Pelagic Fish Communities and Eutrophication in Lakes of an Andean Basin of Central Chile
作者:
F. Scasso,
H. Campos,
期刊:
Journal of Freshwater Ecology
(Taylor Available online 2000)
卷期:
Volume 15,
issue 1
页码: 71-82
ISSN:0270-5060
年代: 2000
DOI:10.1080/02705060.2000.9663723
出版商: Taylor & Francis Group
数据来源: Taylor
摘要:
Biomass, production, and yield of the pelagic fish communities were estimated in Laguna Grande of San Pedro (eutrophic), Laguna Chica of San Pedro (mesotrophic) and Lake Icalma (oligotrophic), all belonging to the Andean basin of the Biobío river (36°45′-39°S), Chile. Fish biomass showed differences that were related to the trophic state of the lakes. The highest biomasses were in the eutrophic lakes, with mean values of 563 kg ha−1in Laguna Grande of San Pedro and 591 kg ha−1in Laguna Chica of San Pedro. The lowest biomass was in Lake Icalma with a mean of 164 kg ha−1. The estimated annual yields were 170 kg ha−1in Laguna Grande of San Pedro, 157 kg ha−1in Laguna Chica of San Pedro, and 32 kg ha−1in Lake Icalma. In Laguna Grande of San Pedro, the highest percentage of fish yield was the non-salmonid species, including Cyprinids (Cyprinus carpioandCarassius carassius) with 87.2%, and only 12.8% wasOncorhynchus mykiss, the only salmonid species in this lake. The same pattern was observed in Laguna Chica of San Pedro, with 78.6% forOdontesthes bonariensisand 21.4% forO. mykiss. In Lake Icalma the pattern was opposite, with a 90.2% for the salmonid species (O. mykissandSalmo trutta) and only 9.8% forPercichthys trucha.
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