Hi, reddit! I am a Ph.D. student at the University of Miami's Abess Center for Ecosystem Science and Policy, where I study shark ecology and conservation. I went to Duke for undergrad and have a Masters in Marine Biology from the College of Charleston.

I've interacted with over 3,000 sharks on 3 continents. Our lab, the RJ Dunlap Marine Conservation Program, took over 1,000 high school students into the field with us last year to help with our shark research, so let me know if you're a high school teacher (RJD.Miami.Edu/Participate)!

I write for Southern Fried Science (southernfriedscience.com), one of the most widely read ocean science blogs on the internet. I also tweet about sharks @WhySharksMatter , and am always happy to answer any questions that anyone has about sharks.

Happy Shark Week! Ask me anything. UPDATE: After 600 questions and 3 hours, I'm exhausted. You can find me on twitter @WhySharksMatter and I'll answer your questions later. Thanks for having me, reddit!

Comments: 1263 • Responses: 100  • Date: 

crimjob296 karma

Hey David, I think its great you're doing this AMA, especially timely during a Shark Week frustratingly devoid of science. Thanks for all your tweets and FB posts about shark week, I'm so grateful for your voice of reason and humor!

Do you think Discovery Channel will ever produce a Shark Week that shark scientists and conservationists can all in good conscience get 100% behind or is it a lost cause?

edit: spelling

Whysharksmatter452 karma

Yes! Did you see "Alien Sharks" last night? It was SO GOOD! Natural history, real science, no sensationalism. It's exactly what Shark Week used to be.

Plz_Use_Caution193 karma

How do you feel about the shark week controversy regarding the first documentary on the megladon? What should discovery channel do in regards to it?

Whysharksmatter325 karma

In the interest of keeping language safe for work, I'll refer you to an interview I did on CNN earlier this week about the megalodon nonsense:


I think Discovery should apologize, but they won't.

The_Derpening146 karma

There are so many true, interesting things related to sharks they could have done, why the hell did they have to start making shit up?

I look forward to Shark Week every year because I like to learn about sharks.. This is disappointing.

Whysharksmatter140 karma


Frajer151 karma

Are you really supposed to punch a shark in the nose if they attack you or is that just a myth?

Whysharksmatter314 karma

If I punched you in the face, would you run away or punch me back?

Geohazard130 karma

Hey David! Thanks for doing this AMA. Just want to say thank you. My girlfriend was a student of yours at SeaCamp when she was younger and your love for sharks shaped her into the scientist she is today. She's currently pursuing her masters degree in biological oceanography. I too work in the sciences and feel like communication with the general public about scientific issues is getting increasingly important. What's the hardest part of talking about controversial scientific issues with people who may not know a lot about them?

Whysharksmatter225 karma

Hi! Tell your girlfriend hello for me.

The hardest part about communicating "controversial" science (which typically, these days, means climate change and alternative energy issues) is communicating uncertainty. Scientists often talk in terms of uncertainty, but when the public hears it, they think "scientists aren't really sure".

LordAurora120 karma

Second question: I don't have anything to do with marine biology, I don't live near the coast, I don't know lots of kids to teach. What can I do to help you with conservation?

Whysharksmatter261 karma

There are LOTS of things that you can do to help the ocean, even far from the coast! You're doing the most important one right now: asking questions and learning about it!

The single most important thing you can do, in my opinion, is to purchase only sustainable seafood, and to encourage others to do the same. The single greatest threat facing our oceans (including sharks) is unsustainable commercial fishing.

Highflyn13119 karma

What's the most important job sharks do?

Whysharksmatter259 karma

Sharks help keep the ocean food chain healthy. Where I'm from outside of Pittsburgh, we used to have wolves. Then we killed all the wolves. Now there are too many deer and not enough food for all of them. The deer leave their traditional habitat and cause billions of dollars of property damage each year.

jamintime62 karma

$Billions?? What the hell do these Pittsburgh deer eat?

If we only took care of this deer problem, we could double NASA's budget!

Whysharksmatter99 karma

It's not just what they eat, it's what they destroy. Cars, fences, windows of homes.

Highflyn1388 karma

Do you think academic universities will ever recognize this kind of outreach as equally important to lab achievements?

Whysharksmatter109 karma

I remain cautiously optimistic. I'm blessed with an adviser and department that encourage me to do online outreach.

chooter82 karma

Well we (me and /u/iamapillow and many other people) are thrilled to have you joining us to answer questions. Thanks!

