Habitat preferences of coral-associated fishes are altered by short-term exposure to elevated C[O.sub.2]

• Published in: Marine biology 2013-08, Vol.160 (8), p.1955
• Main Authors: Devine, Brynn M, Munday, Philip L
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Environmental aspects; Habitat selection; Ocean-atmosphere interaction
• ISSN: 0025-3162
• DOI: 10.1007/s00227-012-2051-1

Rising atmospheric carbon dioxide (C[O.sub.2]) concentrations are causing additional C[O.sub.2] to be absorbed by the oceans. Recent studies show that exposure to elevated C[O.sub.2] causes olfactory impairment in reef fishes; however, the ecological consequences of this impairment are largely unknown. This study examined the effects of short-term exposure to elevated C[O.sub.2] on habitat preferences of coral-dwelling gobies. Adult gobies collected from the reef at Lizard Island (Great Barrier Reef, Australia) were exposed for 4 days to ambient C[O.sub.2] (440 µatm) or elevated C[O.sub.2] (880 µatm). Habitat preferences were then tested in laboratory and field experiments at ambient conditions. In olfactory preference tests, Paragobiodon xanthosomus displayed a strong preference for odour cues of their sole host coral Seriatopora hystrix; however, this preference was absent in gobies exposed to elevated C[O.sub.2]. Habitat choice experiments conducted in the field showed that Gobiodon histrio placed on dead coral colonies located preferred live habitat within 24 h; however, gobies exposed to elevated C[O.sub.2] associated with both preferred and non-preferred habitats in approximately equal frequency. Preferred habitats are known to confer fitness advantages to coral-dwelling gobies. Consequently, these results suggest that future elevated C[O.sub.2] levels might affect the ability of habitat specialist fishes to select favourable habitats.