title: Origin of the mass mortality of the flathead grey mullet (Mugil cephalus) in the Tanshui River, northern Taiwan, as indicated by otolith elemental signatures.
abstract: A massive fish kill of approximately 50 tons of flathead grey mullet (Mugil cephalus) occurred in August 2006 in the Tanshui River, northern Taiwan. To clarify the origin of these mullets, 42 individuals were randomly collected to determine their ages by reading otolith annuli and to measure the trace elements in the otolith. The total lengths of the fish averaged 32.7±4.4 cm, and most of the individuals were 2 years old, indicating that the mullets in the mass fish kill event were in the immature and growth stages. The Sr/Ca and Ba/Ca ratios of a subsample of 14 otoliths showed that half of the fish killed were estuarine residents, and the rest originated from marine and freshwater habitats. The multiple causes involved in this fish kill implied that additional unknown factors influenced the mullet populations on a large scale and induced them to move quickly and gather at this estuary.
authors.affiliation: Department of Environmental Biology and Fisheries Science, National Taiwan Ocean University, Keelung 104, Taiwan, ROC.
authors.forename: Chia-Hui
authors.initials: CH
authors.lastname: Wang
authors.forename: Chih-Chieh
authors.initials: CC
authors.lastname: Hsu
authors.forename: Wann-Nian
authors.initials: WN
authors.lastname: Tzeng
authors.forename: Chen-Feng
authors.initials: CF
authors.lastname: You
authors.forename: Chih-Wei
authors.initials: CW
authors.lastname: Chang
mesh_terms: D000818:Animals; D017753:Ecosystem; D005399:Fishes; D008670:Metals / Q000633:toxicity*; D009026:Mortality; D010037:Otolithic Membrane / Q000187:drug effects* / Q000378:metabolism; D045483:Rivers / Q000737:chemistry*; D023701:Smegmamorpha / Q000254:growth & development / Q000502:physiology*; D013624:Taiwan; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D008670:Metals; D014874:Water Pollutants, Chemical