84 research outputs found
Distribution and abundance of Norwegian spring-spawning herring during the spawning season in 2024
During the period 13-26th of February 2023 the spawning grounds of Norwegian spring-spawning herring from MĂžre (62Âș15 Ë N) to TromsĂžflaket (71 Âș N) were covered acoustically by the commercial fishing vessels MS Eros and MS Vendla. The estimated biomass was about 15 % lower, and the estimated total number was about 5 % higher this year compared to last yearâs survey. The uncertainty of the estimates in 2024 was much lower than last year. The surveyed population was dominated by the 2016 year class; 50 % in numbers and 57 % in biomass. Most of the spawning stock was found west of Lofoten and VesterĂ„len this year, more northerly distributed than in earlier years. More young herring was observed in the north than normal on this survey which is a positive sign in terms of future recruitment to the spawning stock. The estimates of abundance by age group from the survey in 2024 are recommended to be used in this yearâs ICES stock assessment of Norwegian spring-spawning herring.Distribution and abundance of Norwegian spring-spawning herring during the spawning season in 2024publishedVersio
Arbeidsflyt i byggproduksjon - analyse av mÄlemuligheter
De siste Ärene har det vÊrt satt fokus pÄ produktivitet i byggeprosjekter. Det ble i fÞlge
statistisk sentralbyrÄ omsatt for i underkant av 275 milliarder kroner i bygge- og
anleggsbransjen i 2009. Forbedringspotensialet er altsÄ stort dersom man kan finne metoder
for Ă„ effektivisere produksjonen. Et tiltak har vĂŠrt Ă„ trekke erfaringer fra bilindustriens lean
thinking og lean production. Lean construction er byggebransjens tilnĂŠrming til denne
tenkningen. Et sentralt fokus for lean-tankegangen er Ă„ skape flyt i produksjonen. Uttrykket
flyt er flittig benyttet til tross for at det ennÄ ikke er klart definert eller konseptualisert. Man
kan enkelt forestille seg at det er en kobling mellom flyt i produksjonen og produktivitet.
Denne koblingen er imidlertid ikke enkel Ä pÄvise eller mÄle. Man savner en metode for
mÄling av flyt. Dette gjelder bÄde for operasjoner og hele prosesser. For Ä kunne mÄle flyt er
man avhengige av Ă„ ha en entydig oppfatning av hva flyt er. Da flyt forelĂžpig er en metafor
uten klare rammer og begrensninger, har vi fÞrst gÄtt gjennom store mengder litteratur bÄde
fra byggrelatert forskning, men ogsÄ teori som omhandler vareproduserende industri, for Ä se
hvorvidt det er mulig Ă„ presisere uttrykket flyt.
Oppgaven er i hovedsak basert pÄ gjennomgang av publisert litteratur som kan relateres til
flyt i byggeprosjekter. Hensikten med dette er Ă„ undersĂžke om det lar seg gjĂžre Ă„ definere og
konseptualisere flytbegrepet. Som utgangspunkt for litteratursĂžket er det utfĂžrt sĂžk i ulike
akademisk anerkjente databaser av tidsskrifter, bĂžker, protokoller og andre publikasjoner.
