Contamination of livestock due to the operation of a small waste incinerator: a case incident in Skutulsfjörður,Iceland, in 2010

Background

Declining fertility is a major concern for dairy farmers today. One explanation is shorter and weaker expression of oestrus in dairy cows making it difficult to determine optimal time for artificial insemination (AI). Chemical communication is of interest in the search for tools to detect oestrus or to synchronise or enhance oestrous periods. Pheromones, used in chemical communication within species, can influence reproduction in different ways. The aim here was to investigate whether oestrous cycle length, and duration and intensity of oestrous expression in dairy heifers could be manipulated through exposure to pheromones in oestrual substances from other females.

Methods

Beginning on day 16 of two consecutive control oestrous cycles, ten heifers of the Swedish Red Breed (SRB) were exposed to water. During the two following cycles the heifers were exposed to urine and vaginal mucus, obtained from cows in oestrus. Cyclicity parameters were monitored through hormone measurements, oestrus detection and ultrasonographic examination.

Results

We found no difference in cycle length or in duration of standing oestrus between control and treatment. We did, however, find a tendency of interaction between type of exposure (control or treatment) and cycle number within type of exposure for cycle length (p = 0.068), with the length differing less between the treatment cycles. We also found a tendency of effect of type of exposure on maximal concentration (p = 0.073) and sum of concentrations (p = 0.063) of LH during the LH surge, with values being higher for the control cycles. There were also significant differences in when the different signs of oestrus occurred and in the intensity of oestrous expression. The score for oedema and hyperaemia of external genitalia was significantly higher (p = 0.004) for the control cycles and there was also a significant interaction between type of exposure and time period for restlessness (p = 0.011), with maximum score occurring earlier for treatment cycles.

Conclusions

No evidence of altered oestrous cycle length or duration of oestrus after exposure of females to oestrous substances from other females was found. Expression of oestrus, and maybe also LH secretion, however, seemed influenced by the exposure, with the effect of treatment being suppressive rather than enhancing.     

Rhizoclonium riparium (Roth) Harvey: a cryptogenic species with an invasive behaviour in Reyðarfjörður,Iceland

Rhizoclonium riparium is a cryptogenic macroalga that freely inhabits fresh, sea and brackish waters and is able to compete in a variety of habitats. In the summers of 2018 and 2019, this alga was found to form huge filamentous mats, covering all rocks, down to a depth of 3 m in a harbour in Reyðarfjörður, east Iceland. The species taxonomy was confirmed by molecular data. Here, we report the invasive behaviour of this species in Reyðarfjörður, which may represent a pool source for R. riparium dispersal, as hull fouling is the most likely vector for the spread of this species.     

Spring diet of common eiders (Somateria mollissima) in Breiðafjörður, West Iceland, indicates non-bivalve preferences

Breiðafjörður is an important molting, breeding, and wintering area for about 25 % of the Icelandic common eider (Somateria mollissima) population. However, feeding habits of eiders in this area have not been investigated until now. Prey selection was analyzed from 192 stomach samples (esophagus and proventriculus) collected in spring 2007–2010. Thirty-five prey species were identified; the highest percentage occurrences were of gastropods (79 %), chitons (polyplacophorans) (58 %), crustaceans (43 %), bivalves (26 %), and echinoderms (8 %). The most common food species was the mottled red chiton Tonicella marmorea (58 %), followed by the common whelk Buccinum undatum (40 %), the spider crab Hyas arenarius (39 %), and the chink shell Lacuna vincta (35 %). The majority of the food items was of small size and consumed in high quantity. The chitons and mussels were of similar average sizes (11.7 and 13.4 mm, respectively), which might suggest that prey size could be as important as species in food selection. There were some inter-annual differences in dominant prey classes between years. For example T. marmorea was found in 60–70 % of birds in the years 2007 and 2009 but only in 30 % of the birds in the other years investigated. Diets of males and females were equally diverse and similar when all months and years were pooled. Prey selection was highly variable but most individuals focused on few or a single species in the hours prior to collection. Results indicate that the most common prey species for common eiders is a chiton and not blue mussels as reported elsewhere.     

