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Michelle Staudinger, associate professor of fisheries science, is leading a new study at the 91���� to find out whether lobsters are being consumed by a long-known fish predator, cunner, in a new way. 

These small, vibrant fish, often associated with rocky habitats, are native to the Gulf of Maine. They are known to eat young lobster in the benthic stage, as well as small clams and snails.

Increasingly, the Maine Department of Marine Resources and commercial lobstermen are finding cunner caught in their traps. Staudinger said the lobstermen have shared photos of cunner with lobster eggs in their mouths and are concerned it’s impacting the fishery. 

The to study keystone species in the U.S., in honor of the nation’s 250th anniversary. Selected projects, including Staudinger’s lobster research, are receiving funding, equipment and other support to advance innovative solutions to contemporary conservation challenges.

Lobster and cunner have coexisted for a long time, but this would be a new behavior and new dynamic within the rocky substrate where they reside.

Cunners are unique in that they have tiny teeth throughout their jawline, which helps them capture food from rocky surfaces. They use their teeth to crush shells and other food, making it hard to recover evidence. Because of this, Staudinger said her research team will be studying the contents of cunners’ stomachs using environmental DNA. 

While shifts in community composition, distribution and timing of occurrence are all well known ecological responses to environmental change, Staudinger said researchers have a poor understanding of how these responses affect predator-prey and competitive interactions among species.

“We don’t know if this behavior has been happening and gone unnoticed or if there is an environmental factor causing it to happen now,” she said. “We would like to gather evidence to determine how widespread it is happening, and the best way to do that is to work with the fishermen who are on the water every day and see them in their traps.”

If fishermen or other stakeholders find cunner with lobster eggs in their mouths, the Staudinger Lab is asking they use the provided QR code to share photos and information or send photos to 508-348-9039 or cunner.maine@gmail.com with the date the fish was captured and its location. More information is available on the lab’s website.

91���� News recently spoke with Staudinger about what to expect from this upcoming research.

Do you suspect water temperature, population shifts and predator dynamics could be contributing to what’s happening between lobster and cunner?

These are all testable hypotheses that we’re going to be working through in this project. It’s possible there’s been a shift in timing. It could be a spatial distribution or a temporal shift that is bringing these two species together during certain life phases that they didn’t meet in previously. 

I found old historical papers that show cunner ate a lot of mollusks and other benthic invertebrates. One paper I found suggested that cunner really like to eat mussels, which have been less abundant in recent years. There is the possibility that they are exploring new food sources because others have decreased. They also might just be opportunistic, and that behavior could be leading them to take advantage of something they didn’t before.

Between equipment and personnel, what’s it going to take to find the answers?

We’re working with the Maine Department of Marine Resources to collect bycatch cunner in their ventless trap survey. When we bring those fish back to the lab, we’re doing a visual inspection of their guts and mouths, where we find and record all diet items that can be identified, such as broken shells of snails and sometimes small clams.

One fun fact about this fish is that they use their teeth to pluck organisms off vertical, complex surfaces. They also have teeth in the back of their mouths that allow them to crush things. The diet of this fish is very difficult to assess, because it can mash or chew its food with its teeth. Most other fish swallow their prey whole. So we’re using environmental DNA to detect lobster in the cunner’s stomach contents and get a full biodiversity panel of what they’ve been eating.

How might the results of this upcoming study translate to help groups like fishermen make informed management decisions?

We’re not seeing a blanket amount of evidence, so there may be hot spots where this interaction is more likely to occur. One potential result would be to show hot spots where populations of egg-bearing female lobster and cunner are overlapping. That would provide spatial information to fishermen to make informed choices about when and where they fish. There is also the possibility of developing trap modifications to exclude or deter cunner.

We might find out that this is not a widespread occurrence, which could help alleviate concerns. Regardless, understanding a species that we don’t yet have a lot of information about is always going to be advantageous.

Contact: Ashley Yates; ashley.depew@maine.edu