Spatio-temporal patterns in the copepod community in Malangen, Northern Norway

The objective of this study was to identify the key copepodspecies and their life cycles, and provide evidence for anyseasonal and spatial changes in the copepod community in Malangen,a fjord located 30 km to the south of Tromsø in NorthernNorway (69°30'N, 18°21'E). As a result of high levelsof freshwater run-off in May, the fjord became highly stratifiedwith a sharp pycnocline at 10–30 m depth from May to August.The generation patterns of six copepod species are described.Calanusfinmarchicus produced one generation during the spring thatyear, whereas two generations appeared to be produced by bothPseudocalanus acuspes and P.minutus: one in spring (March-June)and the other in autumn (August-December). However, it is uncertainto what extent P.minutus regularly produces a second generation.Two peaks of CI-CIII Metridia spp. were found; there were differencesalong the length of the fjord in the timing of these, but therelative contributions of M.longa and M.lucens are uncertain.Chiridius armatus CI-CIII peaked in abundance in the spring,which indicates that one main generation was produced at theouter station of the fjord. The copepod community in Malangencould be grouped into three entities according to their numericalabundance during the year one group of highly abundant forms,generally with maxima >50 000 individuals m^–3 (C.finmarchicus,Microcalanus sp., Oithona similis , Oithona spinirostris, Acartiasp. and Pseudocalanus spp.), a second group of less abundantspecies with a clear seasonality in abundance, varying from500 to 50 000 individuals m^–3 (M.longa, M.lucens, Calanushyperboreus, Carmatus, Tenwra longicornis, Oncaea sp., Euchaetanorvegica and Scolecithrwella minor), and a third group of 14holoplanktonic species, sporadically occurring in the fjord.The study demonstrates clear gradients in the abundance of fivespecies along the length of the fjord: the recruiting generationof C.finmarchicus occurred in higher abundances at the outerstation in May and June compared to the other inner sites. Laterin the season, the reverse situation appeared, in which thepopulation was more abundant in the inner part of the fjorcCalanw hyperboreus increased abruptly in abundance from lowwinter levels to a maximum in April-May, and declined steadilyduring the season (except at the innermost station). Metridialucens, M.longa and C.armatus demonstrated different distributionpatterns in Malangen that matched their preferred areas of distribution.Both M.lucens and C.armatus are known as oceanic and deep-waterspecies, respectively, and these were prevalent at the two outersites in Malangen. Metridia longa is a more nentic species andwas found in highest numbers at the two innermost sites. Themechanisms for the differences in abundance among these specieswithin the fjord are discussed.     

Distribution and species-specific egg production of Pseudocalanus in the Gulf of Alaska

Pseudocalanus species are important contributors to the secondaryproduction of the northern hemisphere mid- to high-latitudeoceans. In the coastal Gulf of Alaska, Pseudocalanus are presentyear round and are represented by three species. In 2001, Pseudocalanusmimus was the dominant Pseudocalanus species on the shelf duringspring and summer, comprising 30–100% of the total, whilePseudocalanus newmani dominated in Prince William Sound (10–90%).Pseudocalanus minutus were only abundant in Prince William Soundduring early spring. Egg production (by number and volume) wasa function of female prosome length and decreased from springto summer; however, significant variability was attributableto regional influences that were independent of size. For thesame sized female, P. newmani produced more eggs per clutchthan P. mimus. Pseudocalanus mimus, however, tended to havea larger mean egg size than P. newmani. Consequently, clutchvolumes of the two species were indistinguishable. Pseudocalanusegg production rates (EPRs) (eggs female^–1 day^–1)were lower in July and August (ca. 2–4) than April andMay (ca. 1–9), but total egg production by the population(eggs day^–1) was nearly equivalent for the two time periodsdue to higher female concentrations in summer.     

