The effect of turbation on zinc relocation in a vertical floodplain soil profile

Turbation is hypothesized to affect the redistribution of heavy metals in polluted floodplain soils by effects on mobility. This hypothesis was tested in microcosms by turbation of zinc-spiked sediment top layers. Manual turbation caused a fast decrease of the zinc content in the upper 15 cm of the soil, even though turbation was only applied to the upper two centimetres. It was especially zinc attached to colloid and organic matter particles that was redistributed from the top layer. Percolation processes resulted in the attached zinc being drained to depths of more than 15 cm. The decrease in zinc content of the topsoil was even stronger in combination with inundation. No indications were found for the redistribution of zinc as a result of an increase of the extractability with 0.01 M CaCl2 or changes in pH. The findings suggest that mechanical turbation and bioturbation may redistribute heavy metals from topsoils in polluted floodplains just after inundation as observed in these turbation experiments.     

Data search and environmental hazard assessment for post-seveso chemicals

After the serious accident with a chemical industrial plant at Seveso (Italy) in 1976, the Commission of the European Communities has made a directive on major accidents, usually called the Post-Seveso Guideline. In its annex III, a list of 178 substances is given for which potentially dangerous volumes in case of an accident are defined on the basis of human health criteria. For the implementation of environmental criteria, information on toxicity to aquatic organisms, dilution, and physical behavior in water is needed. A literature search for relevant data on these 178 substances revealed aquatic toxicity data for 116 substances, but only for 87 substances sufficient data were available to make a hazard assessment. As an example, the River Rhine was used to calculate the critical quantities that, after a sudden discharge in the Swiss part, could cause damage at the Dutch part some 800 km downstream. In the absence of a common opinion on the criteria for being a major accident and a serious environmental hazard, the impact of different criteria quantities is discussed. If, for example, in the whole River Rhine a mortality of 5% of the aquatic species is chosen as the criterion for damage to the ecosystem, the critical quantities as mentioned in the EEC directive have to be lowered drastically for the majority of the substances. For 18 substances it could be shown that release of the mentioned quantities would be catastrophic for aquatic life in the whole river.     

Responses of wintering humpback whales (Megaptera novaeangliae) to playback of recordings of winter and summer vocalizations and of synthetic sound

Summary Three natural sounds and one synthetic sound were played back to humpback whales during their 1985 and 1986 winter residency in Hawaiian waters. Playback was conducted from a vessel positioned within visual range of an elevated shorestation equipped with a high-precision surveyor's theodolite, used to determine the positions and movements of observed whale and of the playback vessel. A playback session consisted of 20 min of pretest observation with the vessel in place and underwater speaker deployed, followed by a 20-min test phase during which sound, or a blank tape control, was introduced. A total of 143 playback sessions, involving a total of 338 pods (a single whale or a group of whales), were completed over the two winter seasons. The major response observed during playback was a rapid approach to the playback vessel, characterized in some cases by velocities up to 9 km/h and approaches to within 50 m or less. Whales approaching were mainly singletons and, secondly, apparent adult pairs. No cow-calf pair ever approached. The approach was selective: 21.6% of targeted pods approached in response to a feeding sound recorded in summer feeding grounds in Alaska; 8.3% approached in response to social sounds recorded in the Hawaiian winter grounds in the presence of large surface-active pods; 3.4% responded to playback of winter song; and 4.1% responded to playback of synthetic sound. There were no approach responses to the blank tape control. Singing whales have been identified as males by many researchers. Data from Alaska suggested that the feeding sound was produced by a female; data from Hawaii suggests that the social sounds were produced by males. The different rates of response were attributed to the behavior of sexually active males seeking to affiliate with sexually mature females. Although a female may be present in pods producing social sounds, the presence of multiple males exhibiting aggression may inhibit the approach of other males. Song did not serve as an attractant for females, as measured by direct approach, but may still serve as a basis for female choice.     

