Mitochondrial control region sequence analyses indicate dispersal from the US East Coast as the source of the invasive Indo-Pacific lionfish Pterois volitans in the Bahamas

Lionfish are popular aquarium fish from the Indo-Pacific that have invaded the western Atlantic. Two species, Pterois volitans and P. miles, were well established along the United States east coast before the first lionfish were reported from the Bahamas in 2004, where they quickly dispersed throughout the archipelago by 2007. The source of the Bahamian lionfish invasion has been in question because of the hypothesized low connectivity between Florida and Bahamas reef species as well as the temporal lag in their arrival in the Bahamas. Mitochondrial control region haplotypes (680 bp) were determined and analyzed for lionfish specimens from the Bahamas, North Carolina, and two sites within their native range (Indonesia and the Philippines). Exact tests, pairwise F _st and AMOVA analyses all showed no significant differentiation between the Bahamas and North Carolina specimens. The similarity between the Bahamas and North Carolina lionfish was also reflected in a minimum spanning network and neighbor-joining distance tree generated from the data. Sequence analyses also revealed the presence of only Pterois volitans, as no P. miles were detected in the Bahamian sample. These results indicate that the source of the Bahamian lionfish is egg and larval dispersal from the United States east coast population, and support previous models of reef fish dispersal that suggest a low level of connectivity between the Bahamas and east coast of Florida.     

Tracer studies to characterize the effects of roadside noise barriers on near-road pollutant dispersion under varying atmospheric stability conditions

A roadway toxics dispersion study was conducted at the Idaho National Laboratory (INL) to document the effects on concentrations of roadway emissions behind a roadside sound barrier in various conditions of atmospheric stability. The homogeneous fetch of the INL, controlled emission source, lack of other manmade or natural flow obstructions, and absence of vehicle-generated turbulence reduced the ambiguities in interpretation of the data. Roadway emissions were simulated by the release of an atmospheric tracer (SF₆) from two 54 m long line sources, one for an experiment with a 90 m long noise barrier and one for a control experiment without a barrier. Simultaneous near-surface tracer concentration measurements were made with bag samplers on identical sampling grids downwind from the line sources. An array of six 3-d sonic anemometers was employed to measure the barrier-induced turbulence. Key findings of the study are: (1) the areal extent of higher concentrations and the absolute magnitudes of the concentrations both increased as atmospheric stability increased; (2) a concentration deficit developed in the wake zone of the barrier with respect to concentrations at the same relative locations on the control experiment at all atmospheric stabilities; (3) lateral dispersion was significantly greater on the barrier grid than the non-barrier grid; and (4) the barrier tended to trap high concentrations near the “roadway” (i.e. upwind of the barrier) in low wind speed conditions, especially in stable conditions.     

Male and female developmental differences in chemosensory investigations by African elephants (Loxodonta africana) approaching waterholes

Although communication is vital for members of a social species, the sexes may differ in the type and degree of information sought. In many polygynous societies, males search for reproductively active females and compete intrasexually for access to females with older males often being most successful. In social mammals, females may mature sooner than males and thus at an earlier age behave more like adults. This maturation may include the assessment of potential mates directly or via indicative signals. In this study, we observed the behavior of African elephants (Loxodonta africana) during their approach to waterholes. Waterholes provide an opportunity for elephants to investigate conspecific chemical signals from feces and urine, and each other. We examined the presence of sexual dimorphism in behaviors of the trunk that are indicative of olfactory investigation. We predicted that upon approach to a waterhole, adult males would show greater interest than females in conspecific chemical signals. Females were predicted and observed to exhibit adult-like rates of investigatory behavior at a younger age than males because females mature sooner. Adult males took the longest to reach the waterhole in the last 100 m of approach; they also demonstrated greater investigatory rates to conspecific feces. Each sex showed adult-type investigative behaviors with the trunk before the age of reproduction. Rather than showing a common chronological developmental pattern across sex, the exhibition of investigatory, chemosensory behaviors reflected sex-specific changes in reproductive development, perhaps reflective of the relative strength of intra- and intersexual selection on communication patterns.     

A tribute to Trevor Kletz: What we are doing and why we are doing it

The goal of my tribute to Trevor Kletz is to show a view of his overall influence on many of the elements of process safety: how he helped establish a strong foundation on which we are building our future process safety risk reduction efforts.     

Acid Rain Emission Allowances and Future Capacity Growth in the Electric Utility Industry

While the new source emission offset provision contained in recent acid rain proposals would result in increasing utility costs over time, the demand for emission offsets from new powerplant units should be satisfied even under conditions of high future growth in electrical generating capacity. This is because the amount of emissions from new generating units will be small relative to the quantity of offsets that could be made available in the emission “allowance” market.

Under the President’s July 1989 proposal, most utilities would be able to reduce their emissions well below their allowance levels via fuel switching, the installation of control technology, or the use of other emission reduction techniques, in order to create more “headroom” for the construction of new generating units. Retirements and decreasing utilization of existing power plants over time would liberate other emission allowances for use by new units. Industrial sources could “opt in” to the acid rain program and provide allowances for new generating units as well. A number of provisions in the recently passed Senate and House bills would make still further sources of allowances available to offset emissions from new generating capacity.

Hoarding of allowances by utilities is unlikely to be a problem since allowances would be distributed to at least 88 utilities in 34 states, and many of these utilities would have the ability to cost-effectively free up more allowances through “overcontrol” than they would need to cover their own future growth. Even a relatively small number of utilities in a limited number of states would have the ability to supply all of the allowances needed to cover new capacity growth from those entities that could not otherwise provide their own offsets. At projected prices of up to $800/ton, the incentives for utilities to sell allowances would be considerable. Moreover, if hoarding did begin to occur, the price of allowances would respond by rising to higher levels and the incentives for utilities to sell allowances would become even more compelling, as greater opportunities would develop for reducing costs (and electricity rates).     

summary of the California aerosol characterization experiment

This report gives a brief summary of the experimental plan and the early results of field observations from the California Aerosol Characterization Experiment (ACHEX). The objectives of the program center on questions of the sources and evolution of aerosols in urban air, as they are superimposed on a natural background, particularly as they relate to visibilitydegradation. The project initially nvolved the use of an elaborately instrumented mobile laboratory combined with a fixed station in San Jose, in Pasadena, and in Riverside, and later incorporated several satellite monitoring stations in the Los Angeles Basin. Intensive field observationswere taken from July 1972 to November 1972 in several urban and nonurban locations between the San Francisco Bay area and the South Coast Basin, covering the Los Angeles area. In a second phase of the ACHEX, aerosols accompanying photochemical smog were studied intensively in the Los Angeles Basin during the period between July and October of 1973. The observations cover a wide variety of parameters including physical and chemical properties of aerosols, pollutant gas concentrations, and meteorological variables. The initial results show the great importance of sulfate, nitrate, noncarbonate carbon, and liquid water to the mass concentration of airborne particles and their relation to reduction in visibility. The anthropogenic contribution to atmospheric aerosols is consistently found to be allocated primarily to the submicron or fine particle size range.