The Influence of Season and Phenology on Freezing Tolerance in Silene acaulis L., a Subarctic and Arctic Cushion Plant of Circumpolar Distribution

Changes in the freezing tolerance for Silene acaulis L., a subarcticand arctic species of circumpolar distribution, were examinedto understand the extent of cold hardening and dehardening thatoccurs seasonally and with changes in plant phenology. Shootsof whole plants collected on a mountain ridge near Tromsø,Norway (69° N, 700 m above sea level) were frozen undercontrolled conditions at cooling rates of 3 to 4°C h^-1.The extent of freezing-induced injury was examined both by chlorophyllfluorescence and by visual inspection with a microscope. A freezingtolerance level of -30°C was observed in mid-winter, basedon a 50% lethal point for freezing injury. Loss of cold hardinesswas substantial in mid-summer, with freezing tolerance of -8·5to -9°C observed in mid-July. Plants still covered by snowin mid-July had a freezing tolerance of -12·5 to -13°C.The maintenance of a basic level of freezing tolerance throughoutthe summer may be adaptive in the northern latitude-regionsbecause of the occurrence of episodic frosts during the growingseason.Copyright 1993, 1999 Academic Press Silene acaulis L., Caryophyllaceae, freezing tolerance, chlorophyll fluorescence, cushion plant     

Temperature-dependent development of parthenogenetic embryos in Daphnia pulex de Geer

An in vitro study of the embryonic stages of Daphnia pulex deGeer was carried out by way of removing and isolating eggs fromthe females. The temperature-dependent development rates andthe developmental features were recorded photographically. Thetotal development time was 351 h at 5°C, 161 h at 10°Cand 87 h at 15°C. The relative times of development of embryonic‘stages’ also showed significant variation betweentemperatures. The observed variations in relative developmenttime of D.pulex embryos at different temperatures will questionthe accuracy of previously used methods for estimations of populationbirth rates using egg age determinations. ¹Present address: Akvaforsk, N-6600 Sunndalsøra, Norway ²Present address: Raadgivende Biologer as., Ladegaardsgaten9, 5035 Sandviken, Norway     

Temporal and regional variation in the copepod community in the central Barents Sea during spring and early summer 1988 and 1989

In this study, we examined a 3000 km² area to the southeastof Bear Island in the central Barents Sea with respect to copepodabundance and depth distribution at nine stations in March,April and May of 1988 and 1989. In order to describe the populationdynamics of the most prominent species in the area during theperiod of study, the annual ascent and abundance of Calanusfinmarchicus, Metridia longa and Calanus glacialis are shown.Stage abundance, vertical distribution and cohort developmentdid vary between species and years at one site. The number ofspecies and the complexity of the data for the entire area studiedhave encouraged us to search for more significant and persistentpatterns by using a canonical correlation analysis (CCA). Weincluded a total of 27 species and stage categories, latitude,salinity and sigma from the nine stations in 1989 We performedthis analysis for 1989. since we only have environmental data(CTD) available from the same stations in that year The species-environmentrelationship showed that the zooplankton community could notbe grouped according to area (latitude) or environmental (sigma,salinity) conditions during March–May in 1989. This meansthat the differences in environmental conditions in the areaof study in 1989 do not mediate any consistent gradient in thezooplankton community. When comparing the copepod data for bothyears. the largest differences are associated with the depthand month vectors. The largest interannual variation is seenin the copepod community in the depth strata from 100 to 400m. and is related to a lesser degree of similarity among thespecies and stages found in this depth interval throughout thestudy. Two species were particularly responsible for the interannualdifferences: Pseudocalanus acuspes CV and females, and C glacialisCV and adults. Changes in these two species are clearly relatedto major shifts in the hydrographic conditions between the 2years, where 1988 was generally colder compared to 1989.     

Nutrient status of phytoplankton communities in Norwegian waters (marine, brackish, and fresh) as revealed by their chemical composition

The chemical composition of nutrient-saturated cultures of Emilianiahuxleyi, Amphidinium carterae, and Staurastrum luetkemuelleriwas studied. The variation in chemical composition of naturalphytoplankton communities in the North Sea, the Trondheimsfjord,and a eutrophic lake was also studied. Nutrient status was evaluatedby measurement of the algal protein/carbohydrate, N/C, P/C,and N/P ratios. Tests for P-deficiency were carried out by measuringthe increase in ATP upon addition of phosphate. At saturationthe N/C ratio was {small tilde}0.14 in marine species and {smalltilde}0.05 in Staurastrum. Saturation P/C ratios (excludingpolyphosphates) were species-dependent, ranging from 0.017 (Skeletonema)to 0.006 (Amphidinium). Amphidinium and Staurastrum store polyphosphateswhen grown in P-rich media; true marine planktonic species donot. Natural communities tended to be close to nutrient saturationat low biomass densities and nutrient deficient at high densities.In the North Sea, nitrogen was clearly limiting. In waters offthe Møre coast and in the Trondheimsfjord, growth wasnearly balanced with respect to N and P at high salinities (>25)and clearly P-limited in brackish fjord waters. In dense communities,the N/P ratio was inversely related to salinity. Freshwatercommunities were clearly P-limited, but responses were dampenedwhen daphnia or whitefish were introduced, due to increasedexcretion of nutrients. ¹Contribution No. 212, Trondheim Biological Station, N-7001Trondheim, Norway.     

