Relative acute effects of low pH and high iron on the hatching and survival of the water mite (Arrenurus manubriator) and the aquatic insect (Chironomus riparius)

• Published in: Environmental toxicology and chemistry Vol. 16; no. 10; pp. 2144 - 2150
• Main Authors: Rousch, J.M, Simmons, T.W, Kerans, B.L, Smith, B.P
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Periodicals, Inc 01.10.1997; SETAC
• Subjects: ACID MINE DRAINAGE; ADVERSE EFFECTS; AGUA DE DRENAJE; Animal, plant and microbial ecology; Applied ecology; Arrenurus manubriator; Biological and medical sciences; CALIDAD DEL AGUA; Chironomus riparius; DRAINAGE WATER; EAU DE DRAINAGE; Ecotoxicology, biological effects of pollution; EFECTOS SECUNDARIOS; Effects of pollution and side effects of pesticides on protozoa and invertebrates; EFFET SECONDAIRE; Freshwater; Fundamental and applied biological sciences. Psychology; Iron; POLLUTION DE L'EAU; POLUCION DEL AGUA; QUALITE DE L'EAU; SIDE EFFECTS; TOXICIDAD; TOXICITE; TOXICITY; Toxicity tests; WATER POLLUTION; WATER QUALITY; Chironomidae; Chironomus riparius; Hatching; Toxicity; Insecta; Zoobenthos; Acidity; Iron; Survival; Freshwater environment; Pollutant; Arachnida; Acari; Arthropoda; Mine; Water pollution; Invertebrata; Diptera; Effluent
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1002/etc.5620161022

We investigated the relative effects of low pH and high iron on a water mite, Arrenurus manubriator and an aquatic insect, Chironomus riparius. Eggs and active stages were exposed in static renewal toxicity tests to pH 6, 5, 4, 3, and 2, made by adding sulfuric acid to reconstituted soft water, or to iron levels of 200, 400, 600, 800, and 1,000 mg/L, made by adding ferrous sulfate to soft water at pH 4. Experiments were conducted at 22 degrees C with a 16:8-h photoperiod, and treatments were replicated three times with at least nine individuals per treatment. Data were analyzed with a logistic response function and one-way ANOVA for pH and iron tests, respectively. Egg hatching was reduced at pH 2 for midges and at pH 3 for mites. Iron had no effect on hatching for either species. Survival of midge larvae was partially reduced at pH 4, and survival of mite deutonymphs, larvae, female and male adults was reduced at pH 3. Survival of midge larvae, and mite deutonymphs and male adults was reduced at 400, 200, and 1,000 mg Fe/L, respectively. Mite female adults and larvae were unaffected by iron. Higher metabolic requirements of unfed immature stages, the gelatinous covering of mite and insect eggs, the longer incubation period of mite eggs, and the greater osmoregulatory potential of adult mites may have contributed to the differences observed