Mitochondrial DNA and electronic tracking reveal population structure of Atlantic bluefin tuna (Thunnus thynnus)

Population subdivision was examined in Atlantic bluefin tuna (Thunnus thynnus) through sequencing of the control region of the mitochondrial genome. A total of 178 samples from the spawning grounds in the Gulf of Mexico, Bahamas and Mediterranean Sea were analyzed. Among the samples from these locations were 36 electronically tagged bluefin tuna that were tagged in the North Atlantic and subsequently traveled to one of these known spawning grounds during the spawning season. Bluefin tuna populations from the Gulf of Mexico and the Mediterranean Sea were found to be genetically distinct based on Φ_st, and sequence nearest neighbor analyses, showing that these two major spawning areas support independent stocks. Sequence nearest neighbor analysis indicated significant population subdivision among the Gulf of Mexico, western Mediterranean and eastern Mediterranean Sea. However, it was not possible to find significant pairwise differences between any sampling areas when using all samples. If only samples that had a high likelihood of assignment to a specific spawning site were used (young of the year, spawning adults), the differentiation increased among all sampling areas and the Western Mediterranean Sea was distinct from the Eastern Mediterranean Sea and the Gulf of Mexico. It was not possible to distinguish samples from the Bahamas from those collected at any of the other sampling sites. These data support tagging results that suggested distinctness of the Gulf of Mexico, Eastern and Western Mediterranean Sea spawning areas. This level of stock differentiation is only possible if Atlantic bluefin tuna show strong natal homing to individual spawning grounds.     

A new approach to the estimation of the probable number of fatalities in accidental explosions

This paper presents a new methodology for estimating the probable number of fatalities in accidental explosions in fixed installations, as a function of the amount of the flammable substance involved. A review of the procedure proposed by Marshall (1977) (Marshall, V.C., 1977 How lethal are explosions and toxic escapes? The Chemical Engineer, August 1977, 573–577). reveals its limitations, given the great dispersion of ungrouped data. The proposed alternative enables the estimation of the maximum probable number of fatalities and the percentage of cases in which a certain number of fatalities is reached, based on the knowledge of the amount of material presumably involved and through the application of the historical analysis of accidents. It must be pointed out that the proposed method considers not only fatalities derived directly from the overpressure wave but also those due to thermal radiation or missile impact.     

Low priorities for black american leaders: Environmental and occupational health

Summary Black Americans face increased health risks from environmental and occupational exposures when compared with white Americans, but they also face increased risks for more immediate health problems such as HIV infection/AIDS, alcohol and drug abuse, violence, and infant mortality. A survey of more than 1,000 black public health and black political leaders solicited opinions on the relative importance of 1) environmental health and 2) occupational health and safety compared with other public health problems faced by the black community. The survey also determined opinions about the degree to which specific health problems are amenable to change for black Americans and who (or what agency) should spearhead efforts aimed at specific public health objectives.Responding black leaders felt environmental health and occupational health and safety goals were somewhat important for black Americans, but among the most difficult of all public health objectives to meet. Those who felt that the above objectives were very important identified the federal govemment as the primarily responsible party for seeing that the objectives are met.Dr Dona Schneider is Assistant Professor of Public Health at Rutgers University. She teaches epidemiology and biostatistics for the New Jersey Graduate Program in Public Health at the University of Medicine and Dentistry of New Jersey, and holds memberships in both the Environmental and Occupational Health Sciences Institute and the National Institute for Environmental and Health Sciences. Her research spans the health problems of children and minorities. She regularly reviews books for theEnvironmentalist.     

