<p> Several sections of the Milk River Formation were measured and studied in detail at Writing on Stone Provincial Park in Southern Alberta. The observed vertical facies succession consists of, from base to top: 1) interbedded, sharp-based sandstones and bioturbated shales; 2) dominantly swaley cross-stratified sandstones; 3) dominantly cross-bedded sandstones; 4) non-marine shales and various thin sandstone and lignite interbeds; 5) local, non-marine cross-bedded sandstones.</p> <p> The sharp-based sandstones have been episodically emplaced on top of offshore muds. The dominantly swaley cross-stratified sandstone is a storm-dominated shoreface deposit in which fairweather deposits (eg. medium scale cross-bedding), are rarely preserved. The cross-bedded sandstones record deposition in tidally-influenced estuaries which cut into beach and shoreface deposits. The section is capped by vertically accreted muds and thin lignite seams which represent floodplain and terrestrial deposition landwards of the strandline. The non-marine cross-bedded sandstones are local representatives of fluvial channel deposits.</p> <p> Paleoflow directions measured in the cross-bedded sandstones indicate that the regional strandline was oriented southwest - northeast at Writing on Stone.</p> <p> Petrographic analysis of the swaley cross-stratified and cross-beddedm sandstones indicate that they are Subarkoses. A definite upward coarsening trend from fine to medium grained quartz is observed in the main sandstone body.</p> / Thesis / Bachelor of Science (BSc)

Clay-based compounds are globally the most advanced and widely used method of direct suppression of marine harmful algal blooms, and are currently undergoing investigation as an option to control Karenia brevis blooms in Florida. Before clay may be accepted for widespread use, there are multiple concerns and challenges that must be addressed regarding the environmental safety of this method, such as effects on water quality, the fate of toxins, and potential impacts of clay treatment to non-target organisms. To contribute to ongoing assessments of clay as a potential control method for K. brevis blooms, we conducted experiments with a formulation of kaolinite clay modified with polyaluminum chloride known as Modified Clay II (MC II). In these experiments, we evaluated water chemistry dynamics and physiological responses in several bottom-dwelling marine species with ecological and economic significance, including blue crab (Callinectes sapidus), sea urchin (Lytechinus variegatus), and hard clam (Mercenaria campechiensis). First, we conducted an experiment with blue crabs in 20 L aquarium tanks (N = 48), exposing the animals to cultured K. brevis (1 x 106 cells L-1) and MC II (0.5 g L-1) and measuring mortality and reflexes over 192 hours. In our second experiment, K. brevis (1x106 cells L-1) and MC II (0.2 g L-1) were applied to 1,400 L mesocosms (N = 9) containing blue crabs, sea urchins, and hard clams, which were observed over 96 hours. In our final experiment, we modified the methods of the previous experiment to again examine K. brevis (1x106 cells L-1) and MC II (0.2 g L-1) with the same model species in 1,400 L mesocosms (N = 12) over 72 hours. In these two mesocosm experiments, we observed cell and toxin removal, changes in water quality characteristics including nutrients and carbonate chemistry, and measured mortality, respiration rate, reflexes, and internal toxin content. Our results were congruent across our three experiments. Treatment with MC II significantly reduced cell concentrations but did not reduce toxin concentrations in the water column. We found no notable impacts of clay treatment to reflexes, respiration rates, or internal toxin content for either of our three species. No significant differences in mortality were found for our three species, excluding crabs in the first mesocosm study, which were found to have pre-existing infections that confounded our results. Analyses of nutrients indicates MC II may remove dissolved phosphorus from the water column, and the potential to improve water quality which may make this formulation of clay desirable to managers. Overall, treatment with this formulation of clay did not appear to induce any significant measured effects on the model species within the observed time frames of these experiments. Clay appears to be a promising option to treat K. brevis blooms given its low cost, ease of application, and negligible impacts to the environment, and its use may relieve the damaging effects of K. brevis blooms by preventing mortalities that would otherwise occur were blooms allowed to persist. We therefore recommend that clays, including MC II, be considered for additional laboratory and field tests, with the goal of obtaining further information on potential ecological impacts so that managers and researchers can make informed decisions on the use of bloom control technologies in Florida waters.