Copepod egg production, moulting and growth rates, and secondary production, in the Skagerrak in August 1988

Measurements of hydrography, chlorophyll, moulting rates ofjuvenile copepods and egg production rates of adult female copepodswere made at eight stations along a transect across the Skagerrak.The goals of the study were to determine (i) if there were correlationsbetween spatial variations in hydrography, phytoplankton andcopepod production rates, (ii) if copepod egg production rateswere correlated with juvenile growth rates, and (iii) if therewas evidence of food-niche separation among co-occumng femalecopepods The 200 km wide Skagerrak had a stratified water columnin the center and a mixed water column along the margins. Suchspatial variations should lead to a dominance of small phytoplanktoncells in the center and large cells along the margins; however,during our study blooms of Gyrodinium aureolum and Ceratium(three species) masked any locally driven differences in cellsize: 50% of chla was >11 µm, 5% in the 11–50µm fraction and 45% <50 µm. averaged for allstations. Chlorophyll ranged from 0.2 to 2.5 µg l^–1at most depths and stations. Specific growth rates of copepodsaveraged 0.10 day^–1 for adult females and 0.27 day^–1for juveniles The latter is similar to maximum rates known fromlaboratory studies, thus were probably not food-limited. Eggproduction rates were food-limited with the degree of limitationvarying among species: 75% of maximum for Centropages typicus, 50% for Calanus finmarchicus, 30% for Paracalanus parvus and 15% for Acartia longiremis and Temora longicornis. Thedegree of limitation was unrelated to female body size suggestingfood-niche separation among adults. Copepod production, summedover all species, ranged from 3 to 8 mg carbon m^–3day^–1and averaged 4.6 mg carbon m^–1 day^–1. Egg productionaccounted for 25% of the total.     

Mass occurrence of planktonic oligotrichous ciliates in a bay in southern Norway

A reddish-brown discoloration of the surface water in FlødevigenBay, southern Norway on May 15, 1985 was due to planktonic oligotrichousciliates occurring in densities of 2079 cells ml^–1. Strombidiumreticulatum (Leegaard, 1915) Bush, 1921 and Tintinnopsis beroideaStein, 1867 accounted by numbers for 59.7 and 35.1% respectively.Both the build-up and decline were probably mainly due to wind-inducedhydrographical conditions. No fish mortalities were reported.     

The production and ingestion of faecal pellets by nauplii of marine calanoid copepods

The downward transport of organic matter as zooplankton faecalmaterial is influenced by copepods which fragment, ingest andrecycle some of the pellet contents. Most of this activity hasbeen attributed to the later copepodite stages and the adults,but little is known about the role of nauplii. Stage-relateddefaecation rates during the naupliar development of two speciesof copepod, Calanus helgolandicus and Pseudocalanus elongatus,were quantified in a series of laboratory experiments. The productionof faecal material commenced soon after the appearance of theNIII in both species and increased throughout naupliar development.The causes of the increase were the formation of larger pelletsby later stages in Calanus and an increased rate of productionby Pseudocalanus. Calanus nauplii, when supplied with algalfood at concentrations that would support full naupliar development,ingested or broke up the pellets of the smaller Pseudocalanusspecies at rates of 1.15 pellets nauplius^–1 h^–1This consumption increased to 2.96 pellets nauplius^–1h^–1 when the concentration of algal food was reduced toa limiting level. Pseudocalanus was not able to consume thepellets of Calanus. Ingestion of Pseudocalanus faecal pelletsby Calanus could supply a nutritional benefit to a food-limitednauplius.     

