The interactions of abiotic and biotic factors influencing perch Perca fluviatilis and roach Rutilus rutilus populations in small acidified boreal lakes

Four small, acidified boreal lakes, all sustaining populations of perch Perca fluviatilis, roach Rutilus rutilus and pike Esox lucius, were studied in four successive years. Three lakes were moderately acidified (mean pH of 5·61–5·83), while the fourth was more acidic (mean pH of 5·16) and had a sparse population of R. rutilus. Perca fluviatilis density was higher in this lake (1004 ha−1) than in the other three (355–717 ha−1), where R. rutilus dominated in terms of numbers (981–2185 ha−1). Large, potentially predatory, P. fluviatilis were most abundant in the lake with clearest water, and these seemed to have a negative effect on P. fluviatilis density. Perca fluviatilis mean mass was negatively correlated with R. rutilus biomass and was highest in the most acidic lake with the sparse R. rutilus and the highest P. fluviatilis density. Perca fluviatilis mass correlated positively with pH in two lakes (with the highest fish biomass), suggesting that low pH affected P. fluviatilis mass negatively. Perca fluviatilis growth correlated positively with summer (July to August) air temperature in the lake with sparse R. rutilus, thus differing from P. fluviatilis and R. rutilus growth in the other three lakes. The mean age of P. fluviatilis was generally lower than that of R. rutilus and was lowest in the two lakes with the highest fish biomass, indicating that adult mortality was affected by density-induced factors

Recent improvement of fish populations in the Jarfjord Mountains in northern Norway due to reduced surface water acidification

Appendix 10/15 of the publication "State of the environment in the Norwegian, Finnish and Russian border area 2007" (The Finnish Environment 6/2007)

Distribution of non-native brook trout (Salvelinus fontinalis ) across Norwegian waterbodies – is it an invasive species?

Non-native brook trout (Salvelinus fontinalis MITCHILL, 1815) was introduced into Norway in 1883. However, it was not until the late 1970s that this acid-tolerant salmonid species was stocked into many acidified lakes that many populations became established. In 2004, all brook trout stocking in Norway ceased. In this study, we surveyed the distribution of brook trout in Norwegian water bodies. A totally of 202 self-sustaining populations were identified, mostly in unregulated lakes (n=101), streams (n=71) and also to some extent in reservoirs (n=25). Only four populations were found in inland rivers, and one population in a river with Atlantic salmon (Salmo salar L.). Localities with brook trout covered a wide range of altitudes and sizes. Analyses of time-series catches in sympatric populations of brown trout (Salmo trutta L.) and brook trout from 12 lakes (1997-2012) revealed a strong decline in brook trout stocks. A similar development in abundance has also emerged from other studies in recent years. Generally, lake-dwelling brook trout is regarded as a low-risk species with respect to invasiveness. However, brook trout/brown trout interactions may be habitat-specific, as brook trout may dominate in small and relatively cold streams.publishedVersio

The winter food of the gobies from one of the deeper channels of the Belt Sea, with particular reference to the Sand Goby, Pomatoschistus minutus (Pallas)

The contents of the stomach and intestine of 272 gobies of five species, viz. Ciystallogobius linearis, Aphia minuta, Chaparrudo flavescens, Pomatoschistus microps, and Pomatoschistus minutus, collected with Beyer's 50 cm epibenthic closing net were studied. All proved to be principally carnivorous and crustaceans were the most important food organisms. Although Diastylis rathkei was the most frequently found crustacean of suitable size in the net samples, this cumacean was of minor importance as food for P. minutus, the most common goby in the material. This discrepancy is explained by the nature of the exo-skeletone of Diastylis. In night samples the number of P. minutus caught was much higher than in the hauls taken during day, a result which might be due to higher nocturnal activity in the goby, and/or the fish perceiving the approaching net on daylight and being able to escape. A day and night feeding activity is suggested

Diurnal and seasonal variations in the near-bottom fauna -the hyperbenthos- in one of the deeper channels of the Kieler Bucht (Western Baltic)