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The initiation, persistence, and termination of harmful algal blooms (HABs) can all be influenced by nutrient availability. Recent studies have highlighted the role of both organic and inorganic nitrogen sources in HAB dynamics. The pelagophyte Aureoumbra lagunensis causes ecosystem disruptive algal blooms and is responsible for the longest recorded harmful algal bloom (1989-1997). Because of Aureoumbra's small size and its inability to use nitrate, it has been hypothesized that its ability to use ammonium and organic nitrogen, especially at low concentrations, contributed to the unusual persistence of this bloom. This project aimed to assess the response of Aureoumbra to inorganic and organic nitrogen sources by examining the expression of genes responsible for nitrogen assimilation, with an eventual intent of developing expression assays that are indicative of nitrogen source use and/or sufficiency in Aureoumbra. Large volume batch cultures of Aureoumbra were grown with either ammonium or urea as a nitrogen source. Physiological characteristics (C:N, chlorophyll [alpha] cell⁻¹, and Fv/Fm) were monitored throughout the growth period, and the expression of the AMT-1, AMT-2 and UREC genes was assayed at early-, mid- and late-exponential phases. The results show that Aureoumbra can use both ammonium and urea, and that it is well adapted to low-nutrient environments. Only one gene, AMT-1, appeared to be transcriptionally regulated in response to changing nitrogen concentration, and only to ammonium. The results of this study contribute to our understanding of how algae in general cope with low nutrient availability and should ultimately help to define the dynamics of these HAB events. / text

Thesis (S.M. in Biology)--Joint Program in Biological Oceanography (Massachusetts Institute of Technology, Dept. of Biology; and the Woods Hole Oceanographic Institution), 1999. / Includes bibliographical references (leaves 23-30). / Phytoplankton mortality (herbivory) and bacterivory were examined experimentally in West Neck Bay and Coecles Harbor, Long Island, NY from April through September, 1998. Small algae (<5 [tm diameter) dominated phytoplankton communities in both ecosystems throughout the summer, and zooplankton were also small (mostly <40 tm). Generally, plankton abundances were indicative of eutrophic ecosystems. Oscillations in standing stocks and mortality of prey indicated tight coupling of growth and grazing mortality in both bays. Phytoplankton mortality rates accounted for the removal of 14% to 65% of total phytoplankton standing stocks daily, while bacterivory accounted for the removal of 14% to 88% of total bacterial standing stocks daily. Estimates of carbon consumption revealed high energy flux through the nano- and microzooplankton assemblages of these estuarine environments. / by Katie Rose Boissonneault Cellineri. / S.M.in Biology

Karenia brevis (Davis cf. Hansen & Moestrup = Gymnodinium breve) is the non-peridinin containing dinoflagellate responsible for many harmful algal blooms (red tides) in the Gulf of Mexico. These recurrent blooms can have significant negative ecological, economic, and human health impacts including fish kills, tainting of shellfish, poisoning of marine mammals, loss of tourism revenue due to beach closures, and respiratory distress and food poisoning in humans. A method for detection of Karenia brevis was developed based upon amplification of the mRNA for the plastid-encoded gene of the carbon fixing enzyme ribulose 1, 5-bisphosphate carboxylase/oxygenase (RuBisCO) large subunit (rbcL). Using sequence information from a primer set targeting a 554-bp region of the Karenia rbcL gene, a small (91 bp amplicon) primer and probe set was created for TaqMan(registered trademark) real time RT-PCR of K. brevis rbcL. The primer/probe set is sensitive to as little as 0.1 fg of target transcript and as little as 1 pg of total cellular K. brevis RNA extract, corresponding to less than 1 cell reaction-1. The primer/probe set did not amplify rbcL transcript from any of the non-target algae tested. Bloom samples analyzed by this method have shown the assay to be a reliable method, with effective enumeration and a linear relationship showing good correlation to the cell counts by microscopy (r2= 0.8344). The assay has been shown to be robust and perform well even in non-ideal conditions, with pre-extraction RNA from unialgal culture stable at room temperature for up to 3 days and up to a month at -80 degrees C in Stratagene's lysis buffer. The transcription of the rbcL gene demonstrated minor variation throughout the diel period, however the variation was not linked to the diel cycle or to carbon fixation, which showed a distinct diel signal. Due to the relatively constant expression of the rbcL gene, the real-time RT-PCR assay developed should be able to reliably enumerate K. brevis populations in the natural environment, as long as the sample is placed in Stratagene's lysis buffer and processed within one or two days or frozen at -80 degrees C and processed within a month.

