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Episode 3 - The One A-boat Sharks

July 27 2022

In this episode, Lauren and Mikey are joined by Heather Bowlby, Research lead for Canadian Atlantic Shark Research Laboratory for Fisheries and Oceans Canada, along with Mackenzie Collard, fishery officer from the Maritimes. They delve into many interesting facts and stories about sharks, including species that live in Canadian waters and safety tips to keep in mind when out on the water.

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Episode 3 - The One A-boat Sharks – Audio transcript


(Sound a whale call and waves)

… It’s just how different their perception of the world would be than our perception of the world. A lot of people don’t realize that they have two extra senses relative to ours.

Lauren Ehrenworth (Co-Host): Hi there, and welcome to the DFO Deep Dive.

I’m Lauren.

Mikey Rouleau (Co-Host): And I am Mikey.

Lauren: And it is that time of year, Mikey. We have one thing on the brain, and it’s sharks. Of course, it’s sharks!

On today’s show we’re going to explore sharks swimming in our Canadian waters, there’s a dozen different types of sharks in Canada. Did you know that?

Mikey: I did not, Lauren. But luckily enough we sat down with some of our experts to discuss sharks and some misconceptions, along with some interesting facts.

Lauren: Yeah, there’s a lot of interesting discussions about to take place, like the role Canada plays to keep these sharks safe.

So today, we’re sitting down with Dr. Heather Bowlby, who’s the Research Lead of Canadian Atlantic Shark Research Laboratory, here at Fisheries and Oceans Canada; as well as Mackenzie Collard, a fishery officer from the Maritimes Region.

So, without further ado, let’s dive right in.

Welcome Heather.

Dr. Heather Bowlby (Research Lead, Canadian Atlantic Shark Research Laboratory, Fisheries and Oceans Canada): Thank you for having me.

Lauren: Oh, thank you for joining us. Now we have a very exciting topic this week, and it’s the topic of sharks, which I think everyone is pretty fascinated by.

So, could you maybe go through, right off the top, and let us know what kind of sharks can we find here in Canadian waters?

Dr. Heather Bowlby : A lot of people don’t realize how diverse the community of sharks is in Canada. We can have everything from smaller sharks, like spiny dogfish or black dogfish, that most people would consider to be similar to groundfish, like cod and haddock, but then we also get a lot of the larger species. There’s porbeagle shark, shortfin mako, basking shark frequent Canada, white shark. A lot of the larger shark species also frequent Canada, common visitors would include shortfin mako, porbeagle shark, basking shark, and of course everyone's favorite white shark.

But we also do get seasonal visitors, you can find tiger sharks up here, oceanic white tip and some of the ones you'd more commonly associate semi-tropical waters in the U.S..

Lauren: Sounds like a lot of sharks.

Dr. Heather Bowlby: (laughs)

Lauren: Now obviously, you can't study all of them, so which kind of sharks do you specialize in?

Dr. Heather Bowlby : What's interesting is they often need a catch-all for all pelagic species, so typically any question related to a pelagic species or an ocean-going shark, so most of the species that got mentioned second are ones that I would deal with.

So the ones that I think about for stock assessments, for example, would be blue shark porbeagle and shortfin mako in the North Atlantic. But species at risk processes, I've been asked questions about basking shark

Michael: That's very interesting. It sounds like you've got a whole array of different sharks that you look into.

In terms of interesting facts, is there anything you can share about some of the sharks you just mentioned?

Dr. Heather Bowlby : Some really interesting facts, that I think about sharks, is just how different their perception of the world would be than our perception of the world. A lot of people don't realize that they have two extra senses relative to ours. They have something called a lateral line as well as something in their snouts called ampullae of Lorenzini, which is a great name for a little oil-filled sacks that detect electromagnetic signals.

So not only can they feel pressure waves in the water, they can also detect something like a fish's heart beating, even if they can't see it. And this probably help sharks be very effective when they spend a lot of their time below the layer in the ocean that has light.

For example, a porbeagle shark might dive to 1,000 meters deep in the ocean. Well, there's no light down there, and they can use these extra two senses to still be very effective. I think that's really cool.

