Intensive fishing of marine consumers causes a dramatic shift in the benthic habitat on temperate rocky reefs

Intensive fishing can cause dramatic, long-lasting shifts in benthic habitat. This study used three approaches to test whether overharvesting of blacklip abalone (Haliotis rubra) can cause a shift in benthic habitat to a configuration that is unsuitable for abalone, on the east coast of Tasmania, Australia. After 18 months of removing abalone from rocks, encrusting red algae (ERA) became overgrown by filamentous and foliose algae, sessile invertebrates and accumulated sediment. The differences in the community composition between locations, sites nested within locations and rocks were minor. Throughout the study, abalone were largely associated with areas of rock covered in ERA but avoided other habitats. A transplant experiment demonstrated that abalone preferred areas of rock covered in ERA but move away from overgrown rocks. These results suggest overharvesting of abalone results in a shift to benthic habitat poorly preferred by abalone. This could form a positive feedback loop that limits recovery of abalone populations and ERA.     

Lipid composition and partitioning of deepwater chondrichthyans: inferences of feeding ecology and distribution

The composition of lipids and fatty acids was determined for the livers, muscle, pancreas, kidney and stomach fluids of deepwater chondrichthyan species (including 11 squaliformes, 3 chimaeriformes, 1 hexanchiforme and 3 carcharhiniformes) caught as bycatch from continental waters off south-eastern Australia. The lipid class, fatty acid and fatty alcohol composition differed markedly in each tissue and in each species. The lipid and fatty acid composition of large, lipid-rich (38–70% wet weight, ww) livers demonstrated the multifunctional role of this organ in: lipid distribution, storage and biosynthesis, and buoyancy regulation. In the liver, the importance of certain lipids (including squalene, diacylglyceryl ethers, triacylglycerols and to a lesser extent wax esters) as mediators of buoyancy varied according to lifestyle and habitat. Less variability was observed in the muscle profiles, characterized by low lipid content (<1.0% ww) and high relative levels of polar lipids (>70%). The lipid and fatty acid profiles of the kidney and pancreas showed the highest intraspecific variability, suggesting these organs also have complex roles in lipid storage and metabolism. Overall intra- and interspecific differences in the tissue fatty acid profiles could be related to differences in a number of factors including phylogeny, habitat (depth), buoyancy regulation and diet and presumably also reflect different ecological roles. The lipid and fatty acid profiles are the first published for Rhinochimaera pacifica, Chimaera lignaria and Figaro boardmani and the first to demonstrate interspecific variation in lipid profiles of various tissues of deepwater chondrichthyans. The application of multivariate analysis to lipid class and fatty acid tissue profiles in chondrichthyans inferred dietary differences and metabolic preferences between species and habitats. These results have important implications for the future use of fatty acids as dietary tracers in chondrichthyan research.     

三峡库区香溪河库湾土壤多环芳烃时空分布特征及风险评价

为了全面评价三峡库区土壤多环芳烃（polycyclic aromatic hydrocarbons,PAHs）环境行为,以香溪河库湾不同淹没类型土壤［消落带上缘（>175 m）、消落带（145~175 m）和沉积物（<145 m）］为研究对象,通过高效液相色谱检测方法,分析3个区域土壤16种美国环保署优先控制的PAHs含量.结果表明,香溪河库湾土壤PAHs总量表现为消落带上缘>消落带>沉积物,沉积物PAHs以3环和4环为主,而消落带及其上缘土壤PAHs以4环和5环为主,其中消落带土壤PAHs变异系数相对最高,与其它两个区域PAHs组成之间的相关性相对较弱.各区域土壤PAHs分布呈现季节差异,夏季和冬季土壤PAHs含量相对较高,主要与库区各季节居民能源消费类型有关;空间分布特征表现为,沉积物PAHs空间分布整体较为均匀,而消落带及其上缘土壤PAHs在峡口镇和长江入江口处PAHs含量相对较高,主要与空间水平上各样点频繁的人类活动有关.PAHs异构体比值法分析表明,香溪河库湾各区域土壤PAHs来源具有季节性差异,化石燃料和生物质的不完全燃烧是消落带土壤PAHs的主要来源;终身致癌风险评价模型分析表明,土壤PAHs通过误食和皮肤接触暴露途径对人体健康产生潜在致癌风险,并且消落带上缘土壤PAHs致癌风险相对较大.研究结果扩展了对香溪河库湾土壤PAHs环境行为的认识,为三峡库区香溪河库湾土壤PAHs污染防治提供有益参考.     

