Below the Surface: Recent Biological Monitoring Reveals Rich Aquatic Communities

November 25, 2014

When you look at a creek, river, or stream, what do you see? Flowing water, reflections of the sky, wave patterns...maybe a dragonfly skimming by. But what’s under the surface? Is it healthy? Polluted? Full of aquatic life…devoid of life? There’s only one way to find out: get into the water, under the surface, and look.

Biological Monitoring at Twin Creeks

A healthy stream requires significant bufferlands along its banks. In fact, the backbone of the greenways plan for the Chicago region relies on the protection of over 4,000 miles of river and tributary systems, which serve as the primary linkage between larger habitat preserves. These corridors in turn allow for the movement of animals and plants (and their genes), healthy outdoor trail-based recreation, and personal or shared experiences with nature.

Biological Monitoring at Twin Creeks

For the past 20 years, Openlands has conducted aquatic monitoring surveys to determine the quality of our region’s underwater habitats. In the Boone and Dutch Creek watersheds of Bull Valley, McHenry, McCollum Lake, and Johnsburg, Openlands has been assisting the Chicago Metropolitan Agency for Planning and local communities in the preparation of a watershed plan to maintain these valuable areas. The planned actions would minimize pollution, mitigate flooding and stormwater impacts, and protect the aquatic biodiversity that was thought to be present based on old aquatic inventories. But in developing this plan, a problem arose: The biological inventories were outdated. Even the most recent were a decade old. The solution: throughout August and September a team of biologists helped Openlands staff and volunteers accomplish a rapid assessment of 14 different locations.

Biological Monitoring at Twin Creeks

(Native bullhead)

The first stretch sampled, a very small headwater of Dutch Creek, turned up over 100 rainbow darters (one of the most beautiful fish in the state, and an uncommon darter species that depends on cold, clean water). Overall, the team discovered six species listed in the State Wildlife Action Plan as “Species in Greatest Need of Conservation” throughout the two creek systems. These included mottled sculpins, brook sticklebacks, Iowa darters, southern red belly dace, blacknose dace, and central mudminnows. From these inventories Openlands reached an exciting conclusion: These aren’t just creeks – these are among the richest creek systems in northeast Illinois. We’d never have known had we not looked under the surface.

Biological Monitoring at Twin Creeks

(Slippershell mussel)

Elsewhere, Openlands used fish surveys to assess the quality of the greenway corridors of two Nippersink Creek tributaries, which flow through its recently acquired Twin Creeks conservation development in McHenry County. The survey was completed in late October, a season that in terms of fish presence is rarely sampled and not well understood. Much of the aquatic plant life had gone through its autumn die off by then, causing the food chain to undergo big shifts. Despite this, the team found 14 species of fish, including several listed in the State Wildlife Action Plan. They also discovered the remnants of a state-threatened slippershell mussel, apparently recently eaten by a muskrat, raccoon, or otter. At Twin Creeks and its surrounding protected lands, there’s a remarkable story to be told of the life underwater.


Openlands would like to extend its deepest thanks to the volunteer aquatic biologists who assisted in these surveys: Roger Klocek, Phil Willink, Jim Bland, Randy Schietzelt, Cindi Jablonski, and Brad Woodson.

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