Effectiveness of centralized bilge water treatment — a field study

Instrumentation and procedures were developed for gross and detailed characterization of oily wastewaters. The methodology was applied to the assessment of effectiveness of a centralized oily waste treatment facility. Generated data included total, dissolved, and suspended organic content and detailed chemical characteristics of oily water samples.The usefulness of the methodology was demonstrated in a real-life field study involving operation of a centralized oily waste treatment facility operated by the U.S. Army at Fort Eustis, Virginia, in 1976. It was found that the concentration of suspended organics ranged between 5 and 335 ppm and dissolved organics between 14 and 156 ppm in untreated bilge water.Treated bilge waste effluents contained essentially no suspended oil, but rather high (769–1262 ppm) amounts of dissolved organic matter.It was determined that physical methods of waste treatment based on gravity separation and coalescence are effective in removal of suspended petroleum, and that prolonged contact between an oil film and water results in water solubilization of petroleum, leading to very high concentrations of dissolved organic material in the treated effluent.     

Is it possible to mitigate greenhouse gas emissions in pastoral ecosystems of the tropics?

Climate change science has been discussed and synthesized by the world's best minds at unprecedented scales. Now that the Kyoto Protocol may become a reality, it is time to be realistic about the likelihood of success of mitigation activities. Pastoral lands in the tropics hold tremendous sequestration potential but also strong challenges to potential mitigation efforts. Here we present new analyses of the global distribution of pastoral systems in the tropics and the changes they will likely undergo in the next 50 years. We then briefly summarize current mitigation options for these lands. We then conclude by attempting a pragmatic look at the realities of mitigation. Mitigation activities have the greatest chance of success if they build on traditional pastoral institutions and knowledge (excellent communication, strong understanding of ecosystem goods and services) and provide pastoral people with food security benefits at the same time.     

Estimated effects of climate change on flood vulnerability of U.S. bridges

We assessed the potential impacts of increased river flooding from climate change on bridges in the continental United States. Daily precipitation statistics from four climate models and three greenhouse gas (GHG) emissions scenarios (A2, A1B, and B1) were used to capture a range of potential changes in climate. Using changes in maximum daily precipitation, we estimated changes to the peak flow rates for the 100-year return period for 2,097 watersheds. These estimates were then combined with information from the National Bridge Inventory database to estimate changes to bridge scour vulnerability. The results indicate that there may be significant potential risks to bridges in the United States from increased precipitation intensities. Approximately 129,000 bridges were found to be currently deficient. Tens of thousands to more than 100,000 bridges could be vulnerable to increased river flows. Results by region vary considerably. In general, more bridges in eastern areas are vulnerable than those in western areas. The highest GHG emissions scenarios result in the largest number of bridges being at risk. The costs of adapting vulnerable bridges to avoid increased damage associated with climate change vary from approximately $140 to $250 billion through the 21st century. If these costs were spread out evenly over the century, the annual costs would be several billion dollars. The costs of protecting the bridges against climate change risks could be reduced by approximately 30% if existing deficient bridges are improved with riprap.     

Algae: the world��s most important ��plants����an introduction

Early in the history of life, algae changed the planet??s atmosphere by producing oxygen, thus paving the way for the evolution of eukaryotic organisms. In an era in which the consumption of fossil fuels is a prime topic of concern, few people realize that the oil we currently exploit comes mostly from Cretaceous deposits of marine algae. Moving from ancient times to the present, the algae remain more important than most people realize. Today, the production of oxygen by algae (ca. 50% of all oxygen production) is another reason for saying ??our lives depend on algae.?? Those who love seafood should thank the algae because algae are the primary producers upon which aquatic ecosystems depend. Thanks should come from all who are vegetarians or omnivores, because all land plants derive from a freshwater class of green algae and all land-animals??including the cows that provide the steaks for meat-lovers??depend directly or indirectly on land plants for food and often for shelter as well. As we use up the oil deposits provided by the ancient algae, we are turning to the modern algae for help. Given the photosynthetic abilities of the algae, they are one of the major focuses for sustainable biofuel production and CO₂ consumption. Finally, the algae that give us the air we breathe, the food we eat, and the fuel for our cars (past and, perhaps, future), are also a source of active pharmaceutical compounds that can be used against drug-resistant bacterial strains, viruses (including Herpes Simplex and AIDS), and cancers. Roses are pretty and oak trees are impressive, but no other groups of ??plants?? have done so much, for so long, and, for so many as have the algae!     

Much ado about nothings: using zero similarity points in distance-decay curves

Distance decay is used to describe the (usually exponential) decay in ecological similarity of assemblages between two sites as a function of their distance apart along an environmental gradient. Exponential distance-decay curves are routinely fitted by calculating the ecological similarity between each pair of sites, and fitting a linear regression to the points on a scatter plot of log-similarity vs. distance (x-axis). However, pairs of sites where the assemblages have no species in common pose a problem, because the similarity is zero, and the log transformation cannot be applied. Common fixes to this problem (i.e., either removing or transforming the zero values) are shown to have undesirable consequences and to give widely disparate estimates. A new method is presented as a special case of a generalized dissimilarity model. It is fitted very quickly and easily using existing software, and it does not require removal or transformation of the zero similarity points. Its simplicity makes it convenient for use in conjunction with the resampling methods that are routinely employed to test hypotheses, to obtain standard errors of estimated parameters, or to compare distance-decay curves. A word of caution about standard application of the bootstrap is noted, and modified bootstrap and jackknife alternatives are demonstrated.     

