The Farmingdale State College (FSC) campus community recently gathered in Gleeson Hall for a compelling research presentation by President Robert S. Prezant, PhD. It’s a Shell-of-a-Problem: The Asian Clam Conundrum showcased the beauty and wonder of marine biology and President Prezant’s decades of study on the “pesky” Asian clam, Corbicula fluminea. 

“The critter that I am working with is a fascinating organism,” President Prezant said to a packed auditorium. “And it’s a great laboratory organism, basically because it is rough-and-tumble. It is highly adaptable to laboratory conditions. It’s very sensitive to environmental change. Most importantly, nobody cares about it in terms of taking it out of the wild and bringing it into the laboratory because it is an invasive, nonindigenous clam.”  

First discovered in 1938 in Washington State, it is believed that immigrants to North America imported the clams, which are native to the freshwaters of eastern and southern Asia, as a food source and subsequently released them into the wild, according to the U.S. Department of Agriculture’s National Invasive Species Information Center.  

“The animal is a bivalve,” said President Prezant. “It has one shell, but two parts to that shell. It falls into a large group called phylum, and that phylum is Mollusca. Mollusca translates from German to actually mean, ‘soft body.’ Because once you get under that hard shell, which is made out of calcium carbonate, basically chalk, it’s a very soft body.  

“How many of you eat mollusks?” he asked to a sea of raised hands. “There you go. You’re going to put me out of business,” he quipped, receiving chuckles around the room. 

The clam’s round, yellow-green to dark brown shell grows only one to two inches long—about the size of a dime. But this diminutive shellfish makes waves, becoming a successful invasive species throughout the world. “The beauty of this animal is multifold,” said President Prezant. 

“It came here about 90 years ago and it literally took over the waterways in an incredible way,” he said. “It is highly, highly invasive once it leaves its natural geographic range. The number of predators, the number of parasites, the number of viruses, the number of things that control the population are gone. So, like any good invasive species, it begins to take over. 

“Here's what gives them the competitive edge in North America,” he added. “They are what we call simultaneous hermaphrodites. They can self-fertilize and they have a huge number of babies, up to 100,000 a year. They grow very rapidly. They disperse very rapidly. Remember, they're male and female at the same time--so, all you need is one.” 

President Prezant shared a timeline animation of the clam rapidly spreading across a map of the United States, where it can now be found in nearly every state dominating freshwater systems, clogging pipes, and even shutting down power plants. 

“This is what got people's attention, Corbicula began to show up in industrial plants that use cooling water,” said President Prezant. “A lot of plants pull water from nearby waterways to cool whatever they've got going on inside the plant. And what you're seeing is Corbicula clogging their pipes. And that led to a failure of the power plants. Back in 1980 in Arkansas, a nuclear plant was shut down when the nuclear material began to heat up. They shut it down just in the nick of time.” 

President Present highlighted details about the Asian clam’s anatomy and behaviors, and some “pearls” about them, including their ability to filter and clean water, and their use in some health supplements, as fishing bait, or as a household addition. “And for those of you who like pets at home, they're a great pet,” he said. “They’re peaceful. They don’t bother anybody. They just sit at the bottom of your aquarium.” 

President Prezant concluded the presentation with his exciting research findings on the clam’s ability to monitor environmental changes and water quality. “It’s the canary in the coal mine,” he said. 

“We took specimens of the Asian clams of different sizes into the laboratory, and we thought about environmental perturbations that are very common across the East coast. One of them is thermal change, because of climate change. How will our creeks, rivers, streams and the animals that live there react to that? And how can we monitor whether there's a problem or not?  

“The other thing we looked at is the impact of the road salt used every winter,” he added. “Thousands and thousands of tons of road salt are poured on our streets, and it runs off with melt into our streams. We took the shells when we were done, and we threw them in an electron microscope to look at the microstructure of the shell. The shell of a mollusk is a great indicator of the health of the mollusk.” 

Remarkably, President Prezant saw incredibly complex differences in the organic components of the shells including size, shape, color, and even beautiful spiral patterns. He looks forward to continuing his research at FSC. 

“So where are we now? We are looking at a continuation of this work with other environmental perturbations that are facing us,” he said. “There's a lot of work left to be done. Thanks for your attention.”  

"I really enjoyed the lecture," said Assistant Professor of Biology Peter Park, PhD. "Overall, I thought the talk was excellent because our President took a very complex, multi-layered topic and presented in a way that was truly accessible to all in the audience. He engaged everyone and took time to compassionately answer all questions asked during and after the presentation. Also, the story itself of Corbicula fluminea was presented in such a well-rounded way, first exploring its invasiveness and then its potential benefit as an indicator species."

A marine biologist, President Prezant has more than 50 articles in peer reviewed journals, many co-authored by students. His research has focused on environmental modification of shell microstructure, molluscan reproductive ecology, impact of microplastics on filter feeding mollusks, and bivalve dispersal mechanisms. Dr. Prezant has generated more than $20 million in external support for research and program development. He has taught courses in ecosystems and environmental concerns, marine biology, marine ecology, invertebrate zoology, malacology, electron microscopy, and oceanography. Learn more about Dr. Prezant’s background here. 

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