Rappoort nr 101: Uppföljning av färgtrafikens effecter och långtidsförändringar I algvegetationen i Ålands skärgård
BERGLUND, J; ROOS, C (2000)
BERGLUND, J
ROOS, C
Åbo Akademi, Husö biologiska station
2000
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:952-12-0611-X
https://urn.fi/URN:ISBN:952-12-0611-X
Tiivistelmä
Large ferries affect the shore vegetation in two ways, by waves and the surge produced by the ferries. During the last 20 years, the ferries have been reconstructed for optimal speed, which has resu/ted in less waves. In the 1970's a study was conducted in order to c/arify the effects of /arge ferries on rocky shore vegetation. The main conclusions were that there was a definite effect of the ferry traffic on rocky shores in the Åland archipelago. The number of species was higher further away from the fairway, and the biomass of Fucus vesicu/osus was lower in the vicinity of the fairway. In the current study same of the study sites from the previous study were revisited, and /ong-term changes were observed. The study was conducted by SCUBA diving, species were visual/y observed a/ong a transect and random biomass samples were taken from the C/adophora- and Fucus-belts. The resu/ts from the current study show that the surge from the ferries keep the hard bottoms c/ear from filamentous a/gae. The number of species is /ower, whereas biomasses are similar in sites exposed and sheltered from the ferry traffic. The similarity in biomasses can be seen as an effect of eutrophication. The abundance of F. vesicu/osus is /ower now than in 1970's.