Pioneer Microbial Communities of the Fimmvörðuháls Lava Flow,Eyjafjallajökull,Iceland

Little is understood regarding the phylogeny and metabolic capabilities of the earliest colonists of volcanic rocks, yet these data are essential for understanding how life becomes established in and interacts with the planetary crust, ultimately contributing to critical zone processes and soil formation. Here, we report the use of molecular and culture-dependent methods to determine the composition of pioneer microbial communities colonising the basaltic Fimmvörðuháls lava flow at Eyjafjallajökull, Iceland, formed in 2010. Our data show that 3 to 5 months post eruption, the lava was colonised by a low-diversity microbial community dominated by Betaproteobacteria, primarily taxa related to non-phototrophic diazotrophs such as Herbaspirillum spp. and chemolithotrophs such as Thiobacillus. Although successfully cultured following enrichment, phototrophs were not abundant members of the Fimmvörðuháls communities, as revealed by molecular analysis, and phototrophy is therefore not likely to be a dominant biogeochemical process in these early successional basalt communities. These results contrast with older Icelandic lava of comparable mineralogy, in which phototrophs comprised a significant fraction of microbial communities, and the non-phototrophic community fractions were dominated by Acidobacteria and Actinobacteria.     

The benthic algal vegetation of the Mjóifjörđur,Eastern Iceland

The benthic algal vegetation of Mjóifjör?ur, situated in the central area of the East Icelandic coast, is described regarding the species distribution from the head to the mouth of the fjord, the main algal associations and zonation patterns. The vegetation gradient along the fjord coast is related to the hydrographic conditionsviz. the influence of freshwater discharge in the inner area and that of the cold water masses of the East Icelandic Current in the outer area. Comparisons are made with the vegetation of other Icelandic fjords investigated during surveys of the Icelandic algal vegetation as a whole.     

Narcolepsy due to Parkinson’s disease with a decrease in cerebrospinal-fluid orexin: a case report

Sleep and Biological Rhythms - A 57-year old man became affected by excessive daytime sleepiness. Thereafter, he had difficulty in moving his left limbs and began to walk slowly. He had no...     

Isotope palaeotemperatures from the Tjörnes beds in Iceland: evidence of Pliocene cooling

The mid-Pliocene warming episode is well established along the margins of the North Atlantic and probably affected areas as far north as Iceland. Rich marine mollusc faunas have been described from the 500 m of Pliocene siliciclastic deposits on the Tjörnes Peninsula in northeast Iceland. The faunal compositions indicate a development from warm-water to arcto–boreal conditions. We have analysed the oxygen isotope composition of 96 well-preserved specimens of the bivalves Arctica islandica and Pygocardia rustica and interpreted the data as palaeotemperatures. After corrections for the isotopic composition of Pliocene seawater, the temperatures are in accordance with other palaeotemperature proxies. We interpret our data as reflecting a gradual change from warm-water conditions (summer temperatures between 10 and 15°C) during the deposition of the lower part of the Tjörnes beds (Tapes Zone and lower part of Mactra Zone) to cold-water conditions (summer temperatures between 5 and 10°C) at the top (top of Mactra Zone and Serripes Zone). The coldest interval is found in the middle of the Serripes Zone, where summer temperatures (5–8°C) are comparable to those of the present environment off northern Iceland. The arrival to Tjörnes of cold-water molluscs of Pacific origin postdates the cooling of the seas around Iceland. We suggest that the cold interval in the Serripes Zone represents a cooling event prior to the final warm period (ca. 3.3–3.0 Ma [Dowsett et al. (1999) Middle Pliocene paleoenvironmental reconstruction: PRISM2. US Geol. Survey Open File Rep. 99–53]) of the mid-Pliocene warming.     

