Kuvat: Jouko Högmander Itämeren hyljekannat ovat vankistuneet ja sen myötä myös haitat kalastukselle ovat kasvaneet. Onko metsästys keino rajoittaa kannan kasvua vai olisiko siitä myös elinkeinoksi? Hyljeasioita pohdittiin Arkipelagia-seuran iltamissa maaliskuussa. Hyljekannan koon arviointi on pohja suojelu- ja kannanhoitotoimille. Hyljetutkija Markus Ahola Naturhistoriska Riksmuseetista kuvasi hyljekantojen koon arviointimenetelmiä, jotka eroavat eri hyljelajien välillä. Harmaahylkeiden eli hallien määriä lasketaan kevättalvisilta karvanvaihtoajan lepäilyluodoilta lentolaskentoina. Norppamääriä sen sijaan arvioidaan linjalaskentoina. Karvanvaihtoaikoina hylkeet ovat parhaiten havaittavissa
Pääuutiset
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Tuoreimmat
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