Litteratur som er referert fra og benyttet som kilde i de mest relevante funnene er fremskaffet
og gjennomgÄtt i hÄp om Ä finne informasjon av interesse for oppgavens tema. I oppgaven er
det ogsÄ lagt vekt pÄ intervjuer, workshops og mÄlinger pÄ byggeplass. Intervjuene er utfÞrt
ustrukturert og kvalitativt. Det er ogsÄ utfÞrt tilfeldige spÞrringer og samtaler blant
hÄndverkere i forbindelse med tidsmÄlinger pÄ byggeplass. BÄde samtalene og intervjuene
har vist at det er forskjell pÄ folks oppfatning av hva flyt er og hvordan som prosjektleder
man skal prioritere
The Norwegian in-year monitoring fishery for sandeel in the North Sea using satellite-based VMS data and landings information
Due to the critically poor status of the sandeel stock in the North Sea, the Norwegian Ministry of Fisheries and Coastal Affairs decided to conduct a monitoring fishery in April/May 2006 with a limited number of Norwegian commercial vessels. An eventual re-opening of the sandeel fishery (in the Norwegian Economic Zone) was to be based on the results from the monitoring fishery. It was later decided that the monitoring fishery should take place in week 16-18. One of the main goals with the monitoring fishery is to obtain an estimate of the strength of the 2005 year class (since age 1 is the most important age group in the fishery). This requires estimation of a relationship between Catch Per Unit Effort (CPUE) and abundance. Logbooks from the Norwegian sandeel fleet are not recorded electronically and it is therefore difficult to perform traditional CPUE calculations. However, data from the Norwegian satellite-based vessel monitoring system (VMS) can be used to measure effort, and CPUE can then be estimated by combining VMS and landings data (which exist electronically on trip level). In this work, some of the preliminary analyses conducted in advance of the monitoring fishery are presented. The correlation between estimated CPUE of age 1 (based on VMS data) and estimated abundance of age 1 (from the latest ICES assessment) was positive and significant (p < 0.05) for the years 2001-2005
Distribution and abundance of Norwegian spring-spawning herring during the spawning season in 2023
publishedVersio
Distribution and abundance of Norwegian spring-spawning herring during the spawning season in 2022
Toktnummer 2022821 og 2022822Distribution and abundance of Norwegian spring-spawning herring during the spawning season in 2022During the period 14-27th of February 2022 the spawning grounds of Norwegian spring-spawning herring from MĂžre (62Âș15ËN) to Troms (71ÂșN) were covered acoustically by the commercial vessels MS Eros and MS Vendla. The estimated biomass was about 18 % lower, and the estimated total number was about 29 % lower this year compared to the last yearâs survey. The uncertainty of the estimates in 2022 was approximately equal to last year. The surveyed population of NSS herring was dominated by the 2016 year class; 52 % in numbers and 46 % in biomass. The 2016 year class was reduced by 37 % in numbers from last yearâs survey. Most of the spawning stock was found outside Lofoten and VesterĂ„len this year, further north and more concentrated than usual. The observed maturity indicates a bit later spawning compared to last year and like last year a more northern spawning than normal. As usual, the herring in the southern part of the spawning area were older than those found in the northern part. The estimates of relative abundance from the survey in 2022 are recommended to be used in this yearâs ICES stock assessment of Norwegian spring-spawning herring.publishedVersio
Arbeidsflyt i byggproduksjon - analyse av mÄlemuligheter
Masteroppgave i industriell Ăžkonomi og informasjonsledelse 2010 â Universitetet i Agder, GrimstadDe siste Ă„rene har det vĂŠrt satt fokus pĂ„ produktivitet i byggeprosjekter. Det ble i fĂžlge
statistisk sentralbyrÄ omsatt for i underkant av 275 milliarder kroner i bygge- og
anleggsbransjen i 2009. Forbedringspotensialet er altsÄ stort dersom man kan finne metoder
for Ă„ effektivisere produksjonen. Et tiltak har vĂŠrt Ă„ trekke erfaringer fra bilindustriens lean
thinking og lean production. Lean construction er byggebransjens tilnĂŠrming til denne
tenkningen. Et sentralt fokus for lean-tankegangen er Ă„ skape flyt i produksjonen. Uttrykket
flyt er flittig benyttet til tross for at det ennÄ ikke er klart definert eller konseptualisert. Man
kan enkelt forestille seg at det er en kobling mellom flyt i produksjonen og produktivitet.
Denne koblingen er imidlertid ikke enkel Ä pÄvise eller mÄle. Man savner en metode for
mÄling av flyt. Dette gjelder bÄde for operasjoner og hele prosesser. For Ä kunne mÄle flyt er
man avhengige av Ă„ ha en entydig oppfatning av hva flyt er. Da flyt forelĂžpig er en metafor
uten klare rammer og begrensninger, har vi fÞrst gÄtt gjennom store mengder litteratur bÄde
fra byggrelatert forskning, men ogsÄ teori som omhandler vareproduserende industri, for Ä se
hvorvidt det er mulig Ă„ presisere uttrykket flyt.
