Bedömning av mänsklig påverkan i och i närheten av, samt klassificering och utvärdering av grunda havsvikars undervattensväxtlighet på Åland

D4 Published development or research report or study

Internal Authors/Editors

Publication Details

List of Authors: Hans-Peter Huhtala
Publisher: Åbo Akademi, Forskningsrapporter från Husö biologiska station
Publication year: 2018
Start page: 1
End page: 51
ISBN: 978-952-12-3767-6


In the summer of 2018 the coverage data for underwater macrophytes was
analysed to determine the degree of protection necessary with regards to
79 individual shallow bays on the Åland Islands. This was accomplished
by using data gathered by previous research associated with the
biological station, but also by mapping seven bays where studies on
vegetation cover had yet to be performed. The bays were located all over
the islands, and bays from 10 of the islands 16 municipalities were
analysed with the NANNUT method, which uses data on vegetation cover to
classify and assign ecological value to underwater habitats. The
surrounding area of the bays was also analysed to estimate its
anthropogenic impact. This was done by counting buildings, determining
the area covered by roads, farmland and buildings, determining total
meters of jetty, the proportion of modified coastline and the number of
streams discharging into the bay. This was accomplished by using GIS
data, and by analysing satellite imagery.

53 of the 79 bays were determined to need protection to safeguard
their important ecological status. These were bays who were determined
to be of NANNUT-ecological value of 3 or more. One further bay with a
score less than 3 was also determined to be worthy of protection is also
included in these 53 bays. The bays derived their ecological value due
to the presence of stonewort meadows, dense and species rich vegetation,
red-listed species and habitats especially important to juvenile fish.

With regards to the survey of the surrounding area of the bays; 76
of the 79 bays were found to have a high or good rating when estimating
the anthropogenic impact on the bays, which suggests that the impact of
the surrounding area is moderate for shallow bays on the Åland Islands.
It should be noted that the impact is based on a mean value of several
parameters, and that these individually often had poorer ratings,
especially the parameter based on the amount of buildings in the
surrounding area.

Last updated on 2020-18-09 at 06:45