Birth, growth and death rates for enclosed populations of calanoid copepods

Rates of birth, growth and death are inferred for enclosed populationsof the marine copepods Pseudocalanus elongates, Acartia clausiand Temora longicomis. The rates are determined by fitting apopulation dynamics model to the time series of developmentalstage abundances observed over 87 days in four 310 m³ enclosures.Two enclosures were treated with ‘produced’ waterfrom North Sea oil production platforms and two were untreatedcontrols. The pollutant mainly affected recruitment to the populations.Development times varied considerably between enclosures, thoughnot in any apparent relation to the pollutant. Mortality wasmost strongly related to the population size of herring larvaeintroduced to all four enclosures. Levels of secondary productionderived from the model were compared with those calculated directlyfrom population densities.     

Planktonic copepods of the Bras d'Or Lakes system,Nova Scotia,Canada

Fifteen species of planktonic copepods are recorded from Bras d'Or Lakes, Nova Scotia, Canada. Pseudocalanus minutus, Oithona similis, Temora longiremis, and Tortanus discaudatus are the dominant species. The distribution of planktonic copepods in Bras d'Or Lakes as well as in the adjacent Gulf of St. Lawrence is discussed.     

Population genetics of drifting (Calanus spp.) and resident (Acartia clausi) plankton in Norwegian fjords

Kaartvedt distinguished between drifting and resident planktonand hypothesized that the latter were distinguished by theirability to maintain their horizontal position in desired habitats(Kaartvedt, 1993). In this study, we examined the populationgenetic consequences of these two lifestyles for copepods infour fjords of western Norway (Lurefjorden, Masfjorden, Sognefjordenand Sørfjorden) and one fjord in eastern Norway (Oslofjorden).Based on DNA sequence variation of a region of mitochondrial16S rRNA, we contrasted population genetic diversity and structurein drifting populations of Calanus spp. with that of residentpopulations of Acartia clausi. With the exception of Sørfjorden(where Calanus spp. were rare), two or three species of Calanusco-occurred in significantly different proportions in the fjords.Based on a 350 base-pair region of mitochondrial 16S rRNA, Calanusspp. varied in molecular genetic diversity, with the highestvalues for C.helgolandicus. There was no evidence of significantgenetic structure of fjord populations for either C.finmarchicusor C.helgolandicus; the population structure of C.glacialiscould not be evaluated as the species was only abundant in Lurefjorden.Acartia clausi was abundant in all five fjords sampled for thisstudy. Molecular genetic diversity of A.clausi, based on a 220bp region of mt 16S rRNA, was within the range of Calanus spp.values. Populations of A.clausi showed significant genetic structure(i.e. haplotype frequencies differed markedly) among the fjords.The results of this study indicated that little exchange (geneflow) occurs between populations of A.clausi in different fjords,and suggested that the populations are long-term residents ofa fjord. In contrast, most Calanus spp. fjord populations maybe replaced periodically, as they drift with currents flowingto and from coastal and fjord environments.     

A snail's space sets a snail's pace: movement rates of lavigeria gastropods in lake tanganyika, East africa

Endemic Lavigeria gastropods are diverse and common in the benthosof Lake Tanganyika. We used in situ studies of marked individualsto quantify rates of daily movement by three species, and testthe effects of size, sex, reproductive status and parasitismon movement. Average net travel distance was 50 cm day^–1,which corresponds to about 20 times shell length. Male L. coronatamoved significantly farther than L. coronata females or L. grandis,and L. nassa of either sex. There were also significant differencesamong individuals within each group; however, these differenceswere not predicted by size, reproductive status or parasitism.We interpret greater movement of L. coronata males as a reflectionof mate searching; the ratio of males to non-brooding, non-parasitizedfemales was three times as high in L. coronata (21:1) as inthe other species (6:1). Our results indicate that these snailsare capable of moving considerable distances, and that the highlylocalized distribution of L. coronata populations is not simplya reflection of limited movement by individual snails. (Received 20 September 2006; accepted 1 March 2007)     

Motion behavior of nauplii and early copepodid stages of marine planktonic copepods

