Rapport nr 109: Inverkan av vägbankar på vattenmiljön – uppföljande studier
SUOMALAINEN, K (2003)
SUOMALAINEN, K
Åbo Akademi, Husö biologiska station
2003
Publikationen är skyddad av upphovsrätten. Den får läsas och skrivas ut för personligt bruk. Användning i kommersiellt syfte är förbjuden.
This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited.
This publication is copyrighted. You may download, display and print it for Your own personal use. Commercial use is prohibited.
Julkaisun pysyvä osoite on
https://urn.fi/URN:ISBN:952-12-1275-6
https://urn.fi/URN:ISBN:952-12-1275-6
Tiivistelmä
A study on hydrography, sediment, zoobenthos and vegetation was conducted at three road embankment areas in the Aland archipelago June-August 2003. The road embankment areas were previously studied shortly before or after the road embankments were constructed in the sixties-seventies. The aim of this study was to identify changes in zoobenthos and vegetation at these embankment areas 30 years later. The studied road embankment areas were located in areas influenced by different abiotic factors. Husö road embankment area was characterised by the conditions of the inner archipelago whereas Sandö and Nåtö road embankment areas had a higher exposure with marine traits. Differences in exposure between the studied embankments resulted in different water f/ow capacities through the embanked sounds. Hydrography results followed this phenomenon; variation in hydrography results between stations was greater in Husö than in Sandö/Nåtö. For example, salinity was lower on the east side of Husö road embankment area than on the west side. The greatest biomass and number of species in zoobenthos was noticed on a station in Nåtö road embankment area c/ose to the opening for the water flow. The lowest biomass was noticed on a shallow sandy station in Sandö. The fewest number of species was noticed on the deepest station in Husö. Common species were Macoma balthica. Hydrobia spp. Nereis diversicolor and Chironomidae -larvae. Vegetation was dense in all studied road embankment areas. Common were different Potamoqeton and Chara -species, Myriophyllum spicatum and Cladophora qlomerata. Husö road embankment was also surrounded by a dense cane-break (Phraqmites australis).
There had been a change in biomass and species composition of zoobenthos in comparison with the previous studies. Biomass of zoobenthos had decreased on most stations. Species composition had also been altered on all of the stations. Dominance of mussels in biomass had decreased. Snails, insect larvae and crustaceans had become more common. This was partly due to differences in sampling methods between the study of this year and the earlier conducted studies. Vegetation had not been altered that much, the same species could be found in all of the road embankments. Vegetation had probably increased from the seventies.
In conclusion; the embankment affected all the studied road embankment areas. Zoobenthos biomass had decreased and the species composition was altered. Vegetation had not been altered but it had probably increased. At least the cane-break in Husö had increased.
There had been a change in biomass and species composition of zoobenthos in comparison with the previous studies. Biomass of zoobenthos had decreased on most stations. Species composition had also been altered on all of the stations. Dominance of mussels in biomass had decreased. Snails, insect larvae and crustaceans had become more common. This was partly due to differences in sampling methods between the study of this year and the earlier conducted studies. Vegetation had not been altered that much, the same species could be found in all of the road embankments. Vegetation had probably increased from the seventies.
In conclusion; the embankment affected all the studied road embankment areas. Zoobenthos biomass had decreased and the species composition was altered. Vegetation had not been altered but it had probably increased. At least the cane-break in Husö had increased.