Signs of spring in chilly coastal waters

Wind and a cool drizzle did not deter a group of new volunteers as they ventured down to the end of the Harpswell peninsula near Basin Point last Monday to learn how to spot evidence of spring among the tide pools. The group included Lynn Knight, a trustee for the Harpswell Heritage Land Trust, Sandra Lary, a biologist for the U.S. Fish and Wildlife Service in Maine,  and Richard Rotnem, a master gardener, who have all agreed to monitor a marine seaweed commonly called “rockweed” (Ascophyllum nodosum) as part of the Signs of the Seasons monitoring program.

Using their backyards and community open spaces as laboratories, participants in the Signs of the Seasons program help scientists document the local effects of global climate change– a citizen science project that fills a gap in regional climate research. Hundreds of trained volunteers observe and record the phenology (seasonal changes) of 19 common plants and animals living in their own communities. In addition to rockweed, other target species include red and sugar maples, American robins, common lilacs, wood frogs, and monarch butterflies. Species are selected for observation because they are common and easy to identify, and because of their importance for understanding the ecological, economic, and cultural effects of climate change.

For volunteers like Lynn, Sandra, and Richard, with access to the shoreline, Coastal Signs of the Seasons is an opportunity to provide scientists with information on rockweed, an ecologically and economically valuable species with a range that stretches from the Mid-Atlantic coast, all the way up to parts of Greenland. Coastal observers measure the growth and development of rockweed and the timing of reproductive receptacle maturation, triggered by warming coastal waters in the spring.

In addition to learning the protocols for tracking these seasonal reproductive changes, Lynn, Sandra, and Richard learned how to observe and record rockweed age and growth rate, and the salinity and temperature of seawater near their monitoring sites. Signs of the Seasons volunteers in eight other communities from Portsmouth, New Hampshire, to Beals, Maine, have established monitoring sites to track these changes in their local rockweed, and there are many other locations where additional observations could help to fill in the gaps.

This information helps Signs of the Seasons’ collaborating researchers, like Dr. Jessica Muhlin, a seaweed scientist and marine biology professor at Maine Maritime Academy, understand how climate-related changes in the intertidal zone may affect the growth and timing of rockweed reproduction, and related impacts on other species that live there.

University of Maine Cooperative Extension and Maine Sea Grant coordinate the Signs of the Seasons program in partnership with the USA National Phenology Network (USA-NPN), Acadia National Park, Schoodic Institute, US Fish and Wildlife Service, Maine Maritime Academy, Maine Audubon, Coastal Maine Botanical Gardens, and climate scientists and educators at the University of Maine.

To learn more about the Signs of the Seasons program, or to become a volunteer, please visit the Signs of the Seasons website.