May 8, 2026 | Evolutionary Fish Ecology | University of Connecticut

By Emma Siegfried.

In 2019, the Evolutionary Fish Ecology lab at the University of Connecticut led by Dr. Hannes Baumann published their first paper investigating the effects of ocean acidification and warming on Ammodytes dubius. They found that levels of ocean acidification predicted for the year 2300 significantly decrease hatching success of embryos. The finding has begged the question if congener species are similarly susceptible – indicating the potential evolutionary conservation of this trait.

I began my PhD with the goal of doing similar experiments to other closely related species. One location where this would be possible is at the Institute of Marine Research (IMR), where a few scientists, notably Prescilla Perrichon, the leader of the Norwegian AQUASERV programme, have been spawning and raising Ammodytes marinus for a few years now. I applied to the AQUASERV transnational access program from the European Union and was fortunate to receive funding.

I arrived at the Austevoll Research Station at IMR in December 2025 unsure of what my time in Norway would bring. I had attempted similar experiments with Ammodytes americanus the previous winter and was not successful. In mid-January, the adult A. marinus that Reidun Bjelland had gone out and caught before I arrived began spawning. The fertilized embryos were placed in a rearing system, created with the help of Helen and Sam Rastrick, which exposed them to a combination of two different temperature and four carbon dioxide levels.

So far, we have collected data on the number of individuals hatched and how many embryos were in each individual tank initially. These values will be used to analyze hatching success and compare the impacts of ocean acidification and warming on A. marinus to the effects on A. dubius. In addition, we have photos of larvae that we can use to measure length, body area, and energy reserves. Finally, videos of the larval heart beating were taken for measurements of heart rate. In time, all this data will be analyzed and published.

I’m continuously grateful for the time I was able to spend at the Austevoll research station. It was truly the experience of a lifetime. I came out of my time in Norway with more knowledge and experience than I even thought possible and some new friends to boot. I am grateful for the support of all the staff at IMR, but particularly Prescilla, Reidun, Helen and Sam, and none of this research would have been possible without the AQUASERV program. I am very grateful for the support I received and the people that I have met through this program and look forward for potential opportunities for collaboration in the future.

16 April 2026. We are excited to share that Marine Ecology Progress Series today published our synthesis paper on Black Sea Bass in Long Island Sound!

The publication combines laboratory research on juvenile and adult black sea bass with ocean and climate modeling to make the case that these fish are already or at some point soon likely to change their habit of moving offshore in winter. This is because inshore waters are warming, so the fish can stay longer in fall and return earlier in spring, but also because the whole Northwest Atlantic shelf is warming, which reduces the distance the fish need to swim to reach overwinter habitat.

In the laboratory, PhD student Max Zavell with the help of his dedicated undergraduate assistants Matt Mouland and David Barnum conducted 2 overwinter experiments on juveniles to simulate their thermal experience of migrating offshore or remaining within Long Island Sound (LIS). Surprisingly, this showed that overwintering inshore caused only minor reductions in survival (100→84%), led to no loss in lipid reserves, but incurred a growth cost in both length and weight.

Thanks to the involvement of two inhouse physical oceanography groups (James O'Donnell, Samantha Siedlecki), we were able to project how mean LIS winter temperatures will increase from 3.2°C to 4.8°C by mid-century, which reduces the average time black sea bass cannot live in LIS by 30%, from 95 to 68d per year. A separate shelf model projected the rapid northward movement of the 10°C isotherm in February bottom temperatures on the Northwest Atlantic shelf - this reduces the overwinter migration distance from ~600 to ~120 km by mid-century!

Inshore overwintering will become increasingly feasible for black sea bass, perhaps lead to partial migration that furthers the poleward range expansion of this species.

The publication results from a particularly strong interdisciplinary collaboration of no less than 5 research labs: The Baumann and Schultz lab dedicated to fisheries and evolutionary fish ecology, the Matassa Lab with expertise in benthic ecology, the O'Donnell and Siedlecki groups dealing with modeling projections for nearshore and offshore waters in the North-Atlantic. The publication is an example of inclusiveness, given that the list of authors not only includes the graduate student as the lead, but also two particularly engaged undergraduate students, in addition to two post-doctoral researchers and the 5 more senior faculty.

Month: April 2026

Emma reflects on her research stay in Norway

A grouper on its way north – MEPS publishes Black Sea Bass synthesis paper