Whysharksmatter42 karma

Thank you!

Schousing80 karma

What abilities/perks does a shark possess that a human should be jealous of?

Whysharksmatter175 karma

Sharks have the ability to detect electromagnetic fields given off by prey. I feel like that would be pretty sweet.

akochirka72 karma

What is the craziest/scariest shark you have seen in person? What sharks are out there that haven't made it into the public eye?

Whysharksmatter166 karma

I wrote my Duke admissions essay about a time in high school that I went SCUBA diving in a shark tank and stared down a 12 foot sand tiger shark. The most scared I've ever been, however, was the time I saw a bull shark on my first night dive. I was 15. And let's just say it's a good thing that my wetsuit was black.

jsantanna45 karma

I've always wondered though about those black wetsuits. Aren't they seal-looking like? I saw an ad the other day for a white and blue "camouflage" wetsuit and a striped "anti-shark" suit. Is there anything to that?

Whysharksmatter67 karma

I'm skeptical, but they look awesome.

sinverguenza72 karma

  1. what is your favorite shark and why?

  2. What were obstacles you faced in your career path?

  3. Is it possible for a thirtysomething to change careers and pursue this?

Whysharksmatter101 karma

1) Sandbar sharks. They were my Masters study animal have a special place in my heart.

2) I've been fortunate. I think my parents sort of always assumed that I'd grow out of this and become a lawyer or doctor, but they've been very supportive. Dad has even come on the research boat with me.

3) Totally.

sinverguenza53 karma

awesome! I got married in an aquarium and have a picture of me and the husband with a sandbar shark in the background.

Thanks so much for doing this AMA. I want to go back to school really bad and find a few weeks long volunteering gig working with Shark researchers, to help get my foot in the door experience wise, this is inspiring me to really go for it.

Whysharksmatter63 karma

Tweet me @WhySharksMatter, happy to give some more specific (and private) advice

PhillyTerp1125 karma

Hi David! It's been a pleasure following you on Twitter the past few months, especially this week. I have a Masters in Epidemiology & Biostatistics, but like this commenter I've always had loved sharks and the ocean. My epidemiology degree is a public health degree but is this something that could translate to the oceans? To sharks? It would be an absolute dream to be able to do what you do.

PS - I did my undergrad at Maryland, I'm going to miss the Duke games...

Whysharksmatter49 karma

Sure! There is a place for basically any scientific background to apply research towards marine science and sharks.

I'm sorry you went to Maryland, but nobody's perfect.

stabzmcgee71 karma

How do you feel about sharknado being so popular?

Whysharksmatter210 karma


Though the sequel title they chose, "SharkNado: The second one," is lame. I suggested "SharkNado Harder"

stabzmcgee145 karma

What about SHARKNADO: SHARKER, SharkNado Sharkie Goes West, SharkNado: A Good Day to Shark hard, SharkNado In Vegas: CardSharks, SharkNado in Space: Shark Trek, Thy Holy SharkNado: Noah's Shark

Whysharksmatter92 karma

All better than "the second one"

wakbat63 karma


Whysharksmatter86 karma

Check out SeaCamp, a marine science camp in the Florida Keys. I went there for 5 years and taught there for 2.

mikeyReiach57 karma

Hi. Thanks for doing this AMA.

I grew up in the Caribbean and some folklore said that sharks don't urinate in the wild thus making their bodies decompose very quickly after death and humans shouldn't consume their flesh. Is this based on any truth?

Whysharksmatter101 karma

Very, very, very loosely. Sharks have urea in their tissues, which they use for osmoregulation. But sharks, like all animals, do excrete waste.

iwanttofork55 karma

How difficult is it to collaborate with China for shark conservation considering shark fin soup is a delicacy there?

Whysharksmatter119 karma

Attitudes are changing, particularly among the youth in China

GunnerWookie55 karma

What's one weird thing that not many people would know about a shark or sharks?

Whysharksmatter137 karma

There are more than 500 species of sharks, and a new species of shark, skate, or ray has been discovered approximately every two weeks for the last decade. Most people only hear about the sharks that bite people.

Blacky3149 karma

There seems to have been quite an increase in shark attacks in recent years, at least around my area (Australia).

Do you think that has more to do with increasing shark numbers, more people in the water or changes in weather?

