Long term impact on Juday Creek invertebrate populations from the 1997 restoration for construction of the University of Notre Dame Warren Golf Course, St. Joseph Co., Indiana
- Student
- Emma Heston
- College(s)
- College of Science
- Faculty Advisor
- Ronald Hellenthal
- Class Year
- 2022
Abstract
In 1997, two four-hundred-meter reaches of Juday Creek were relocated to accommodate construction of the Warren Golf Course on the campus of the University of Notre Dame (Notre Dame, Indiana). Following golf course construction, benthic macroinvertebrate populations were monitored in stream sites in restored and unrestored parts of the golf course for 5 years, between 1997 and 2002. In this study, benthic macroinvertebrate populations in Juday Creek on the Notre Dame Warren Golf Course were sampled three times between September and December of 2022 at four previously monitored sites. Generally, 20 years after construction, the restored areas of the stream supported more benthic invertebrates than unrestored areas. This suggests that the restoration techniques used in the stream remain effective. However, there was an overall reduction in stream macroinvertebrate abundance and biodiversity in both restored and unrestored areas, indicating that stream water quality and habitat may have declined over the past 20 years. This study suggests that while site-specific stream restoration efforts may be effective for long periods, they can’t completely compensate for deleterious changes in a stream’s watershed.
Introduction and Background
Juday Creek is a third-order tributary of the St. Joseph River. Historically it was one of only three streams in Indiana known to support a naturally breeding brown trout (Salmo trutta L.) population, which require cool water (Shirey, et al. 2016). Although cool water streams are relatively uncommon in Indiana, the lower portion of Juday Creek is fed largely from ground water (Silliman & Booth 1993), which makes it a suitable habitat for brown trout. Juday Creek also supported large numbers of net-spinning caddisflies in the early 1980s (Schwenneker, 1985). However, in 1986, St. Joseph County began performing stream “maintenance” that resulted in increased amounts of sediment in the stream. Gary Kohlhepp found that during this period the population of net-spinning caddisflies decreased by 86% (Kohlhepp 1991, Kohlhepp & Hellenthal 1992). Following this decline, Jeffrey Runde performed laboratory experiments on the effects of inorganic suspended sediment concentration on hydropsychid caddisflies that confirmed their intolerance to high levels (Runde 1999, Runde & Hellenthal 2000a,b). Although stream “maintenance” was discontinued after 1990, little improvement was noted in the aquatic invertebrate populations in lower portions of the stream (Hellenthal, personal communication).
In 1997, two four-hundred-meter reaches of Juday Creek were relocated to accommodate construction of the Warren Golf Course on the campus of the University of Notre Dame (Notre Dame, Indiana). New “ideal” stream habitat was created for these stream sections (Lee & Lovell 1998). Various restoration measures, including increasing stream length, canopy cover, and log, boulder, and gravel abundance, addition of a vegetative buffer strip, installation of an upstream sediment trap, and application of plastic netting to retain the substrate and reduce shore erosion, were employed to make the relocated parts of the stream healthy ecosystems that should support high biodiversity (Inter-Fluve, Inc. 1997). These restoration measures were intended to reduce fine sediment and create a self-maintaining fish channel with the hope of minimizing the effects of the golf course and its construction and to increase the biodiversity and abundance of the stream’s insect and fish faunas (Shirey, et al. 2016).
Notre Dame graduate student Jo Latimore studied the initial colonization of the two relocated stream sections, neither of which is known to have been part of the stream channel in the past. She placed colonization trays in both new reaches that were collected 10, 17, 32, 46, 80, 116 days, and 1 year after the stream was diverted into the new areas, measuring invertebrate diversity and colonization rates. She found that the new steam areas were rapidly colonized and concluded that the relocated areas were habitable for insects so it likely was lack of suitable habitat, rather than reduced water quality, that was responsible for the past reduction in the stream invertebrate populations (Latimore 2000).
Notre Dame graduate student Kerry Gerard sampled the invertebrates in the stream and measured various environmental factors from 1997 to 2002, as part of a monitoring project. She collected and compared the benthic invertebrates in both the restored and unrestored portions of the stream and found that the benthic invertebrate population was more diverse and dense in the restored portions of the stream, indicating that the habitat improvement in the restored reaches had been maintained for six years following the restoration (Gerard 2005).
The goal of both the Latimore and Gerard projects was to assess the efficacy of the restoration techniques performed at Juday Creek. Although both studies found that the restorations were largely successful in increasing invertebrate populations, it was unknown whether the stream improvements implemented during golf course construction would be effective for the long term.
Land use change, such as stream “maintenance” and the addition of the golf course, is not the only factor associated with environmental change that might negatively impact stream ecosystems. Changes in the chemical composition of the stream due to an influx of nitrogen, phosphorus, or pesticides from agricultural practices also may impact stream health. The area surrounding the stream is a combination of urban, suburban, and agricultural land use (Latimore 2000). Agricultural land use can lead to excess nutrients that result in stream eutrophication. Eutrophication can decrease the dissolved oxygen available to aquatic insects and other organisms that could impact their emergence and survival (Nebeker 1972).
Aquatic invertebrates are incredibly important to the health of the stream and to the surrounding riparian area. Aquatic insects are a vital part of the food web both in the stream and for vertebrates living in riparian areas. A decrease in aquatic invertebrates could have drastic effects on the ecosystem as a whole (DeBano & Wooster 2003). Larvae of net-spinning caddisflies (Trichoptera: Hydropsychidae) are commonly found in Juday Creek. Hydropsychids, which filter water and consume suspended organic particles, are an important food source for trout and other fish, which aids the nutrient cycling and energy flow in Juday Creek (Schwenneker 1985). Riffle beetles (Coleoptera: Elmidae) commonly occur in Juday Creek in both the larval and adult stages. They, too, are an important food source for fish (Braun 2019). Benthic invertebrates, such as elmids and hydropsychids, can be indicators of environmental health, and monitoring their abundance and diversity is a good way to assess stream condition (Funnell et al. 2020). Moerke and Lamberti (2004) stated, “Each restoration project that is not evaluated is potentially a loss of critical information that could benefit future restoration projects.”
Although short term (1-5 year) follow-up studies of stream restoration projects such as that of Gerard are quite common, long-term studies are very rare (Moerke et al. 2004). While considerable funding goes toward stream restoration projects, there is little understanding of whether these projects are effective beyond just a few years. My study adds to our understanding of stream restoration and helps determine to what degree the restoration techniques used in Juday Creek have been effective over the years and provides a rare opportunity to address this question using a long term set of extensive data on the stream macroinvertebrate population that extends back over 40 years (Schwenneker 1985, Berg 1989, Kohlhepp 1991, Latimore 2000, Gerard 2005).
Endnotes