Search results for "BIO500"
showing 9 items of 9 documents
Feeding Ecology of Harbour Seals (Phoca vitulina) in Southern Norway
2017
Master's thesis Aquatic Ecology BIO500 - University of Agder 2017 In order to understand ecosystem dynamics and functions it is vital to have knowledge about relationships between predator and prey. Harbour seals (Phoca vitulina) are piscivorous marine mammals found at or near the top of marine food webs. Being mainly piscivores, harbour seals have the potential to come into conflict with fishermen and fisheries. Recently, as the Skagerrak and Kattegat population of harbour seals has increased, claims that seals are depleting the cod population have surfaced. Using scat sampling and otolith identification, harbour seal diet was estimated in four separate locations along the coast of souther…
Natural selection against offshore Atlantic cod (Gadus morhua) in Skagerrak fjords?
2016
Master's thesis Aquatic Ecology BIO500 - University of Agder 2016 The marine environment was previously presumed to be demographically “open”, and marineorganisms were thought to have pronounced gene flow over vast areas due to their potentialof dispersal during early life stages. However, recent studies have suggested a degree of selfrecruitmentwithin segments of coastal and offshore areas for several marine species. Two ofthe forces acting on this structuring are retention of early life stages and homing of adultindividuals. This study looks at the distribution of early life stages of the Atlantic cod (Gadusmorhua) in two Norwegian fjords divided into inshore-offshore transects, and study…
Analysering av miljø-DNA for kartlegging av marin fiskefauna
2016
Masteroppgave akvatisk økologi BIO500 - Universitetet i Agder 2016 Marine ecosystems worldwide are currently threatened due to overfishing and other humanimpacts. To monitor marine fish, which represents a main component in present monitoring ofmarine ecosystem health, one is mainly depending on invasive and selective methods. Thesemethods are also dependent on physical identification of species, which in many cases can bedifficult, or in some cases, impossible. Such limitations of traditional surveillance methodshave created a demand for alternative methods. One such alternative is the environment-DNAmethod, i.e. analysis of genetic material from a sample collected in the environment.In th…
Kartlegging av vandringshindre og kvantifisering av europeisk ål (Anguilla anguilla) ved bruk av miljø-DNA
2019
Masteroppgave akvatisk økologi BIO500 - Universitetet i Agder 2019 Europeaneel (Anguilla anguilla) is an endangered species nationally and internationally, and the EU-Commissionhas decided that conservation effort is needed. One of the challenges in Norway is obstacles in migration routes, especially where riversareput in pipes underneath roads. In addition, knowledge regarding biomass is essential in conservation work. In this study, environmental DNA (eDNA) has been investigated as a tool for mapping migration obstaclesfor eel.The possibility of usingindividual differences in eDNAto separate individuals, as an estimation of biomass, was also investigated. eDNA is DNA that organisms shed t…
Responses of European lobster (Homarus gammarus) and lobster fishers to protective management
2017
Master's thesis Aquatic Ecology BIO500 - University of Agder 2017 Marine protected areas (MPAs) are valued for their conservation benefits to harvested species. However, potential benefits of MPAs to neighboring fisheries are less well-understood. This study quantifies how the European lobster (Homarus gammarus) and the fishery for this valued catch respond to the establishment of a relatively small (5.2 km2) MPA on the Norwegian Skagerrak coast. A series of yearly standardized trap surveys was conducted to estimate lobster abundance and catch weights both inside and outside the MPA before (2010- 2011) and after the MPA was established (2012-2016). Lobster abundance and catch weights were d…
Genomic analysis of anadromous brown trout (Salmo trutta) reveals new insights into connectivity patterns and population divergence
2018
Master's thesis Aquatic Ecology BIO500 - University of Agder 2018 A large body of studies on brown trout genetics currently exists. However, fewer of these studies have been conducted on anadromous brown trout (sea trout) and have been limited to only a few genetic markers like allozymes, mtDNA or microsatellites. Here we analyzed population structure and connectivity in sea trout applying a modern genomic approach, analyzing 503 single nucleotide polymorphic variants (SNP’s) by next generation sequencing. We studied four streams along the Skagerrak coast and found an overall significant population structure (FST = 0.0161; P<0.01) which further seemed to constitute of three genetically dist…
Kopepoder langs Skagerrakkysten - En oversikt basert på morfologisk og molekylærgenetisk identifisering
2018
Masteroppgave akvatisk økologi BIO500 - Universitetet i Agder 2018 Konfidensiell til / confidential until 01.07.2023
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 …
Embryonic development of corkwing wrasse, Symphodus melops
2016
Master's thesis Aquatic Ecology BIO500 - University of Agder 2016 Eggs from corkwing wrasse, Symphodus melops were described, photographed and illustrated to characterise the embryonic development of this species. Egg development was divided into 8 stages from fertilisation until hatching with descriptions of key features for each stage. The rate of development in corkwing wrasse eggs at temperatures commonly found along the Norwegian coast (12, 15 and 18 C) was also investigated. The rate of development was faster at higher temperatures. Keywords: labridae, cleaner fish, embryonic development, corkwing wrasse