Whysharksmatter148 karma

Shark "attacks" increase slightly just about every year. The leading theory is that there are just more people in the water.

way_fairer43 karma

1) Do sharks really have 7 sets of teeth?

2) Can sharks get cancer?

3) Does punching a shark in the snout actually do anything?

Whysharksmatter154 karma

Some species of sharks have much more than 7 sets of teeth. Sharks can't go to the dentist, and they often bite big, tough animals. Teeth fall out and it's helpful to be able to replace them.

Sharks do get cancer. Every animal gets cancer. Even if they didn't, eating shark cartilage pills wouldn't help cure cancer, any more than I'd get better at basketball if I ate Michael Jordan.

rachelannyes42 karma

What is the least scary thing about sharks?

Whysharksmatter112 karma

Goblin sharks can be bubble gum pink.

akornblatt41 karma

What are some of the biggest misconceptions about sharks out there and what can those in the Ocean and Conservation world do to correct it?

Whysharksmatter70 karma

Due in no small part to Shark Week, people are afraid of sharks. The best thing you can do is tell your friends and family the truth.

jpreiner41 karma

How do you feel about duck-sized horses?

Whysharksmatter87 karma

Thank you for this question that I definitely didn't plant via twitter after days of preparing an answer!

People seem fascinated by this, but despite the fact that I work with sharks, I'm afraid of ducks and geese. I was attacked by a Canada goose while I was a little kid.

I'd much rather fight duck-sized horses.

Db3st37 karma

Do you like dolphins?

Whysharksmatter66 karma

You could say that I'm not their biggest fan.

Our official blog t-shirt says "I got your dolphins right here, pal".

samistahpp36 karma

I live on Cape Cod, MA, and a few of our beaches have been shut down due to sharks. What's the reasoning behind sharks swimming closer and closer to the Atlantic shores every year?

Whysharksmatter61 karma

One of the leading theories for this is seal population recovery in New England. More food = more sharks.

Jmunnny36 karma

Do all these UN-interesting shark shows during shark week piss you off as bad as they do me?

Whysharksmatter53 karma

I'll refer you to an interview I did in Wired this week. http://www.wired.com/underwire/2013/08/international-shark-week/

Dkandler36 karma

What are some myths about sharks that people believe?

Whysharksmatter93 karma

People think of sharks as mindless killing machines, but they actually have larger-than-expected brains for their body size and lots of complex social and ecological behaviors.

LordAurora33 karma

Hey David! Thanks for doing an AMA. Other than marine science and sharks, what are you passionate about? What other field might you have gone into?

Whysharksmatter68 karma

I feel like most little boys (and a lot of little girls) go through a shark thing or a dinosaur thing. I did both, and chose sharks.

jpreiner27 karma

You don't get to be a shark scientist overnight, and you don't get on the boat until you've put in a lot of work. What path did you take to get to where you are now from an education/training/lab standpoint?

Whysharksmatter47 karma

I studied biology and marine science at Duke University, and got my Masters in Marine Biology at the College of Charleston.

el_skootro26 karma

Is it sustainable/okay to eat shark?

Whysharksmatter46 karma

1 in 6 species of sharks, skates, rays or chimeras are Threatened with Extinction, according to the IUCN Red List, with some species suffering reported population declines of over 90% since the 1970's.

However, some countries (the U.S. and Australia in particular) have relatively well-managed shark fisheries.

AtheistComic25 karma


Whysharksmatter60 karma

The BP Oil Spill has been devastating to marine animals, including some species of sharks. Pollutants and toxins "bioaccumulate", which means that they increase in concentration as you move up the food chain.

johnplatt23 karma

Hey David! With so many shark species in decline, is it becoming harder for scientists to find enough live samples to conduct their research?

Whysharksmatter30 karma

To some extent. I've been on about 60 sampling trips with my lab here in Miami, and we've caught 0 sharks on 4 of them. It depends on the research question, as some require higher sample sizes than others.

cephalic_symbol22 karma

Are there any cultural norms within ocean science? For example, jokes that everyone gets, or common rites of passage?

Whysharksmatter63 karma

See the first rule about Fight Club. For good measure, also see the second rule about Fight Club. :)

4InchesOfury20 karma

What are your thoughts on the culling of sharks on Reunion Island? The officials at the island have banned entering the water and are now culling 45 bull sharks and 45 tiger sharks for "scientific purposes". This was caused by a large amount of shark attacks on the island.