Populations of ducks and trout of the River Laxá, Iceland, in relation to variation in food resources

We examined annual variation in production, recruitment and density of the three most abundant vertebrate species of the River Laxá at Lake Myvatn, Iceland: Barrow’s goldeneye, Bucephala islandica, harlequin duck, Histrionicus histrionicus, and brown trout, Salmo trutta, in relation to food resources and other environmental variables. The study is largely based on correlations from long-term monitoring series in the period 1975–2002. Production of young in the harlequin duck was significantly correlated with food resources (the blackfly, Simulium vittatum) of the river, as was the recruitment of brown trout to the angling stock. In Barrow’s goldeneye, which uses both the lake and the river, dispersion of adults in spring and young in August was influenced by the availability of aquatic insects in each habitat. The dispersion of Barrow’s goldeneye tracks the availability of aquatic insects in each of these two main habitats. Introduced Amercian mink, Mustela vison, may have affected spring numbers and dispersion of harlequin ducks, but the evidence was not conclusive. Numbers of both duck species and the trout (as CPUE) were relatively stable, although a sharp drop in numbers followed by slow recovery was observed in Barrow’s goldeneye, and an increase was observed in harlequin ducks in the first year of study.     

Morphological and genetic divergence of intralacustrine stickleback morphs in Iceland: a case for selective differentiation?

The evolutionary processes involved in population divergence and local adaptation are poorly understood. Theory predicts that divergence of adjacent populations is possible but depends on several factors including gene flow, divergent selection, population size and the number of genes involved in divergence and their distribution on the genome. We analyse variation in neutral markers, markers linked to putative quantitative trait loci and morphological traits in a recent (<10000 years) zone of primary divergence between stickleback morphs in Lake Thingvallavatn, Iceland. Environmental factors, especially predation, are clearly implicated in reducing gene flow between morphs. There is continuous morphological and genetic variation between habitats with a zone centre similar to secondary contact zones. Individual microsatellite loci are implicated as being linked to adaptive variation by direct tests as well as by differences in cline shape. Patterns of linkage disequilibria indicate that the morphs have diverged at several loci. This divergence shows parallels and differences with the well-studied limnetic-benthic stickleback morphs, both in phenotypic divergence and at the genomic level.     

Responding to the threat of bioterrorism: a microbial ecology perspective – the case of anthrax

Anthrax is a disease of herbivores caused by the gram-positive bacterium Bacillus anthracis. It can affect cattle, sheep, swine, horses and various species of wildlife. The routes for the spread among wildlife are reviewed. There are three kinds of human anthrax – inhalation, cutaneous, and intestinal anthrax – which differ in their routes of infection and outcomes. In the United States, confirmation of cases is made by the isolation of B. anthracis and by biochemical tests. Vaccination is not recommended for the general public; civilians who should be vaccinated include those who, in their work places, come in contact with products potentially contaminated with B. anthracis spores, and people engaged in research or diagnostic activities. After September 11, 2001, there were bioterrorism anthrax attacks in the United States: anthrax-laced letters sent to multiple locations were the source of infectious B. anthracis. The US Postal Service issued recommendations to prevent the danger of hazardous exposure to the bacterium. B. anthracis spores can spread easily and persist for very long times, which makes decontamination of buildings very difficult. Early detection, rapid diagnosis, and well-coordinated public health response are the key to minimizing casualties. The US Government is seeking new ways to deter bioterrorism, including a tighter control of research on infectious agents, even though pathogens such as B. anthracis are widely spread in nature and easy to grow. It is necessary to define the boundary between defensive and offensive biological weapons research. Deterring bioterrorism should not restrict critical scientific research. Electronic Publication     

Simulation,quantification and comparison of in-channel and floodplain sediment processes in a lowland area – A case study of the Upper Stör catchment in northern Germany

