Selenium Bioaccumulation in Stocked Fish as an Indicator of Fishery Potential in Pit Lakes on Reclaimed Coal Mines in Alberta, Canada

Pit lakes are a common reclamation strategy for open pit mines; however, there is a concern about their water quality and suitability as fish habitat because they are often contaminated by metals or metalloids. This study assessed the exposure of fish and invertebrates to selenium (Se) and other metals and metalloids in pit lakes formed by open pit coal mining in Tertiary (thermal coal) and in Cretaceous (metallurgical coal) bedrock. Juvenile hatchery rainbow trout, Oncorhynchus mykiss, and brook trout, Salvelinus fontinalis, were stocked into two thermal coal pit lakes (water Se < 2 μg/L, low water Se) and two metallurgical coal pit lakes (water Se > 15 μg/L, high water Se). Se accumulation in stocked fish and concentrations in invertebrates were characterized over a period of 2 years. In the metallurgical pits, invertebrates had higher Se concentrations and fish accumulated Se to higher levels (exceeding USEPA tissue Se guidelines) than biota in the thermal pits. Rainbow and brook trout accumulated similar concentrations of Se in their muscle and exhibited a similar relationship between whole-body and muscle Se concentrations. These results may be used by resource managers to assess compliance with whole-body tissue Se guidelines and to determine if pit lakes in coal mining areas pose a significant Se risk to wildlife or human health. The high Se exposure in metallurgical coal pits indicates that under the current mining and reclamation strategy, these lakes are not suitable for management as recreational “put and take” fisheries.     

Review of pollutants in petroleum refinery wastewaters and effect upon aquatic organisms

In the past decade, the number of organic chemical contaminants identified in oil refinery wastewaters has risen from less than 20 to over 300. This increase in knowledge was made possible by advances in gas chromatography-mass spectrometry instrumentation and new techniques to maximize resolution of capillary chromatography. The types of compounds identified in refinery wastewaters are similar to those identified in crude oils; i.e., aliphatic, aromatic, alkyl aromatic, polynuclear aromatic hydrocarbons, and some hydrocarbons containing nitrogen, sulfur, and oxygen. The contaminants in oil refinery wastewaters acutely lethal to aquatic organisms can be removed by biological treatment systems. However, biological treatment systems may not be capable of removing all deleterious contaminants. Long-term fathead minnow bioassays of biologically treated refinery wastewaters resulted in 10%–50% mortality after 14–16 days of exposure. The lethal effects were eliminated by sequential treatment with dual media filtration-activated carbon adsorption.     

Eco‐hydraulic Evaluation of a Whitewater Park as a Fish Passage Barrier

Whitewater parks (WWPs) typically consist of instream structures that enhance recreational boating by constricting flow into a steep chute that generates a hydraulic jump in a downstream pool. Concerns have been raised that high velocities resulting from WWPs may be inhibiting fish movement during critical life stages. We evaluated the effects of WWPs on upstream fish passage by concurrently monitoring fish movement and hydraulic conditions at three WWP structures and three adjacent natural control (CR) sites in a wadeable river in northern Colorado. Fish movement was tracked with a network of Passive Integrated Transponder antennas over a 14‐month period. Individual fishes (n = 1,639), including brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss), were tagged and released within WWP and CR sites. Detailed hydraulic conditions occurring during the study period were evaluated with a fully 3D model. Results reveal the WWPs monitored in this study are not a complete barrier to upstream salmonid movement, but differences in passage efficiency from release location range from 29 to 44% in WWP sites and 37 to 63% for CR sites and the suppression of movement is related to body length. Small numbers of monitored nonsalmonids were inadequate to directly observe effects on their movement; however, it is highly probable that movement of smaller native fishes is also suppressed. Hydraulic modeling helps in the design of WWP structures that protect fish passage.     

Evaluation of an occupational stress intervention in a public agency

Only in several controlled studies have organizational or situational stressors (in contrast to individuals) been targeted for change in order to reduce occupational stress. This study evaluates the impact of an intervention which was based on organizational development, action research and Karasek's job strain model. Employee committees conducted problem diagnosis, action planning, and action taking in two departments in a public agency. Waiting list control departments and pre- post- and follow-up assessment were utilized. Results indicated a mixed impact of the intervention in one department, but a negligible or negative impact in the other. Obstacles to the effective implementation of the intervention strategy are discussed. These included a limited focus for the committees (department-wide rather than agency-wide), the negative impact of a major agency reorganization, and the lack of a more formal management and labour commitment to maintaining the stress reduction and organizational change process.     