The goal of this study was to quantify periods of activity andvelocities of late naupliar and early copepodid stages of planktoniccopepods occurring regularly on the southeastern continentalshelf of the USA. We obtained quantitative information on eightspecies, including adult females of Oithona plumifera. All studieswere conducted at food concentrations near or above satiationlevels. Activities ranged from 0.85% (adult females of O.plumifera)to 100% of time (nauplii and copepodids of various calanoidspecies). Motion velocities (excluding escape motion) coveredmore than one order of magnitude: from 0.39 mm s^–1 fornauplii of Temora stylifera to 5.24 mm s^–1 for naupliiof Oncaea mediterranea. Ranges of activities of species rangefrom occasional for early juveniles to adult females of O.plumiferato 100% for the same range of T.stylifera, the latter creatinga feeding current from N III onwards, the former not at all.Of notable interest is Centropages velificatus which moves intermittentlyas a late nauplius, continuously as an early copepodid and intermittentlyas an adult. All observed calanoid late nauplii and copepodidsmove in three dimensions, excluding copepodids of the shelfbreak/oceanicParacalanus aculeatus. The results indicate not only significantdifferences in motion behavior between cyclopoids and calanoids,but also between calanoid species. Yet, some calanoid speciesshow little ontogenetic changes at all.     

Copepod abundance in the western Irish Sea: relationship to physical regime, phytoplankton production and standing stock

The distinct patterns of stratification in the North Channeland stratified region of the western Irish Sea influence theseasonal abundance of phytoplankton. The 3–4 month productionseason in the stratified region was characterized by productionand biomass peaks in the spring (up to 2378 mg C m² day^–1and 178.4 mg chlorophyll m^–2) and autumn (up to 1280 mgC m^–2 day^–1 and 101.9 mg chlorophyll m^–2).Phytoplankton in the North Channel exhibited a short, late productionseason with a single summer (June/July) peak in production (4483mg Cm^–2 day^–1) and biomass (–160.6 mg chlorophyllm^–2). These differences have little influence on copepoddynamics. Both regions supported recurrent annual cycles ofcopepod abundance with similar seasonal maxima (182.8–241.810³ind. m^–2) and dominant species (Pseudocalanus elongatusand Acartia clausi). Specific rates of population increase inthe spring were 0.071 and 0.048 day¹ for the North Channel andstratified region, respectively. Increased copepod abundancein the stratified region coincided with the spring bloom, andwas significantly correlated with chlorophyll standing stock.Increased copepod abundance preceded the summer production peakin the North Channel. This increase was not correlated withchlorophyll standing crop, suggesting that a food resource otherthan phytoplankton may be responsible for the onset of copepodproduction prior to the spring bloom. Hetero-trophic microplanktonas an alternative food source, and advection of copepods fromthe stratified region, are proposed as possible explanationsfor copepod abundance increasing in advance of the summer peakin primary production.     

The reproductive biology of the depressed river mussel, Pseudanodonta complanata (Bivalvia: Unionidae), with implications for its conservation

Pseudanodonta complanata is listed as ‘Near Threatened’on the IUCN Red List (IUCN, 2006) and is a species of conservationpriority on the UK Biodiversity Action Plan. The UK is hostto some of the largest populations of this species, but littleis known about their reproductive biology. Two populations werestudied in the Great Ouse catchment and the Waveney and Yarecatchment, East Anglia, UK. Both populations are reproductivelyactive, producing viable glochidia. Small mussels (<30 mmlength) in both catchments indicate that recruitment is occurring.A short non-gravid period in May is followed by three monthsof glochidial formation in June, July and August; by Septembermussels contain mature glochidia ready for release the followingApril. Females brood between 5,000 and 50,000 glochidia, andthis scales with mussel length L (mm) as: n_glochL^2.1. The sexratio is skewed towards females (2.5 females:1 male), and malesare larger than females. No hermaphrodites were found duringthe histological examination of the gonads of 24 mussels. Thein vivo examination of demibranchs is shown to be an effectivenonsacrificial means of determining sex and gravidity. Conservationrecommendations include: minimizing management operations inriver stretches containing large populations; avoiding formsof management which preferentially remove large mussels (i.e.males and the most fecund females); performing management duringthe non-gravid period to avoid causing the premature releaseof glochidia; leaving sufficient time between management operationsfor populations to recover; and temporarily translocating musselsto refugia during management operations. (Received 9 February 2005; accepted 2 May 2007)     

In situ egg production and hatching success of the marine copepod Pseudocalanus newmani in Funka Bay and adjacent waters off southwestern Hokkaido, Japan: associated to diatom bloom

