Effects of harbour excavating and dredged sediment disposal on the benthic invertebrate fauna of River Danube (Austria)

Autor: Otto Moog, Ilse Stubauer, Patrick Leitner, Helmut Habersack, Marlene Haimann
Rok vydání: 2015
Předmět:
Zdroj: Hydrobiologia. 814:109-120
ISSN: 1573-5117
0018-8158
DOI: 10.1007/s10750-015-2476-x
Popis: Dredging Austrian Danube harbours becomes necessary to keep the navigation channel free from bed sediment and to insure safe navigation, especially after major floods. In most cases, the excavated substrate is deposited in the free-flowing river section in the vicinity of the mouth of a harbour. The effects of harbour dredging on the biota need to be studied to minimize possible outcomes that may endanger the ecological status of the river system in order to implement the aims of the European Water Framework Directive. This study presents the first quantitative information on the colonisation of benthic invertebrates with respect to Danube harbours. One sampling at Linz Harbour was conducted before dredging and four samplings were carried out after dredging. Four transects were documented in the affected river section. The study used an air-lift sampler and a grab sampler to investigate if and to what extent the benthic invertebrate community is disturbed. It found that the sediment dredging heavily affected the benthic invertebrates (decline of 82% of biomass), while the dumping of the material had no effects on the benthic Danube biota. As a rough estimate (conferring to a simple trend line analysis) the harbour bottom fauna would recover after 235 days.
Databáze: OpenAIRE
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