Discovery of a Great Hammerhead Nursery

Happy Shark Week (if you celebrate), and I’m so excited to share our newly published open access paper about our research on juvenile great hammerheads (Sphyrna mokarran) with you! (It’s been hard to keep this one to ourselves).

Great hammerheads are an iconic shark species which have undergone significant population declines globally. In 2019, they were assessed as Critically Endangered by the IUCN Red List, which reported overfishing as the greatest threat to their survival. Great hammerheads are known to make incredible long-range migrations and cross state and international boundaries, making them challenging to protect as adults. Little is known about where they are born or where they spend their early years of their life, although there have been scattered reports of juveniles from the Gulf of Mexico, the Florida Keys, and one report from Georgia.

Identifying habitats that are important to juvenile sharks matters because young sharks are often the most vulnerable individuals in a population, and their survival is vital to the future of their species. Many juvenile sharks spend time in “nursery areas”—places where they are less likely to be eaten by predators, or where food resources are abundant. They then expand their ranges as they age, covering more distance as they grow larger. Identifying nurseries has long been a conservation priority for managers and scientists. After several years of research, our team has collected the first scientific evidence of a nursery area for great hammerhead sharks on the Atlantic coast of the United States—within sight of the skyline of Miami, Florida.

There’s a three-part established test for an area to be identified as a shark nursery: 1) Juvenile sharks are more commonly encountered in that habitat than elsewhere; 2) they remain in the area for extended periods; and 3) The area is used repeatedly over years. Our results demonstrate that this area definitely meets two of these criteria, with preliminary evidence that it also meets the third. We’ve found the same habitat may be a nursery area for several other shark species too, including scalloped hammerheads, another Critically Endangered species!

Although great and scalloped hammerheads are protected in Florida waters and must be released if caught, hammerhead sharks often die or suffer serious harm from capture stress. Some of these juvenile individuals were caught with hooks from prior encounters with recreational anglers still embedded in their jaws. We hope learning more about this nursery can help us reduce threats to and better protect these small sharks. We can’t wait to share further updates as new results come in from the project’s telemetry expansion, supported by the Nature Trust of the Americas and a National Geographic Explorer Grant.

Our short scientific paper documenting this work is available open access through the journal Conservation Science and Practice, you can visit the project website here, or I hope you will watch the incredible video (also embedded at the top of the post).

Sharks, Squalene, and a SARS-CoV-2 vaccine

A bluntnose sixgill shark (Hexanchus griseus). Photo credit: NOAA Ship Okeanos Explorer.

Hi, friends at Southern Fried Science!

You’ve probably seen in the media lately that there’s been a lot of coverage about whether sharks are being killed for SARS-CoV-2 vaccines. With an awesome undergraduate co-author, I’ve tried to gather some facts about what is happening (or might happen) and what it means. You can read a preprint of that work here, or read on for a short FAQ in plain English.

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Creating Healthy Working Cultures in Marine Science Education

Below you’ll find a document I’ve been thinking about for more than a decade. I teach marine science field skills to undergraduates and graduate students at Field School and the University of Miami, and I’ve had a lot of opportunities to observe science and scientific learning in action. This is my best effort to distill the key principles I’ve learned about creating a healthy, supportive working environment. Starting the year, my students at Field School will all read and sign on to these principles before working with us.

It feels important to add that cultures are the product of choices and actions (or inaction). They don’t create themselves; they are created by the people within them. That means, sadly, that in every toxic organization there are people who choose, and benefit (or think they benefit) from that toxicity. The good news is that it also means we can choose something else. It’s not out of our hands.     

I’ve spent a lot of my time thinking about how to create welcoming, supportive learning environments for all of my students. And no: I don’t believe compassion and acceptance mean you have to sacrifice scientific rigor—in fact, I think students learn and grow more in these settings.

If you are also engaged in looking for solutions to the systemic problems in how we train future marine scientists, please feel free to join me by sharing this, implementing it in your own teaching, or reaching out with suggestions for how it can be improved based on your knowledge and practice. If you are a student who is struggling with these issues and you need advice or a friendly ear, please know that you are not alone, and my inbox is always open to you.

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Meet the newest Southern Fried Science contributor, Dr. Catherine Macdonald

Hello, world of Southern Fried Science.

The Field School team restrains a blacktip shark for a quick work-up during a female-scientist-led trip with the amazing non-profit Terranaut Club.

I’m Catherine—if we’re being official about it, Dr. Catherine Macdonald—and I’m the newest contributing writer around here. Before we get into science, I thought it might be helpful to get better acquainted.  

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