. Clutch size and egg viability were examined for wild femalesof Pseudocalanus newmani collected from four different stationsinside and outside Funka Bay, southwestern Hokkaido, Japan,during pre-phytoplankton-bloom conditions in 1997, and froma single station outside the bay during the period from pre-to post-blooming seasons in 1998, to examine spatio-temporalvariability of the reproductive parameters and to detect deleteriouseffects of diatom blooms on in situ copepod reproduction. Clutchsize and hatching success in P.newmani were relatively similarat the four stations in 1997. The eggs almost always hatchedcompletely, but deformed nauplii occurred in 20–40% ofthe cases. The proportion of deformed nauplii gradually decreasedwhen the females were fed on non-diatom Pavlova sp. in the laboratory,suggesting that the occurrence of deformed nauplii was relatedto the quality of in situ food particles, including diatoms.Clutch size varied from 12 to 30 eggs female^–1 duringthe study period in 1998; more than 90% of the variation couldbe explained by the body size of the females which dependedon ambient water temperature. Hatching success also varied,from 15 to 80%, but was not related to either clutch size, femalebody size, water temperature or diatom biomass. These resultssuggest that not only egg production but also hatchability shouldbe measured routinely when estimating recruitment of the copepodinto the planktonic population, and show that neither clutchsize nor egg viability are directly affected by diatom biomass.Although we could not obtain clear evidence of in situ deleteriouseffects of diatoms on abnormal embryos and nauplii, this mightbe related to methodological problems and properties or characteristicsof prey–predator interactions. Also, deformities of copepodnauplii have not yet been observed for reasons other than feedingon diatoms.     

Boron Mobility in Two Coniferous Species

In contrast to earlier beliefs, it is now known that boron (B)can be retranslocated complexed with sugar alcohols in someplant species. Conifers had been thought not to translocatesugar alcohols in the phloem. However, 1 d after applying¹⁰Benriched boric acid to shoots of Scots pine and Norway spruceseedlings, we found increases in both the amount and proportionof¹⁰B in the root systems in both species. We conclude thatB is translocated in the phloem from shoots to roots in spruceand pine, and therefore it is possible that these species retranslocateB. Copyright 2000 Annals of Botany Company Scots pine, Pinus sylvestris, Norway spruce, Picea abies, conifers, boron retranslocation, roots, stable isotopes, sugar alcohols, boron complexes, mineral nutrition, forest trees     

On the trophic fate of Phaeocystis pouchetii (Harlot). III. Functional responses in grazing demonstrated on juvenile stages of Calanus finmarchicus (Copepoda) fed diatoms and Phaeocystis

The objective of this study was to quantify the functional responsein feeding rate in the various developmental stages of Calanusfinmarchicus to different concentrations of the diatoms Thalassiosiranordenskioeldii and Porosira glacialis, and the haptophyseanPhaeocystis pouchetii. Grazing of copepodite stage I–VC.finmarchicus was measured using two different approaches.Feeding rates were obtained from either incubation experiments,estimating the rate of removal of particles from suspension,or by quantifying the turnover rate of the plant pigments inthe gut. Clearance as a function of algal concentration (1–30µg plant pigment 1^–1) was described in juvenilestages of C.finmarchicus fed the diatoms T.nordenskioeldii [20µm equivalent spherical diameter (ESD)], P.glacialis (40µm ESD), and two size categories (30–100 µmand >100 µm ESD) of the gelatinous alga P.pouchetii.When the copepodite stages were fed T.nordenskioeldii, the gutcontent of plant pigments was in general higher than when fedP.glacialis. Rates obtained were variable when the same copepoditestages were offered the two size categories of P.pouchetii,but within the same order of magnitude as those obtained forthe larger diatom. At unialgal diets, diatoms were more readilyconsumed than the larger size fraction among colonies of P.pouchetiiby copepodite stage I–III C.finmarchicus. But given anappropriate prey size, C.finmarchicus grazed both diatoms andcolonies of gelatinous algae at equal rates. A linear relationshipbetween gut content and food concentrations <10 µgchlorophyll 1^–1 was found. This indicates that the ingestionrate in C.finmarchicus is directly proportional to the ambientfood concentration during the most productive period in Mayand June in high latitudes irrespective of algal species present. ¹Present address: Marine Biological Laboratory, University ofCopenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark ²Present address: Greater Copenhagen Council, Gl. KøgeLandevej 1–3, DK-2550 Valby, Denmark