An integrated river basin-coast-sea modelling scenario for nitrogen management in coastal waters

Linked river basin and coastal water models were applied to analyse the effects of an optimal nitrogen management scenario in the Oder/Odra river basin on water quality in the Oder (Szczecin) Lagoon and the Pomeranian Bay (Baltic Sea). This scenario would reduce nitrogen loads into the coastal waters by about 35%, a level which is similar to the load of the late 1960’s. During summer the primary production and algae biomass in the Oder estuary is limited by nitrogen, which makes a nitrogen management reasonable. The comparison of the late 1960’s and the mid 1990’s shows that an optimal nitrogen management has positive effects on coastal water quality and algae biomass. However, this realistic nitrogen reduction scenario would not ensure a good coastal water quality according to the European Water Framework Directive. A good water quality in the river will not be sufficient to ensure a good water quality in the lagoon. Nitrogen load reductions bear the risk of increased potentially toxic, blue-green algae blooms, especially in the Baltic coastal sea. However, to reach water quality improvements in lagoons and inner coastal waters, nitrogen cuts are necessary. A mere focus on phosphorus is not sufficient.     

Archetypical patterns and trajectories of land systems in Europe

Regional Environmental Change - Assessments of land-system change have dominantly focused on conversions among broad land-use categories, whereas intensity changes within these categories have...     

Extremes of Temperature, Oxygen and Blooms in the Baltic Sea in a Changing Climate

In the future, the Baltic Sea ecosystem will be impacted both by climate change and by riverine and atmospheric nutrient inputs. Multi-model ensemble simulations comprising one IPCC scenario (A1B), two global climate models, two regional climate models, and three Baltic Sea ecosystem models were performed to elucidate the combined effect of climate change and changes in nutrient inputs. This study focuses on the occurrence of extreme events in the projected future climate. Results suggest that the number of days favoring cyanobacteria blooms could increase, anoxic events may become more frequent and last longer, and salinity may tend to decrease. Nutrient load reductions following the Baltic Sea Action Plan can reduce the deterioration of oxygen conditions.     

Spatial and temporal trends of metals and arsenic in German freshwater compartments

Cadmium, lead, mercury, copper, nickel, zinc, and arsenic were analyzed in suspended particulate matter (SPM), zebra mussels, and bream sampled yearly under the program of the German Environmental Specimen Bank (ESB) in the rivers Rhine, Elbe, Danube, Saar, Mulde, and Saale and in Lake Belau. Temporal and spatial trends were analyzed, correlations between metal levels in different specimen types assessed, and sampling sites ranked according to their metal levels by calculating a Multi-Metal Index (MMI) for every specimen type and site. SPM: Highest metal loads were detected in Mulde, Saale, and Elbe right downstream of the Saale confluence. In the Elbe, metal loads in SPM were mostly highest in the upper and middle section of the river while in Rhine and Saar concentrations increased downstream. Temporal trends since 2005 were detected only at three sites. Zebra mussel: MMIs were highest in the tidal section of the Elbe and the lower Rhine and lowest in Lake Belau and the upper Danube. Different temporal trends were detected since the early 1990s depending on site and metal. Bream: As, Pb, Cu, and Hg were analyzed in muscle tissue and Pb, Cd, Cu, and Zn in liver. For both tissues, MMIs were highest in Mulde and Saale and the lower and middle Elbe. Since the early 1990s, Hg, Pb, and Cu decreased in bream muscle at many sites while As increased at 6 of the 17 sites. The findings indicate that Hg, Pb, and Cu have obviously decreased in many freshwater ecosystems in recent years, whereas As and Ni levels have increased at several sites. Metal levels and temporal trends mostly differed between the specimen types under investigation and only few correlations between specimen types were detected. This underlines the importance of including different components of an ecosystem when assessing its environmental quality.     

Information content of female copulation calls in wild long-tailed macaques (<Emphasis Type="Italic">Macaca fascicularis</Emphasis>)

Primates are unusual in that many females display sexual signals, such as sex skin swellings/colorations and copulation calls, without any sex role reversal. The adaptive function of these signals remains largely unclear, although it has been suggested that they provide males with information on female reproductive status. For sex skin swellings, there is increasing evidence that they represent a graded signal indicating the probability of ovulation. Data on the functional significance of copulation calls are much scarcer. To clarify the information content of such calls, we recorded copulation calls in wild long-tailed macaques (Macaca fascicularis) and analysed the structure of these calls during the ovarian cycle. Specifically, we correlated selected call parameters with the female oestrogen to progestogen ratio (obtained from faecal samples), which are known to be elevated during the female's fertile phase. In addition, we ran a general linear mixed model for these call parameters, testing factors (cycle phase, occurrence/absence of ejaculation, male dominance status, occurrence/absence of mate guarding) which potentially influence female copulation calls in primates. Our results show that copulation calls of female long-tailed macaques signal mating outcome and rank of the mating partner, but not female reproductive status. They also show for the first time on primates that copulation calls can convey information on whether a female is mate guarded or not. We suspect that the function of these calls is manipulation of male mating and mate-guarding behaviour and that in this way the degree of sperm competition and ultimately male reproductive success is influenced.     

LIMPACT: Ein Expertensystem zur Abschätzung der Pflanzenschutzmittel-Belastung kleiner Fließgewässer mittels der Makroinvertebraten-Fauna

The development and the evaluation of a biological indicator system for pesticide pollution in streams are presented. For small headwater streams with an agricultural catchment area, the expert system LIMPACT estimates the pesticide contamination according to the four classes of Not Detected, Low, Moderate and High contamination without any specification of the chemical agents. The input parameters are the abundance data of benthic macroinvertebrate taxa within four time frames in a year (March/April; May/June; July/August; September/October) and 9 basic water-quality and morphological parameters. The heuristic knowledge base was developed with the shell-kit D3 and contains diagnostic rules with scores to either establish or de-establish a contamination class. We differentiate between positive indicator taxa, which indicate contamination by high abundance values and positive abundance dynamics, and negative indicator taxa, a high abundance of which rules out contamination and indicates an uncontaminated site. We analysed 39 taxa and found 13 positive and 24 negative indicators. The database is comprised of 157 investigations per stream and year. For the evaluation of LIMPACT, we used the same cases. The correct diagnosis for the 157 investigations per stream and year is established by LIMPACT in 66.7 to 85.5% of the cases, with better results for uncontaminated sites. In most of the remaining cases no diagnosis is established instead of an incorrect one.     

International research into occupational safety and health protection.

Are we doing the right thing? Are we setting the right priorities for the future in occupational safety and health research? How does BG (Institution for Statutory Accident Insurance and Prevention) research compare nationally and internationally? As a mosaic of answers to these questions, this article explores international research on priorities in occupational research and analyses these against the backdrop of the nearly 1,000 research projects conducted by 9 institutions from 8 countries in the year 2003.