Never smoker lung cancer risks from exposure to particulate tobacco smoke

The average particulate environmental tobacco smoke (ETS) exposure of never and current smokers and the average lung cancer mortality rate for current smokers is estimated from empirical data. These estimates are used in a linear downward extrapolation of the lung cancer risk/mg of particulate ETS exposure for current smokers to calculate the average lung cancer risk for never smokers and the number of never smoker lung cancer deaths (LCD) in the U.S. in 1980 from exposure to particulate ETS. The estimated average daily inhaled particulate ETS exposure for never smokers is 0.62 mg/day for men and 0.28 mg/day for women. The average never smoker is estimated to retain 11% of the inhaled exposure, for a daily retained exposure of 0.07 mg for men and 0.03 mg for women. Other estimates are: a daily retained exposure for current smokers of 310 mg for men and 249 mg for women, a smoking-attributable lung cancer risk for current smokers in 1980 of 284 LCD/100,000 men and 121 LCD/100,000 women, and an annual retained-exposure lung cancer risk for never smokers of 0.64 LCD/100,000 men and 0.015 LCD/100,000 women. These risks and exposures estimate 12 lung cancer deaths among never smokers from exposure to particulate ETS: 8 among the 11.96 million male never smokers and 4 among the 28.85 million female never smokers in the U.S. in 1980. Conversely, between 655 and 3,610 never smoker lung cancer deaths are estimated from methods based on the average lung cancer risk observed in epidemiological studies of exposure to ETS. Three possible reasons for the discrepancy between the exposure and risk-based estimates are discussed: the excess risks observed in epidemiological studies are due to bias, the relationship between exposure and risk is supralinear, or sidestream tobacco smoke is substantially more carcinogenic than an equivalent exposure to mainstream smoke.     

Helper contributions to reproductive success in the splendid fairy-wren (Malurus splendens)

Summary In Malurus splendens, helpers were present in 65% of 226 group-years with at least one helper female in 37% of group-years. Most females helped for only one year, while many males did so for at least two years. Most were offspring of one or both present breeders, and in 53% of helper-years, helped both parents. For 159 helpers of known age and parentage, the mean coefficient of relatedness to the offspring was 0.47. Novice females with or without helpers produced fewer fledglings per season than females with one year breeding experience and the same level of help. Helpers did not affect production of fledglings per year by females with one year of experience. Females with two or more years experience and at least two helpers produced more fledglings than equivalent birds with one or no helpers. Experience and helpers have little effect on production of fledglings per nest but they lead to more females renesting after a first brood has been raised. Fewer than 20% of novices renest after fledging one brood, while for females with at least two years experience, the percent renesting after success is 40% with no help, 56% with one helper and 69% with 2 or more helpers. Experienced females begin their first clutch earlier than novices, and helpers reduce the time to renest after success from 66 days for an experienced female with no helpers to 50 days for females with at least two years experience and two or more helpers. Breeding females with helpers survive better (76%) than those with no helpers (55%), and helpers thus gain future indirect fitness. Despite their close relatedness to breeders and offspring, in only 19% of group-years did helpers increase their indirect fitness from an increase in productivity.     

“Philandering” — a mixed mating strategy in the splendid fairy-wren Malurus splendens

Summary In a population of the splendid fairy-wren Malurus splendens, we describe 202 intrusions by solitary adult males in full breeding plumage into the territories of conspecifics. Intrusions were not secretive and although silent they involved conspicuous flight above the vegetation and several characteristic display elements, including petal-carrying. Fifteen intrusions were observed in the 2 months before eggs were laid, but the rest occurred during the period of nest-building and egg-laying when the breeding female was presumed to be fertile, and were by males from adjacent territories. A high level of extra-pair fertilization has previously been determined in this species and we interpret many of these intrusions as attempts by males to obtain extra-pair copulations (EPC); we call this activity philandering. The costs and benefits of EPC for males and females are discussed and the promiscuous mating strategy of M. splendens is contrasted with the persistent social pairing in stable groups of this long-lived cooperatively breeding species.Offprint requests to: I. Rowley     

过去10年来世界各地21世纪地方议程中的 住区经验：方法与汲取的教训

本文评述联合国人类住区中心推动21世纪地方议程的经验.它依据促进21世纪地方议程举措的两个最主要的人类住区方案，即可持续城市方案(SCP)和落实21世纪地方议程方案过程中所取得的经验，对构成参与城市规划和管理的一个共同框架的几个不同阶段做了解释.本文还提出了在全世界40个城市所汲取的几点重要教训.