<Emphasis Type="Italic">Lyngbya majuscula</Emphasis> blooms and the diet of small subtropical benthivorous fishes

Increasing concerns about the ecological impacts of ongoing and possibly worsening blooms of the toxic, carcinogenic cyanobacteria Lyngbya majuscula in Moreton Bay, Australia, led us to assess differences in meiofaunal prey assemblages between bloom and non-bloom substrates and the potential dietary impacts of dense L. majuscula blooms on the omnivorous benthivore, the Eastern Long-finned Goby, Favonigobius lentiginosus and the obligate meiobenthivorous juveniles of Trumpeter Whiting, Sillago maculata. Marked differences in invertebrate communities were found between sandy and L. majuscula bloom foraging substrates, with copepods significantly more abundant (18.49% vs. 70.44% numerical abundance) and nematodes significantly less abundant (55.91% vs. 1.21% numerical abundance) within bloom material. Gut analyses showed that bentho-planktivorous fishes exposed to L. majuscula in captivity had consumed a significantly greater quantity of prey by both total number (P < 0.0019) and volume (P < 0.0006) than fish exposed to sand treatments. Thus, it is likely for such fishes that L. majuscula blooms increase rates of prey encounter and consumption, with consequent changes in trophic relationships through shifts in predator–prey interactions between small benthivorous fishes and their meiofaunal prey.     

Nest desertion is not predicted by cuckoldry in the Eurasian penduline tit

Engagement in extra-pair copulations is an example of the abundant conflicting interests between males and females over reproduction. Potential benefits for females and the risk of cuckoldry for males are expected to have important implications on the evolution of parental care. However, whether parents adjust parental care in response to parentage remains unclear. In Eurasian penduline tits Remiz pendulinus, which are small polygamous songbirds, parental care is carried out either by the male or by the female. In addition, one third of clutches is deserted by both male and female. Desertion takes place during the egg-laying phase. Using genotypes of nine microsatellite loci of 443 offspring and 211 adults, we test whether extra-pair paternity predicts parental care. We expect males to be more likely to desert cuckolded broods, whereas we expect females, if they obtain benefits from having multiple sires, to be more likely to care for broods with multiple paternity. Our results suggest that parental care is not adjusted to parentage on an ecological timescale. Furthermore, we found that male attractiveness does not predict cuckoldry, and we found no evidence for indirect benefits for females (i.e., increased growth rates or heterozygosity of extra-pair offspring). We argue that male Eurasian penduline tits may not be able to assess the risk of cuckoldry; thus, a direct association with parental care is unlikely to evolve. However, timing of desertion (i.e., when to desert during the egg-laying phase) may be influenced by the risk of cuckoldry. Future work applying extensive gene sequencing and quantitative genetics is likely to further our understanding of how selection may influence the association between parentage and parental care.     

A fast and accurate method for specific detection and quantification of the bloom-forming microalgae Karlodinium veneficum in the marine environment

Environmental Science and Pollution Research - Karlodinium veneficum is a toxic benthic globally distributed dinoflagellate which has direct impacts on human health and the environment. Early and...     

Monitoring and Post-auditing in Environmental Impact Assessment: A Review

Environmental impact assessment (EIA) is a procedure for predicting environmental impacts of projects prior to their development, while post-auditing seeks to assess the accuracy of such predictions. A literature review examines the need for post-auditing, highlighting several benefits to EIA performance that could arise if the results were effectively used. This reveals that, in practice, post-auditing activities are not widespread, and suggests reasons why this is so. An overview of post-audit findings from a survey of published studies is then presented, and it is concluded that there is much scope for raising the profile of post-auditing in EIA world-wide. Preliminary results from a recent UK post-auditing study based on eight projects are described. Information on impact predictions was gathered and compared with actual impacts. A total of 366 impact predictions were made of which 78% were qualitative in nature; 57% of the predictions were auditable and of these nearly three-quarters were accurate. Reasons for inauditability were ascertained including, for all cases, a lack of data or unsuitable information.     