Mikey: That is really cool. Do sharks in general have good vision, or is that not really… I mean clearly they rely on what you just mentioned, but overall do they see well in the water? I'm just kind of curious.

Dr. Heather Bowlby: It's generally accepted that they are still visual predators, particularly when they're at the surface. Some of them will close what's called a nictitating membrane if they have it. Blue shark are a good example of this, that before they bite a prey object, they have eyelids that kind of close from the bottom to protect their vision, which would suggest that their eyes are quite important to them for this type of thing to have evolved.

Lauren: Now I'm really curious, because I grew up in an age where obviously the big movies were Jaws and things like that, were we get a very interesting picture painted of sharks.

So, maybe you can go through some of the misconceptions around sharks, some of the things we maybe have been taught to believe that aren't totally so?

Dr. Heather Bowlby: One of the things that I think a lot of people forget is sharks spend a lot of time at sizes too small to be any threat for humans, even a white shark, even a powerful top predator like a white shark would still be born to be too small to pose any significant threat. And for the majority of species’ life history, they are definitely fish predators instead of marine mammals or larger prey.

So, I think that even the species we think about, or maybe would be scared about, for the most part they're generally harmless just on the basis of size. A lot of sharks in Canada also spend a lot of time off shore, so it would be very rare, for example, to see a shortfin mako – and particularly a very large shortfin mako – commonly right along the coast, and so it there's also a little bit lower potential for overlap than you might assume. Although sharks can and will come close… come into shallower water, a lot of species like shortfin mako and porbeagle spend a significant amount of time well offshore.

Mikey: That's interesting. You mentioned that they were fish predators, so what kind of role do they play in terms of the ecosystem of our oceans and how important are sharks to a healthy ocean?

Dr. Heather Bowlby : I tend to come down on the side that all species are important to the health of an ecosystem, and I think it's very telling that if an ecosystem can support a top predator like sharks, it has to be quite productive, so there has to be sufficient prey for any number of components in that ecosystem, from the small forage fish all the way up to something like an adult white shark.

I think that having a diversity of species in our waters says something about the ecosystem's ability to support them.

Often though, population sizes are a bit lower than they would have been historically, quite a few species are considered to be at risk in Canada. So hopefully, as we can bring the populations back, it will increase the health of the entire ecosystem off the coast of Canada.

Lauren: And that's very interesting, because I don't know how typical… how common it is for people to know that some population of sharks are endangered or at risk. So, what are some of the issues that are putting sharks in danger, that are putting them at risk, and maybe things we can do to help with that?

Dr. Heather Bowlby: Shark populations have one big threat, and this is true almost the world over, and it's capture in fisheries.

In Canada we have no directed fisheries for sharks, which means that people are not going out trying to catch them to bring them into the dock, but there is incidental capture or bycatch of sharks off the coast in any number of fisheries, and it's… the reason that sharks are so sensitive to capture in fisheries is because of their life history.

So, unlike a fish that can have million… or thousands of eggs, for example, in a year, sharks have a defined reproductive schedule and they can have a low number of… One of the most productive sharks – you asked about cool facts – and goes back to the blue shark; they can have upwards of 35 pups in a litter, which is really quite cool.

But a lot of species like, say porbeagle shark, they have an average of four pups a litter. And so you can imagine that the population's ability to increase in size is quite low relative to something like a fish, that could have thousands of eggs fertilized and larvae in a year.

Mikey: What's the succession rate of a shark pup… like do they all survive, or there’s 50% that usually survive, what's…?

Dr. Heather Bowlby : This is a very, very cool question that I cannot answer. (laughs)

Mikey: (laughs) Fair enough.

Dr. Heather Bowlby: It would be partially species-specific, so different species would be expected to have slightly different rates of survival. But the biggest problem with answering this question it’s a very, very hard to follow an individual shark over its lifetime.

So, you only get very little snapshots of the population, either from tagging data or from commercial captures in fisheries, and you often don't get information on the same individual over its lifetime. And what that does is it makes it very difficult to say, “oh, on average say, 70% of newborn sharks will live to be one.” We just don't have that kind of observational capacity, I guess.

Mikey: Fair…

Dr. Heather Bowlby: And we're always relying on modeled rates.

