Interview with Monte McGregor

Monte McGregor is director of the Kentucky Department of Fish and Wildlife Resources, Center for Mollusk Conservation, in Frankfort, Kentucky. The Center was founded in 2002 “to restore and recover rare and imperiled freshwater mollusks in Kentucky”. Monte works with researchers doing freshwater mussel propagation all over the United States and also extensively with the Freshwater Mollusk Conservation Society. He focuses his conservation efforts on endangered or rare freshwater mussels and has worked with more than 60 species over 18 years including 15 federally endangered species. He’s even worked with the last individuals of several species and remarkably restored some from the brink of extinction. His team releases thousands of mussels into streams and lakes each year to supplement and augment low populations.

“Any facility that wants to do freshwater mussel cultures, they come here, visit us and see how we’re doing things. We share our information with them and show them all the cool stuff we’re using.” ‑Monte

Monte got his start, as an undergrad in 1988, working with mussels at a biological station for $3.35/hour. Once introduced to them, he saw the need for conservation and propagation. He got into the aquaculture side of things to reverse the trend of decline in the wild and for the last 25 years, Monte’s been taking rare animals from the last places they’re found, and restoring them to their historical habitats through propagation, culture, and translocation.

Freshwater mussels are unlike most marine mollusks, because they have a parasitic life-stage that needs to live on a fish for up to 3 weeks as they become juveniles. At the Center for Mollusk Conservation they use the novel in vitro technique that allows them to “host” developing mussels on petri dishes, instead of fish. Traditionally, 500-600 fish would be needed to host 10,000-20,000 juveniles, but now they can easily produce hundreds of thousands of them, or even millions with in vitro.

Since 2004, they’ve increased the number of North American fauna that can be transformed on a petri dish (in vitro) from 19 species to over 70 species today. Once off the fish (or dish), they develop anatomically: starting with a rudimentary gill, with limited separation ability, growing into a fully functional siphoning juvenille. It takes 10-20 weeks for this development and is also one of the most critical stages. After that, they can feed from naturally occurring lake algae at a nursery-like facility.

“These different developmental stages require different food. But no one really has published that information; there are only a couple of us out there that know that.” ‑Monte

In 2004, a gap in knowledge of freshwater mussel diets lead Monte and his team to start identifying appropriate feed for raising juveniles. They started experimenting and eventually settled on 3 to 4 algal species to define different diets. They started purchasing algae, but some of the most integral diatoms for providing lipids are not available commercially, so they needed to grow them themselves.

“We’ve got to have that mixture…no one algae species is going to work for everything.” ‑Monte

“This diatom is so difficult. We need to keep that culture going, so we’ll harvest a little bit of it, and let the bioreactor fill back up, and culture and harvest a week later, and do it again, and it won’t get contaminated.” ‑Monte

They assessed several methods and technologies for growing these strains of diatoms and even developed their own reactors, but all the methods had tradeoffs and downsides. In 2015, after assessing available technology, they purchased an Algae Bioreactor from Industrial Plankton to grow this critical diatom: Phaeodactylum. They inoculate directly into the Bioreactor with a pure strain from the lab and are able to to consistently produce it in mass, without contamination for up to 6 months as time.

“The bioreactor, gives us the ability to produce a lot more than we could have before. We start out in a lab, but being able to move into a thousand liters, is pretty important in order to raise the mussels we have.” ‑Julianne, (algae biologist)