Erosion and sedimentation processes within the channel and on the floodplain are indicative of catchment hydrodynamic procedures, as well as the associated nutrient and contaminant transportation. In this paper, we linked the SWAT model with the hydraulic HEC-RAS model to set up a sediment model for 10 river sections in the Upper Stör catchment and simulated the sediment processes from 2001 to 2010. Based on the HEC-RAS output, quantification and comparison of channelized and floodplain sediment processes were conducted. The results indicate that (1) with an average sedimentation depth of 2.85 cm, the deposition process dominated the Upper Stör catchment at the decadal time scale, and the land use/cover condition resulted in differences in sedimentation amounts between different sub-catchments, and (2) the mean deposition rates were 1.75 g/m²/d in the channel and 1.69 g/m²/d on the floodplain, and the floodplain deposition accounted for only 1% of the total sedimentation amount. This observation was mainly caused by the stream power distribution in the channel and on the floodplain. (3) The granularity of the channelized sedimentation was determined by the altitude of the river section, while the granularity of the floodplain sedimentation was positively correlated with the stream power of the flood. The D50s of the channelized and floodplain sediments were 0.92 mm and 0.16 mm, respectively, while the D90 of the sediment was 4.2 mm in the channel and 0.32 mm on the floodplain. Despite the higher uncertainty of the sediment simulation, the results yielded by the combination of the HEC-RAS and SWAT models are comparable to the traditional radioactive dating, sediment trapping or combined model methods used in similar and nearby catchments.     

Spring development of a Chlamydomonas population in Lake Nimetön,a small humic forest lake in southern Finland

Biomass development and vertical distribution of a Chlamydomonas population in a small humic forest lake was followed by daily sampling in May-June, 1984. Chlamydomonas dominated the phytoplankton spring bloom, forming 71% of the maximum phytoplankton biomass on 18 May. In early May the outflow rate was high and during the 24 hour period when the maximum rate of surface runoff was recorded (8–9 May), 43% of the Chlamydomonas biomass was flushed out of the lake, which delayed the onset of biomass increase. When surface runoff had slowed down Chlamydomonas biomass started increasing and during wax of the population most cells were < 10 µm in diameter. Population maximum lasted for one day (18 May) and there-after Chlamydomonas biomass decreased towards the end of the study. During wane of the population most cells were > 10 µm in diameter.     

Modeling the foodweb in coastal areas: a case study of Ringkøbing Fjord,Denmark

This work utilizes the CoastWeb model, a foodweb model for coastal areas that also includes a mass-balance model (CoastMab) for phosphorus and many abiotic/biotic interactions, to study the development in Ringkøbing Fjord, Denmark, from 1985 to 2004. This shallow coastal lagoon has an area of 300 km² and a mean depth of 1.9 m. The water exchange between the lagoon and the North Sea is regulated by a sluice. In 1996 there was a major regime shift in this lagoon with drastic reductions in chlorophyll-a concentrations, significant increases in water clarity (Secchi depth) and major changes in the number and biomass of clams as well as in macrophyte cover. Regime shifts is a “hot” topic in aquatic ecology and in this work the CoastWeb model is used as a tool to understand and quantify the causes behind this regime shift. The CoastWeb model is general and can also be used for other coastal areas. The basic model calculates monthly production values and changes in biomasses of ten functional groups of organisms (phytoplankton, bacterioplankton, herbivorous, and predatory zooplankton, benthic algae, macrophytes, jellyfish, zoobenthos and prey and predatory fish) and in Ringkøbing Fjord, also for clams (Mya arenaria). In spite of its complexity, the model is relatively simple to use, since all driving variables may be readily accessed from maps or monitoring programs. The model includes much abiotic/biotic feedback and it can also be used to address other causes for regime shifts other than the changes in salinity and nutrient inflow, which have caused the changes in Ringkøbing Fjord. The model has previously been tested for more than 20 smaller coastal areas and was shown to predict variations in foodweb characteristics very well. The focus of this paper is on temporal variations within one well-studied coastal area. The paper compares modeled values to empirical data for Ringkøbing Fjord and discusses fundamental ecosystem features such as regime shifts and compensatory effects in a way that is not practically feasible without the use of quantitative models.     