This work is based on 63 samples obtained by Beyer's 50 cm epibenthic closing net and 43 vertical hauls with a 70 cm Hensen-net from December 1969, and March, June and November 1970. The depth in the sampling locality, Vejsnäs Rinne, varied between 28 and 32 meters. Only abundant and particularly interesting species and animal groups have been treated here. Seasonal variations were studied in the cumacean Diastylis rathkei, some mysids, the euphausid Thysanoessa raschii, the decapod Crangon crangon, the chaetognath Sagitta elegans and in some fishes. During winter there are, relatively, a higher number of species (including some rare ones), as well as of individuals. This may partly be ascribed to a stronger inflow of water from the Kattegat in winter, and partly to seasonal horizontal migrations in the animals. It is furthermore apparent that by the present sampling method a larger fraction of the more vagile near-bottom fauna is collected than by more conventional sampling techniques. The diurnal variations in the hyperbenthos were studied in benthic as well as some pelagic groups of animals. Based on the results, it is possible to recognise at least three main patterns of vertical migrations in the hyperbenthos: A. The relatively few pelagic animals found stay just above the bottom during the day. They leavethe region sampled by the epibenthic closing net (i.e. from the bottom to about 80 cm above it) about sunset and stay away until the next morning when they reappear at this level. B. Some of the benthic animals at certain seasons or developmental stages are sparsely represented in the epibenthic closing net samples during day. The catches are increased at dusk, but decrease again later in the evening. In the morning the animals appear once more in the hyperbenthos, only to disappear again after sunrise. The reduced number collected around midnight is either due to midnight sinking, i.e. the animals burrow in the sediment and thus avoid the epibenthic net, or the animals ascend above the level sampled by the net. This last pattern is particularly found in juveniles and in gravid females. C. The majority of the migrating benthic species seem to come sufficiently far off the bottom to be caught in higher numbers in the epibenthic closing net during the dark hours. They are often considerably less numerous throughout the day. The value to an animal of performing diurnal vertical migration has been briefly discussed. It seems possible that some of the more important demersal fishes in the area are able to exploit the migrating animals as food, particularly at dawn and dusk

To what extent and in what way are the students cultural capital recognized and visible in school?

Mastergradsoppgave i tilpasset opplæring, Avdeling for lærerutdanning og naturvitenskap, Høgskolen i Hedmark, 2014.Norsk: Denne masteravhandlingen omhandler synliggjøring av kulturelt mangfold i klasserommet. Med utgangspunkt i Pierre Bourdieus begrep kulturell kapital og Axel Honneths anerkjennelsesteori drøftes det hvorvidt språklige og kulturelle minoriteter anerkjennes eller krenkes innen kjærlighetssfæren, den rettslige og den solidariske sfæren, og hvordan dette kommer til syne i klasserommet. Problemstillingen for prosjektet er I hvilken grad og på hvilken måte anerkjennes og synliggjøres elevenes kulturelle kapital i skolen? De kvalitative metodene som jeg benytter i undersøkelsen min er klasseromsobservasjon, halvformelle samtaler og semistrukturert intervju. Jeg har en etnografisk design på masteravhandlingen og datamaterialet tolkes og analyseres i lys av dette. Mine empiriske funn viser mange eksempler på at elevene opplever at deres individuelle, språklige og kulturelle kompetanse anerkjennes i alle sfærene. De tre sfærene står innbyrdes i forhold til hverandre og jeg har sett at det synes som om lærers relasjonelle kompetanse og anerkjennelse i kjærlighetssfæren får positive ringvirkninger for den solidariske sfæren. Videre kan krenkelse i den rettslige sfæren i forhold til deltagelse på segregerte tilbud synes som anerkjennelse i den solidariske sfæren i forhold til å nyttiggjøre seg en samlet språkkompetanse.English: This thesis deals with the promotion of cultural diversity in the classroom. Based on Pierre Bourdieu's concept of cultural capital and Axel Honneth's theory of recognition, it is discussed whether the language and cultural minorities are recognized or violated in the love sphere, the legal and the solidarity sphere, and how this appears in the classroom. The problem addressed in this project is To what extent and in what way are the students cultural capital recognized and visible in school? The qualitative methods that I use in my research are classroom observation, semi-formal conversations and semi-structured interviews. I have an ethnographic design of the thesis and the data are interpreted and analyzed in this light. My empirical findings show many examples of students find that their individual, language and cultural skills are recognized in all spheres. The three spheres are interconnected and I've seen that it seems the teacher's relational competence and recognition in the love sphere can have positive consequences for the solidarity sphere. Furthermore infringement in the legal sphere in relation to participation in segregated settings appears as recognition in the solidarity sphere relative to utilize overall language skills

