North Texas Daily

Zebra mussels are an invasive species that have been traveling throughout Texas lakes, establishing themselves in around 23 lakes from San Antonio to Dallas — and now in Grapevine Lake, 18 miles from Denton. This is important to be aware of due to the proximity of the spread to Denton’s primary water source, Lewisville Lake.

You may be thinking, “It’s just some mussels in a lake, what’s wrong with that?” Well there are two specific effects of this type of invasive species. The first is its impact on the native species already in the lake. The mussels will either vastly outcompete the natives for resources such as food and space or hybridize with them, diluting the existing gene pool with an invasive mix, according to a study by Gary Huxel.

This can be disastrous to local food webs, hindering the flow of energy from one species to the next and causing unwelcoming population and nutrient shifts. It’s like throwing a wrench in a gear system and trying to keep turning it like before. It just won’t work unless something is done.

The second effect of Zebra mussels is they completely clog the pipes that carry our drinking and showering water. If I had to specify a worst-case scenario of these pipes being clogged, I would point to the water situation in Flint, Michigan. I’m not saying the outcome would be this drastic, it is just to point out the importance of proper water transportation systems and access to clean drinking water, and how these pesky mussels can interfere with both of those needs.

Like many invasive species, these mussels reproduce rapidly once they find a new habitat. They cover the bottoms of rivers and can depopulate whole areas, and the further they spread, the higher the chance of them finding a home in our water pipes. A 1993 report from the Office of Technological Assessment estimated that over a 10-year period, it would cost close to $3.1 billion to clear the blocked pipes affected by a prior outbreak of these same Zebra mussels.

The best solution is a preventative one — identifying and confronting the problem before it can spread further — but that isn’t how these things usually work. As for preventing the spread of mussels, boat owners, specifically ones that use Grapevine Lake and Lewisville Lake, should pay close attention to their hulls and clean them after each use. Traveling on the bottom of boats is how this species initially got to North America and is still the main method of spread from water system to water system.

Removal efforts have been conducted using various chemicals such as chlorine and metal-based solutions, but these never work because there needs to be focus on alleviating the rapidly reproducing mussels as well.

There is hope in a bacterium called Zequanox created by research scientist Daniel Molloy. This bacterium has been proven to eradicate Zebra mussels specifically, but the problem is the EPA has banned its use in commercial lakes. It’s the same concept as a pesticide but for Zebra mussels. Except with pesticides and the volumes they are used in, the unintended effects could be disastrous to a drinking water supply or a recreational lake.

There are other similar microorganisms and viable chemical solutions that could work in theory, but they are still in development.

Zebra mussels are a fast-spreading, hyper-competitive invasive species that are spreading throughout the US, not just Texas. One of the first outbreaks was in the Great Lakes near Michigan in the ‘90s, and now there are literally millions of them lining the bottoms of the Great Lakes. We must stop the spread of these and other invasive species, or pay the hefty price later.

Featured Illustration by Allison Shuckman