Temporal scales and patterns of invertebrate biodiversity dynamics in boreal lakes recovering from acidification

Despite international policy implementation to reduce atmospheric acid deposition and restore natural resources from cultural acidification, evidence of ecological recovery is equivocal. Failure to meet recovery goals means that acidification still threatens biodiversity in many areas of the world. Managers thus need information to manage biodiversity, especially its components that are sensitive to stress (acid-sensitive taxa). We analyzed 20-year time series (1988-2007) of water quality and littoral invertebrates in acidified and circum-neutral lakes across Sweden to evaluate regional biodiversity dynamics and the extent to which changes in water quality affect these dynamics. We used multivariate time series modeling to (1) test how individual species groups within invertebrate communities track changes in the abiotic environment and (2) reveal congruencies of taxon contributions to species group change across lakes. Chemical recovery in the lakes was equivocal, and increases of pH and alkalinity were observed in subsets of acidified and circum-neutral lakes. Time series analyses revealed two different patterns of species groups for invertebrate communities across lakes; the first species group showed monotonic change over time, while the second group showed fluctuating temporal patterns. These independent species groups correlated distinctly with different sets of environmental variables. Recovery of pH and alkalinity status was associated with species group patterns only in a few lakes, highlighting an overall weak recovery of invertebrate species. The sets of species, including acid-sensitive taxa, composing these species groups differed markedly across lakes, highlighting context-specific responses of invertebrates to environmental variation. These results are encouraging because disparate local-scale dynamics maintain the diversity of sensitive invertebrate species on a regional scale, despite persisting acidification problems. Our study can inform and help refine current acidification-related policy focused on sensitive biodiversity elements.     

Sea lamprey orient toward a source of a synthesized pheromone using odor-conditioned rheotaxis

Characterization of vertebrate chemo-orientation strategies over long distances is difficult because it is often not feasible to conduct highly controlled hypothesis-based experiments in natural environments. To overcome the challenge, we couple in-stream behavioral observations of female sea lampreys (Petromyzon marinus) orienting to plumes of a synthesized mating pheromone, 7α,12α,24-trihydroxy-5α-cholan-3-one-24-sulfate (3kPZS), and engineering algorithms to systematically test chemo-orientation hypotheses. In-stream field observations and simulated movements of female sea lampreys according to control algorithms support that odor-conditioned rheotaxis is a component of the mechanism used to track plumes of 3kPZS over hundreds of meters in flowing water. Simulated movements of female sea lampreys do not support that rheotaxis or klinotaxis alone is sufficient to enable the movement patterns displayed by females in locating 3kPZS sources in the experimental stream. Odor-conditioned rheotaxis may not only be effective at small spatial scales as previous described in crustaceans, but may also be effectively used by fishes over hundreds of meters. These results may prove useful for developing management strategies for the control of invasive species that exploit the odor-conditioned tracking behavior and for developing biologically inspired navigation strategies for robotic fish.     

Implications of research on endocrine disruption for the environmental risk assessment, regulation and monitoring of chemicals in the European Union

We assess the implications which research on endocrine disrupting chemicals (EDCs) has for the regulation of synthetic substances and for the protection of the environment, particularly under the forthcoming European Union (EU) REACH legislation. EDCs present regulatory problems inter alia because they can act additively at concentrations which are individually harmless, and they may have non-classical dose (concentration)-response relationships at low exposure levels. Furthermore, current in vivo testing routines were not specifically designed to assess the endocrine disrupting properties of chemicals, whilst in silico and in vitro methods have only limited applicability and availability for this purpose. We need to ensure that the assessment approaches specified in the draft REACH legislation and Technical Guidance are able to evaluate EDCs efficiently. However, it must also be recognised that environmental monitoring procedures in Europe will need to be improved to detect EDCs that have evaded identification, and where appropriate, control, under REACH.     