Mikey: Right. In terms of your job, what's the day-to-day life of a scientist that studies sharks?

Dr. Heather Bowlby: Oh, you want me to tell you the day-to-day is going out on the boat and finding sharks and tagging them! But very, very honestly, the vast majority of questions that I get asked are analysis-based using historically collected data, so either data collected in fisheries or a very small number of tag deployments. And I do a lot of math; everyone go do math if you want to be a shark scientist! (laughs)

Lauren: Well this leads me to my next question, because as a scientist, you can study a whole whack of things. What led you down this career path, what led you to be so interested in sharks that you've made in your career?

Dr. Heather Bowlby: Oh dear! I'm an accidental shark biologist, which I think is great! My interest in science is in population dynamics, which is basically understanding how and why populations either increase or decrease in size, and I very much like to apply that to species at risk.

And so, originally in my career, I worked on diadromous fish, like Atlantic salmon, but then could apply the same concepts to something like sharks. And that's what's led me to be a shark biologist.

Mikey: So, it wasn't Jaws that led you to wanting to work on sharks?

Dr. Heather Bowlby : You know what, I'm probably the only person of my generation who has never seen…

Mikey: Do you tune into Shark Week at all?

Dr. Heather Bowlby: I tend not to watch a lot of popular culture around sharks, it's just personal preference. I'm a woodworker in my spare time, instead of watching documentaries, and at the end of the day I often am in the field during Shark Week and have other obligations for work, and so it's a… it's a bit of a tricky time of year, truth be told. (laughs)

Lauren: What advice would you have for people this summer? They're out on the water, they're having fun, maybe they see a shark. What in parting words do you have for them?

Dr. Heather Bowlby: If you do see a shark, I congratulate you, because they're very hard to see in Canada and it's a pretty rare occurrence.

That said, depending on the species, it is prudent to understand that this can be a very powerful predator that's in the water, that we have relatively little ability to, let's say, out-maneuver. And at the end of the day, it's important to be aware.

There’s some very good kind of rules of thumb that are put out by the Atlantic White Shark Conservancy out of Cape Cod, where they recommend things like not surfing alone, for example, or not being alone in the ocean environment, potentially not being in the middle of a large group of seals or other prey items that a white shark might be interested in, and just being aware.

Lauren: See, these things I would've never thought.

So, this has been great. Heather, you're such a delight to speak to.

Dr. Heather Bowlby: Thank you. Thank you for having me. I think it's a wonderful that one of the perks of my job is people are so interested in what I do and so it's really gratifying as a scientist to be able to talk to people and to be able to talk about such a cool animal.

Lauren:  And frankly we're thrilled that we get to speak to you, like this is one of the perks of our job, we get to sit down with you and talk about sharks, which has been fascinating. I've learned so much, I have to go and process all this information.

Dr. Heather Bowlby: (laughs)

Lauren: So, thank you so much for joining us, Heather, it's greatly appreciated.

Dr. Heather Bowlby: It was fun.


Lauren: That was a really interesting stuff coming from Heather.

Mikey: Yeah, it certainly was. She really kind of shined the light on the importance of sharks and the reality of what they really do in the ocean, and that perhaps we shouldn’t be as scared.

Lauren: Like there's so much more depth to sharks and their behaviour and how they react, so it's really interesting information.

Mikey: I agree, and I think it'll be interesting too, leading into our next conversation with our very own fishery officer, we're going to get kind of the boots on the ground aspect of what's it like to protect those sharks and to interact with them in our Canadian waters.

Lauren: That's right.

Let's see what Mackenzie has to say. Welcome Mackenzie.

Mackenzie Collard (Fisheries Officer, Fisheries and Oceans Canada, Conservation and Protection Branch): Hi.

Lauren: Now let's start off with why don't you talk to us a bit about your role here at Fisheries and Oceans Canada?

Mackenzie Collard : So, I am a fishery officer, which means that I deal with the enforcement side of things at DFO. That means that I'm dealing with everything from the commercial side of fishing to recreational, we also deal with assisting marine mammals that get stranded or making sure that they are protected according to the regulations, construction around water, and we just make sure that all of the rules for fish and fish habitat are followed.

