Casey Snook
woman holding butterfish wearing binoculars thumbs up


Olivia Smith, a longtime Shoaler, recently had her first paper published on the diets of common terns on White and Seavey Islands. In collaboration with Dr. Liz Craig, our Director of Seabird Conservation, Olivia surveyed the types of fish consumed by nesting terns and how this can be an indicator of climate change in the Gulf of Maine. Her paper is titled Effects of Atlantic butterfish (Peprilus triacanthus) in diets of Common Terns (Sterna hirundo): a case study of climate change effects in the Gulf of Maine. 

Casey Snook, SML’s communications coordinator, interviewed Olivia to learn more about her study.  


C: Tell me a bit about yourself. Where did you go to school and what’s your history with Shoals? 

O: I did my undergrad at UNH, and I met Liz (Dr. Craig) in my freshman seminar course. She gave a talk on the tern project, and I thought it was so cool. I hadn't been interested in seabirds before then. I mean, I've always loved birds, but I was like, wait, these are so cool! 

So that's how I got connected with Liz, and then she had an opportunity for me to do undergrad research with her, so that's how I started doing that. For my independent project work, I was reviewing the video cam footage of the terns, so I did that remotely. I then asked a couple of research questions and those are what eventually got developed into the paper that came out. 

C: Is this your first paper that you’ve gotten published? 

O: Yes, it is. 

C: Congrats, that’s a big deal! 

O: Thanks! 

C: I'm wondering what drew you to study the terns at Shoals in the first place?

O: Well, like I said, I always liked birds, but I was doing marine biology and I never thought there would be an opportunity to combine those two until that talk about seabirds.

I think it was really amazing to be able to observe, especially with the cam footage, [because] you're not impacting the bird's behavior at all. It's kind of like a window into what their life is like. They have really great parental care, it's super interesting. I think the terns especially are expert samplers of the ocean. Since we can see the fish that they're bringing back and visually ID their diet, that's super special, especially since they're bringing back fishes that are normally not captured by human data collection because they're so small. I think those are the most interesting things about those birds.  

C: What was the origin of this study that turned into the paper? Did this study come about because it's a long-term project or did you develop research questions? 

O: It's rooted in the long-term diet data set, and Liz had this idea about butterfish which have been observed being consumed in other seabird species, but they're becoming more common in the Gulf of Maine because they prefer warmer waters. They’re really deep bodied, they're shaped like a goldfish cracker.

C: I’ve seen them on the menu at sushi places before. 

O: Yeah, I need to try it sometime. 

They're very difficult for chicks to swallow because of their shape, so Liz had some ideas of looking into how butterfish are impacting chick growth and how they interact with that prey item.  

C: How can the diet of terns inform us about climate change? 

O: So, like I just talked about, they're such good sentinels that they're sampling these fish communities, so we can see how their diet is changing and we can compare that to water temperature. That's a pretty clear indicator of the impact of climate change on marine communities.  

C: What does the trend look like? 

O: There are significantly more butterfish seen during the more recent decade on White and Seavey [Islands] and that correlates pretty well to increasing water temperatures.  

[For] my research, I only looked at three years of data so we couldn't make those broad generalizations. I think that's something that Liz is looking at, because she's looking at a longer-range data set, but yeah, the trend is warmer water is correlated to higher proportions of butter fish in the diet. 

C: What is it like working with Dr. Craig and the rest of Shoals Marine Lab? 

O: It's so much fun! I think I only have positive things to say. Being able to live on the colony is really unique because you're so immersed in it. You hear the birds 24/7 and you step outside and you're seeing your study species. I think that's really unique- to be living in close quarters with your studies species. 

Shoals is a pretty good community to be part of. I was part of it before I even went to undergrad. I took the Marine Immersion course as an incoming freshman. Shoals has definitely offered me things through many different phases of my academic career.  

C: That's awesome. So, did you take any other classes here?  

O: Yeah, I took Marine Immersion, and then after I talked to Liz, she suggested that I take Field O[rnithology] to get bird stuff down, so I did that. And then I was a SURG (Shoals Undergraduate Research Group intern) remotely in 2020, and then I did two seasons on White and Seavey. 

C: So, you have a really long history of Shoals! 

O: Yeah, I do. I miss it! 

C: Are you from this area?  

O: Yeah. From New Hampshire. 

C: What's next for you?  

O: I have a job now in Boston with National Parks [Service]. I have a climate- focused internship there.  

C: What do you think, based on your findings, will happen in the future both to the terns and the Gulf of Maine in general? 

O: I think for future impacts, the study highlights the importance of preserving fishes that are suitable prey for terns. Probably there's going to be more butterfish because the Gulf of Maine is warming. I think that means it's even more important that we make conservation efforts for those other fishes that are good prey for those chicks. 

C: Do you think the terns are at great risk because of climate change and warming seas and the butterfish? What can we do to help them? 

O: Protecting those fishes. Herring is a really great fish for them, and a large portion of herring stock goes towards lobster bait, so that's an interesting thing. I don't really know enough about that to speak about what else could be used. 

[We need to] make sure that there are more suitable prey available to them in the future, especially when the waters are warming and maybe these fish that aren't as good for them are becoming more common. 

C: Is there anything else that you want to mention? 

O: I did get a scholarship for Field O[rnithology] and that really enabled me to get involved in this. I'm working with birds right now too, so that was definitely a huge financial help. Without that, I don't know how involved I would be. 


A big thank you to Olivia for sharing her story with the Shoals community. We can’t wait to see where her birdy career takes her!