Toxicity of Trace Metal Mixtures to American Flagfish (Jordanella floridae) in Soft, Acidic Water and Implications for Cultural Acidification

Abstract

Laboratory exposures over 1.3 generations showed that trace metal mixtures played a dominant role in the reproductive failure of American flagfish (Jordanella floridae) in soft (6.0 mg∙L−1 as CaCO3 total hardness), acidified (pH 5.8) water. This finding may also apply for native fish species inhabiting culturally acidified waters. Reproductive failure was complete when pH 5.8 water contained a mixture of Al, Mn, Fe, Ni, Zn, Cu, and Pb at 57% of the concentrations found in acidified waters (or 0.57 ALC). Fry died within 6 d of exposure, adults transferred into the treatment ceased spawning, and hatching of transferred eggs was reduced. The onset of steady spawning activity was delayed by addition of smaller amounts (0.09–0.27 ALC) of metals, but reductions in size of juvenile fish did not persist to maturity. At pH 5.8 with no metals, no effects on any stage of the life cycle were observed. Subsequent testing of fry showed that lethality of a mixture of Al, Zn, and Cu was equivalent to that of all seven metals. The threshold acute LC50 for flagfish fry at pH 5.8 occurred with the simultaneous presence of Al, Zn, and Cu at 29, 5, and 2.3 μg∙L−1, respectively, or with 95 μg Al∙L−1 alone. Future research on trace metal stress in culturally acidified waters should consider Zn and Cu, in addition to Al.

Freshwater acidification: effects on the early life stages of fish

“…However, ovulation was delayed in the acid water group. Delayed time to spawning was recorded for flagfish (Jordanella floridae, Cyprinodontidae; a species not found in acid waters) subjected to acid and heavy metal mixtures, although egg production was unaffected (Hutchinson and Sprague, 1986). Delayed, but not inhibited, spawning of perch (Vuorinen et al, 1992) and ovulation in whitefish (Coregonus wartrnanni, Salmonidae; Vuorinen et al, 1990) has been recorded in acid lakes.…”

Joint and single toxicity of Cd and Fe related to metal uptake in the mayfly Leptophlebia marginata (L.) (Insecta)

“…Spehar et al (1978) demonstrated that Cd and Zn had a less than additive effect on larval survival of the flagfish Jordanella floridae . Comparisons with studies involving experiments with complex metal mixtures (Hutchinson & Sprague, 1986) are difficult, because it is not known which of the components in the metal mixture caused the observed effects . Comparisons with shortterm experiments ( de March, 1988 ;Thorp & Lake, 1974 ;Herkovits & Peres-Coll, 1991) are difficult, as there may be different mechanisms of toxicity during short and long term exposure.…”

“…Few studies have considered the combined effects of metal mixtures on freshwater invertebrates (EIFAC, 1987), whilst fish have been used more often as test organisms (Hutchinson & Sprague, 1986 ;Spehar et al ., 1978 ;Spehar & Fiandt, 1986 ;Enserink et al, 1991) . In particular chronic toxicity studies on the effects of metal mixtures on aquatic organisms are rare (Enserink et al, 1991 ;Kraak et al, 1994) .…”

The effects of eight trace metals in acid soft water on survival, mineral uptake and skeletal calcium deposition in yolk‐sac fry of brown trout, Salmo trutta L.

“…Some of these metals are present in concentrations high enough to be toxic to fish in very soft water. At these levels copper and zinc in mixtures with aluminium are lethal to American flagfish, JordanellaJEoridae, a species not found in the affected waters (Hutchinson & Sprague, 1986). Similar concentrations of cadmium (Rombough & Garside, 1984) and manganese can produce sublethal disturbances in salmonids held in soft, acid water.…”