Policy and practice reviews

Environmental planners and managers may want to do their work without political interference, using rational and objective knowledge only. They may also want to serve the common good, be accountable and encourage public participation. This paper explores the tensions between the two approaches and argues that a great deal of politics goes into the very definition and selection of what is considered rational and objective. Too often policy‐makers claim to rely exclusively on objective scientific or economic knowledge, while ignoring other forms of knowledge which may be as essential for the solution or management of the problem. Difficult choices have to be made, and it may well be the political scientist, sociologist or psychologist who can help. Expertise has its own interest in the policy process—it is mainly concerned with perpetuating itself and the search for more knowledge. To be effective as well as rational, environmental managers need to be aware of a broad range of useful knowledge, as well as suspicious of claims that promise too much. They need to be in open communication with society, and this may well require institutional reform.     

Effects of the insect growth regulator Dimilin® (TH 6040) on larval development of two estuarine crabs

Effects of Dimilin^® (TH 6040), an insect growth regulator which interferes with the formation of the insect cuticle, were studied on the larval development of Rhithropanopeus harrisii (Gould) and Sesarma reticulatum (Say) (Crustacea: Brachyura). When larvae were exposed to 0.5 (R. harrisii only), 1, 3, 5, 7, and 10 ppb Dimilin from hatching to the first crab stage, survival in both species decreased in relation to increased concentrations of Dimilin. Survival of R. harrisii larvae wa significantly lower at 1 ppb and higher levels compared with control experiments, and in S. reticulatum a significant decrease in survival began at the 3 ppb level. At 10 ppb Dimilin, no larvae survived to the megalopa stage in either of the two species. The results indicate that early stage larvae of R. harrisii are more sensitive to Dimilin than those of S. reticulatum. When R. harrisii larvae were treated with 10 ppb Dimilin during the intermolt period of each of the 4 zoeal stages, nearly all larvae died during molting to the succeeding stage. First zoeal larvae of R. harrisii exposed to 10 ppb Dimilin at various days during the intermolt period were more sensitive to the compound late than early in the period. It is suggested that Dimilin also may interfere with the formation of the cuticle in crab larvae.     

Political influence compatibility: fitting the person to the climate

This study investigated a person–climate fit model in order to explain the effect of organizational politics on work attitudes. A unique index of compatibility was developed based on the congruence between preferences for political influence processes and those processes perceived to be prevalent in the employment context. A survey of 138 non academic employees of a large public university, representing a variety of jobs, demonstrated that political influence compatibility was clearly related to a wide range of work attitudes (e.g. satisfaction with co-workers, trust in management, evaluation of self). Directions for future research investigating PIC and potential applications of political influence compatibility in human resource management are discussed. © 1997 John Wiley & Sons, Ltd.     

Bite forces and evolutionary adaptations to feeding ecology in carnivores

The Carnivora spans the largest ecological and body size diversity of any mammalian order, making it an ideal basis for studies of evolutionary ecology and functional morphology. For animals with different feeding ecologies, it may be expected that bite force represents an important evolutionary adaptation, but studies have been constrained by a lack of bite force data. In this study we present predictions of bite forces for 151 species of extant carnivores, comprising representatives from all eight families and the entire size and ecological spectrum within the order. We show that, when normalized for body size, bite forces differ significantly between the various feeding categories. At opposing extremes and independent of genealogy, consumers of tough fibrous plant material and carnivores preying on large prey both have high bite forces for their size, while bite force adjusted for body mass is low among specialized insectivores. Omnivores and carnivores preying on small prey have more moderate bite forces for their size. These findings indicate that differences in bite force represent important adaptations to and indicators of differing feeding ecologies throughout carnivoran evolution. Our results suggest that the incorporation of bite force data may assist in the construction of more robust evolutionary and palaeontological analyses of feeding ecology.     

