title: Assessment of the effects of cage fish-farming on damselfish-associated food chains using stable-isotope analyses.
abstract: To assess the effect of cage fish-farming on the coral reef ecosystem off Xiaoliuchiu Island, southern Taiwan, geographical differences in the food chain of each of two damselfishes, Pomacentrus vaiuli and Chromis margaritifer, were examined using a stable-isotope approach. For each damselfish, individuals were found to consume similar foods at all sites. However, specimens collected at sites near the cage farm (as the experimental sites) exhibited lower δ(13)C and higher δ(15)N signatures compared to those from reference sites. Similar trends also occurred in the zooplankton and detritus, two major food sources for both damselfishes. This finding indicates that particulate organic matter released by the farm may have entered the coral reef ecosystem through the pelagic food chain. Artificial reef emplacement is recommended to provide extra habitats under cage farms to support additional pelagic-feeding fish populations, thereby reducing environmental impacts of cage farming on coral reefs.
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan.
authors.forename: Rong-Quen
authors.initials: RQ
authors.lastname: Jan
authors.affiliation: Research Center for Environmental Changes, Academia Sinica, Taipei 115, Taiwan.
authors.forename: Shuh-Ji
authors.initials: SJ
authors.lastname: Kao
authors.affiliation: Institute of Oceanography, National Taiwan University, Taipei 106, Taiwan.
authors.forename: Chang-Feng
authors.initials: CF
authors.lastname: Dai
authors.affiliation: Biodiversity Research Center, Academia Sinica, Taipei 115, Taiwan. Electronic address: alexhol@gate.sinica.edu.tw.
authors.forename: Cheng-Tze
authors.initials: CT
authors.lastname: Ho
mesh_terms: D000818:Animals; D017756:Aquaculture; D057894:Coral Reefs; D005399:Fishes / Q000502:physiology*; D020387:Food Chain; D006801:Humans; D052638:Particulate Matter; D011157:Population Dynamics; D013624:Taiwan; D015048:Zooplankton / Q000502:physiology
chemical_list: D052638:Particulate Matter
keywords: Cage fish farming; Chromis margaritifer; Damselfish; Pelagic food chain; Pomacentrus vaiuli; Stable isotope