StructureSpot

The problem

Habitat loss has occurred and accelerated dramatically in the past 50 years from fill, alterations to the shoreline, and development, resulting in smaller and less diverse fish and wildlife populations. A 1987 Remedial Action Plan for the White Lake Area of Concern prepared by the Michigan Department of Natural Resources documented problems in the lake caused by industrial and municipal discharges from the 1950s through the 1970s. It noted a number of impairments to the local fishery, including the loss of the white bass fishery, and reduced walleye, perch, and northern pike populations. The cause of the impairments was attributed to damage from pollution to the community of tiny aquatic organisms (benthic or bottom dwelling organisms) that live in and on the lake bottom. Fewer and less varied types of benthic organisms lived on the polluted lake bottom which made less food available for frogs and turtles, fish and waterfowl, reducing their populations. A 1995 updated plan noted there were also areas deep in the lake with low oxygen, where certain fish and their prey could not live and a decline in critical fish and wildlife habitat in the littoral zone (the part of the lake closest to the shore) from development and invasive species.

What’s been done to address the problem

The White Lake Public Advisory Council (PAC) formally identified eight problems, termed Beneficial Use Impairments, for White Lake as part of the 1995 Remedial Action Plan update. Two impairments associated with the loss of fish and wildlife habitat and degraded fish and wildlife populations were identified. Between 1995 and 2005, a number of studies were done to evaluate fish and wildlife habitat, and provide the information needed to take action. The information from these studies, along with GIS data, was used to develop a ‘blueprint’ for restoring shoreline habitat around White Lake. The blueprint identified priority habitats to protect, degraded habitats to restore, and other actions needed to restore fish and wildlife habitat in White Lake. These actions would build upon a healthier benthic community and improved water quality achieved from the diversion of industrial and municipal discharges to the Whitehall wastewater system, and contaminated sediment cleanups in 2002 and 2003. Following the studies, the PAC, Muskegon Conservation District, and state developed a process for determining how and when the impairments could be removed.

The PAC determined that the loss of fish habitat and degraded fish populations Beneficial Use Impairment would be considered restored when:

An average Index of Biotic Integrity (IBI) score of 39 is obtained for White Lake three years in a row. If this is not achieved, monitoring of fish populations and habitat would continue for another three years. This target was based on data collected for White Lake between 2004 and 2006.

Dr. Carl R. Ruetz, associate professor at the GVSU-Annis Water Resources Institute (AWRI) took on the task of assessing the health of White Lake’s fish populations. To do this, Dr. Ruetz used an Index of Biotic Integrity, or IBI, a common tool used by scientists to monitor water quality. The IBI developed for White Lake measures the health of fish populations and their habitat. According to Dr. Ruetz, “A fish-based IBI can be used to address questions concerning both fish populations and habitat because the IBI is an indicator of both fish community health and the overall ecological health of the lake.” The index assesses a number of factors that show whether or not White Lake is healthy for fish, focusing on the composition and abundance of various groups of fish species. A score is calculated for each factor to be measured as part of the IBI. The total for all the factors results in a final IBI score, which is then compared to Pentwater Lake, a similar drowned river mouth lake.

Is the goal being met?

Dr. Ruetz sampled fish populations in White Lake in 2009, 2010, and 2011, adding to annual fish-sampling records collected by AWRI between 2004 and 2006. Preliminary results from the most recent sampling show the IBI score has exceeded the restoration targeted. According to Dr. Ruetz, this is good news. “It shows that the lake has made great strides from when it was listed as an Area of Concern in terms of the fish community,” he says. “The monitoring builds on what anglers already know, that the lake is doing well. There are still some issues that could pose problems, such as invasive species, but they are not unique to White Lake.”

This positive trend will be bolstered by completion of the White Lake Shoreline Habitat Restoration Project in 2012, which will restore fish and wildlife habitat at seven sites around White Lake.

Final monitoring and removal of the impairment

After completion of the habitat restoration project, monitoring will be conducted to ensure area habitat has been satisfactorily restored. The PAC will also review local municipal ordinances to ensure valuable fish and wildlife habitat around the lake is permanently protected. The impairment can then be formally removed.

Stay tuned for next month’s column, about wildlife populations and habitat in White Lake.

This column is part of a project funded by the U.S. Environmental Protection Agency through the Michigan Department of Environmental Quality and the Great Lakes Commission to the Muskegon Conservation District for the White Lake Public Advisory Council.BY TANYA CABALA

For more information, www.muskegoncd.org/whitelakepac