Here's an article about it for anyone interested

Whysharksmatter44 karma

"Culling" is stupid, ineffective, short-sighted, and environmentally harmful.

alicat33120 karma

Hey David, I'm an undergrad at the University of Miami studying Marine Affairs and Anthropology. I've been interning at the Cape Eleuthera Institute doing shark research for the last two months. Besides applying for an internship with RJ Dunlap what other ways can I get involved with shark conservation in Miami? Thanks, Alice

Whysharksmatter31 karma

Hi Alice! I may be biased, but applying to work with our lab is probably your best bet for hands on shark research in the Miami area.

mikeyReiach14 karma

Just out of curiosity, is the research site in Bimini still ongoing?

Whysharksmatter16 karma


sassamafracken19 karma

Do you have any predictions of what the oceans would be like without sharks? Does climate change put sharks at risk?

Whysharksmatter39 karma

The loss of sharks will have a variety of negative ecological consequences. It won't be pretty.

Climate change isn't great for most animals, but sharks face a much, much, much greater threat from commercial overfishing.

LomoSaltado19 karma

What is your favorite beer at WetLab?

Whysharksmatter38 karma

Whatever's on special. There are no bad choices for beer at WetLab.

WetLab, for those who don't know, is the on-campus bar at the University of Miami's marine lab. The motto is "providing scientific support services".

thracc19 karma

Have you ever or would you ever eat shark? What does it taste like?

Whysharksmatter34 karma

Yes. It tastes like grouper, a very rich flavor. I don't recommend it because of sustainability issues, but the ones I ate were sacrificed for another scientist's research project, and there was no sense wasting it.

ChampionOfNorrath19 karma

Do sharks only exist to a certain level of depth in the ocean? Also, how come shark isn't as common as a food source as other undersea life?

Whysharksmatter24 karma

Sharks can go pretty deep, but not to the absolute bottom of the deepest parts of the ocean.

skunklvr18 karma

You did a great job of getting kids to love the ocean and everything about it at Seacamp. Your passion definitely rubbed off on us, and I thank you for that. Charismatic Megafauna was the best class I ever had in my 5 years of Secamp. Sorry this wasn't a question.

(And you're the only reason I know how to do the Cotton-Eyed Joe)

Whysharksmatter19 karma

Thanks! FB message me so I know which one of my former students this is!

victoriaqnerdballs16 karma

Hi David, thanks for doing this! In your opinion, when did the trouble with Discovery Channel's Shark Week really start? Do you think the vocal frustration directed towards the current state of Shark-related programming is a recent development, or has it been bubbling under the surface for a while in marine biologist circles?

Thanks again!

Whysharksmatter30 karma

Shark Week used to be about science, about inspiring wonder towards the natural world. Some of it, like "Alien Sharks" last night, still is.

PostYourSinks16 karma

What shark do you think is the most badass And why?

Whysharksmatter44 karma

Greenland sharks have been found with polar bears, the largest land predator on Earth, in their stomach.

Deaffreedom16 karma

What do you know about the correlation of heightened stress hormones in sharks linked to decreased immune function? I know that increased and prolonged levels of stress in mammals weakens the immune system and am wondering if something similar occurs with sharks.

Whysharksmatter26 karma

I'm not trained extensively in stress physiology, but heightened stress hormones have a variety of sublethal effects and I believe that a weakened immune system is among them.

juanlee33716 karma

What is the single fact that makes sharks the most amazing animal in the planet?

Whysharksmatter43 karma

There were animals recognizable as sharks swimming in the oceans many millions of years before there were dinosaurs. These are ancient vertebrates.

h2so4hurts15 karma

Hi David, I was wondering if you could comment on Tara Reid's recent discussion regarding the generation of whale sharks. Are these the offspring of a kinky dolphin-whale-shark-animal-mammal orgy as Reid implied, or is there an actual scientific evolutionary explanation for the "Whale shark?"

Whysharksmatter106 karma

Tara Reid is...not an expert.

Whale sharks are sharks. Fish. Not whales. They're called whale sharks because they're really big.

bakedbads14 karma

Hey David,

Outside of this Megalodon chicanery, what was the worst, facepalm-inducing moment you've had when it comes to the media's portrayal of sharks?

Also, if the Megalodon were to face a juvenile Sharktopus, who would win?

Whysharksmatter38 karma

"Top 10 Sharkdown" was pretty bad this year. Literally every sentence that wasn't an interview with a scientist had at least one wrong thing in it.

