Triclosan,a commonly used bactericide found in human milk and in the aquatic environment in Sweden

High levels of the commonly used, effective bactericide Triclosan was found in three out of five randomly selected human milk samples. It was also found in the bile of fish exposed to municipal wastewater and in wild living fish from the receiving waters of the three wastewater treatment plants.     

Determination of nitrate and other water quality parameters in groundwater from UV/Vis spectra employing partial least squares regression

The use of UV/Vis spectroscopy in combination with partial least squares (PLS) regression for the simultaneous prediction of nitrate and non-purgeable organic carbon (NPOC) in groundwaters was evaluated. A model of high quality was obtained using first order derivative spectra in the range 200-300 nm. Inclusion of non-UV-absorbing constituents in the modeling procedure, i.e., chloride, sulfate, fluoride, total carbon (TC), inorganic carbon (IC), alkalinity, pH and conductivity was also evaluated. This model seemed to be useful for prediction of chloride, TC, IC, alkalinity and conductivity, while its ability to predict sulfate, fluoride and pH was poor. In conclusion, application of PLS regression, which requires neither filtration of samples nor addition of chemicals, is a promising alternative for fast interpretation of geochemical patterns of groundwater quality.     

Toxicity and detoxification of Swedish detergents and softener products

Detergents and softeners are used in large quantities and some of their ingredients are highly toxic to aquatic organisms. In the present study the acute toxicity to Daphnia magna was determined for 26 detergents and five softener Swedish products. Only one of the detergents had a 48-h EC50 > 100 mg/l. The 48-h EC50 for the other 25 detergents ranged from 4 to 85 mg/l. The 48-h EC50 for the five softeners ranged from 15 to 166 mg/l. Detoxification tests, with and without inoculum of sewage organisms, showed that all tested products were detoxified to some extent after 16 days and that the rate of detoxification was considerably higher with addition of sewage organisms. Toxicity to D. magna of the detergents and softeners, and the biotic detoxification rate was correlated with the concentration of surfactants used in formulating the products (more surfactants increased toxicity and a slower rate of detoxification). These results emphasize the importance of biological purification of domestic wastewater containing detergents and a suggested development of less toxic and more easily degradable surfactants.     

Root establishment of perennial ryegrass (L. perenne) in diesel contaminated subsurface soil layers

The efficiency of rhizosphere biodegradation of petroleum hydrocarbons heterogeneously distributed in soils is dependent on the ability of plant roots to prospect into contaminated zones. Rhizobox experiments were conducted to study the influence of diesel contaminated layers on the spatial distribution and the development of the roots of perennial ryegrass. Root distribution and root and shoot development were monitored over time. The final root and above ground biomass and the final TPH concentration were determined. The spatial distribution of the contaminant as well as the irrigation method used affected root distribution, plant development and TPH degradation and therefore ryegrass remediation potential. The results show that roots colonise fully uncontaminated soil and grow preferentially between zones of contamination. Conversely, when no immediate uncontaminated soil is available, roots grow through contaminated zones in order to prospect for uncontaminated soil.     

Book review

Environmental Management, (3 Volumes) Editors B. Nath, L. Hens and D. Devuyst (Brussels, Vubpress: 1993. Approx. 890 Pp. Paperback) (£25 Per Volume) Isbn 90 5487 035 4-6

The Chemistry and Deposition of Nitrogen Species in the Troposphere, Editor A. T. Cocks, Publisher Royal Society of Chemistry, 1993, X + 134pp., Isbn 0 85186 355 8, Price £35.00.     

Possibility to implement invasive species control in Swedish forests

Invasive alien species constitute an increasing risk to forestry, as indeed to natural systems in general. This study reviews the legislative framework governing invasive species in the EU and Sweden, drawing upon both a legal analysis and interviews with main national level agencies responsible for implementing this framework. The study concludes that EU and Sweden are limited in how well they can act on invasive species, in particular because of the weak interpretation of the precautionary principle in the World Trade Organisation and Sanitary and Phytosanitary agreements. In the Swedish case, this interpretation also conflicts with the stronger interpretation of the precautionary principle under the Swedish Environmental Code, which could in itself provide for stronger possibilities to act on invasive species.     

Land sharing complements land sparing in the conservation of disturbance-dependent species

Alteration of natural disturbances in human-modified landscapes has resulted in many disturbance-dependent species becoming rare. Conservation of such species requires efforts to maintain or recreate disturbance regimes. We compared benefits of confining efforts to habitats in protected areas (a form of land sparing) versus integrating them with general management of production land (a form of land sharing), using two examples: fire in forests and grazing in semi-natural grasslands. We reviewed empirical studies from the temperate northern hemisphere assessing effects of disturbances in protected and non-protected areas, and compiled information from organisations governing and implementing disturbances in Sweden. We found advantages with protection of areas related to temporal continuity and quality of disturbances, but the spatial extent of disturbances is higher on production land. This suggests that an approach where land sparing is complemented with land sharing will be most effective for preservation of disturbance-dependent species in forests and semi-natural grasslands.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-022-01820-1.     

Quantifying male attractiveness and mating behaviour through phenotypic size manipulation in the Trinidadian guppy, Poecilia reticulata

Although many studies have examined the effects of male size on attractiveness and mating behaviour, few have taken genetic background into consideration. Phenotypic manipulation permits the experimental adjustment of morphological traits while keeping genetic background constant. Here, male guppies, Poecilia reticulata, an ideal model for this type of manipulation, were raised at different temperatures to produce sibling pairs that differed in size. These were then used to investigate male mating behaviour and male attractiveness, assessed through female mate choice, in relation to this size dimorphism. Further, male–male competition, which is intrinsic to male mating behaviour, is also likely to be affected by their size. Through the use of repeated measures analyses we demonstrate that females significantly prefer larger males and male size and competition significantly affect several aspects of male mating behaviour. Larger siblings perform more sneaky mating attempts and spend more time chasing females. The frequencies of both these behaviours increase with competition. While display frequency is unaffected by male size and competition, display duration and the amount of time spent attending females are reduced in the presence of competitors. This study highlights the use of phenotypic manipulation as a valuable tool for investigating behavioural interactions and confirms that both male size and competition are significant factors in the guppy mating system.