Characterization of carbonaceous combustion residues. I. Morphological,elemental and spectroscopic features

Scanning electron microscopy, surface area determination, elemental analysis, organic matter extraction and solid-state cross polarization/magic angle spinning and Bloch decay/magic angle spinning 13C nuclear magnetic resonance (NMR) spectroscopy were used to investigate distinctive features among carbonaceous combustion residues. Black carbon (BC) samples included diesel soot, urban dust, carbon black, chimney soot, vegetation fire residues, wood and straw charcoals. Particles varied from small spheres (<50 nm) in fossil BC (>100 m(2)/g), to large layered structures in plant-derived BC (generally <8 m(2)/g). Chimney soot also included large (>1 micrometer) liquid-like structures, while spherules >100 nm were unique to urban dust. The ratios of amorphous to soot carbon (SC) (isolated by thermal degradation) were not necessarily correlated with the degree of aromaticity estimated from H/C ratios. In particular, values of SC in diesel soot were clearly overestimated. Solvent-extractable organic matter (SEOM) was <2% for charcoals and carbon black, but >13% for urban dust, chimney and diesel soot. SEOM is thought to clog pores or to form large waxy globules, hence reducing surface areas. The ratio of polar/nonpolar SEOM was generally <7 for fossil BC, but >30 for plant-derived BC. NMR analysis revealed essentially one chemical shift in the aromatic C region of charcoals, while diesel soot also showed important aliphatic contributions. Aliphatic and oxygenated C predominated over aryl C in urban dust and chimney soot. These morphological and chemical characteristics of the BC samples are discussed in terms of their environmental implications.     

Seasonal bioavailability of sediment-associated heavy metals along the Mississippi river floodplain.

A value of simultaneously extracted metal to acid-volatile sulfide (SEM-AVS) can provide important information regarding metal availability in anaerobic sediment. SEM and AVS concentrations were obtained by the cold-acid purge-and-trap technique during spring and summer at six locations along the Mississippi River floodplain. SEM-AVS values and AVS concentrations did not vary significantly between locations during both seasons. AVS concentrations were significantly greater during summer than spring, resulting in significantly lower SEM-AVS values in summer. Total SEM concentrations did not significantly vary between seasons or specific locations. SEM-AVS values were greater than one at each location during both seasons. Sediment metal toxicity was predicted to be absent for benthic organisms along the river floodplain.     

Determination of commonly used polar herbicides in agricultural drainage waters in Australia by HPLC

The present study describes the application of different extraction techniques for the preconcentration of ten commonly found acidic and non-acidic polar herbicides (2,4-D, atrazine, bensulfuron-methyl, clomazone, dicamba, diuron, MCPA, metolachlor, simazine and triclopyr) in the aqueous environment. Liquid-liquid extraction (LLE) with dichloromethane, solid-phase extraction (SPE) using Oasis HLB cartridges or SBD-XC Empore disks were compared for extraction efficiency of these herbicides in different matrices, especially water samples from contaminated agricultural drainage water containing high concentrations of particulate matter. Herbicides were separated and quantified by high performance liquid chromatography (HPLC) with an ultraviolet detector. SPE using SDB-XC Empore disks was applied to determine target herbicides in the Murrumbidgee Irrigation Area (NSW, Australia) during a two-week survey from October 2005 to November 2005. The daily aqueous concentrations of herbicides from 24-h composite samples detected at two sites increased after run-off from a storm event and were in the range of: 0.1-17.8 microg l(-1), < 0.1-0.9 microg l(-1) and 0.2-17.8 microg l(-1) at site 1; < 0.1-3.5 microg l(-1), < 0.1-0.2 microg l(-1) and < 0.2-3.2 microg l(-1) at site 2 for simazine, atrazine and diuron, respectively.     

The indirect relations of workplace incivility with emotional exhaustion and supportive behaviors via self‐blame: The moderating roles of observed incivility and trait emotional control

Drawing from the social cognitive theory of self‐regulation, we develop a model linking experienced incivility to emotional exhaustion and supportive behaviors via self‐blame, with observed incivility experienced by coworkers as a first‐stage moderator and trait emotional control as a second‐stage moderator. We contend that employees will experience self‐blame if they perceive themselves to be distinct targets of incivility (i.e., observed incivility experienced by others is low). Self‐blame can potentially trigger prosocial responses for improving the situation, but self‐blaming targets rarely respond in a prosocial manner because rational attempts to do so are thwarted by deleterious negative emotions accompanying self‐blame. We argue that trait emotional control provides resources for managing these negative emotions to unleash a bright side of self‐blame, such that the relation of self‐blame with prosocial responses (i.e., being supportive to coworkers) will be more positive and the relation of self‐blame with emotional exhaustion will be less positive for individuals with high (vs. low) trait emotional control. Multiwave data collected from a sample of 220 police officers largely support our hypotheses, indicating that the indirect relation of experienced incivility with supportive behaviors via self‐blame is strongest at lower levels of observed incivility and higher levels of emotional control.