(<Emphasis Type="Italic">Z,Z</Emphasis>)-11,13-Hexadecadienyl acetate and (<Emphasis Type="Italic">Z,E</Emphasis>)-11,13,15-hexadecatrienyl acetate: synergistic sex pheromone components of oak processionary moth,Thaumetopoea processionea (Lepidoptera: Thaumetopoeidae)

Summary. Our objective was to identify sex pheromone components of the oak processionary moth, Thaumetopoea processionea (Lepidoptera: Thaumetopoeidae), whose larvae defoliate oak, Quercus spp., forests in Eurasia and impact human health. Coupled gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric (MS) analyses of pheromone gland extract of female T. processionea revealed two consistently EAD-active compounds. They were identified as (Z,Z)-11,13-hexadecadienyl acetate (Z11,Z13-16:OAc) and (Z,E)-11,13,15-hexadecatrienyl acetate (Z11,E13,15-16:OAc) by comparative GC, GC-MS and GC-EAD analyses of insect-produced compounds and authentic standards. In replicated field experiments (2000, 2001) in Nordbaden, Südbaden and Sachsen-Anhalt (Germany), Z11,Z13-16:OAc and Z11,E13,15-16:OAc in combination, but not singly, attracted significant numbers of male moths. It will now be intriguing to investigate whether Z11,E13,15-16:OAc, or its corresponding alcohol or aldehyde, serves as a pheromone component also in other species of the Thaumetopoeidae.     

Evaluation of pollution-related stress factors for forest ecosystems in central Europe

Since the early eighties air pollution by SO2 and Pb and, to a lesser degree by NOx and NH3, have been significantly reduced in Europe. This was done in part for the protection of forest ecosystems. The reductions are reflected in the pollutant impacts and inputs and have been verified through the bioindicator Norway spruce. In contrast, ozone concentrations increased at most of the evaluated measuring locations and trends were calculated based on the results of about 100 stations in Austria and Germany. Despite reduced emissions, large parts of the forest ecosystems are still affected by air-pollution impacts. Negative effects can be assessed using different legal standards and Critical Levels and Critical Loads, respectively: The legal standard for the evaluation of SO2 impact, as used in Austria, is well suited. The provisional European Critical Level for ozone, the AOT40 must, in order to be a meaningful criterion for field applications, be further refined. Continuing the Critical Load concept, the spatial risk of acid depositions in areas of high geomorphic variability were evaluated using the new parameter of 'critical soil depth'. With the help of the newly defined 'lead accumulation index', the accumulation of Pb from air pollution could be evaluated. Air-pollution inputs and the spatial acidification risk is directly related to altitude. Up to altitudes of 1000 m and 1100 m, SO2 impact and acid depositions, respectively were indicated and elevated ozone doses and Pb inputs were observed in the sensitive sub-alpine areas. These results underline the necessity for increased protection of mountain forest ecosystems, among others through a further reduction of emissions or forest-related strategies.     

Marine ecosystem appropriation in the Indo-Pacific: a case study of the live reef fish food trade

Our ecological footprint analyses of coral reef fish fisheries and, in particular, the live reef fish food trade (FT), indicate many countries' current consumption exceeds estimated sustainable per capita global, regional and local coral reef production levels. Hong Kong appropriates 25% of SE Asia's annual reef fish production of 135 260-286 560 tonnes (t) through its FT demand, exceeding regional biocapacity by 8.3 times; reef fish fisheries demand out-paces sustainable production in the Indo-Pacific and SE Asia by 2.5 and 6 times. In contrast, most Pacific islands live within their own reef fisheries means with local demand at < 20% of total capacity in Oceania. The FT annually requisitions up to 40% of SE Asia's estimated reef fish and virtually all of its estimated grouper yields. Our results underscore the unsustainable nature of the FT and the urgent need for regional management and conservation of coral reef fisheries in the Indo-Pacific.