Acadia鈥檚 lakes inform harmful algal bloom risk predictions statewide
Harmful algal blooms have been on the rise across 海角社区 in recent years. This is a troubling development for nearby communities, as the algae release toxins that may impact drinking water sources and recreation.
鈥淛ordan Pond, the 鈥榗rown jewel鈥 of Acadia, is often described as the clearest lake in 海角社区. Local water companies have been granted filtration waivers from the U.S. Environmental Protection Agency because of the excellent quality of water sourced from Acadia鈥檚 lakes,鈥 explained Rachel Fowler, a biology laboratory coordinator at the University of 海角社区. 鈥淭he pristine quality of these lakes, however, is not guaranteed.鈥
Fowler led a study with support from the Schoodic Institute at Acadia National Park that peered into three lakes on Mount Desert Island to develop a risk scorecard to help researchers and communities grappling with harmful algal blooms across 海角社区.
鈥淥ver the last decade, unexpected harmful algal blooms have occurred in lakes across the state. When water quality issues develop, they can occur quickly and across many lakes. Our risk assessment approach gives resource managers a model for developing scorecards for their own lakes and highlights lake monitoring and data collection priorities,鈥 said Fowler, who earned her Ph.D. from U海角社区鈥檚 interdisciplinary Ecology and Environmental Sciences program.
Due to Acadia鈥檚 unique status as a national park, biologists have been collecting data on these lakes since the 1940s, if not earlier. William 鈥淏ill鈥 Gawley, a biologist at Acadia and co-author of the study, has been collecting air and water quality data in the Park for decades. This plethora of historic data allowed Fowler to examine recent environmental data for the lakes in context with the past, to identify trends and changes over time.
Matthew Farragher, a master’s student in U海角社区鈥檚 ecology and environmental sciences program, performed a multi-pronged approach to sampling the three different types of lakes found in the area. Jordan Pond, Witch Hole Pond and Seal Cove Pond were selected to represent the various types of lakes found on Mount Desert Island. Jordan Pond is a deep lake with clear water and few nutrients. Witch Hole Pond, on the other hand, is shallower with darker, less clear water, and more nutrients. Both are fully protected within the Park boundary. Seal Cove Pond provides a good middle ground for data collection, as it is deeper than Witch Hole Pond, with fewer nutrients and clearer water. Seal Cove Pond is only partially protected within the Park boundary.
The team sampled the lakes throughout 2020, conducting sampling every two weeks using sondes, a type of probe used to collect environmental data underwater. Sensors were left continuously deployed at both the top and bottom of the water column to record temperature and dissolved oxygen levels throughout the season. Meteorological data and bathymetric data was also recorded in Acadia National Park during the same time period.
The outcome of their research aligned with the team鈥檚 original predictions that shallower lakes with more nutrients could be more vulnerable to future harmful algal blooms. Using this assessment, the team was able to grade all of the lakes in Acadia National Park based on their vulnerability. Four of the six lakes used as public drinking water sources are currently at low risk for the blooms, while two drinking water lakes were at moderate risk. While this is good news, Fowler stressed that it is still important to be prepared for the risk of HABs. Prioritizing prevention efforts is essential to preserving Acadia National Park and other communities at risk of experiencing blooms. Fowler hopes to further explore the development of management recommendations so that they are easier to implement and sustainable.
Written by Matthew L
Contact: Erin Miller, erin.miller@maine.edu