...if our kelp tank fish eat... other fish? (with Erin Shusterman)

Ever Wonder? / March 16, 2022

...if our kelp tank fish eat... other fish? (with Erin Shusterman)

Image
Wearing a wetsuit with her hair pulled back as she stands in the California Science Center's dive locker, Erin Shusterman holds her coffee mug in a gesture that seems to say "cheers"
Image attribution
Courtesy of Erin

If you ever visit the kelp tank at the Science Center, you might notice that we have a complete ecosystem on display, including both predators and prey. So, naturally, people often ask our staff if the fish eat each other. 

Ever wonder if our kelp tank fish eat… other fish? 

It is a rare event. But to answer this question, we’re digging into our archives to bring you an unaired clip from our past interview with Erin Shusterman, the interim director of husbandry here at the Science Center. She leads the team of keepers and aquarists that takes care of all our animals. In this clip, Erin breaks down how her team carefully feeds the animals in the kelp tank to keep everything in balance. 

Have a question you've been wondering about? Send an email or voice recording to the podcast team to tell us what you'd like to hear in future episodes. 

Subscribe to our show on Apple Podcasts, Spotify, or Google Podcasts. To see a full list of episodes, visit our show’s webpage

Transcript

Perry Roth-Johnson (00:06):

Hello! This is Ever Wonder? from the California Science Center. I'm Perry Roth-Johnson.

Perry Roth-Johnson (00:12):

If you ever visit the kelp tank at the Science Center, you might notice that we have a complete ecosystem on display, including both predators and prey. So, naturally, people often ask our staff if the fish eat each other. Ever wonder if our kelp tank fish eat... other fish? It is a rare event. But to answer this question, we're digging into our archives to bring you an unaired clip from our past interview with Erin Shusterman, the interim director of husbandry here at the Science Center. She leads the team of keepers and aquarists that take care of all our animals. In this clip, Erin breaks down how her team carefully feeds the animals in the kelp tank to keep everything in balance. Talk to me a little bit more about how you feed the animals. Uh, you used this phrase in the, the past... target feeding, is that right? Explain what target feeding is and how that works.

Erin Shusterman (01:06):

Um, so there's two types of feedings that we do, uh, what we call broadcast feeding, where we just kind of throw chopped up food into the water and scatter feed it for the animals. And then they're kind of responsible for getting little pieces for themselves. And then the other type that you've mentioned is target feeding, where we actually go down, we'll have a container of food that's specially prepared for a group of animals. And we clearly define what each group of animals should be like, what species should be included in it. Um, most of those groups are created based on the size of their mouth so that we can prep similar size pieces of food, um, for them. But we'll go down with the container that has that food that's already prepared for them. And we actually use, like, they're kind of like plastic salad tongs to be really honest.

Erin Shusterman (01:46):

Oh really? Yeah. Like we literally get them at, at the same places as you might go to get, you know, stuff, if you're having a picnic with your family. Um, but we do all plastics, so it doesn't hurt them cause metal or things like that could, but we basically just take a piece out of our container and we offer it to them. We really like kind of hand it. Sometimes we'll dangle it in front of their face if they're more of like an ambush predator, um, or if they're more of like a shy type of animal, um, we might just kind of throw it close to them and then they're responsible for eating it or then, you know, if they don't, we'll pick it up, sometimes we'll put it back sometimes we'll offer it again. So we do that with, I would say probably 75%, if not more of the population in the kelp tank to make sure that everybody is getting, um, really what they need. Um, again, that exhibit is very special in the fact that we have predator and prey together, which not many places choose to do, but our whole message with that tank is that it's a complete ecosystem. It has live algae in it all the way up to the top predators, um, that would exist in an ecosystem. And so that's a fine balance with predator and prey in the same environment, but we balance it through feeding. So by target feeding as much as we do, it's a lot more work, but it also kind of helps to make sure the animals are getting really what they need.

Perry Roth-Johnson (03:05):

And since you have predators and preys, like the natural question is, do the fish ever eat each other? Like we've seen sharks, you know, not, not huge sharks, but uh, there's, there's definitely, uh, sharks and other predators in there. How, how do you guys handle that?

Erin Shusterman (03:17):

That's a really good a question and it's one that we get asked quite frequently. Um, every once in a while nature does take its course and we will have where a predator looks like they've gone after a prey species. For the most part though, I have to say again, we've balanced it really well through their diets. So, you know, that may mean that we up the amount we feed, like our sharks and our large giant sea bass or things like that. Um, but for the most part, we have been very it's it's been a long time coming and a lot of hard work, but we've been able to balance that well enough where oftentimes like the other day, um, I was walking by the, the big wind to the big viewing window that we have and our large giant sea bass literally had what would normally in nature be his favorite snack, but it literally just swam right in front of his face and he just watched it.

Perry Roth-Johnson (04:12):

Really?

Erin Shusterman (04:13):

You know, and I think, yeah, I think that's, uh, a testament to how well we balance their diet so that, um, again, it's not in possible, but for the most part, it doesn't happen very often.

Perry Roth-Johnson (04:23):

That's our show, and thanks for listening. Until next time, keep wondering. Ever Wonder? from the California Science Center is produced by me, Perry Roth-Johnson, along with Devin Stewart and Jennifer Aguirre. Liz Roth-Johnson is our editor. Theme music provided by Michael Nickolas and Pond5. We'll drop new episodes every other Wednesday. If you're a fan of the show, be sure to subscribe and leave us a rating or review on Apple Podcasts. It really helps other people discover our show, have a question you've been wondering about, send an email or voice recording to everwonder@californiasciencecenter.org to tell us what you'd like to hear in future episodes.