Effects of deodorants on treatment of boat holding-tank waste

A literature search and survey of Virginia, USA, campgrounds with RV pump-out stations were used to determine whether boat holding-tank deodorant chemicals would have deleterious effects on marina septic systems or package treatment plants. Laboratory studies reported in the literature indicate that these chemical additives could affect septic system function in three ways: (1) active ingredients in the additives can impair sewage degradation in septic tanks, causing sludge buildup and overflow of solids into the drainfield, (2) additive chemicals might enter the drainfield and, in high enough concentrations, reduce the drainfield's ability to degrade waste, or (3) toxic additive chemicals might migrate from the drainfield to ground or surface water. Laboratory studies also show that some ingredients added to holding tanks interfere with functioning of activated sludge treatment process. Experience in the field and in other laboratory studies suggests that factors such as dilution of treated waste with untreated waste and the characteristics of the sewage to be treated can reduce the possibility of damage to septic and activated sludge systems. The campground owners surveyed indicated that they have few problems with their septic systems in spite of the presence of chemical additives in the RV waste. However, most of them practice good septic system maintenance and have devised other means of ensuring that their systems function efficiently. In addition, the survey indicates that most Virginia campgrounds get only seasonal use (as would marinas in Virginia), allowing their systems to recover between peak seasons.     

Designing effective community relations programs

• Cleanup of a contaminated site is halted as community residents launch a legal challenge against the method that those responsible for the site have selected for remediation.
• Parents and teachers at a public school call for an investigation to determine if substances in the building are making students and staff sick. Midway into the investigation, they also become concerned as to whether the right tests are being performed to detect contamination that may be present, and how they will know what the test results mean.
• Industrial neighbors of a facility oppose its air permit application out of concern for the effects the facility's emissions might have on their own workers.

Virtually no business enterprise or government entity is immune from the potential for public interest in or concern about environmental issues. Within the public arena, environmental issues are rarely viewed only in terms of their scientific, technical, or regulatory merits. Instead, they are invariably intertwined with other issues and perceptions regarding health and safety, property values, social justice, and overall quality of life. As such, environmental issues have the potential to create significant controversy, concern, and opposition among community residents. Fortunately, in many cases, much, if not all, of the anger and fear that community residents feel can be relieved through a substantive dialogue that either corrects misinformation or provides a platform for discussing actions that could, should, or are taking place to remedy a situation. Promoting and sustaining such dialogues is the goal of community relations. This article covers the process of designing and implementing a community relations program plan to address serious or long-term environmental issues surrounding facilities, sites, or projects.     

A prospective study of amniotic fluid cholinesterases: Comparison of quantitative and qualitative methods for the detection of open neural tube defects

The value of quantitative and qualitative methods of cholinesterase (ChE) analysis in the detection of open neural tube defect (NTD) has been assessed in a prospective survey of 1495 mid-trimester amniotic fluids. Using a quantitative method the mean ChE values were much lower in fluids from pregnancies of normal outcome but it was not possible to discriminate these fluids completely from those associated with NTD pregnancies. particularly when the specimens were contaminated with blood. Similarly, measurement of acetylcholinesterase (AChE) activity alone by three different methods also failed to eliminate the overlap between the two groups. In contrast, polyacrylamide gel electrophoresis revealed only a single band of ChE activity in 1408 out of 1410 fluids from pregnancies with a normal outcome whilst amniotic fluids from all 60 cases of open NTD. 6 out of 7 cases of exomphalos and 3 out of 4 cases of intra-uterine death gave the characteristic second faster-running AChE band. A qualitative gel method which requires the same amount of ChE activity to be loaded from each amniotic fluid is an effective method for pre-natal diagnosis of NTDs.     

The prenatal diagnosis of the cerebro-hepato-renal syndrome of Zellweger

The prenatal diagnosis of the cerebro-hepato-renal syndrome of Zellweger (CHRS) was made by assaying the levels of very long chain fatty acids (VLCFAs) in amniotic fluid cell cultures, obtained by amniocentesis at 16 1/2 weeks of pregnancy. The family-at-risk, because they had previously borne a child with CHRS, accepted these results as indications of an affected fetus, and chose to terminate the pregnancy at 20 1/2 weeks of gestation. The diagnosis was confirned by the phenotype of the aborted fetus and the presence of markedly elevated levels of VLCFAs in fetal liver homogenates. The prenatal diagnosis of CHRS, which can now readily be determined from amniotic fluid cell cultures, is an important step in genetic counselling of families-at-risk for this disease.