Whysharksmatter33 karma

Sharktopus has steel-tipped tentacles, right?

yousaidicould13 karma

Hi David!

When you lecture or discuss why sharks are important, do you ever discuss why the math on shark attacks doesn't match up to the math? With hundreds of different types sharks, so few that have attacked people, and so many people who DON'T get attacked...

What's a good statistic to share with people who are unreasonably scared of sharks?

Whysharksmatter61 karma

Here are some of my favorites:

More people are bitten by OTHER PEOPLE on the New York City Subway each year than by sharks in the whole world.

More people are killed by vending machines, toasters, lawn mowers, and flower pots each year.

le_trout13 karma

How much of your job is spent doing what you imagined you would before you entered the field? In your opinion, is that good or bad?

Also, what is your favorite shark?

Whysharksmatter32 karma

My typical day is probably pretty similar to most of your typical days. I answer e-mail and do data entry in Excel. However, I go on about 30-40 shark research trips a year, and those are awesome. If you're with a high school class, community group, etc, you should come RJD.Miami.Edu/participate

delarivaguard12 karma

Hey David, thanks for the AMA. I lived in the caribbean for a couple of years and was fortunate to encounter nurse sharks and reef sharks diving and snorkeling, on multiple occasions, naturally (not in chummed water or a feeding frenzy), and not once did I feel threatened. Watching shark week yesterday, there was a show about people who had, unfortunately, lost limbs to shark bites. That was it. The whole premise to the show was, people scared who had limbs amputated as a result of a shark attack. I thought shows like that one and the megladon "documentary" are doing way more harm by instituting fear of sharks. What are your thoughts on shows highlighting attacks and instilling fear that there is a large carnivorous shark prowling the oceans?

Whysharksmatter13 karma

I'll refer you to a recent interview I gave in Wired http://www.wired.com/underwire/2013/08/international-shark-week/

NienieG11 karma

What are some things that you would suggest to a college student who wishes to follow in your footsteps?

Whysharksmatter26 karma

Study math and science, volunteer in labs, read, read, read.

rachelannyes11 karma

You mentioned that you were recently the victim of a toaster attack. DETAILS.

Whysharksmatter21 karma

A certain someone who shall remain nameless didn't clean up the crumbs tray, which almost resulted in a small fire when I tried to make an English muffin.

wiredpersona10 karma

Would you rather fight a shark sized duck or 100 duck sized sharks?

Whysharksmatter13 karma

100 duck sized sharks.

Sofa_SoGood10 karma

As a shark expert, what was your professional opinion of the movie Sharknado?

Whysharksmatter32 karma

Almost as good as "mega shark vs. giant octopus"

Cfx9910 karma

With the recent discussions on the decoding of the Mammoth genome, do you think it would be wise to clone and resurrect the species (I ask because you study living creatures and their place in the world) and if so, are there any shark species you would like to see brought back?

Whysharksmatter27 karma

I'd prefer that we focus our efforts on not letting current species go extinct. Many extinct animals became extinct because their food source or habitat isn't there anymore, and de-extinction won't fix that. However, I'd love to see a Stellar's Sea Cow (basically a giant manatee), an animal that sailors hunted to extinction in just a few decades.

ladro510 karma

Hi David, I have been (and would love to go again) shark cage diving with great whites in South Africa: do I risk disturbing the animals in their environment or even worse getting them used to humans when doing so or is it an acceptable practice?

Whysharksmatter13 karma

There are dive operators that are extremely responsible.

captain_wiggles_10 karma

Have you seen any of:

  • mega shark vs giant octopus
  • sharktopus
  • Shark in venice

If so what did you think?

Whysharksmatter14 karma

Loved 'em, particularly mega shark vs. giant octopus.

ldd-9 karma

David - I've really enjoyed your writing and work!

What sites/sources do you read on a daily basis to keep up with sharks, the oceans, etc (Aside from Southern Fried Science, of course)?

This is a shameless plug, but a good friend and I have been working to build a site to try to amplify great writing and conversations about the Oceans and SCUBA in particular - http://www.daily-scuba.com . . .

We'd absolutely love your thoughts on the site sometime . . . we're trying hard to create a great resource for people who love the oceans.