Habitat biodiversity as a determinant of fish community structure on coral reefs

Increased habitat diversity is often predicted to promote the diversity of animal communities because a greater variety of habitats increases the opportunities for species to specialize on different resources and coexist. Although positive correlations between the diversities of habitat and associated animals are often observed, the underlying mechanisms are only now starting to emerge, and none have been tested specifically in the marine environment. Scleractinian corals constitute the primary habitat-forming organisms on coral reefs and, as such, play an important role in structuring associated reef fish communities. Using the same field experimental design in two geographic localities differing in regional fish species composition, we tested the effects of coral species richness and composition on the diversity, abundance, and structure of the local fish community. Richness of coral species overall had a positive effect on fish species richness but had no effect on total fish abundance or evenness. At both localities, certain individual coral species supported similar levels of fish diversity and abundance as the high coral richness treatments, suggesting that particular coral species are disproportionately important in promoting high local fish diversity. Furthermore, in both localities, different microhabitats (coral species) supported very different fish communities, indicating that most reef fish species distinguish habitat at the level of coral species. Fish communities colonizing treatments of higher coral species richness represented a combination of those inhabiting the constituent coral species. These findings suggest that mechanisms underlying habitat-animal interaction in the terrestrial environment also apply to marine systems and highlight the importance of coral diversity to local fish diversity. The loss of particular key coral species is likely to have a disproportionate impact on the biodiversity of associated fish communities.     

Classification of multiple types of organic carbon composition in atmospheric particles by scanning transmission X-ray microscopy analysis

A scanning transmission X-ray microscope at the Lawrence Berkeley National Laboratory is used to measure organic functional group abundance and morphology of atmospheric aerosols. We present a summary of spectra, sizes, and shapes observed in 595 particles that were collected and analyzed between 2000 and 2006. These particles ranged between 0.1 and 12 μm and represent aerosols found in a large range of geographical areas, altitudes, and times. They include samples from seven different field campaigns: PELTI, ACE-ASIA, DYCOMS II, Princeton, MILAGRO (urban), MILAGRO (C-130), and INTEX-B. At least 14 different classes of organic particles show different types of spectroscopic signatures. Different particle types are found within the same region while the same particle types are also found in different geographical domains. Particles chemically resembling black carbon, humic-like aerosols, pine ultisol, and secondary or processed aerosol have been identified from functional group abundance and comparison of spectra with those published in the literature.     

Organic and Inorganic Characterization of Marine Colloids

Isolates of the organic matter in the particulate, colloidal and dissolved states were obtained by tangential flow ultrafiltration through 0.40 μm polycarbonate and ∼ 1 nm (1000 NMWL*) regenerated cellulose membranes and by solid-liquid reverse phase extraction techniques. the material was analyzed qualitatively by mass spectroscopy, proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, high performance liquid chromatography with fluorescence detection of labelled primary amines and amino acids, and inductively coupled plasma/mass spectroscopy. All three states are characterized by similar organic chemistries. the marine colloidal state in coastal waters off the Californian coast contains primarily carbohydrates, fatty acids, minor amounts of proteinaceous compounds and electropositive elements including aluminium and iron. Aromatic molecules and olefinic functional groups are in low concentration. the colloidal state differs qualitatively from the particulate and dissolved states. Yet all three could be derived, with degradation, from algal or macroalgal surface components.     

Growth and mortality of subtidal red sea urchins (Strongylocentrotus franciscanus) at San Nicolas Island,California, USA: problems with models

Red sea urchins, Strongylocentrotus franciscanus, were tagged with tetracycline in 1990 at subtidal sites off San Nicolas Island, California, USA. After one year in the field, the sea urchins were collected and growth increments were measured based on tetracycline marks, which indicated initial slow growth, a maximum rate, and finally a prolonged period of very slow growth. Small red sea urchins (4 cm diam) were estimated to be 3 to 4 yr old, which is much older than has previously been reported. It is estimated that about 12 yr would be required to attain 10 cm diam. Survival has previously been modeled assuming a constant rate. If the population of red sea urchins is assumed to be stable and stationary, annual survival rate was between 71 and 77% yr^-1. Census data for the two years of study have permitted annual survival to be estimated without assuming stable and stationary population structure. Under these conditions, annual survival rate was between 79 and 86% yr^-1. Analysis of transitions in the size distributions from 1990 to 1991 suggested that annual survival may have been sizespecific: 91% yr^-1 for individuals 1.1 to 4.0 cm diam, 82% yr^-1 for individuals 4.1 to 7.0 cm diam, and 63% yr^-1 for those of 7.1 to 10.0 cm diam. An alternative explanation to size-specific survival in our study is sizespecific immigration.