Corallines for Climate

Post by Scallop Research Intern, Bailey Moritz

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Branwen (left) and Cait (right) get ready to plunge into the cold Acadia waters in search of coralline algae.

Collaboration in science is really useful for carrying out successful research. Maybe you don’t live in the same place as what you are studying. This is the case for Dr. Branwen Williams, a researcher and professor for the Claremont Colleges in California, who is investigating coralline algae from its southern limit in Maine all the way up to the Arctic. Cait has collected samples for the past couple summers to send back to Branwen, but this year she made the cross-country trek to dive for the algae in Acadia National Park herself. The Schoodic Institute was generous enough to host us while we carried out a total of 5 dives to first find the algae, deploy a temperature probe at depth to monitor the algaes growing environment, and collect about 140 coralline samples to be shipped live back to the lab.

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Field work can require a lot of gear and talent to pack it all in.

A “modern paleo oceanographer using marine organisms as tools to look at environmental change,” Branwen is interested in the calcium carbonate skeleton of the domed, deep-pink algae that can be used as a proxy for reconstructing past climate. Tropical corals are commonly used to understand how climate has changed in equatorial regions, but less is known about paleo climate in the mid to north Atlantic region, an area particularly susceptible to modern climate change. Depending on the water temperature, the algae will substitute Mg for Ca when building its carbonate skeleton. The Mg/Ca ratio serves as a proxy for the temperature of the ocean when the algae were growing. Similarly, analyzing boron isotopes provide insight into past pH conditions. The coralline algae can be 100’s of years old and Branwen hopes to reconstruct a record of ocean conditions back to the 1700’s.

Coralline algae, which form a crust-like cover over anything from rocks to mussel shells, may be threatened by warming waters as they grow best in the colder climes. This could take an ecological toll, as they are substantial habitat builders in more northern latitudes. We’re excited to hear what Branwen and her colleagues discover from these little corallines! The more we understand about how climate change is impacting marine creatures, the better we can prepare ourselves and our local environment.

Maine Science Festival: Climate Change Panel

On Saturday, March 21st, 2015, I participated on a panel about climate change in Maine at the first Maine Science Festival, which was a fantastic event that drew 10,000 people of all ages to interact with science through presentations, workshops, and other events. The panel was moderated by Linda Silka, the former Director of the Margaret Chase Smith Policy Center and a Professor in the School of Economics. Our panel group opened with an overview of climate change in Maine by Dr. Ivan Fernandez. He is a professor at the University of Maine in the forestry department and the Climate Change Institute and he played a significant role in writing the 2009 Maine's Climate Future report and the 2015 update, the culmination of a voluntary effort undertaken by a number of researchers in Maine at the request of Governor Baldacci. 

 Dr. Mathew Chatfield, an assistant professor of conservation biology at Unity College, followed Dr. Fernandez's talk. Dr. Chatfield studies amphibians and reptiles and he focused his presentation on talking about the challenges certain species with narrow ecological niches face as temperatures increase and precipitation patterns change; those species face real barriers to survival.  

One of my presentation slides

My presentation focused on evidence of warming water temperatures and ocean acidification, and the ecological and socioeconomic implications these changes have for important species in the Gulf of Maine. Scientists at the Gulf of Maine Research Institute believe the Gulf of Maine is warming faster than 99% of the world's ocean. Others in the state have attributed the lack of the Northern shrimp (Pandalus borealis) fishery, which is closed for the second season in a row, to warmer water temperatures altering the timing of the spring phytoplankton bloom and the release of shrimp eggs into the water column. The two events used to be synchronized so that larval shrimp could maximize feeding on the ready supply of phytoplankton; however, the timing of each event has shifted due to changes in water temperature. The result is that shrimp larvae are not getting the nutrition they need to survive. I also pointed to other examples of changes in the marine system, including the range expansion of black sea bass and the devastating effects green crabs have had on valuable nursery habitats and on our clam fishery, the third most valuable commercial fishery in the state. These examples are occurring partially because of warming waters and ocean acidification.

Finally, Dr. Caroline Noblet, a professor in the School of Economics at the University of Maine, concluded the discussion by speaking about the public perception of climate change and how to tailor messaging about evidence to initiate action. Once we wrapped up our presentations, the audience asked excellent questions about how to move policy and other initiatives forward to mitigate climate change effects and how communities can adapt to changing conditions. The discussion was engaging and I left the presentation feeling encouraged that people are paying attention and thinking about solutions to this critical issue.