Whysharksmatter23 karma

My Google Reader was full of over 200 marine science news sites and blogs, including Daily SCUBA. I know use Feedly, but it ain't the same. I miss my Google Reader.

bluefire5799 karma

I have an argument with my marine biologist friend in which she insists that tiger sharks are better than great whites, while I insist the opposite is true. Can I count on you, as an expert in this field, to back me in this noble endeavor, or have you also fallen victim to the propaganda that seeks to dethrone the great white from its rightful place at the top?

Also, thanks for the AMA, sharks are awesome!

Whysharksmatter16 karma

I prefer great hammerheads. :)

Whysharksmatter9 karma

Ok, everyone! After hundreds of questions and 3 hours, I'm exhausted. You can find me on twitter @WhySharksMatter and I'll answer your questions later. Thanks for having me, reddit!

ollienorth197 karma


Whysharksmatter14 karma

I'm skeptical of their effectiveness, but they look awesome.

zuce7 karma


I wanted to know what your least favorite shark/marine animal is

And also, if you had a pet shark what would you name it?

Thank you!

Whysharksmatter25 karma

My least favorite shark at the moment is the nurse shark, because one recently slapped my ass so hard with it's tail that I couldn't sit for three days. I also don't particularly care for dolphins, but that's longstanding.

If I had a pet shark, his name would be Steve.

breeks6 karma

Why do sharks matter?

Whysharksmatter6 karma

As top predators, they help keep the ocean ecosystem in balance.

MyTeamSucks6 karma

Have you had any scary encounters with sharks? Like one tried to attack you or a student/coworker?

Whysharksmatter26 karma

I've never been bitten, and I've interacted with over 3,000 animals both in the water and on the boat. I have hundreds of pictures of sharks, and most are of them swimming away, because that's what they do when they see us.

throwaway_idiot16 karma

Do you think that sharks matter in terms of ecosystem stability and resilience? Could you provide some peer reviewed research to support where you think the weight of evidence lies.

Are there some potential benefits to low shark abundance that outweigh the benefits of high shark abundance?


Whysharksmatter11 karma

Here's a good review of shark ecosystem importance that's freely available online: http://www.fmap.ca/ramweb/papers-total/Heithaus_etal_2008.pdf

There are no benefits to low shark abundance that I'm aware of.

vauntedsexboat6 karma

Do you think Shark Week does more harm or more good for the study and appreciation of sharks? It realy seems like a double-edged sword to me. On the one hand, raising awareness of ocean science seems important. On the other, 99% of it seems to be scary-voice "documentaries" with lots of slow motion black and white footage and titles like "Sharks: Nature's Most Lethal Killer." And it seems to me that a significant portion of it is just reinforcing peoples misconceptions about sharks in particular, and predators/wildlife in general.

Whysharksmatter7 karma

designut5 karma

Hi David!

It sounds like you're passionate about your job, and I think that's fantastic!

This is kind of a question, kind of not. When I was in grade 7, we watched documentaries on commercial fishing for tuna, and the techniques they use to find tuna (basically, throw a net in an area around dolphins, since dolphins feed off tuna)... bringing the "dolphin friendly" slogan so many tuna companies now write on the can. The trouble is, my seven grade class wrote letters to these "dolphin friendly" companies, asking if they could explain their alternative "dolphin friendly" technique. Their response (from more than one commercial tuna company) was basically "you're in grade 7. You wouldn't understand." Since I read their responses, I have not had a single bite of any sea or lake dwelling creature, because it made me realize how easy it would be to exploit creatures of the sea, (think of all the over-fishing which has been clearly proven) and I wanted no part of it. It's been 18 years!

What information could you give me about this? I feel like the ocean is the forgotten land of animals - even "vegetarians" I know eat fish - and this AMA is the first time I've heard mention of sustainability. Could you point me in the right direction? Also - because then I will have a better retort when people bug me about how I'm weird and picky for not eating fish (in fact, I loved it). And then, maybe I can enjoy seafood again - responsibly and sustainably.

Tl;dr - I think I was a fish in another life. I don't eat fish. I'd like to learn more about sustainability, and also, what effect fishing has on oceanic environments.

Edit: clarity

Whysharksmatter4 karma

"Sustainability" is confusing. I like the Monterrey bay Aquarium's seafood watch guide. http://www.montereybayaquarium.org/cr/seafoodwatch.aspx

reddit_all_before5 karma

Does Megalodon exist?

Whysharksmatter11 karma

Not anymore. They've been extinct for between 1.5 and 2 million years.

marinekatpat4 karma

How do you try to invoke change in friends/family members that reply to your conservation posts by saying things like "I love Shark fishing, I just like to hook the big ones."