Organisering og samarbeid i byggeprosjekter

Denne oppgaven har tatt for seg problemstillingen hvordan Forsvarsbygg ivaretar brukerens behov. Forsvaret i Østerdal garnison har siden 2007 jobbet med å identifisere og fremme det fremtidige behovet for forlegning til vervede soldater og befal. I denne sammenhengen har det vært gjennomført fem byggetrinn for å møte dette behovet. Forsvarsbygg, som Forsvarets eiendomsaktør, har ledet arbeidet med prosjektering og bygging av disse og må derfor forholde seg til Forsvarets (brukeren) behov for bygningsmasse. Oppgaven fokuserer på hvordan Forsvarsbygg organiserer sine byggeprosjekter, og hvordan brukerens behov kommer til syne i disse. Dette er gjort gjennom å undersøke de generelle retningslinjer for fremming av behov, samt å visualisere disse i en case. Datainnhenting er gjennomført ved kvalitativ metode – intervju av respondenter i de to undesøkelsesenhetene Forsvaret og Forsvarsbygg

Arctic charr (Salvelinus alpinus) re-established in a formerly acidified and highly dilute mountain lake under declining acidic deposition

Arctic charr in Lake Ronvatn, a mountain lake in southern Norway was re-established through stocking. The population went extinction during the early 1980s due to acidification, when the lake was highly acidified with a mean pH of 5.2-5.4 with occasional declines to 4.3-4.7. However, from the mid to late 1990s, the pH and acid-neutralising capacity (ANC) of the lake rose to 5.8-5.9 and 13-15 µeq L-1, respectively. The lake is extremely dilute with a mean conductivity and calcium concentration of 7.7 µS cm-1 and 0.35 mg L-1, respectively. The lake was stocked with 250 Arctic charr from a neighbouring lake between 1998 and 2000. These introductions were highly successful, as test-fishing in 2004, 2008 and 2012 revealed a relatively dense population of Arctic charr, and the presence of several young age groups. Water quality has remained stable since the late 1990s, or has slightly improved

Upper thermal threshold of Lepidurus arcticus (Branchiopoda, Notostraca) in lakes on the southern outreach of its distribution range

Qvenild T, Fjeld E, Fjellheim A, Hammar J, Hesthagen T and Lakka H-K. 2021. Upper thermal threshold of Lepidurus arcticus (Branchiopoda, Notostraca) in lakes on the southern outreach of its distribution range. Fauna norvegica 41: 50–88. The Arctic tadpole shrimp Lepidurus arcticus has a circumpolar distribution and the Scandes (Fennoscandian Mountains) marks its southernmost limit in Europe. Within this area, 391 natural and 88 regulated lakes with L. arcticus have been identified, of which 87% are above the treeline. The lakes hosting L. arcticus decrease in altitude from south to north, which results from its temperature preferences. The majority of the locations are at a lower lake air temperature than 11°C which is equivalent to a water temperature near 14°C. This is assumed to be near the upper thermal threshold for L. arcticus. In lakes that exceed this average summer water temperature (1 July – 15 September), sustainable populations seem to be rare. In warmer lakes, life cycle mismatches are assumed to explain the absence of L. arcticus, most likely by affecting the embryo and juvenile stages. The distribution appears to be dichotomous, with one large northern area north of 65°N and one separated southern “island”. Only two locations of L. arcticus are known for the area between latitudes 62.88 and 64.39°N. In this part of the Scandes, the lakes are likely too warm to host L. arcticus as most of them are situated below 700 m a.s.l. This may also be the case in the northernmost region, north of 70°N, where only 11 populations are recorded. Most of the lakes in this area typically occurs below 400 m a.s.l. L. arcticus populations are sensitive to fish predation, and dense fish populations may be another stressor limiting its distribution. In contrast to water bodies in the High Arctic where L. arcticus only exists in shallow, fishless ponds, in the Scandes they co-exist with fish in 97% of the findings. Global warming has already modified the environment of the Scandes, and populations of L. arcticus are at threat in many of the small and shallow water bodies at low altitudes