Lugares de freza del esturión en los afluentes del río Oder: una valoración inicial
As part of a feasibility study for the re-establishment of Acipenser sturio L., 1758 in its previous range in German and Polish waters, a habitat assessment was initiated for the Odra River watershed. Spawning habitat for sturgeons is considered to be of major importance for the successful restorati...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Article in Journal/Newspaper |
| Language: | unknown |
| Published: |
2001
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| Online Access: | http://hdl.handle.net/10508/1302 http://hdl.handle.net/10261/320056 |
| Summary: | As part of a feasibility study for the re-establishment of Acipenser sturio L., 1758 in its previous range in German and Polish waters, a habitat assessment was initiated for the Odra River watershed. Spawning habitat for sturgeons is considered to be of major importance for the successful restoration and subsequent reproduction of the species, since it supports the most vulnerable life stages. The ongoing restoration project comprises three distinct phases; the first phase included the evaluation of readily available habitat. Habitat requirements were identified based on published information on sturgeon reproduction, historical catch data, and early life history. Potential spawning habitats were determined in a first step based on historic records. For the identified historic spawning sites, recent data on migration obstacles and water pollution were evaluated, thus excluding non-accessible or adversely affected sites. In the Drawa River -described as a sturgeon spawning habitat until 1939- potentially suitable habitats were determined to be readily available. Data were gathered on the dynamic of the discharge, water quality, longitudinal profiles and cross-sections of the river, as well as substrate composition. Five river stretches comprising approximately 15 000 m³ were identified as being potentially suitable for sturgeon spawning. Assuming an average fertility of 1 million eggs per female and a maximum density of 3 500 eggs/m³, the spawning-site surface required for an average female would comprise approximately 350 m³. Thus, the Drawa River could provide a spawning habitat for approx. 50 females. Como parte de un estudio de viabilidad para el restablecimiento de Acipenser sturio L., 1758 en su distribución original en aguas alemanas y polacas, se inició una valoración del hábitat en la cuenca del río Oder. Se considera que el hábitat de freza para los esturiones es de mayor importancia para el éxito de la recuperación y subsecuente reproducción de las especies, ya que mantiene los estados vitales más ... |
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