GEOFF BENNETT: This year marks the 50th anniversary of "Jaws," Steven Spielberg's 1975 blockbuster about a ravenous great white shark.

The film, which drew big crowds during a special rerelease this weekend, terrified audiences back then, packed theaters and left behind a lasting fear of sharks.

But while many Americans remain afraid of them, shark attacks are rare and the species itself is widely misunderstood.

William Brangham is back with more.

WILLIAM BRANGHAM: On one hand I mean, it makes perfect sense why many of us fear sharks.

But the fact is, the general public really doesn't know all that much about these ancient creatures.

So to sort out some common misconceptions, we are joined by Keith Cowley.

He's a shark historian and conservationist.

Keith, thank you so much for being here.

Thanks to movies like "Jaws" and more recent shark movies, as well as The Discovery Channel's seemingly ubiquitous "Shark Week," it is no wonder that Americans view sharks as these ravenous, bloodthirsty killers.

Overall, though, when you look at the species, how accurate a portrayal is that?

KEITH COWLEY, Curator, Living Sharks Museum: Well, I don't think it's an accurate portrayal at all.

Of course, we all fear that which is primal, whether it's lions, tigers or bears or sharks.

We have a visceral reaction to this idea of a toothy predator in a domain that we can't control.

Historically, we have always been very intrigued.

I think, as different networks and different programs continue to produce content that taps into that, sharks are always going to be a topic of conversation worldwide.

But I don't think this is the right message to send in the majority of cases.

But it can be a gateway to talk about the actual science and the real life behind the sharks.

WILLIAM BRANGHAM: I mean, a lot of your work is about helping us understand sharks better, to understand them, even demystify them.

What do you think that the -- most of the rest of us don't quite get yet?

KEITH COWLEY: Well, I mean, I'm guilty of this too, especially as a youngster.

When you cherry-pick that one animal that really excites you and you pull it out of its environment mentally and in your heart, of course, when you're really passionate about it, it's easy to forget that they're actually a core member of a complete ecosystem.

And without the rest of the organisms in that ecosystem, the shark doesn't survive.

And without the shark, the rest of that ecosystem doesn't survive.

So I think, in order to better understand the shark and sort of shed our fear of it, we start to get to learn the environment that the shark lives in and demystify it, if you will.

WILLIAM BRANGHAM: Sharks are also at risk now, with nearly a third of the species that are currently threatened with extinction.

What is it that is threatening sharks today?

KEITH COWLEY: Yes, the biggest threat facing sharks today, unfortunately, is overfishing.

That's what the data shows for us.

And that means it's a human threat.

So the issue is that there are lots of improved types of fishing gear being utilized all over the world.

And there's a lot of different types of indiscriminate fishing going on as well.

So sharks end up as bycatch.

Sometimes in places where sharks are not protected, they're being overfished.

And, unfortunately, they're being overfished to the speed that we're not even ready to study all these different species.

And we're just scratching the surface of really getting to know them.

WILLIAM BRANGHAM: People always want to know, is there something that they can do in their own consumer behavior that can protect sharks?

Is that -- oftentimes, that's like what kind of fish they buy or eat.

Is there anything that you would counsel people to do who care about shark preservation to change about their own habits?

KEITH COWLEY: Yes, I think, as a whole, it's probably a healthy, good practice to read the ingredients on everything we consume.

It's really important to know where our food comes from.

We do a relatively good job in the United States with that, but sometimes things get renamed or mixed in with other ingredients that we think are one thing and happen to be another.

Sharks are a whitefish that tends to get lumped in with fish and chips in other countries.

Sometimes, you see it as a fried bite.

Obviously, shark fin soup is a major issue in other countries, shark liver oil and other products.

But as far as the consumer is concerned, I think it's just important that you know where your food is coming from.

We prefer you don't buy shark products or anything that's related to shark just because we are trying to protect them as a species overall.

Unfortunately, we had hunted them down to near extinction around the world after "Jaws" in 1975.

WILLIAM BRANGHAM: We know that sharks, generally speaking, are not that aggressive towards people.

There's I think it's roughly 100 attacks per year, compared to the millions of people that get into the ocean every year.

But let's just say someone does encounter a shark.

What are they supposed to do?

KEITH COWLEY: I always tell folks that come into the museum that ask me this question that anything I tell you to prepare yourself for an interaction with a shark, you're going to forget immediately when it happens.

So there's a lot of folks out there trying to give some great advice about interacting with sharks.

There's a lot of different conditions that can occur when sharks might be in our proximity.

And, unfortunately, there's no foolproof answer to that question.

I think what's more important to take away from that is that the odds are extremely slim.

I mean, I think, be aware of your surroundings.

There's a lot of communities that are doing some great public outreach to help people become more educated in the situation that they're putting themselves in.

For example, in Cape Cod, in the waters off Cape Cod, where sharks, great white sharks, in particular, are cruising in seven to 10 feet of water all day long, there are some scenarios where you don't really need to put yourself at risk.

But, in most oceans in the United States, this is not an issue that you have to be concerned with.

WILLIAM BRANGHAM: All right, Keith Cowley, shark historian and conservationist, thank you so much for your time.

KEITH COWLEY: You're welcome.

Thank you for having me.