An ecological study of a small New Zealand stream with particular reference to the Oligochaeta

✍ Scribed by J. W. Marshall; M. J. Winterbourn

• Publisher: Springer
• Year: 1979
• Tongue: English
• Weight: 718 KB
• Volume: 65
• Category: Article
• ISSN: 1573-5141
• DOI: 10.1007/bf00038860

✦ Synopsis

channel . As well as providing baseline data for use in assessing the impact of treated effluent on the biota of the drain, it represents the first comprehensive account of the benthos of a small, lowland stream in New Zealand .

An ecological study of the Leeston drain, a small stony stream enriched by septic tank and dairy shed effluents was conducted over a one-year period in 1972-'73 . Physical and chemical factors, sediment composition and benthic fauna were sampled at four stations along the drain . Dissolved oxygen concentration was always high but BOD5 was high variable . Nitrate-N concentration declined from source to mouth but phosphate-P levels were elevated in the vicinity of Leeston township where heavy growths of aquatic macrophytes occurred . The benthic fauna was dominated by Oligochaeta (15 species) and a gastropod, Potamopyrgus antipodarum. Differences in size and species composition of the fauna along the drain reflected differences in flow rate, organic enrichment and the nature of the substrate .