Responses of wild fishes to alarm chemicals in pristine and metal-contaminated lakes

• Published in: Canadian journal of zoology Vol. 82; no. 5; pp. 694 - 700
• Main Authors: McPherson, Taryn D, Mirza, Reehan S, Pyle, Greg G
• Format: Journal Article
• Language: English
• Published: Ottawa, Canada NRC Research Press 01.05.2004; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: Agnatha. Pisces; Alarm systems; Animal and plant ecology; Animal behavior; Animal populations; Animal, plant and microbial ecology; Animals; Applied ecology; Autoecology; Biological and medical sciences; Chemicals; Contamination; Distilled water; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Etheostoma; Etheostoma exile; Fish; Fish populations; Freshwater; Fundamental and applied biological sciences. Psychology; Lakes; Littoral zone; Metals; Pisces; Population decline; Predators; Prey; Vertebrata; Water pollution; Xiphophorus helleri; Canada; North America; Ontario; America; Ontario Canada; Canada, Ontario; USA, Iowa; Freshwater environment; Chemical communication; Animal communication; Vertebrata; Pisces; Lakes; Chemoreception; Alarm pheromone; Water pollution; Perturbation; Semiochemicals; Heavy metal
• ISSN: 0008-4301; 1480-3283; 1480-3283; 0008-4301
• DOI: 10.1139/z04-034

Responses of wild fish populations to alarm chemicals were examined in clean and metal-contaminated lakes in northern Ontario. Approximately 20 groups of three minnow traps were placed randomly in the littoral zone of each study lake. Within each minnow trap group, one trap was treated with a chemical alarm stimulus (Iowa darter (Etheostoma exile (Girard, 1859)) skin extract, prey-guild species, alarm cue present), one with swordtail (Xiphophorus helleri Heckel, 1848) skin extract (phylogenetically distant and allopatric from darters, alarm cue present but not recognized by darters), and one with distilled water (neutral control). Data included the identification and enumeration of fish captured in each trap after a 10-h set. Darters avoided areas labelled with the alarm stimulus relative to controls only in the clean lake; in contaminated lakes, darters did not avoid areas labelled with the alarm stimulus relative to controls. No effects of contamination on chemosensory function were observed for heterospecific non-darter prey-guild or predator-guild species. These findings suggest that chemical alarm systems do exist in nature, and that these systems appear to be affected by the presence of metals. Such pollution-related effects could lead to increased susceptibility of some fish species to predation and to population declines.