News Photo by Darby Hinkley Maddy Saddler collects a water sample from Thunder Bay while on the Lady Michigan glass-bottom boat on July 5. Saddler is a Northern Michigan University student and Michigan Sea Grant Environmental intern with Thunder Bay National Marine Sanctuary. She will give a presentation at 7 p.m. on Thursday at the Great Lakes Maritime Heritage Center.

ALPENA — Thunder Bay National Marine Sanctuary is full of history, recreation opportunities, and adventure. But it’s also a hub of scientific research.

Learn about some of the freshwater acidification research being conducted in the sanctuary in Thursday’s lecture by Maddy Saddler, called “Student Stewardship: Monitoring Freshwater Acidification in the Sanctuary.”

This free presentation in the Sanctuary Lecture Series will be held at 7 p.m., with doors opening at 6:30 p.m., at the Great Lakes Maritime Heritage Center, 500 W. Fletcher St., Alpena.

Saddler is a Northern Michigan University undergraduate student and Michigan Sea Grant Environmental intern. She will discuss what freshwater acidification is, its relevance to the Great Lakes ecosystem, and its implications. She will give details about her role as a research intern working on the ongoing freshwater acidification monitoring project with TBNMS, Great Lakes Environmental Research Laboratory, and Michigan Sea Grant. Saddler will also talk about ways community members can learn more about and get involved in climate change science in the sanctuary.

“As our planet continues to warm due to anthropogenic activity, waterbody temperatures rise simultaneously,” a press release from TBNMS explains. “Accounting for nearly 70% of the Earth’s surface, both marine (salt) and freshwater bodies act as massive carbon sinks, absorbing atmospheric CO2, largely emitted by humans.”

Saddler, an Alpena native, recently collected water samples from Thunder Bay while out on the Lady Michigan glass-bottom boat.

“Through research, education, and community involvement, the sanctuary team works to ensure that future generations get to enjoy these underwater treasures like you’ve seen today,” Saddler told Lady Michigan passengers over the sound system on the boat on July 5. “Not limited to shipwrecks, we also facilitate other science in the sanctuary, such as climate change, invasive species, lake biology, geology, and water quality.”

She went on to explain the current freshwater project.

“For the next few years, we will be looking at acidification of the Great Lakes,” Saddler said. “You may have heard of ocean acidification, as that has been heavily studied, but a similar process occurs in freshwater bodies like Lake Huron. So, the process of acidification starts with a gas called carbon dioxide. Water bodies like Lake Huron absorb atmospheric carbon dioxide. That carbon dioxide reacts with the water and creates carbonic acid, which reduces the water’s alkalinity, or its resistance to acidity.”

Saddler talked about the dangers to living organisms.

“Increasing acidity in water can make it difficult for fish to perform basic activities like eating, growing, and reproducing,” she said. “Acidification is often referred to as the osteoporosis of the sea because it also makes shells thinner and more brittle. Increased acidity can also increase the growth of harmful algal blooms that are toxic to humans, animals, fish species, and it can really disturb the lower food chain population of the Great Lakes.”

On July 5, she took samples from the site of the William P. Rend shipwreck.

“To learn more about this problem, we will be taking water samples from six sites here in the Thunder Bay National Marine Sanctuary,” Saddler said. “For our freshwater acidification research, we had our scuba dive team take samples at depth during this season’s mooring buoy deployment.”

She uses a peristaltic pump that transfers water from the tube into a sample vial, which is then sent to GLERL in Ann Arbor to be processed and analyzed by Dr. Reagan Errera. The results are analyzed for changes in water chemistry to determine how much climate change is affecting the Great Lakes.

For more information, call 989-884-6200.