Assessment of seasonal variability of biomarkers in three-spined stickleback (Gasterosteus aculeatus L.) from a low contaminated stream: implication for environmental biomonitoring

In this study, wild three-spined sticklebacks were sampled every six weeks, between April and October, in a low contaminated stream. For all fish, physiological indexes, such as condition factor, hepato-, gonado- and nephro-somatic index were calculated to determine fish condition and reproductive status. Moreover, a set of biomarkers including biotransformation enzymes, oxidative stress parameters, neurotoxicity and endocrine disruption markers was measured. The results allowed to determine biomarker variability due to fish gender or sampling season. For example, 7-ethoxyresorufin-O-deethylase activity, glutathione peroxidase as well as vitellogenin and spiggin exhibited strong gender differences. Conversely, lipoperoxidation and acethylcholinesterase activity were characterised by a lack of gender and seasonal variation, and can be considered as more robust parameters for a field application. The present work allowed to establish practical guideline for biomarker measurements in wild sticklebacks and to define a reference system which can be used to analyze variations in future monitoring studies.     

Importance of landscape heterogeneity to wood storks in Florida Everglades

Declines in populations of and reproductive success of wood storks and other wading birds have occurred in the Florida Everglades over the past several decades. These declines have been concurrent with major changes in the Everglades’ landscape characteristics. Among the plausible hypotheses that relate to landscape change are the following: (1) general loss of habitat; (2) heavy loss of specific habitat, namely, short-hydroperiod wetlands that provide high prey availability early in the breeding season; and (3) an increase in frequency of major drying out of the central slough areas, which can affect prey availability late in the breeding season. These three hypotheses were compared using an individual-based model of wood stork (Mycteria americana) reproduction. This model simulated the behavior and energetics of each individual wood stork in a breeding colony on 15-min time intervals. Changes in water depth and prey availability occurred on daily time steps. Simulation results showed a threshold response in reproductive success to reduction of wetland heterogeneity. Model comparisons in which (1) only short-hydroperiod wetlands were removed and (2) wetlands of both long and short hydroperiods were removed showed that, for the same loss of total area, the specific habitat removal caused a much greater reduction in wood stork reproduction, indicating hypothesis 2 may be a more likely explanation than hypothesis 1. Reduction of initial prey availability in the central slough areas (simulating frequent drying; hypothesis 3) reduced fledging success by an average of more than 90% in the model.     

Finger and hand protection on circular table and panel saws

Several hundred accidents involving the use of circular saws and resulting in injury, to hands or fingers occur each year in Germany.In the presented project, new approaches for the prevention of hand injuries and for the contactless detection of fingers are being investigated for comprehensive protection on circular saws. The basic principles can be applied to other machines with manual loading and/or unloading. This paper describes several principles to distinct human skin and wood and a safety guard that prevents touching the rotating blade. In a first approach a reliable protective device with functional diversity has been developed using a passive infrared sensor in combination with a capacitive field sensor. Second the distinction between skin and wood or other material is done by dedicated kind of spectral analysis in the near infrared region. With a kind of light curtain the intrusion into the dangerous zone near the blade can be prevented.The safety guard protects the operator’s hand within 50 ms. The forces of the protective system peak at no more than 120 N. We are presenting a complete strategy for such different tasks as cutting wedges, stopped cutting and hidden cutting, which have a very high odds ratio.     

New concepts in product use for sustainable consumption

The paper presents the main results of a recent study on sustainable use of products. It reveals that strategies of use intensification and useful life extension are environmentally beneficial. Moreover, analysis of household washing and winter sports illustrated that successful implementation of sustainable use patterns occurs as a shift of use regimes. Such regimes are the result of a complex interplay of supply and demand side factors, relationship among actors, technical trajectories, organisational structures etc. One decisive factor is the presence of strategic players, so called “change agents”. In addition, four user types have been identified in a representative survey (“ownership-oriented”, “open-minded”, “consumption-oriented”, “low interest”) to which use intensification and useful life extension can be targeted.     

Herbizide in der aquatischen umwelt

The relevance of artificial pond-systems for the ecotoxicological evaluation of pesticides is discussed. It is the primary advantage of such systems that effects and exposure of a chemical can be examined simultaneously. For the herbicide Metolachlor it was demonstrated that the ecotoxicological evaluation of the herbicid in artificial pond-systems leads to reality-nearer ecotoxicological limits in comparison to “single-species-rests”. Up to a concentration of 500 μg/L, the application of the herbicide had no effects on the physico-chemical parameters and biocoenoses examined, even though the test period was extended over 150 days, which can be regarded as chronic exposure for most of the organisms examined. The results presented indicate once again the importance of pond-studies for a realistic evaluation of pesticides.     

Trace elements in sediments,blue spotted tilapia Oreochromis leucostictus (Trewavas, 1933) and its parasite Contracaecum multipapillatum from Lake Naivasha,Kenya, including a comprehensive health risk analysis

This study presents the distribution of 15 major and trace elements in sediments and fish and their pericardial parasites from Lake Naivasha, Kenya. The lake is one of the few freshwater lakes in the Great Rift Valley and is under strong anthropogenic pressure mainly due to agricultural activities. Its fish provide a valuable protein source for approximately 100,000 people in the area. Fish and their parasites have been acknowledged as indicators of environmental quality due to their accumulation potential for both essential and nonessential trace elements. A total of 34 specimens of the blue spotted tilapia Oreochromis leucostictus and pooled samples of their pericardial parasite, the anisakid nematode Contracaecum multipapillatum (larvae 3), were examined. Element concentrations were determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES) and graphite furnace atomic absorption spectrometry (GF-AAS). The concentrations of elements in the sediments reflected the geology of the area and did not point to pollution: none of the investigated trace elements, including Pb, Cd, Cu, and Zn, showed elevated values. In contrast, concentrations in the fish muscle were elevated for Li, Sr, Cd, and Zn, with high target hazard quotients (THQ?>?0.1) indicating a potential health risk to the consumers of this fish. Fish liver showed significantly higher concentrations of the trace elements Fe, Mn, Cd, and Cu compared to the muscle and C. multipapillatum. In the parasite, Zn had the highest concentration, but the worms only minimally accumulated trace elements in relation to their fish host.