The role of glacier mice in the invertebrate colonisation of glacial surfaces: the moss balls of the Fallj?kull, Iceland

Glacier surfaces have a surprisingly complex ecology. Cryoconite holes contain diverse invertebrate communities, while other invertebrates, such as Collembola, often graze on algae and windblown dead organic material on the glacier surface. Glacier mice (ovoid unattached moss balls) occur on some glaciers worldwide. Studies of these glacier mice have concentrated on their occurrence and mode of formation. There are no reports of the invertebrate communities. But, such glacier mice may provide a suitable favourable habitat and refuge for a variety of invertebrate groups to colonise the glacier surface. Here, we describe the invertebrate fauna of the glacier mice (moss balls) of the Fallj?kull, Iceland. The glacier mice were composed of Racomitrium sp. and varied in size from 8.0 to 10.0?cm in length. All glacier mice studied contained invertebrates. Two species of Collembola were present. Pseudisotoma sensibilis (Tullberg, 1876) was numerically dominant with between 12 and 73 individuals per glacier mouse, while Desoria olivacea (Tullberg, 1871) occurred but in far lower numbers. Tardigrada and Nematoda had mean densities of approximately 200 and 1,000, respectively. No Acari, Arachnida or Enchytraeidae were observed, which may be related to the difficulty these groups have in colonising the glacier mice. We suggest that glacier mice provide an unusual environmentally ameliorated microhabitat for an invertebrate community dwelling on a glacial surface. The glacier mice thereby enable an invertebrate fauna to colonise an otherwise largely inhospitable location with implications for carbon flow in the system.     

Nuclear and mitochondrial genetic variation in the Yanomamö: a test case for ancient DNA studies of prehistoric populations

Ancient DNA provides a potentially revolutionary way to study biological relationships in prehistoric populations, but genetic patterns are complex and require careful interpretation based on robust, well-tested models. In this study, nuclear and mitochondrial markers were compared in the Yanomam?, to assess how well each data set could differentiate among closely related groups. The villages selected for the study share a recent fission history and are closely related to each other, as would likely be the case among prehistoric peoples living in the same valley or region. The Yanomam? generally practice village-level endogamy, but some migration and gene flow are known to occur between villages. Nuclear and mitochondrial DNA data were compared using F-statistics and genetic distance analyses. The nuclear data performed as expected, males and females from the same village were similar, and the villages were genetically distinct, with the magnitude of genetic differences correlated with historical relationship. However, mtDNA analyses did not yield the expected results. The genetic distances between villages did not correlate with historical relationship, and the sexes were significantly different from each other in two villages. Both the Lane and Sublett and the Spence methods, used to test for archaeological residence patterns, were consistent with endogamy. Hence, ancient DNA can, in principle, provide us with a unique opportunity to study genetic structure and gene flow in archaeological populations. However, interpretations, particularly those based on single loci such as mitochondrial DNA, should be cautious because sex-specific migration and sampling issues may have dramatic effects.     

Phytoplankton dynamics in relation to connectivity,flow dynamics and resource availability—the case of a large,lowland river,the Hungarian Tisza

Large lowland rivers with sufficient hydrological storage capacity are capable of supporting primary production, but the dynamics of the advecting phytoplankton is poorly understood. Our study aimed at exploring how longitudinal versus lateral connectivity, flow dynamics versus resource availability and continuous versus discontinuous environmental gradients shaped the species composition of phytoplankton. Samples were taken from February to October 2000 along the Hungarian Tisza River (HTR) and in its main tributaries. Longitudinal and seasonal patterns were related to resources (light and nutrients) availability and flow dynamics derived from a 1D hydrodynamic model. The HTR was autotrophic during the study period, but tributary input considerably exceeded net autochtonous production. The Szamos River was the major source of both phytoplankton and nutrients in the HTR. Chryso- and euglenophytes were flushed into the main river from floodplain oxbows during high discharge. Imported algae experienced discontinuity in environmental gradients when entering the main river. The merged impact areas of two dams (IAD) that separate the two large meandering patches of the HTR disrupted the longitudinal profiles of both physico-chemical variables and attributes of algal assemblages (biomass, species composition, richness, similarity between adjacent sampling sites). Hydraulic storage along the IAD selectively favoured the recruitment of cryptophytes that, however, could not compensate for the enhanced sedimentation of diatoms in terms of biomass. Although the meandering patches presented several small-scale differences in major environmental gradients, both patches supported the growth of planktonic diatoms. Changes in algal biomass were decoupled from nutrient availability. We conclude that various measures must be applied in various lowland rivers within the same catchment to control their trophic status as a component of the ‘good ecological status’ defined in the Water Framework Directive.