collection at Cabrillo, and has been used for public education as well as research. The egg case is one of many that wash up on California beaches.

The original horn shark specimen and the 3D model of it, courtesy Alex Warneke, Cabrillo National Monument

Learn more about horn sharks and their egg cases below!

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An open letter to the Florida Fish and Wildlife Conservation Commission on revising land-based recreational shark fishing regulations

Note: The Florida Fish and Wildlife Conservation Commission (FWC) is holding a public meeting on April 25th which will include the issue of land-based recreational shark fishing. Part of my dissertation research focused on this topic, so I am submitting expert testimony, but since I no longer live in Florida I am submitting it remotely. I am sharing my testimony here. Anyone else who is interested in attending the meeting in person (Fort Lauderdale Marriott on April 25th), or submitting testimony remotely, is free to quote my talking points below if the appropriate references are cited. 

Dear Chair Rivard, Vice Chair Spottswood, Commissioner Kellam, Commissioner Lester, Commissioner Nicklaus, Commissioner Rood, and Commissioner Sole of the Florida Fish and Wildlife Conservation Commission (FWC),

My name is Dr. David Shiffman, and I studied land-based shark fishing in Florida as part of my Ph.D. dissertation at the University of Miami’s Abess Center for Ecosystem Science and Policy. This research was published in the peer-reviewed scientific journal Fisheries Research (here’s a link to an open access copy) and covered in major media outlets including National Geographic, Nature, and the Miami Herald. Accordingly, I would like to provide expert testimony for your April 25th public hearing on this topic. Since I no longer reside in Florida I am submitting this testimony remotely. As a conservation biologist who spent years studying harmful practices among some elements of the land-based Florida shark fishing community, I am grateful to see FWC holding a public meeting that includes this important issue, and I am grateful for the opportunity to contribute.

Overall, the scientific evidence is clear and overwhelming that while many anglers are rule-following and conservation-minded, many common land-based shark fishing practices represent a significant conservation threat to threatened, protected shark species in Florida. Additionally, the evidence is clear and overwhelming that in many cases anglers are breaking existing laws and regulations, and that in some of those cases the anglers are aware that they are breaking the law and are explicitly stating that they don’t care. Finally, the evidence is clear and overwhelming that many of the arguments put forward by land-based anglers in support of the status quo are not argued in good faith, and are intentionally crafted to misrepresent the facts of the situation.

It is obvious to me, and to many expert colleagues with whom I have discussed this issue, that the FWC can and must do more to protect threatened sharks, building off of early successes that made Florida a leader in shark conservation. Specifically, the FWC can and must do more to regulate these harmful practices, enforce clear violations of existing regulations, and educate anglers about these issues. Below I will elaborate on each of these points and propose specific regulatory, enforcement, and public education changes that can be made to protect sharks without significantly infringing on anyone’s rights. I will also counter several common arguments that are put forth by bad actors in the recreational angling community.

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Sea monsters and saving kelp: Thursday Afternoon Dredging, April 12, 2018

Cuttings (short and sweet): 

Spoils (long reads and deep dives):

Please add your own cuttings and spoils in the comments!

If you appreciate my shark research and conservation outreach, please consider supporting me on Patreon! Any amount is appreciated, and supporters get exclusive rewards!