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

Abstract

In the Willamette River Basin (Oregon, USA), various residential, municipal, industrial, and agricultural activities produce physical, biological, and chemical stressors that may impinge on the basin's aquatic ecosystems. For > 30 years, numerous water-quality and biological-condition data have been accumulated by often disparate monitoring programs. This diagnostic analysis explored whether these legacy data could be used to correlate the presence of chemical stressors with biological condition impacts with the understanding that association is not necessarily causation. Other natural or anthropogenic stressors that may also impact biological conditions were not considered in this study. Acute-toxicity indices were calculated separately for trace metals and organic chemicals detected in surface waters between 1994 and 2010 and then compared with land-use metrics and vertebrate- and invertebrate-assemblage indices from surveys conducted basin-wide during this same period. Half of the possible relations between land use, biological condition, and toxicity were statistically significant at p ≤ 0.10. These results suggest that conditions for aquatic receptors improve either as agricultural or urban land decreases or as forested land increases and that chemical mixtures (primarily involving pesticides) may have impacted components of the basin's aquatic ecosystems. There may be a need for strengthened chemical-management practices on agricultural and urban lands and for maintaining undisturbed forested land to limit chemical migration into adjacent waters. Although these results indicate some utility for legacy data, they also suggest that a more defensible assessment of chemical stressors requires a program specifically designed for that purpose.

Threats and opportunities for freshwater conservation under future land use change scenarios in the United States

“…In addition, hydrological alterations used to support agricultural systems can reduce in stream flows and groundwater stores (Scanlon et al, 2007), attenuate flood pulses, and reduce riparian habitat (Poff et al, 1997) and native fish movement (Schlosser, 1995). Similarly, even seemingly small proportions of urban land cover (i.e., 10-20%; Allan, 2004) can lead to substantial increases in the amount of chemical and thermal pollution in rivers (Hope, 2012), and decreases in stream-channel habitat structure and biodiversity (Roy et al, 2003;King et al, 2011).…”

Physiological Dysfunction in Fish After Insecticides Exposure

“…Several studies reported that some of surface waters and surrounding environments were contaminated with different insecticides (Arjmandi et al, 2010;Bagheri et al, 2000;Ghassempour et al, 2002;Rahiminezhhad et al, 2009;Tarahi Tabrizi, 2001). The continuous presences of insecticides are the consequence of application (timing, rate, frequency) and the rainfall during the application period (Lydy and Austin, 2004; U.S.A. EPA, 2005;Bouldin et al, 2007;Mast et al, 2007;Echols et al, 2008;Vryzas et al, 2009;Werimo et al, 2009;Ding et al, 2011;Hope, 2012). Although monitoring the presence of insecticides in surface water and ground water are generally poor in much of the world and especially in developing countries, the effect of these pollutants on aquatic animals' health frequently was investigated (Chambers et al, 2002;Richards and Kendall, 2002;Lam and Wu, 2003;Scott and Sloman, 2004;Cengiz, 2006;Sun and Chen, 2008;; Banaee et al, 2011; Banaee and Ahmadi, 2011).…”

Assessing Risks to Endangered and Threatened Species from Pesticides

“…The chemical components become diluted in environmental media that already contain other chemicals, including pesticides. For example, in Oregon's Willamette River Basin, only 3.6% of surface-water samples collected during 1994-2010 contained only a single detected chemical; over 50 pesticide mixtures of two to six pesticides each were found in the remaining samples (Hope 2012). Nationally, more than 6,000 unique mixtures of five pesticides were detected in agricultural streams (Gilliom et al 2007).…”