Relationship between biotic ligand model‐based water quality criteria and avoidance and olfactory responses to copper by fish

Abstract

The U.S. Environmental Protection Agency's (U.S. EPA) water quality criteria for Cu were tested to determine whether they protect fish against neurophysiological impairment. From published studies with rainbow trout (Oncorhynchus mykiss), Chinook salmon (Oncorhynchus tshawytscha), coho salmon (Oncorhynchus kisutch), and fathead minnows (Pimephales promelas), 20% inhibition concentrations (IC20s) were calculated for avoidance of Cu-containing water and for impairment of electroencephalogram (EEG) and electro-olfactogram (EOG) responses to natural odorants in Cu-containing water. Additionally, a Cu-olfactory biotic ligand model (BLM) that fits the coho salmon EOG data was parameterized by changing the sensitivity parameter in the ionoregulatory-based BLM. The IC20s calculated from reported Cu avoidance, EEG, and EOG data and IC20s predicted by the olfactory BLM were compared with acute and chronic Cu criteria calculated using U.S. EPA's BLM 2007 or hardness-adjustment equations. The BLM-based chronic criteria were protective in all 16 exposure water-species combinations used in avoidance and olfaction experiments. Additionally, the BLM-based acute criteria were protective in all 11 exposure water-species combinations in which comparisons could be made with olfactory BLM-predicted IC20s but not in two of the 16 exposure water-species combinations in which comparisons could be made with the reported IC20s (which were < or =8% lower than but did not differ significantly from the BLM-based acute criteria; p > 0.05). In effect, the olfactory BLM factored out the relatively high variability in the reported IC20s. It is concluded that the U.S. EPA's BLM-based water quality criteria for Cu protect against these types of neurophysiological impairment in the six species-endpoint combinations analyzed in this paper. However, the U.S. EPA's hardness-based criteria for Cu sometimes were considerably underprotective and sometimes were much less protective than the BLM-based criteria.

Recovery of a mining-damaged stream ecosystem

“…This assumption is not always true, especially with anadromous or other migratory species which need to transit downstream conditions in order to complete their life cycles. Anadromous salmon and steelhead use olfactory cues to return to their natal streams to spawn (Quinn, 2005), and Cu can disrupt chemoreception at sublethal concentrations Meyer and Adams, 2010). Declines of returning adult Pacific salmon also led to decreased delivery of marine-derived nutrients to streams, and locations with no or few salmon carcasses may in turn have lower productivity than streams with more abundant carcasses (Ebel et al, 2014).…”

The canary is alive and singing: Birds continue to provide invaluable information about our changing environment

“…They concluded that chronic BLM-based Cu criteria were protective of the olfactory IC20 values in all 14 waters (Figure 1) and that the acute BLM-based criteria were protective in all but 2 waters. In contrast to the BLM-based Cu criteria, the hardness-based Cu criteria still in use by US states have been shown to be less consistently protective of olfactory impairment based on a comparison of hardness-based Cu criteria to empirical IC20 values for olfactory impairment and avoidance (Meyer and Adams 2010). Meyer and Adams (2010) also parameterized an olfactory-based BLM that can be used to estimate olfactorybased Cu IC20 values for waters with varying chemistry.…”

“…In contrast to the BLM-based Cu criteria, the hardness-based Cu criteria still in use by US states have been shown to be less consistently protective of olfactory impairment based on a comparison of hardness-based Cu criteria to empirical IC20 values for olfactory impairment and avoidance (Meyer and Adams 2010). Meyer and Adams (2010) also parameterized an olfactory-based BLM that can be used to estimate olfactorybased Cu IC20 values for waters with varying chemistry. DeForest et al (2011) used the olfactory-based BLM to estimate Cu IC20 values for olfactory impairment based on the surface water chemistry of 133 western US streams.…”

“…The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the United States Environmental Protection Agency. Table S6 of Meyer and Adams (2010) for additional details on the water chemistry in each test from McIntyre et al (2008). Dashed line notes IC20:chronic criterion ratio of 1.0 (a ratio >1.0 indicates that the criterion is protective of the olfactory-based IC20).…”

Metals as Water Quality Parameters – Role of Speciation and Bioavailability

“…Effects of competing cations have been considered on the basis of empirical regressions of effect concentrations under various conditions. These effects as calculated by the BLM appear to account for the response to copper by fish as a function of varying water composition (Meyer and Adams, 2010). A recent report on metals environmental risk assessment guidance summarizes the speciation approaches both for metals in the water and sediment compartment (ICMM, 2007).…”