Mussel population to be grown in Nippersink Creek, improve tributary’s health

An effort to grow the population of freshwater mussels – the most endangered group of organisms in the U.S. – in Nippersink Creek and its tributaries will be jump-started with a $15,000 contribution by the McHenry County Conservation Foundation.

The money will go toward a partnership project between the McHenry County Conservation District and the DuPage County Forest Preserve District’s Urban Stream Research Center to propagate and head-start juvenile elktoe mussels, the foundation said in a news release.

A healthy population of mussels is important to waterways because they help filter out bacteria, algae and other microorganisms in the stream or river they inhabit and lower overall water pollution levels, according to the release. Just one adult mussel can filter up to 18 gallons of water each day.

The presence of mussels in a stream also are indicators of overall stream health and water quality, according to the release.

One female mussel will release thousands of larva, or glochidia, during propagation. The Urban Stream Research Center currently has more than 4,000 juveniles in its facility specific to this project.

Despite the large number, however, few mussels will survive to full maturity.

The USRC will “head-start” those juvenile mussels that do survive for up to two years to ensure they are healthy and robust before they are released into Nippersink Creek. Given the right conditions, those that are released and survive will help filter the water for decades, according to the release.

Of the 80 mussel species native to Illinois, more than half are currently threatened, endangered, extirpated or extinct, according to the Illinois Department of Natural Resources. Populations have declined dramatically in recent decades because of pollution, siltation, competition from exotic species such as zebra mussels and infrastructure projects such as dams that separate mussels from the fish they depend on for survival.