Changing Phytoplankton Communities in the Gulf of Maine

By Michael Staiger

This fall, I worked with Research Scientist Nicole Poulton to investigate how the species of phytoplankton in water is changing.

What are phytoplankton? In the ocean, phytoplankton are made up of lots of different tiny organisms that just like plants on land, can photosynthesize. They have various forms and strategies for life. These different types of phytoplankton, just like the plants in your garden, all grow best at different times of the year.

In the Gulf of Maine, typically the fall season is dominated by phytoplankton called dinoflagellates. However, recently seasonal trends in community structure have been changing. Just like in a garden, warmer ocean temperatures can affect when and which “plants” grow.

The Gulf of Maine is one of the fastest warming bodies of water in the world. As temperatures continue to increase, communities of phytoplankton in the Gulf could change. And we have seen some of this change already. Using a machine called a Flowcam, we are able to explore what phytoplankton are in the water. A Flowcam funnels water past a camera that takes high speed images of each cell as they go by. This tool allows us to see how the communities  are changing, and get really cool pictures of the critters in the water!

Some of these phytoplankton produce toxins that can be harmful to both the organisms that eat them and to humans. One example of a potentially harmful species we have seen recently in the Gulf of Maine is Dinophysis, which can produce toxins that accumulate in oysters. Eating oysters with high levels of these toxins can make people sick, so high numbers of dinophysis in the water could force oyster farms to close.

As waters continue to warm and phytoplankton communities change, it will be important to know what species have moved into the Gulf of Maine so we can protect industry and our favorite foods from the ocean.

Mike Staiger is a Colby College student in the 2020 Sea Change Semester Program at Bigelow Laboratory. This intensive experience provides an immersion in ocean research with an emphasis on hands-on, state-of-the-art methods and technologies.

Changing Phytoplankton Communities in the Gulf of Maine