Rapport nr 141: Beräkning av ekologisk status för Ålands ytvattenförekomster utgående från kartering av makrofyter: ett förslag till övervakningsprogram och harmonisering av metoder mellan Åland och Finland
SAARINEN, A (2015)
SAARINEN, A
Åbo Akademi, Husö biologiska station
2015
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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:978-952-12-3309-8
https://urn.fi/URN:ISBN:978-952-12-3309-8
Tiivistelmä
A survey of macrophytes was conducted in the summer of 2015 to assess the ecological status of the macrophytes in Åland Islands coastal waters. The survey was an assignment of the provincial Government of Åland Islands. The aim was also to develop a more cost-effective monitoring plan for coastal macrophytes and harmonizing survey and classification methods with mainland Finland. The survey was conducted at all 14 monitoring areas around the Åland Islands. At every monitoring area 1-2 dive transects were surveyed (19 dive transects in total). New dive transects were made to monitoring areas that were lacking data. At each 50 meter long transect the depth distribution of macrophytes was observed from the shoreline towards the sea. The depth distribution of macrophytes along the transects and beyond was used to estimate the ecological status of the monitoring areas. The ecological status was determined with a classification method customized for the Åland Islands. Also the Finnish updated classification method was used to test if it can be used in the Åland Islands. Data from this survey and surveys from 2012 and 2011 was used for the classification. The method developed to Åland worked satisfyingly and showed a slight improvement in the ecological status, whereas the Finnish method didn’t fully work because it is developed only to deep hard bottoms. Most of the dive transects in Åland are a mix of different substrates and many transects were too soft or shallow for determining the depth distribution of macrophytes on hard bottoms. This is also the reason to why the survey and classification methods in Åland and Finland will be challenging to harmonize. A more cost-effective monitoring plan was proposed based on the previous monitoring plan.