Mussels needed but endangered

by Joe Carlson

In an isolated chamber, amid the continuous murmur of bubbling water from the scores of experimental fishtanks, University researcher Mark Hove is studying the intricacies of the life cycle of mussels.
But he wasn’t always so fascinated with the aquatic species. “When I was an undergraduate here, I thought that probably the most boring animal in the world was a freshwater mussel,” Hove said.
But a lot has changed since then, and Hove said that mussels have become his niche in the world of biology.
“They kind of grow on you,” he said. “I figure this is what I can do to make a difference in the world.”
Hove performs his mussel research in the laboratory in Hodson Hall on the St. Paul campus. “A lot of experimental work is going on down here,” said Ira Adelman, head of the Department of Fisheries and Wildlife.
The lab is the smaller of two experimental facilities operated by the Department of Fisheries and Wildlife.
The other building, called the Fisheries and Aquaculture Facility, is much larger and provides the space required for larger experiments.
“Here, we can hold more fish, but up there (in Hodson Hall) we can do more environmental control,” said lab manager Jay Maher.
The larger facility, which is located on the other side of campus, is used for experimental aquaculture. Maher explained that aquaculture is the science of breeding and producing large numbers of fish for various reasons, including human consumption.
“Aquaculture is basically agriculture,” Maher said. “It’s fish farming, but it doesn’t have to be fish. It could be shellfish or algae,” or any number of other aquatic species.
Currently, the facility is experimenting on tilapia, an African freshwater fish that is commonly served in Chinese and Vietnamese restaurants.
The tilapia experiments are an example of the diverse range of research performed by the fisheries department. In Hodson Hall, Hove is strictly concerned with mussels.
He explained that to propagate, mussels release clouds of tiny, “Pac Man-like” organisms that attach themselves to passing fish. The mussels eventually detach themselves and spawn new mussels. However, different types of mussels attach only to specific species of fish.
“We’re trying to figure out what species of fish a mussel needs to attach to in order to complete its life cycle,” he said.
Hove said that the St. Croix River — home to 39 different types of mussels — is “the Amazon of the world in terms of the diversity of mussels.”
“If there was a river I could save, it would be the St. Croix. It’s a really great place,” Hove said.
Hove said that he became involved in mussel research when he found out they were highly-endangered for a number a reasons related to humans. About 70 percent of the species are considered endangered or at-risk.
Among the risk factors is the human manipulation of major rivers such as the Mississippi. Humans have changed many of them from free-flowing waterways to series of small, controlled bodies of water, Hove said. Mussels require steadily-flowing water to propagate and survive, and large-scale human projects have disrupted mussel breeding patterns throughout the nation.
Hove said that mussels are important to the health of the ecosystem. Mussels help to purify river water by feeding on water-born bacteria and nutrients.
Hove said the University is unique in the attention it gives to mussels. “I’m proud to be part of the most forward-looking groups in the nation.”