Bacterial flora of the gut of the African snakehead, Channa obscura (Pisces: Channidae)

A qualitative and quantitative investigation of the bacterial flora of the gut of the African snakehead, Channa obscura was undertaken. The types of bacteria isolated from the different parts of the gut of C. obscura include Pseudomonas, Streptococcus, Citrobacter and Proteus. The coliform (Escherichia coli, Enterobacter) and some other Enterobacteriaceae such as Salmonella were also present. The stomach and intestine were found to have a preponderance of Pseudomonas and Vibrio species. Klebsiella sp. and Bacillus sp. (only in the pyloric caeca) were also isolated. On the whole, the correlation coefficients of the two incubation temperatures showed a high statistical significance. Thus the bacterial load of the gut of C. obscura has been shown as a function of temperature

Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Mid-Atlantic): Alewife/Blueback Herring

This profile covers life history and environmental requirements of both alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis), since their distribution is overlapping and their morphology, ecological role, and environmental requirements are similar. The alewife is an anadromous species found in riverine, estuarine, and Atlantic coastal habitats, depending on life cycle stage, from Newfoundland (Winters et al. 1973) to Soutn Carolina (Berry 1964). Landlocked populations are i n the Great Lakes, Finger Lakes, and many other freshwater lakes (Bigelow and Sch roeder 1953; Scott and Crossman 1973). The blueback herring is an anadromous species found in riverine, estuarine, and Atlantic coastal habitats, depending on life stage cycle, from Nova Scotia to the St. Johns River, Florida (Hildebrand 1963)

Economics of co-managing water quality and invasive species for California and Baja California coastal boats

Regulatory action to protect California’s coastal water quality from degradation by copper from recreational boats’ antifouling paints interacts with efforts to prevent transport of invasive, hull-fouling species. A copper regulatory program is in place for a major yacht basin in northern San Diego Bay and in process for other major, California boat basins. “Companion” fouling control strategies are used with copper-based antifouling paints, as some invasive species have developed resistance to the copper biocide. Such strategies are critical for boats with less toxic or nontoxic hull coatings. Boat traffic along over 3,000 miles of coastline in California and Baja California increases invasive species transport risks. For example, 80% of boats in Baja California marinas are from the United States, especially California. Policy makers, boating businesses and boat owners need information on costs and supply-side capacity for effective fouling control measures to co-manage water quality and invasive species concerns. (PDF contains 3 pages)

Photodissociation and reaction dynamics of chlorine-containing species important in stratospheric ozone chemistry

Chlorine oxide species have received considerable attention in recent years due to their central role in the balance of stratospheric ozone. Many questions pertaining to the behavior of such species still remain unanswered and plague the ability of researchers to develop accurate chemical models of the stratosphere. Presented in this thesis are three experiments that study various properties of some specific chlorine oxide species.

In the first chapter, the reaction between ClONO_2 and protonated water clusters is investigated to elucidate a possible reaction mechanism for the heterogeneous reaction of chlorine nitrate on ice. The ionic products were various forms of protonated nitric acid, NO_2 +(H_20)_m, m = 0, 1, 2. These products are analogous to products previously reported in the literature for the neutral reaction occurring on ice surfaces. Our results support the hypothesis that the heterogeneous reaction is acid-catalyzed.

In the second chapter, the photochemistry of ClONO_2 was investigated at two wavelengths, 193 and 248 nm, using the technique of photofragmentation translational spectroscopy. At both wavelengths, the predominant dissociation pathways were Cl + NO_3 and ClO + NO_2. Channel assignments were confirmed by momentum matching the counterfragments from each channel. A one-dimensional stratospheric model using the new 248 nm branching ratio determined how our results would affect the predicted Cl_x and NO_x partitioning in the stratosphere.

Chapter three explores the photodissociation dynamics of Cl_2O at 193, 248 and 308 nm. At 193 nm, we found evidence for the concerted reaction channel, Cl_2 + O. The ClO + Cl channel was also accessed, however, the majority of the ClO fragments were formed with sufficient internal energies for spontaneous secondary dissociation to occur. At 248 and 308 nm, we only observed only the ClO + Cl channel. . Some of the ClO formed at 248 nm was formed internally hot and spontaneously dissociated. Bimodal translational energy distributions of the ClO and Cl products indicate two pathways leading to the same product exist.

Appendix A, B and C discuss the details of data analysis techniques used in Chapters 1 and 2. The development of a molecular beam source of ClO dimer is presented in Appendix D.