Using historical biological data to evaluate status and trends in the Big Darby Creek watershed (Ohio, USA)

Abstract

Assessment of watershed ecological status and trends is challenging for managers who lack randomly or consistently sampled data, or monitoring programs developed from a watershed perspective. This study investigated analytical approaches for assessment of status and trends using data collected by the Ohio Environmental Protection Agency as part of state requirements for reporting stream quality and managing discharge permits. Fish and benthic macroinvertebrate metrics collected during three time periods (1979–1981, 1986–1989, 1990–1993) were analyzed for the mainstem of Big Darby Creek, a high‐quality warm‐water stream in central Ohio, USA. Analysis of variance of transformed metrics showed significant differences among time periods for six fish metrics. In addition, significant positive linear trends were observed for four metrics plus the index of biotic integrity score, and negative linear trends for two fish metrics. An analysis of a subset of sites paired by location and sampled over the three periods reflected findings using all available data for the mainstem. In particular, mean estimates were very similar between the reduced and full data sets, whereas standard error estimates were much greater in the reduced subset. Analysis of serial autocorrelation patterns among the fish metrics over the three time periods suggests changes in the nature of stressors over time. A comparison within the most recent time period showed significantly better condition for Big Darby Creek mainstem than for Hellbranch Run (the easternmost subwatershed), after adjusting for watershed size. The consistency of paired and nonrandomized results suggested that either type of data might be judiciously used for this watershed assessment. Results indicated that overall biological condition of the mainstem of the Big Darby Creek watershed has significantly improved since the early 1980s.

Assessing ecological risk in watersheds: A case study of problem formulation in the Big Darby Creek watershed, Ohio, USA

“…The federally endangered Scioto madtom ( Noturus trautmani ), known only from the Big Darby Creek, and the eastern sand darter ( Am‐mocrypta pellucida ) (under review for federal listing) have not been collected in the watershed since 1957 and 1960, respectively [2]. Biological surveys by the OEPA have indicated decreases in biological indices of fish and macroinvertebrate communities in some stream reaches, whereas others have shown improvement (OEPA draft report, 1999) [13]. Although the total number of fish species has declined over the past 50 years, longitudinal profiles of the Big Darby suggest that more recently, improvement has occurred in the fish (Fig.…”

“…Seven hypotheses were developed that described relationships in the Big Darby Creek watershed suggested by the conceptual model. The first three have been tested (OEPA draft report, 1999) [13] and the last four are in development.…”

“…With the completion of the Big Darby problem formulation, on‐going analyses are being conducted that will ultimately be integrated into risk characterization and implemented in risk management. Specific analyses that grew out of the problem formulation of the Big Darby Creek watershed ecological risk assessment will be discussed in the papers that follow [13,27,70,71].…”

How Long Should a Long-Term River Study Be?

“…Two thirds of the studies (14 of 21) used historical data sources as a determining factor in setting the study length (Bryant 1985, Poff and Ward 1989, Bradt et al 1999, Onorato et al 2000, Lowell et al 2000, Schubauer-Berigan et al 2000, Haag and Westrich 2002, Jennings and Jamagin 2002, Kovacs et al 2002, Lowell and Culp 2002, Metzling et al 2002, Sosiak 2002, Woodward et al 2002, Papanicolaou et al 2003. Additionally, nearly half of the studies related the time of the study to specific changes in the watershed or river conditions from point sources, non-point sources, or events (Bryant 1985, Sullivan 1985, Onorato et al 2000, Klug and Cottingham 2001, Minshall et al 2001a, Minshall et al 2001b, Minshall et al 2001c, Kovacs et al 2002, Jennings and Jarnagin 2002, Sosiak 2002; in some cases these were before and after designs that essentially covered many years.…”

Using Legacy Data to Relate Biological Condition to Cumulative Aquatic Toxicity in the Willamette River Basin (Oregon, USA)

“…A regional risk assessment within the basin also identified chemicals as one of several possible stressors for fish (Landis and Thomas 2009). Given the considerable resources needed to initiate and operate large-scale monitoring programs, it is thought to be beneficial to take advantage, to the extent practicable, of existing (''legacy'') watershed-assessment data gathered by previous watershed-monitoring programs (Kapo and Burton 2006;Norton et al 2000;Schubauer-Berigan et al 2000). With respect to the basin, the question was whether legacy biological condition and water-quality data, collected at different locations and times by different state and federal monitoring projects, could be combined to evaluate the effects of chemical mixtures on biological conditions throughout the basin.…”