Oppgaven er i hovedsak basert pÄ gjennomgang av publisert litteratur som kan relateres til
flyt i byggeprosjekter. Hensikten med dette er Ă„ undersĂžke om det lar seg gjĂžre Ă„ definere og
konseptualisere flytbegrepet. Som utgangspunkt for litteratursĂžket er det utfĂžrt sĂžk i ulike
akademisk anerkjente databaser av tidsskrifter, bĂžker, protokoller og andre publikasjoner.
Litteratur som er referert fra og benyttet som kilde i de mest relevante funnene er fremskaffet
og gjennomgÄtt i hÄp om Ä finne informasjon av interesse for oppgavens tema. I oppgaven er
det ogsÄ lagt vekt pÄ intervjuer, workshops og mÄlinger pÄ byggeplass. Intervjuene er utfÞrt
ustrukturert og kvalitativt. Det er ogsÄ utfÞrt tilfeldige spÞrringer og samtaler blant
hÄndverkere i forbindelse med tidsmÄlinger pÄ byggeplass. BÄde samtalene og intervjuene
har vist at det er forskjell pÄ folks oppfatning av hva flyt er og hvordan som prosjektleder
man skal prioritere
Effects of local density dependence and temperature on the spatial synchrony of marine fish populations
Disentangling empirically the many processes affecting spatial population synchrony is a challenge in population ecology. Two processes that could have major effects on the spatial synchrony of wild population dynamics are density dependence and variation in environmental conditions like temperature. Understanding these effects is crucial for predicting the effects of climate change on local and regional population dynamics. We quantified the direct contribution of local temperature and density dependence to spatial synchrony in the population dynamics of nine fish species inhabiting the Barents Sea. First, we estimated the degree to which the annual spatial autocorrelations in density are influenced by temperature. Second, we estimated and mapped the local effects of temperature and strength of density dependence on annual changes in density. Finally, we measured the relative effects of temperature and density dependence on the spatial synchrony in changes in density. Temperature influenced the annual spatial autocorrelation in density more in species with greater affinities to the benthos and to warmer waters. Temperature correlated positively with changes in density in the eastern Barents Sea for most species. Temperature had a weak synchronizing effect on density dynamics, while increasing strength of density dependence consistently desynchronised the dynamics. Quantifying the relative effects of different processes affecting population synchrony is important to better predict how population dynamics might change when environmental conditions change. Here, high degrees of spatial synchrony in the population dynamics remained unexplained by local temperature and density dependence, confirming the presence of additional synchronizing drivers, such as trophic interactions or harvesting.publishedVersio
Age-dependent patterns of spatial autocorrelation in fish populations
The degree of spatial autocorrelation in population fluctuations increases with dispersal and geographical covariation in the environment, and decreases with strength of density dependence. Because the effects of these processes can vary throughout an individualâs lifespan, we studied how spatial autocorrelation in abundance changed with age in three marine fish species in the Barents Sea. We found large interspecific differences in age-dependent patterns of spatial autocorrelation in density. Spatial autocorrelation increased with age in cod, the reverse trend was found in beaked redfish, while it remained constant among age classes in haddock. We also accounted for the average effect of local cohort dynamics, i.e. the expected local density of an age class given last yearâs local density of the cohort, with the goal of disentangling spatial autocorrelation patterns acting on an age class from those formed during younger age classes and being carried over. We found that the spatial autocorrelation pattern of older age classes became increasingly determined by the distribution of the cohort during the previous year. Lastly, we found high degrees of autocorrelation over long distances for the three species, suggesting the presence of far-reaching autocorrelating processes on these populations. We discuss how differences in the speciesâ life history strategies could cause the observed differences in age-specific variation in spatial autocorrelation. As spatial autocorrelation can differ among age classes, our study indicates that fluctuations in age structure can influence the spatio-temporal variation in abundance of marine fish populations.publishedVersio
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