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dc.contributor.advisorTorbjørn Haugaasen
dc.contributor.advisorQuentin Mauvisseau
dc.contributor.advisorCintia Oliveira Carvalho
dc.contributor.authorGromstad, William Esbjug
dc.date.accessioned2024-09-06T16:27:34Z
dc.date.available2024-09-06T16:27:34Z
dc.date.issued2023
dc.identifierno.nmbu:wiseflow:6985909:56820762
dc.identifier.urihttps://hdl.handle.net/11250/3150752
dc.description.abstractMarine økosystemer er i økende grad truet av ulike menneskelige aktiviteter. Nøyaktig overvåkning er derfor essensielt for bevaring av naturen og dens arter, men dette forblir spesielt utfordrende i marine miljøer. I oppgaven min vurderer jeg bruken av miljø-DNA (eDNA) for å beskrive sammensetningen av marine virveldyr samfunnet, og sesongmessige endringer heri, i Oslofjorden, sørøst-Norge. I tillegg ble potensielle variasjoner i rikdom mellom prøvetakingssteder, felt- eller laboratoriereplikater analysert. eDNA ble samlet gjennom vannprøver i seks bimånedlige innsamlinger over ett år. Elas02- og MiFish-primerne, rettet mot et fragment av det 12S mitokondriale genet, ble brukt til å amplifisere sekvensområder i PCR-reaksjoner. Dette resulterte i 63 fiskearter, i tillegg til nise og sei-hval. Generelt sett var artsrikdommen ikke forskjellig mellom prøvetakingssteder, men det var variasjoner mellom prøvetakingsmånedene. Å øke antallet feltreplikater syntes ikke å øke antallet påviste arter, men en effekt ble sett for PCR-replikater. Seks arter viser et tydelig mønster av sesongvariasjon. Tre av artene var mer til stede i fjorden i sommermånedene, mens de resterende artene var hkvesaklig tilstede om vinteren. For de fleste artene ble dette mønsteret forklart av sesongmessige migrasjoner tilknyttet deres biologi. Dette indikerer at eDNA-metabarkoding kan være et nyttig verktøy for overvåking av økosystemer i fjorder, også inkludert migrerende arter.
dc.description.abstractMarine ecosystems are increasingly under threat from a variety of human activities. Accurate monitoring is therefore essential for conservation efforts, but this remains particularly challenging in marine environments. In my thesis, I evaluate the use of environmental DNA (eDNA) for describing the marine vertebrate community composition, and seasonal changes herein, in the Oslo fjord, south-eastern Norway. Additionally, potential variation in richness between sampling locations, field, or laboratory replicates was analyzed. The eDNA was collected through water samples in six bimonthly sampling events spanning one year. Elas02 and MiFish primers, targeting a fragment of the 12S mitochondrial gene, were used to amplify sequence regions in PCRs. This resulted in the detection of 63 fish species, in addition to harbour porpoise and sei whale. Overall, species richness did not differ between sampling locations, but there were significant variations between sampling months. Increasing the number of field replicates did not appear to increase the number of detected species, but an effect was seen for PCR replicates. Six species exhibit a clear pattern of seasonality. Garfish, Atlantic mackerel, and painted goby were more present in the fjord during the summer months, while Atlantic herring, harbour porpoise, and Mueller’s pearlside were winter inhabitants. For most species, this pattern was explained by seasonal migrations related to their biology. This indicates that eDNA metabarcoding could be a useful tool for monitoring fjord ecosystems, including migratory species.
dc.languageeng
dc.publisherNorwegian University of Life Sciences
dc.titleHarnessing eDNA metabarcoding to investigate marine vertebrate community composition and its seasonal changes in the Oslo fjord
dc.typeMaster thesis


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