Flame-retardant chemicals could show up in greater concentrations in Lake Erie's small-mouth bass, and scientists say an invasive species could be to blame.

Flame-retardant chemicals could show up in greater concentrations in Lake Erie�s small-mouth bass, and scientists say an invasive species could be to blame.

Researchers at the State University of New York-Buffalo found that concentrations of polybrominated diphenyl ethers, or PBDEs, are likely to increase by nearly 50 percent in Erie�s small-mouth bass, according to a recently published study in the Journal of Environmental Pollution.

That�s not good because a lot of people catch and eat fish from Lake Erie.

The researchers found that small-mouth bass are eating more round gobies, small, invasive fish that have overrun Lake Erie in recent years. Gobies eat zebra mussels, another invasive species that filter water through their bodies.

PBDEs, flame-retardant chemicals used in textiles, furniture and computer parts, have been linked to hyperthyroidism in adults and a slew of health issues in children, including slowed cognitive development, lower IQs and some syndromes on the autism spectrum.

Josh Wallace, one of the authors of the study and a doctoral candidate at SUNY-Buffalo, said scientists believe flame-retardant chemicals found in the lake�s sediment are filtered by the mussels, which are eaten by the gobies, which are food for bass.

The chemicals get into the water, Wallace said, through improper disposal.

Wallace and other researchers studied gobies and bass. An earlier study, by one of Wallace�s colleagues at SUNY-Buffalo, found that as the goby population has increased, so, too, has the number of gobies eaten by small-mouth bass.

When the researchers pulled small-mouth bass from the lake and dissected them, gobies accounted for about 97 percent of what remained in the fishes� guts. Gobies make up a small portion of the diets of other Lake Erie species, including walleye.

The researchers found that PBDEs appeared to be decreasing in other species.

Wallace then used statistical modeling to predict how the amount of PBDEs in the small-mouth bass would change over time.

Their model showed that those levels would increase by 47.6 percent over two years. The actual amount of chemicals inside the fish is still relatively small � about 33 parts per billion, Wallace said. But because the chemicals stay in human fat stores, they accumulate over time. Mothers who breast-feed also can pass along the chemicals to newborns.

That could mean trouble for people who regularly eat Erie�s small-mouth bass.

The Ohio Environmental Protection Agency already recommends people eat no more than one serving of sport fish a week. But even that might be high, Wallace said.

�If you eat a couple of fish a month it�s not going to be a big deal, but if you eat a lot, it will be a problem,� he said.

PBDEs are not a new concern. Studies as far back as 2002 examined how PBDEs accumulate in breast milk and warned that the chemicals could pose a similar risk as PCBs and DDT, both of which were banned in the United States decades ago.

Representatives for the PBDE industry did not return calls or emails requesting comment.

Many manufacturers have voluntarily eliminated PDBEs from their products, but like PCBs, they can persist for years in lake sediment, said Michael Murray, a staff scientist with the National Wildlife Federation�s Great Lakes Regional Center.

�It�ll likely take some time before they eventually get buried or, in some cases, degraded,� Murray said. �But in degradation, they might get transformed to some other chemical that�s also a problem.�

larenschield@dispatch.com

@larenschield