Four zebra mussel myths and where they went wrong

Ridding water bodies and infrastructure of the invasive species is difficult and costly for water utilities and power generation facilities — a real concern that is complicated by fake news.

Zebra mussels are fearsome creatures, considering their small size. They are hardy. They breed in massive numbers. They spread rapidly. Their tenacity in clinging to hard surfaces such as intake screens and pipelines has earned them recognition as one of North America’s most costly and damaging aquatic nuisance species.

Like all fearsome creatures, zebra mussels come with their own set of myths. These are the stories we tell ourselves about zebra mussels, usually in preparation to battle them. They are not necessarily false stories, but they are not always true, either. Knowing the difference is critical to developing efficient and cost-effective zebra mussel management strategies.

Why Are Zebra Mussels A Threat?

Zebra mussels are considered an invasive species because they displace local species and disrupt the natural balance of the watersheds they infest. It is not uncommon for divers to find native mollusks completely smothered by zebra mussels. When so many zebra mussels breed and die, they litter shorelines with a carpet of razor-sharp shells that cut barefooted bathers and walkers.

Zebra mussels are also incredibly efficient filter feeders. One tiny zebra mussel can filter up to one liter of water per day. That may not seem like much, but the impact is significant when the zebra mussel population reaches thousands of individuals per square foot. Their filter-feeding often improves water clarity, but reduces the amount of food available to other organisms.

Mounting evidence even links zebra mussels to increasingly frequent and severe harmful algal blooms. Zebra mussels can feed on green algae, while allowing less-palatable cyanobacteria to pass through their digestive systems. They also transfer nutrients either into the water column or to their pseudofeces, a process that can create a more favorable environment for cyanobacteria

Economic losses from the zebra mussel invasion are especially severe for water treatment and power generation facilities. The annual cost of invasive mussel control at water treatment plants ranges from $44,000 initially to $30,000 after control procedures are optimized. Estimates for power generation facilities are considerably higher, with nuclear power plants topping the list at a whopping $833,000 per year.

Clearly, we must manage zebra mussels effectively when they are present and do our best to stop them from spreading further. To do so, it is important to understand the myths that can accompany them. Otherwise, these myths actually discourage fully informed decisions about when, where, and how best to control zebra mussels . . . . Continue to read Zebra Mussel Myth #1

This article is the first of a five-part series excerpted from “Four Zebra Mussel Myths and Where They Went Wrong.” It is reprinted here with permission. The full article with references is available at Water Online. Copyright 2019.

About The Author

zebra mussel expert Dr. David HammondDavid Hammond is an environmental chemist who has consulted with private industry on topics including pest management, taste and odor problems, biological wastewater treatment, sustainability, and biomimicry. He holds a master’s degree from the Energy and Resources Group and a Ph.D. in Environmental Chemistry, both from the University of California, Berkeley. Dr. Hammond has four patents and several peer-reviewed publications and currently serves as senior scientist with Earth Science Laboratories, Inc.