A comparative study on metal sorption by brown seaweed

This study compared the sorption of Ag, Cd, Co, Cd, Mn, Ni, Pb and Zn by a Ca-treated Sargassum biomass at pH 5.0, under low and high ionic strength (IS) conditions. The sorption isotherms of As [As(V)] and Cr [Cr(III) and Cr(VI)] were also determined at low IS. The isotherm data for the eight cationic metals and Cr(III) were well fitted by Langmuir equations. Generally, the maximum metal uptake (Umax) followed: Cr(III) > Pb approximately Cu > Ag approximately Zn approximately Cd > Ni approximately Mn approximately Co > Cr(VI) > As(V) at low IS and Pb > Cu > Co > Mn approximately Cd > Zn approximately Ag > Ni at high IS. As(V) did not bind to the seaweed at pH 5.0. The results indicated that sorption of Pb was not affected by the increasing IS, though the percentage of free Pb ions in the water was greatly reduced as predicted by the speciation model. High IS lowered Umax by 10-36% (except Co and Pb), and lowered the affinity constant of the metal by 33-91% for all cationic metals, as compared to low IS. Moreover, the removal efficiency of the cationic metals and Cr decreased exponentially with initial metal concentrations and was lower at high IS. Ion-exchange was the mechanism responsible for the cationic metal sorption onto the seaweed, and Na ion interfered with the cationic metal binding through electrostatic interaction. In conclusion, this study showed the differential binding capacity of the Sargassm biomass for different metals and oxidation states and the differential effects of IS. According to the present results, Sargassum may be considered a good biosorbent for cationic metals (especially Pb) in both low and high-salt containing wastewater.     

Size dependent cytotoxicity of fly ash particles

Fly ash samples were collected from the electrostatic precipitator of a coal-fired power plant in Hong Kong. The particles of the respirable range (smaller than 10 μm) were divided into 4 groups according to their particle size (mass median aerodynamic diameters). The surface morphology and the metal contents (Fe, Mn, Al and Zn) of fly ash particles were examined by a scanning electron microscope and an inductively coupled plasma spectrophotometer, respectively. The particles were very heterogenous in size and shape as well as the concentration of metals. The cytotoxicity of these four groups of fly ash particles was evaluated using an in vitro rat alveolar macrophages culture assay. The viability of alveolar macrophages was lower when incubated with smaller size particles. This relationship was also reflected by the damage of the surface morphology of the cells and the release of cytoplasmic (lactate dehydrogenase) and lysosomal (acid phosphatase and β-glucuronidase) marker enzymes into the culture media.     

污泥接种策略与联氨促进垃圾渗滤液厌氧氨氧化工艺快速启动及其运行效果

针对厌氧氨氧化工艺启动速度慢及在垃圾渗滤液中脱氮效率低的问题,探究了厌氧氨氧化工艺在处理高氨氮、低C/N比垃圾渗滤液中的快速启动及稳定运行策略。结果表明,厌氧氨氧化工艺接种反硝化污泥:anammox颗粒污泥=9:1的启动效果最佳,100 d时TN去除率可达75.1%。但由于垃圾渗滤液中COD较高,异养反硝化菌生长迅速且严重影响厌氧氨氧化菌活性。通过投加6 mg·L⁻¹的N₂H₄之后,异养反硝化菌活性受到抑制,反应器内厌氧氨氧菌占据主导地位,Candidatus Kuenenia菌相对丰度由0.2%提升到10.6%,TN去除率及氮去除速率分别达90.6%和0.143 kg·(kg·d)⁻¹以上。在厌氧氨氧化工艺中投加适量N₂H₄可实现垃圾渗滤液的稳定高效自养脱氮。     

Tower crane safety in the construction industry: A Hong Kong study

Tower cranes are extensively used for lifting materials in construction sites. Most construction sites are very confined and close to public. Tower crane accidents not only hazard workers in construction sites, but also pedestrians. This paper investigates tower crane safety in related to the understanding and degree of executing statutory requirements and non-statutory guidelines for the use of tower cranes in the Hong Kong construction industry. A questionnaire survey and structured interviews are conducted. It is found that human factors are attributed to tower crane safety. Indolent performance of requirements or responsibilities of practitioners in tower crane operations is found. Inadequate training and fatigue of practitioners are one of the main reasons causing unsafe practices of tower crane operations. Recommendations for improving safety performance in tower crane operations are also discussed.