Do zebra mussels in our lakes have an upside? State experts say no


Highlights

In less than a year, zebra mussels in Lake Travis have found their way downstream to infest Lake Austin.

The mussel can filter water, a possible benefit, but that doesn’t help the overall ecosystem.

An animal the size of a grain of sand with the growth potential of about an inch and half has infested Lake Travis. Its sharp shell can cut up lakegoers’ feet and its rapid reproduction can cause economic and ecological damage.

In less than a year, the population of zebra mussels in Lake Travis has boomed and found its way downstream to Lake Austin. Because of the size of the lakes, eradication is an unlikely option. Does this invasive species have an upside? At least one state expert says no.

Zebra mussels attach to any stable substrate, including the rock, sand, gravel and concrete in Lake Austin.

RELATED: Zebra mussels spotted in Lady Bird Lake; Lake Austin now ‘infested’

“Just because you don’t see them, doesn’t mean they’re not there,” said Monica McGarrity, aquatic invasive species team leader for the Texas Parks and Wildlife Department. Any perceived benefits that the mussels might have for the lakes come with drawbacks.

Because these voracious mussels filter and feed on plankton, a high density of them can make water in lakes look clearer. A single mussel is capable of filtering a liter of water in a day, which might sound like a benefit, but isn’t for the overall ecosystem, McGarrity said.

Plankton serves as the base of a lake’s food hierarchy. With less of the single-celled algae available for other animals, sport fishers angling for game fish like largemouth bass in Lake Austin can expect to see them get smaller in years to come. Largemouth bass feed on shad fish, which feed on plankton.

“No shad, no bass,” McGarrity said. “If you have this competitor eating their food, catfish may do better, but the bass game fish aren’t going to fare well.”

Clearer water also creates low oxygen levels at the bottom of the lake and even areas with no oxygen, which fish and other animals need to survive.

Some ecosystems, including the Hudson River ecosystem in New York, have seen an invasion of zebra mussels bring more sunlight to rooted plants in the water, which can provide shelter for organisms that fish prey on. This means bottom-feeding fish, including catfish and sunfish, could thrive.

However, native mussels in the lakes are at risk of being smothered, starved and put on the federal endangered species list because they are overmatched by zebra mussels for plankton.

Eradicating zebra mussels is difficult in large lakes because it would require chemical treatments, McGarrity said. She expects the mussels will stay in Lake Austin, but she doesn’t know yet how bad the infestation will get.

Periodic drawdowns of Lake Austin in the peak heat of summer could dry up a few mussels, but they might not die because of the way they can close their shells and retain water.

“Once they’re in a lake, that’s it,” she said.

Overall, McGarrity saw no positive outcomes that would apply to Lake Austin and Lake Travis.

“That’s why it is critical for boaters to take the right steps to clean, drain and dry their boats” to prevent their spread, she said.



Reader Comments ...


Next Up in Local

Slight chance of rain possible Sunday, rain expected through the week
Slight chance of rain possible Sunday, rain expected through the week

Scattered showers continue across the Hill Country to the I-35 corridor today, the National Weather Service said. A 10 percent chance of rain is possible throughout the day. Cloudy skies with a high near 79 and a low of around 69 is forecast for Austin on Sunday. Mostly cloudy skies will keep temperatures below normal with highs ranging from the mid-70s...
Person stabbed man to death, injured woman in Kyle, police say
Person stabbed man to death, injured woman in Kyle, police say

A person who police say stabbed a man to death and severely injured a woman was arrested in Kyle on Saturday evening. Police have not released the identity of the suspect. Kyle police responded to an aggravated assault just before midnight Saturday at a home in the 1200 block of Kirby Lane. When they arrived, police found one man dead and a woman with...
3D gun advocate Cody Wilson jailed in Houston after Taiwan arrest
3D gun advocate Cody Wilson jailed in Houston after Taiwan arrest

Cody Wilson, the Austin man at the center of the national debate over 3D-printed guns, will be brought back to Austin by U.S. Marshals on Sunday evening after being arrested in the Wanhua District of Taipei on sexual assault charges. Wilson was booked into the Harris County Jail in Houston, where he has been turned over to state authorities to begin...
Florida man gets 20 years in state prison for stealing $600 worth of cigarettes
Florida man gets 20 years in state prison for stealing $600 worth of cigarettes

A Florida man convicted of stealing $600 worth of cigarettes from a convenience store was sentenced to 20 years in state prison, the Pensacola News Journal reported. >> Read more trending news  Robert Spellman, 48, was convicted in August of burglary and grand theft for the Dec. 28 incident, the newspaper reported. The length of the...
One dead, two injured in North Austin shooting, police say
One dead, two injured in North Austin shooting, police say

One man is dead, two others are injured following a shooting in North Austin early Sunday morning. Austin police responded to a shooting in the 1900 block of Rutland Drive around 5:30 a.m. One man, who police believe to be in his 20s, was taken to Dell Seton Medical Center with critical life-threatening injuries, where he later died. The two other...
More Stories