Search results for "VDP::Matematikk og Naturvitenskap: 400::Zoologiske og botaniske fag: 480"
showing 10 items of 87 documents
Survival and recruitment in a population of critically endangered northern pool frog (Pelophylax lessonae) in Norway
2020
Master's thesis in Coastal ecology (BIO501)
Tidsanalyse av bentisk bløtbunnsfauna i Kristiansandsfjorden : Har det forekommet endringer i bløtbunnsfauna fra 1983 til 2016?
2017
Masteroppgave akvatisk økologi BIO500 - Universitetet i Agder 2017 Kristiansandsfjorden har i en årrekke vært utsatt for sterk belastning forårsaket av menneskelige aktiviteter. Hovedproblemene i fjorden har vært knyttet til høye konsentrasjoner av organisk materiale, klororganiske forbindelser, PAH og tungmetaller, som hovedsakelig har sin kilde fra utslipp av kommunalt avløpsvann og industriutslipp. Det har blitt iverksatt ulike tiltak i fjorden: utslippsreduksjoner for industri, bygging av kommunale renseanlegg og tildekking av forurenset sediment. Disse tiltakene har ført til en bedring av miljøtilstanden, men den har fortsatt ikke nådd miljømålet satt av Vannforskriften. Det har blitt …
Copepods dominate the mesozooplankton spring-summer community in a South Norwegian fjord
2021
Master's thesis in Coastal ecology (BIO501) In this study the seasonality of the mesozooplankton community in spring and summer of 2019 at Midtfjordsskjær (MFS), South Norway, was investigated. Zooplankton samples were collected using a fine mesh sized plankton net (60 μm) and zooplankton were identified by microscopy based on 5 ml subsamples. Total zooplankton abundance ranged from 754 –1620 ind. m-3and peak abundance was found in May. Holoplankton dominated spring and summer communities at MFS constituting between 85,6 –98,8% of total zooplankton.
Kvalitativ og kvantitativ inventering av fiskesamfunnet i Ytre Oslofjord : En beskrivelse av diversitet og generelle trekk ved fiskesamfunnet i Færde…
2020
Master's thesis in Coastal ecology (BIO501) A three-year study was performed annually from 2017 to 2019 in Færder- and Ytre Hvaler national parks located in outer Oslofjord. Data collection was conducted in shallow- and deep water habitats using catch-based methodologies in 2017 - 2019 (eel fyke net and trap) and visual methodology (stereo-video)in 2019. In the period of study, a total of 9733 individual fish were recorded among 37 species from 19 families. Shallow water fish assemblage (1 - 10 m) sampled by fyke net was dominated by a selection of wrasses (goldsinny wrasse and corkwing wrasse) and small, stationary species of non-commercial importance. Sampled by trap at deeper habitats (1…
Allee effects and the Allee-effect zone in northwest Atlantic cod
2022
According to the theory of compensatory dynamics, depleted populations should recover when the threat responsible for their decline is removed because per capita population growth is assumed to be highest when populations are at their smallest viable sizes. Yet, many seriously depleted fish populations have failed to recover despite threat mitigation. Atlantic cod (Gadus morhua) stocks off Newfoundland, despite 30 years of dramatically reduced fishing mortality and numerous fishery closures, have not recovered, suggesting that drivers other than fishing can regulate the growth of collapsed fish populations, inhibiting or preventing their recovery. Here, using Bayesian inference, we show str…
Biomonitoring of contaminants in blue mussels (Mytilus edulis) from the city fjord in Flekkefjord
2020
Master's thesis in Coastal ecology (BIO501)
Harmonizing circumpolar monitoring of Arctic fox: benefits, opportunities, challenges and recommendations.
2017
Source at http://dx.doi.org/10.1080/17518369.2017.1319602 The biodiversity working group of the Arctic Council has developed pan-Arctic biodiversity monitoring plans to improve our ability to detect, understand and report on long-term change in Arctic biodiversity. The Arctic fox (Vulpes lagopus) was identified as a target of future monitoring because of its circumpolar distribution, ecological importance and reliance on Arctic ecosystems. We provide the first exhaustive survey of contemporary Arctic fox monitoring programmes, describing 34 projects located in eight countries. Monitored populations covered equally the four climate zones of the species’ distribution, and there were large dif…
Spawning coloration and sperm quality in a large lake population of Arctic charr (Salmonidae: Salvelinus alpinus L.)
2009
The modern theories of sexual selection predict that male sexual ornaments may have evolved as reliable signals of male fertilization efficiency. However, among the studies of fishes with external fertilization, the results have yielded ambiguous evidence. In the present study, we present data on the phenotypic relationships between red spawning coloration and ejaculate quality (spermatocrit, sperm motility) from Arctic charr, Salvelinus alpinus. We studied two generations (F1 and F2) of males from a large lake population, reared in a standardized hatchery environment, to determine whether differential hatchery history, or duration of hatchery selection, affected the variation in ejaculate …
Matproduksjon, mattrygghet og miljø - innspill om kunnskapsbehov til gjennomføringen av det grønne skiftet - Uttalelse fra hovedkomiteen i Vitenskaps…
2022
Denne rapporten er utarbeidet av Vitenskapskomiteen for mat og miljø (VKM), en uavhengig, tverrfaglig komité som utarbeider kunnskapsgrunnlag for den norske mat- og miljøforvaltningen på områdene matproduksjon, mattrygghet og biologisk mangfold. De siste tiårene har FNs klimapanel, Det internasjonale naturpanelet, Det internasjonale ressurspanelet og flere andre paneler og organisasjoner levert rapporter som dokumenterer at befolkningsvekst og menneskelig aktivitet fører med seg store og økende utfordringer på miljø-, klima- og ressursområdet. Endringer innen disse områdene påvirker matproduksjon, matsikkerhet, mattrygghet, folkehelse og naturverdier i alle deler av verden (UNEP, 2021). Sam…
Risikovurdering av kombinasjonseffekter av plantevernmiddelrester i stikkprøver fra importerte rosiner, druer, pærer og norske jordbær -Vitenskapelig…
2022
Paid open access