Lauren: Right on. So, this episode we have a focus on sharks.

Mackenzie Collard : Hmm!

Lauren: So, can you talk a bit about how your position relates to sharks?

Mackenzie Collard : Absolutely. So sharks, when it comes to the fishing world, they’re largely considered bycatch. They're not always directed for or targeted when it comes to commercial fishing, they are more often than not caught accidentally when commercial fishermen are out trying to fish for other things, specifically when it comes to longlining gear.

If the shark itself is still alive, then the fishermen are required to release it in the way that causes the shark and the fishermen the least amount of harm, since they can be lively; the sharks that is. And if they’ve died, then the fishermen generally have to land them, bring them to shore and report what the species is.

So, my job is just ensuring, if I'm on the water, that the fishermen are releasing the sharks. And if I'm on land and meeting the boat, that they're recording the right species and size.

Lauren: Actually, this kind of leaves me… because a lot of Canadians don't even realize that having sharks in our waters are normal, so do you… do you see a lot of shark interactions or are they kind of few and far between?

Mackenzie Collard : When it comes to actually interacting with the sharks, I generally see them when I'm out on the water and I don't always directly interact with them. If I'm on a fishing boat when they're releasing them, or when they're unfortunately keeping them because the shark has died, then I'll sort of get a closer look and have more of an interaction with them, but I kind of enjoy just seeing them when I'm on the water doing this thing.

Mikey: For sure. Do you have any interesting or cool shark stories that you've encountered over the years?

Mackenzie Collard :  Yeah. So, I have had quite a few interactions with sharks, but one that I… kind of sticks with me because it's one of the cooler ones that I have, I was out on the water doing inspections on lobster boats in the Bay of Fundy, when I was working on Grand Manan Island out of New Brunswick. And when we are going between boats that we were inspecting, I ended up seeing what was eventually… there were white lines under the water in sort of an oval shape, and it's kind of hard to recognize a basking shark at first because they're so large and you don't exactly see all of them at once, since they’re dark on the top.

Eventually I noticed that it was a basking shark, and the boat that I was on was about 30, 32 feet and the shark was about the same size as our boat; so, a massive shark. We obviously slowed down to let the shark transit around where it was going to do, and after looking around a little bit, we noticed that there was about five or six other basking sharks in the same area, just filter feeding around us. So, like anyone would do, we sort of just hauled off the power and hung around and watched the sharks for a couple of minutes before keeping going on our way.

Lauren: Oh, my goodness, I don't… I honestly don't know how you do it, I would… I would just be terrified, but that’s me!

What fascinates you the most about sharks?

Mackenzie Collard : Sharks themselves are just really complicated. I studied marine biology in school, so I know probably a little bit more about sharks than I should. And to be honest, even though I studied them, we still don't know everything that we could possibly know or would want to know about sharks.

One thing that I think is sort of the coolest thing about them is this ability called tonic immobility. And that’s when a person stimulates the sensory organ in the front of the shark's nose and turns it upside down. And they just sort of freeze like they're paralyzed, until you flip them around the right way and then they’ll keep swimming off, but for a temporary amount of time they just sort of freeze and float there, and it's kind of cool.

Mikey: That's pretty crazy, I had no idea about that.

Mackenzie Collard : Yeah.

Mikey: In terms of misconceptions, is there anything that surrounds sharks that you kind of want to clarify or just kind of share a misconception that people may think?

Mackenzie Collard : Yeah. One of the biggest ones that I hear from people, when I'm going around, is that sharks are contributing to massive fish population decline and that they’re eating all the fish, and that they’re a big problem for the ocean and they should be removed, or their population should be lowered.

From what I know, and from what many other people know, is that's just not true, sharks are incredibly important for the marine ecosystem. Yes, they are a top predator in the ecosystem, but what they do for the ecosystem is help balance other fish populations and ensure that we have a healthy ecosystem to continue.

Lauren: Absolutely. And so, we've had previous episodes just talking about fishery officers, what they do, and we've learned that education is a big component of the job…

Mackenzie Collard : Hmm.

Lauren: … Of a fishery officer. So, can you explain a bit kind of how you go about the education aspect when it comes to sharks?