Whysharksmatter4 karma

My family has a lot of fishermen in it, but they've always been ahead of the curve in conservation and catch-and-release. In the hypothetical situation you're describing, I'd explain the ecological importance of sharks and they're threatened status.

rdearborn4 karma

Who are your heroes and mentors? Who inspired you to go into science, and who inspires you today?

Whysharksmatter7 karma

I liked the ocean long before I knew I could study it professionally. One of my heroes is Eugenie Clark, who I recently met (and, despite being in her late 80's, still hangs out at bars with grad students and is generally awesome).

DecisiveCarton04 karma

Hey David, if I cut the bottom of my foot on let's say a shell in the ocean and I bleed, at what distance could a shark pick up on the blood scent? Thanks!

Whysharksmatter7 karma

Scent doesn't work at distance. Molecules need to actually touch the chemoreceptors (which means that when you smell something nasty, tiny particles of that something are physically in your nose). But sharks can detect blood in very low concentrations.

catmoon4 karma

What has been your favorite place in the world to dive?

Whysharksmatter18 karma

I like Sylvia Earle's answer to this, "anywhere 50 years ago" (i.e. before overfishing.

But the wreck of the Yongala in Australia was my favorite.

PRGrl7184 karma

What do you think about Nelson the Shark found in the subway a few days ago?

Also, I've always wanted to pet a shark to see how they feel. DETAILS MISTER.

Whysharksmatter16 karma

New Yorkers, man. Weird folk.

Sharks are smooth in one direction and feel like sandpaper in the other direction.

chacochaco3 karma

What's your hypothesis for the White Shark Cafe?

Also have you tried Hakarl?

Whysharksmatter5 karma

The leading hypotheses for the White Shark Cafe (as with just about any aggregation site for animals) deal with reproduction or feeding.

I have not tried Hakarl, but I'm an adventurous eater and would probably try a bite. I expect it's not as tasty as sea turtle.

thevault083 karma

I was snorkeling in Hawaii and I saw a sea turtle. I was ecstatic at first but then I was terrified because my cousin (who lives in hawaii) told me that wherever there are turtles, there are most likely sharks. How terrified should I have been?

Whysharksmatter11 karma

Not at all. There probably were sharks nearby, though (not because there are turtles, but because you're in the ocean).

superdude54213 karma

How many species of sharks do you think that we have still yet to discover?

Whysharksmatter5 karma

Scientists have discovered a new species of shark, skate, or ray about every 2 weeks for the last decade or so.

Cornflip2 karma

Aside from the recent controversy surrounding the legitimacy of the Megladon documentary on Discovery, how do you think Shark Week has changed public perception on sharks? Do you think Shark Week has helped, hurt, or increased the prominence of sharks in a neutral way?

Whysharksmatter2 karma

I'll refer you to an article I wrote on this topic for Zocalo Public Square this week: http://www.zocalopublicsquare.org/2013/08/08/dont-gnash-your-teeth-over-shark-week-shark-lovers/ideas/nexus/

Natethegreat00772 karma

What is you Doctoral Thesis covering? And what led you to decided on that topic? I am applying for doctoral programs in marine biology and am curious how you finally select the project you wanted to cover.

Thank you for doing this AMA, it's great for scientist to reach out the public and interpret the findings in a way everyone can understand rather than the esoteric research journals.

Whysharksmatter3 karma

I'm in an interdisciplinary Ph.D. program. I'm studying how sharks impact the food chain, and also how different stakeholder groups (fishers, scientists, conservation activists) perceive how sharks impact the food chain. In other words, Why Sharks Matter

dillion33842 karma

What is the ultimate impact mercury pollution will have on Sharks and other apex, ocean predators?

Can we assume mercury poisoning will lead to erratic behavior for sharks, as it does in other animals?

Whysharksmatter2 karma

Mercury does bioaccumulate, moving up the food chain. It may impact shark behavior and physiology, but I don't think this has yet been confirmed.

The biggest threat facing sharks is commercial overfishing, though.

AnonRaiden2 karma

I envy you! I've been intrested/studying sharks since I was 8 and got certified for Scuba at age 12 so that I can dive with sharks. I too live in Miami and have dove all over south Miami and the keys. I've also dove with sharks in Belize. My wife and I are ocean fanatics, she even has an associates in marine biology on top of her bachelors in Business management.

