Effects of starvation,season, and diet on the free amino acid and protein content of<Emphasis Type="Italic"> Calanus finmarchicus</Emphasis> females

Effects of food availability and season on the free amino acid (FAA) and total protein content of the copepod Calanus finmarchicus females were investigated in two mesocosm experiments on the Norwegian west coast in spring and autumn. Starved C. finmarchicus females showed no change in total FAA content, but the FAA pool composition changed drastically. During the first 10 days of starvation the protein content showed a moderate decline (<2 µg ind ^-1); however, during the following 21 days the total content was drastically reduced, from 63 to 9 µg ind ^-1. This supports the notion of a sequential catabolism of endogenous nutrients during starvation. In females at high food concentrations, the body protein content increased during spring, but decreased during autumn. The FAA pool composition of females differed between spring and autumn in 14 of the 18 FAA investigated. Reduced body protein content and increased proportion of essential free amino acid were observed during starvation. Similar changes were observed in females sampled at the end of the mesocosm experiments in the autumn. The results suggest that mature C. finmarchicus females are in a negative protein balance during autumn, despite high food concentrations, contributing to a lower fitness than in females maturing during the spring.     

Begging affects parental effort in the pied flycatcher, Ficedula hypoleuca

It has been suggested that nestlings use begging to increase their share of parental resources at the expense of current or future siblings. There is ample evidence that siblings compete over food with nestmates by begging, but only short-term effects of begging on parental provisioning rates have been shown. In this study, we use a new experimental design to demonstrate that pied flycatcher (Ficedula hypoleuca) nestlings that beg more are able to increase parental provisioning rates over the major part of the nestling period, thus potentially competing with future siblings. Parents were marked with microchips so that additional begging sounds could be played back when one of the parents visited the nest. By playing back begging sounds consistently at either male or female visits, a sex difference in provisioning rate that lasted for the major part of the nestling period was induced. If each parent independently adjusts its effort to the begging intensity of nestlings, begging may also be the proximate control mechanism for the sexual division of labour. Received: 24 January 1997 / Accepted after revision: 30 August 1997     

Mobilität von Nitroaromaten im Sandstein infolge Schwefelsäureeintrag zur Uranlaugung

As a result of former in situ leaching activities with sulfphuric acid, nitroaromatic compounds have invaded into cenomanian and turonian sandstone aquifers and mining waters in parts of the uranium mining of Königstein, Germany (Saxony). In the mining area contamination levels of nitrobenzene, mononitrotoluene and dinitrotoluene lead to a partial excess in the drining water guide values. For environmental protection, control and remediation efforts by flooding, more knowledge about contaminant mobility in sandstone, and in intercalated clays and silts, is demanded. A selected experimental area has been flooded to realize and study transport processes under real mining conditions. In this work, we have examined the mobilization of nitroaromatic compounds by flooding waters. The interactions between the nitroaromatic compounds, which are dissolved in the mining water, and the host rocks are discussed. The existing data for strata of varying lithologic conditions suggest that the sorption processes of the compounds investigated are negligible in pure sandstone aquifer layers and significant in the lithologic conditions with a complex mixture of mudstone, siltstone and clay. Several lithologic conditions are demonstrated in contaminant sinks and sources caused by adsorption processes and mobilization of newly connected stagnant pore waters.     

