The European dioxin air emission inventory project--final results

Main results of the second stage of the so-called "European Dioxin Emission Inventory" are presented. They cover emission testing data gained from various facilities in the EU (among these the first emission measurements reported from Portugal and Greece) and some central European countries. Further, updated dioxin emission estimates for the most important emission sources in the 17 western European countries and an evaluation of the emission time trend from 1985 to 2005 are presented. The major conclusions are, that at present, iron ore sintering is likely to be the most important emission source type followed by the former "No. 1", municipal waste incineration; measurement data from a considerable number of installations are still missing, in particular from the metal industries in Spain and Italy; there still exist an unknown number of health care waste incinerators with flue gas PCDD/F concentrations above 100 ng I-TEQ/m3 which must be considered as important local sources; in general, considerable emission reduction has been achieved with respect to the industrial emission sources, whereas emissions from non-industrial sources hardly decreased; hence, in the near future the emissions from non-industrial sources are likely to exceed those from industrial installations; the goal of 90% emission reduction set in the 5th EU Action Programme will be achieved for some source types only.     

Sustainability research and practices in enforced residential institutions: collaborations of ecologists and prisoners

Enforced institutional settings such as penitentiaries provide environments to raise awareness, carry out research, and implement and assess practices for sustainable living. Institutions where residence is enforced due to health, recreational, military, or legal reasons (e.g., assisted living centers, summer camps, army bases, prisons) house people who may lack scientific training but have time and need for intellectual stimulation that can be filled by supervised research. These institutions have stable populations, structured social organization, and measurable inputs and outputs of materials and energy to carry out sustainable practices in tasks that affect regional resources such as groundwater quality and landfill use. We report on three examples at a corrections center resulting from partnerships among visiting academic ecology researchers, sustainability practitioners, corrections administrators, and prisoners: (1) research on how to sustainably “farm” moss for the horticulture trade to reduce harvesting pressure on wild moss populations; (2) a vermiculture and thermophilic composting system to reduce the kitchen waste; and (3) a monthly seminar series at the prison. Over 26 months: (1) participants developed methods to optimize moss growth; (2) landfill-bound waste and particulate flow rate destined for wastewater treatment decreased by 50%, to less than 50% of permit limits; (3) resulting compost (ca. 5000 kg) fertilized institutional vegetable gardens; (4) water quality improved so that the prison could return funds allocated to upgrade the prison’s water quality. The lectures encouraged intellectual exchange among researchers, convicts, and guards. Researchers derived new perspectives and broader impacts for their work. This can be a model for other correctional facilities and other enforced residential institutions (ERIs). Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

The Baltic Sea spring phytoplankton bloom in a changing climate: an experimental approach

The response of the Baltic Sea spring bloom was studied in mesocosm experiments, where temperatures were elevated up to 6°C above the present-day sea surface temperature of the spring bloom season. Four of the seven experiments were carried out at different light levels (32–202?Wh?m^?2 at the start of the experiments) in the different experimental years. In one further experiment, the factors light and temperature were crossed, and in one experiment, the factors density of overwintering zooplankton and temperature were crossed. Overall, there was a slight temporal acceleration of the phytoplankton spring bloom, a decline of peak biomass and a decline of mean cell size with warming. The temperature influence on phytoplankton bloom timing, biomass and size structure was qualitatively highly robust across experiments. The dependence of timing, biomass, and size structure on initial conditions was tested by multiple regression analysis of the y-temperature regressions with the candidate independent variables initial light, initial phytoplankton biomass, initial microzooplankton biomass, and initial mesozooplankton (=copepod) biomass. The bloom timing predicted for mean temperatures (5.28°C) depended on light. The peak biomass showed a strong positive dependence on light and a weaker negative dependence on initial copepod density. Mean phytoplankton cell size predicted for the mean temperature responded positively to light and negatively to copepod density. The anticipated mismatch between phytoplankton supply and food demand by newly hatched copepod nauplii occurred only under the combination of low light and warm temperatures. The analysis presented here confirms earlier conclusions about temperature responses that are based on subsets of our experimental series. However, only the comprehensive analysis across all experiments highlights the importance of the factor light.     

Response of Drinking-water Reservoir Ecosystems to Decreased Acidic Atmospheric Deposition in SE Germany: Signs of Biological Recovery

Strongly decreasing atmospheric emissions and acidic deposition during the 1990s have initiated chemical reversal from acidification in several drinking-water reservoirs of the Erzgebirge, SE Germany. We studied responses of phytoplankton, zooplankton and fish stocks in five reservoirs and at enclosure scale after experimental neutralization of 1,200 m³ of lake water. About 4 months after this treatment, diatoms and cryptomonads replaced the predominating chrysophytes and dinoflagellates. The colonization by acid-sensitive species of green algae, cryptomonads, rotifers and Cladocera (e.g. Bosmina longirostris) is explained by the occurrence of dormant stages or by survival of individuals in very low abundances. Analogous to the enclosure experiment, three reservoirs showed significantly (p < 0.01) falling trends of chlorophyll a and phytoplankton biovolume, mainly due to the decline of dinoflagellates. Picoplankton and diatoms increased slightly in two reservoirs. The zooplankton communities were dominated by rotifers and small Cladocera. Representatives of the genus Daphnia were lacking. Two reservoirs were re-colonized by zooplanktivorous fish populations of either perch (Perca fluviatilis) or sunbleak (Leucaspius delineatus). The latter exhibited extremely high fluctuating abundance and biomass and even suffered from a population crash. This natural mortality was caused by a limited food supply. Hence, severe top-down control may delay the recovery of larger zooplankton species like daphnids. Fishery management comprising the introduction of predatory fishes can help to control zooplanktivorous fish populations and to prevent their mass mortality.     

Untersuchungen zum ökotoxikologischen Schädigungspotenzial und Erosionsrisiko von kontaminierten Sedimenten in staugeregelten Flüssen

Particle-bound pollutants accumulate in river-bottom sediments, a process which results in a significant decrease in the ecotoxicological availability of toxicants for the majority of aquatic organisms. Under normal hydrologic conditions, the release of contaminants from bottom sediments is usually of minor importance. In contrast, flood events may remobilize highly contaminated sediments via in-stream erosion. The objective of this study was to develop a combined ecotoxicological and hydraulic approach to elucidate the ecotoxicological implications associated with the risk of erosion of contaminated sediments. This integrated strategy was applied to the lock-regulated Neckar river in Southern Germany. Both the bottom-sediment cores and suspended matter from two intensive flood events were investigated. Sediment samples below an erosional unconformity showed a sharp increase in the ecotoxicological load. Moreover, it was found that major flood events (HQ₅ and higher) could possibly erode even very old, well-consolidated and highlycontaminated sediments. The suspended matter of the high discharge events investigated (return periods of 15 to 20 years) exerted significantly higher cytotoxicity and mutagenicity than a moderate flood with a 1-year return period. These findings support the conclusion that the observed ecotoxicological effects during major floods may at least in part be due to the in-stream erosion of highly contaminated bottom sediments.