What I would do to have a career in Elasmobranchology

Whysharksmatter2 karma

See my blog post on this topic http://www.southernfriedscience.com/?p=8400

jpreiner2 karma

What makes sharks so difficult to track and follow? Is it technology-related and if so, are there efforts to improve what tools you as scientists have available?

Whysharksmatter4 karma

A fisheries scientist once said that counting fish is like counting trees, except they move around and they're invisible. Radio waves don't transmit through water. Most available technology requires that the shark be at the surface to transmit, which, depending on the species, may not happen that often.

Girl_In_The_Wind2 karma

Is the attitude to sharks worse in Florida than other parts of the country?How common are shark attacks along the Florida coast, and how much of a danger are they? Also, is it possible to observe small sharks and other marine life while snorkeling along the coast, or is it better to just stay away from their habitats?

Whysharksmatter5 karma

Shark attacks are incredibly rare, even though Florida is the "shark attack capitol of the world". Tens of millions of people go swimming, and like 30-40 a year are bitten. You're more likely to get bitten by another person on the NYC subway, and more likely to be killed by a vending machine, toaster, or lawnmower.

I swim with sharks all the time.

spilledkittymilk2 karma

What is one of the scariest facts you have learned about sharks? Also what made you go into this field?

Whysharksmatter6 karma

The scariest fact about sharks is that they're one of the most Threatened (in the IUCN Red List sense of the word) group of animals on the planet, with 1 in 6 species Threatened with extinction.

I've always loved sharks, even though I grew up hundreds of miles from the ocean.

smoakbomb2 karma

CoC! I was raised in Georgetown. Have Great Whites always been present off of the SC coast and it simply seems like a new thing because of advances in tracking or is their presence indeed a new thing?

Whysharksmatter4 karma

There's nothing to suggest that great whites weren't always there. I suspect we're just noticing them now because of satellite tracking.

Moomonster2 karma

Is there actually a chance the megalodon is still alive?

Whysharksmatter10 karma


Elasmophile2 karma

Hi David! Thanks for doing this! Keep up the good work, like I told you yesterday!! Have you seen or heard from my advisor lately? ;)

Whysharksmatter3 karma

E-mail only. He's somewhere in Europe I think.

Rabuck2 karma

What's the most intelligent thing Sharks are capable of?

Whysharksmatter3 karma

We put GPS satellite tags on some tiger sharks in the Bahamas. They swam over a thousand miles into the middle of the Atlantic ocean...and then came right back to the same beach we tagged them at.

lobstercrevices1 karma

I remember my sister telling me a few years ago about a co-worker who was fishing and ended up being scratched by a sharks tooth on his arm when he was unhooking it. It ended causing extensive nerve damage in his arm and led to a painkiller addiction. Do you know anything about this type of thing? Was it the actual shark tooth that caused it or some sort of bacteria or something that happened to be on its tooth? I've always been curious but she no longer works with him.

Whysharksmatter3 karma

I'm obviously not familiar with this specific case, but a sharp object could cause nerve damage if it cut the right place. In general, bacterial infection (from the ocean itself as well as from the shark's mouth) is a bigger problem.

rexus01491 karma

If the Sharknado was real, what would be the best evasive action?

Whysharksmatter8 karma

If it was real? Wait, that wasn't a documentary?

I think the lead had the right idea with his strategy of holding a chainsaw above his head. Seemed to work pretty well.

Hofular1 karma

How did you feel about the discovery channel trying to pass off the "megaladon" as a real shark living today?

fanley1 karma

What's the closest you've ever been to getting bitten or injured by a shark?

Whysharksmatter6 karma

I got a fishing hook through my hand once. And shark fishing hooks are quite large.

I've never been seriously injured by a shark, but on a recent research trip, a nurse shark slapped my butt and upper thighs so hard that I couldn't sit for three days.

Shark skin is covered in tiny teeth called denticles, and interacting with them leads to what our research team refers to as "SharkBurn". It is quite uncomfortable.

auldnic0 karma

How the hell did that shark got on the subway/

Whysharksmatter7 karma

New Yorkers, man.

I_Key_Cars-3 karma

Do you know Tickle?

Whysharksmatter4 karma

I'd rather know Blimp from Voodoo Sharks. But Tickle seems fun. And I loves me some moonshine.

Winkley-5 karma

What's your shoe size?

Whysharksmatter2 karma

10 1/2, 3E wide. I have weirdly shaped feet.