Airborne PCB as a contamination risk on freeze-drying of sediment

In a study of polychlorinated biphenyls (PCB) in freeze-dried sediments from Swedish lakes, the samples were found to contain unexpectedly high concentrations of PCBs. In one of the lakes (Bj?rken), e.g. the concentration of PCB-28 was found to be 189 ng/g dw after freeze-drying compared to 7 ng/g dw after air-drying of the sediment and therefore our hypothesis was that the contamination had occurred during the freeze-drying procedure. Hence, a dry reference sediment (RS) was used in order to identify potential sources of PCB contamination. The investigation included freeze-drying of the dry RS in five different laboratories, exposure to the air in the freeze-drying room, storage at room temperature and air-drying in a certain fume hood and in a laminar flow clean bench. The pattern and concentrations of PCBs detected in the exposed RS were strongly influenced by low chlorinated PCB congeners under all of these conditions with exception for air-drying in the fume hood. Storage in the laboratory air resulted in a slight elevation in the concentrations of low chlorinated PCB congeners, whereas higher concentrations of all PCB congeners were observed after freeze-drying. In all experiments the contamination appeared to be due to adsorption of PCB from the laboratory air. On the basis of these findings we recommend that reference material be subjected to the entire procedure, including sample preparation, in order to monitor contamination and that a procedure involving solvent extraction of wet sediment samples is used, whenever possible, instead of procedures involving dry samples.     

Capillary GC-MS analysis of PAH emissions from combustion of peat and wood in a hot water boiler

A preliminary investigation has been made on the emissions of Polynuclear Aromatic Hydrocarbons (PAH) when burning wood chips and peat in a modified commercial hot water boiler. The amount of the investigated eighteen PAH that were filter trapped from peat combustion averaged 2.7 times greater than that from wood combustion per cubic meter flue gas. The total emitted amount (particulate plus gas phase PAH) was 9.7 times greater than from wood combustion. The corresponding values for benzo(a)pyrene only were 1.7 and 3.5 times greater, respectively. The comparison of PAH emitted by the combustion of wood and peat showed a pronounced tendency towards the emission of high molecular weight PAH by the latter.Particulate phase-gas phase distribution ourves are presented for PAH in the boiling point range 336°C – 525°C. In addition, the emission of a polynuclear aromatic ketone is shown.     

The high occurrence of arsenic in macadam products from an iron mine in central Sweden: Significance for environmental contamination

High Arsenic concentrations (up to 200 mg kg^–1) are found in macadam products from Dannemora Iron Mine in central Sweden. Monitoring the As, Pb, Zn and Cu concentrations in different macadam products shows that the highest amounts of the metals investigated appear in the fine fractions, 0–2 mm. Because of these relatively high concentrations, the Department of Environment has stopped all distribution of macadam products with a fraction less than 2 mm. However, the leaching tests show a very low concentration of weathering products which indicates a very low weathering rate for the material. Both the surface water and the ground water analyses also show low concentrations (<30g L^–1) in all the samples.     

Rural landscape, production and human consumption: past, present and future

Production and consumption of food and in a rural area over the last 400 years were reconstructed for a parish in south east Sweden. This was based on a number of different data sources, including historical maps and official demographic and agricultural statistics. Changes in population (and thus consumption) and the production from arable land and livestock were calculated and used to provide an estimate of the area's supply and demand over time, and of the historical sustainability of the area. Overall food productivity was remarkably constant over time, at approximately 0.04 kgC m(-2) y(-1), despite recent changes in population size and the area of cultivated land. The empirical results from the past and the present, together with the future land changes due to shoreline displacement were used to predict the situation in the future. These final estimates can be used in the assessment of risk for exposure to contaminated food for the future population in the area.     

Ocean fertilization for geoengineering: A review of effectiveness,environmental impacts and emerging governance

Dangerous climate change is best avoided by drastically and rapidly reducing greenhouse gas emissions. Nevertheless, geoengineering options are receiving attention on the basis that additional approaches may also be necessary. Here we review the state of knowledge on large-scale ocean fertilization by adding iron or other nutrients, either from external sources or via enhanced ocean mixing. On the basis of small-scale field experiments carried out to date and associated modelling, the maximum benefits of ocean fertilization as a negative emissions technique are likely to be modest in relation to anthropogenic climate forcing. Furthermore, it would be extremely challenging to quantify with acceptable accuracy the carbon removed from circulation on a long term basis, and to adequately monitor unintended impacts over large space and time-scales. These and other technical issues are particularly problematic for the region with greatest theoretical potential for the application of ocean fertilization, the Southern Ocean. Arrangements for the international governance of further field-based research on ocean fertilization are currently being developed, primarily under the London Convention/London Protocol.