Mackenzie Collard : A lot of the time I'll be on a vessel speaking with fishermen and they’ll sort of comment that they've had an interaction with the shark, and I use that as an opportunity to sort of speak about why sharks are important. Apart from that, especially being in Halifax, I have the opportunity to interact with the general public, sort of on public wharves and what have you, and that's also a wonderful opportunity.

But we also have school visits that are scheduled, so we get the opportunity to go speak with grade school kids and talk about the importance of the ocean, the importance of conserving the ocean. And generally, sharks get worked into that because kids love sharks – and who doesn't – and they always want to talk about it know if you've ever seen a shark or been attacked by a shark or… Some of their questions just make me laugh sometimes. But generally, it’s whenever I get the chance to speak with people or if I have a scheduled school visit.

Lauren: I love that. And I think you must run into a lot of interesting thoughts about sharks, because in the movies we see sharks in a certain way, movies like Jaws, when I was growing up, and movies where sharks aren’t portrayed as the friendliest of animals. And I know with that, we have to do a lot of work for conservation efforts, which may… it's hard to mix the two when people are looking at an animal they might be somewhat afraid of.

So, how do you go about with conservation efforts in the face of people kind of maybe not knowing about sharks the way they should?

Mackenzie Collard: Yeah, it's hard. They're not exactly the cute and cuddly type creature that a lot of conservation initiatives have, it's very easy to look at a puppy or a panda and want to immediately try and help it, whereas sharks are a little bit on the… to put it nicely, the uglier and scarier side of the world.

I think the easiest way to understand how and why sharks are important is really to just – and it's not the exciting thing – but it's to do some reading online and really try to figure out why and how sharks are important to the ecosystem, and why not having any sharks is ultimately an unhealthy ocean.

There's also a lot of things you can do apart from just learning, and a lot of that involves either donating to a conservation group, looking into some initiatives that there are for sharks. Or even something as simple as looking up what fish you eat, what fishery that comes from, how that impacts sharks or the products that they buy, whether they be beauty products, cleaning products or the more obvious ones that have fish.

Mikey: That's very interesting. You really touched on different aspects of awareness that could relate to a way that affects the shark in a negative way.

Lauren: It's so interesting because, especially in Canada, we don't hear a lot about sharks in our waters and people are surprised to know that they're here. And I mean, I don't think we even realize how much they are at risk, so this is incredibly eye-opening.

Is there… if you had, I don't know, and I don't want to put you on the spot, but if I asked you what your favorite kind of shark was, would you be able to answer that? (laughs)

Mackenzie Collard : (laughs) Ah, I don't know, they're all really neat. Some of my favourite ones are ones that I've seen in person, which would be a nurse shark, but they're not the biggest and baddest of the oceans.

I have to say that thresher sharks are really neat, or Greenland sharks. And Greenland sharks are an incredibly deep-living ancient species that we don't know a lot about and they're very hard to research, so I just kind of like the mystery around them.

Mikey: We work on the social media team, so we do a lot of the filler content and stuff, and Greenland shark is always one of my go-tos for these quotes and facts…

Mackenzie Collard : Oh really!

Mikey: ... about them. Yeah. And the photos that we got are… there's like one or two, but they’re really neat because they don't look like sharks, they look like different species because they're so deep in the ocean.

Mackenzie Collard : Oh, I know. They look like dinosaurs, it's so cool. I really think the most important thing is that sharks, although they look scary and you should give them their space, they’re ultimately the biggest chickens I've ever encountered and it's really important to protect them.

Lauren: Mackenzie, thank you so much for joining us today, this has been so much fun, and now we get to go and use all our shark knowledge and put it to good use. So, thank you.


That's a wrap on our Shark Episode, what a fun shark time we had. I love talking about sharks, how about you?

Mikey:: Yeah, for sure. I mean talk about sharks is always interesting. I grew fond of it thanks to the Discovery Channel and their Shark Week, which most of us probably have seen a couple times, so doing a podcast on this was a pretty cool experience.

Lauren: Absolutely.

And we also want to hear if there are any topics you want us to delve into, to discuss, our email is in the link below, so feel free to send us a message. Give us some feedback, we always love to hear from people listening.

And we’ll see you next time.

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