Acute Toxicity of Zinc to Several Aquatic Species Native to the Rocky Mountains

Abstract

National water-quality criteria for the protection of aquatic life are based on toxicity tests, often using organisms that are easy to culture in the laboratory. Species native to the Rocky Mountains are poorly represented in data sets used to derive national water-quality criteria. To provide additional data on the toxicity of zinc, several laboratory acute-toxicity tests were conducted with a diverse assortment of fish, benthic invertebrates, and an amphibian native to the Rocky Mountains. Tests with fish were conducted using three subspecies of cutthroat trout (Colorado River cutthroat trout Oncorhynchus clarkii pleuriticus, greenback cutthroat trout O. clarkii stomias, and Rio Grande cutthroat trout O. clarkii virginalis), mountain whitefish (Prosopium williamsoni), mottled sculpin (Cottus bairdi), longnose dace (Rhinichthys cataractae), and flathead chub (Platygobio gracilis). Aquatic invertebrate tests were conducted with mayflies (Baetis tricaudatus, Drunella doddsi, Cinygmula sp. and Ephemerella sp.), a stonefly (Chloroperlidae), and a caddis fly (Lepidostoma sp.). The amphibian test was conducted with tadpoles of the boreal toad (Bufo boreas). Median lethal concentrations (LC(50)s) ranged more than three orders of magnitude from 166 μg/L for Rio Grande cutthroat trout to >67,000 μg/L for several benthic invertebrates. Of the organisms tested, vertebrates were the most sensitive, and benthic invertebrates were the most tolerant.

Larval aquatic insect responses to cadmium and zinc in experimental streams

“…Most toxicity testing with aquatic insects has involved field collections of the taxa of interest [13,43,53,54]. A practical constraint of this approach is that larvae need to be late enough in their development to be large enough to be captured, sorted, and confidently identified without injury and robust enough to be transported and to survive 4 d to 6 d of starvation before and during acute toxicity tests.…”

The Use of Field and Mesocosm Experiments to Quantify Effects of Physical and Chemical Stressors in Mining-Contaminated Streams

“…5 Additionally, laboratory toxicity tests conducted with aquatic insects, particularly those using later instars, show much greater tolerance to metals compared to patterns observed in the field. 36,37 For contaminants that do not show significant acute toxicity (e.g., total dissolved solids, suspended sediments, nutrients, and deposition of metal oxides), traditional laboratory-based toxicity tests may be inappropriate and therefore should be supported by alternative approaches. 38 For example, using a field-based assessment, Linton 11 concluded that a more stringent benchmark for Fe would be necessary to protect mayflies and other grazers from the indirect effects of metal-oxide deposition.…”

Acute and Chronic Toxicity of Nickel and Zinc to a Laboratory Cultured Mayfly (Neocloeon triangulifer) in Aqueous but Fed Exposures

“…Although aquatic insects, particularly mayflies (Ephemeroptera), frequently are among the first taxa to disappear from metal‐contaminated freshwater ecosystems, laboratory testing typically indicates low sensitivity (Brix et al 2011; Poteat and Buchwalter 2014). For example, Brinkman and Johnston (2012) conducted acute zinc (Zn) toxicity tests with a variety of fish and insects native to western North America, and average median lethal concentrations (LC50s) for mayflies were approximately 80‐fold higher than those in fish. Although the US Environmental Protection Agency (1995) water quality criteria (WQC) for nickel (Ni) include a species mean acute value (SMAV) for the mayfly Ephemerella subvaria (Warnick and Bell 1969) among the 4 most sensitive species, a more updated Ni criteria for Illinois (Illinois Environmental Protection Agency 2002) included more sensitive crustaceans and mollusks, revealing that the Ephemerella SMAV was relatively insensitive (i.e., approximately an order of magnitude higher than those for the newly added 4 most sensitive species).…”

“…Aquatic insects are relatively poorly represented in WQC because most are difficult to culture. Frequently, aquatic insects used in testing are collected from streams as later instars (e.g., Warnick and Bell 1969; Brinkman and Johnston 2012). Poteat and Buchwalter (2014) advocated for the development of relevant insect toxicity models to bridge the gap in effect levels observed between field and laboratory data.…”