The pH-dependent adsorption of tributyltin to charcoals and soot

Widespread use of tributyltin (TBT) poses a serious environmental problem. Adsorption by black carbon (BC) may strongly affect its behavior. The adsorption of TBT to well characterized soot and two charcoals with specific surface area in the range of 62-111 m² g⁻¹ have been investigated with main focus on pH effects. The charcoals but not soot possess acidic functional groups. TBT adsorption reaches maximum at pH 6-7 for charcoals, and at pH > 6 for soot. Soot has between 1.5 and 15 times higher adsorption density (0.09-1.77 μmol m⁻²) than charcoals, but charcoals show up to 17 times higher sorption affinities than soot. TBT adsorption is successfully described by a new pH-dependent dual Langmuir model considering electrostatic and hydrophobic adsorption, and pH effects on TBT speciation and BC surface charge. It is inferred that strong sorption of the TBTOH species to BC may affect TBT toxicity.     

Decreasing ice coverage will reduce the breeding success of Baltic grey seal (Halichoerus grypus) females

Baltic grey seals (Halichoerus grypus) alternate between land and ice breeding, depending on ice conditions. We show that the fitness of grey seal females in terms of pup mortality and quality is reduced when breeding on land as compared with ice. The mean preweaning mortality rate on land was 21.1% (range 0% to 31.6%), and correlated with birth density (range 0.5-5.2 pups 100 m(-2)). The mean mortality rate on ice was 1.5%, where the highest density was 0.2 pups 100 m(-2) in particularly dense breeding groups. Mean weights of pups born on ice were significantly greater (48.3 +/- 8.1 kg) at the onset of moult as compared with pups born on land (37.4 +/- 7.8 kg). Because indices of life-time net reproductive rate (pup survival) and pup quality (weaning weight and health) were more auspicious on ice as compared with land, diminishing ice fields will lower the fitness of Baltic grey seal females and substantially increase the risk for quasi-extinction.     

Identification of tetramethylarsonium in rice grains with elevated arsenic content

Tetramethylarsonium has for the first time been identified in a commercially grown food product, rice, constituting up to 5.8% of the total arsenic in the rice.     

Digit ratios have poor indicator value in a wild bird population

Early androgen exposure is known to have long-lasting effects on phenotype, behaviour and even fitness, but difficulties in measuring the exposure hinders the study of its importance in evolutionary context. Digit ratios have been highlighted as a potential easy-to-measure indicator of early steroid exposure, as they have been suggested to reflect steroid, mainly testosterone levels during prenatal development. However, evidence for digit ratios reflecting early steroid levels is weak, as experimental studies, especially in wild populations, are scarce. We studied the association between maternally derived yolk androgens and digit ratios (2D:4D, 2D:3D and 3D:4D) using both correlative data and a rather high level of experimental elevation of yolk androgens in a passerine bird, the pied flycatcher (Ficedula hypoleuca). We also examined whether digit ratios have indicator value in an evolutionary context by studying correlations between digit ratios and reproductive traits, secondary sexual traits and exploratory behaviour. We did not find any association between digit ratios and yolk androgen level either in correlative or experimental data. Digit ratios were neither related to any of the reproductive and secondary sexual traits or exploratory behaviour measured. There was, however, a sex difference in 2D:3D and 3D:4D of adult birds (due to second and fourth digits being shorter in females), which was not apparent in fledglings or captivity-raised juveniles. This suggests that either the sex difference may develop as late as during the sexual maturation for breeding. These results indicate that, in this species, digit ratios are not reliable markers of maternally derived yolk androgen exposure and that they bear little relevance as correlates of the adaptive traits we measured.     

Aufnahme von Cyanid in Pflanzen

Cyanides are waste products from the pyrolysis of coal and are frequent soil pollutants in cities nowadays. Prussic acid (HCN) is a fast acting, highly toxic poison, but iron-complexed cyanides in soil are far less toxic. The phytotoxicity of free CN to basket willows (Salix viminalis) was determined with the tree transpiration test. The EC₁₀ for t=72 h is 0.76 mg KCN (0.3 mg CN) per liter, the EC₅₀ is 4.47 mg/l. 5 mg/l KCN are ultimately lethal. Balsam poplars (Populus trichocarpa) can survive concentrations of up to 2500 mg/l ferroferricyanide (Prussian blue), although with reduced growth. Willows survived in gas work soils with up to 452 mg/kg total CN. More CN was taken up from nutrient solution than from the soil. Complexed cyanide is probably translocated into the leaves as well. Free CN was readily eliminated from Erlenmeyers with plants growing in nutrient solution. Planting appropriate vegetation might be a suitable solution for many former gas work and mining sites.