Many known extra-solar giant planets lie close to their host stars. Around 60 have their semi-major axes smaller than 0.05 AU. In contrast to planets further out, the vast majority of these close-in planets have low eccentricity orbits. This suggests that their orbits have been circularized likely due to tidal dissipation inside the planets. These exoplanets share with our own Jupiter at least one trait in common: when they are subject to periodic tidal forcing, they behave like a lossy spring, with a tidal ``quality factor'', Q, of order 10^5. This parameter is the ratio between the energy in the tide and the energy dissipated per period. To explain this, a possible solution is resonantly forced internal oscillation. If the frequency of the tidal forcing happens to land on that of an internal eigenmode, this mode can be resonantly excited to a very large amplitude. The damping of such a mode inside the planet may explain the observed Q value. The only normal modes that fall in the frequency range of the tidal forcing (~ few days) are inertial modes, modes restored by the Coriolis force. We present a new numerical technique to solve for inertial modes in a convective, rotating sphere. This technique combines the use of an ellipsoidal coordinate system with a pseudo-spectral method to solve the partial differential equation that governs the inertial oscillations. We show that, this technique produces highly accurate solutions when the density profile is smooth. In particular, the lines of nodes are roughly parallel to the ellipsoidal coordinate axes. In particular, using these accurate solutions, we estimate the resultant tidal dissipation for giant planets, and find that turbulent dissipation of inertial modes in planets with smooth density profiles do not give rise to dissipation as strong as the one observed. We also study inertial modes in density profiles that exhibit discontinuities, as some recent models of Jupiter show. We found that, in this case, our method could not produce convergent solutions for the inertial modes. Additionally, we propose a way to observe inertial modes inside Saturn indirectly, by observing waves in its rings that may be excited by inertial modes inside Saturn.

Many known extra-solar giant planets lie close to their host stars. Around 60 have their semi-major axes smaller than 0.05 AU. In contrast to planets further out, the vast majority of these close-in planets have low eccentricity orbits. This suggests that their orbits have been circularized likely due to tidal dissipation inside the planets. These exoplanets share with our own Jupiter at least one trait in common: when they are subject to periodic tidal forcing, they behave like a lossy spring, with a tidal ``quality factor'', Q, of order 10^5. This parameter is the ratio between the energy in the tide and the energy dissipated per period. To explain this, a possible solution is resonantly forced internal oscillation. If the frequency of the tidal forcing happens to land on that of an internal eigenmode, this mode can be resonantly excited to a very large amplitude. The damping of such a mode inside the planet may explain the observed Q value. The only normal modes that fall in the frequency range of the tidal forcing (~ few days) are inertial modes, modes restored by the Coriolis force. We present a new numerical technique to solve for inertial modes in a convective, rotating sphere. This technique combines the use of an ellipsoidal coordinate system with a pseudo-spectral method to solve the partial differential equation that governs the inertial oscillations. We show that, this technique produces highly accurate solutions when the density profile is smooth. In particular, the lines of nodes are roughly parallel to the ellipsoidal coordinate axes. In particular, using these accurate solutions, we estimate the resultant tidal dissipation for giant planets, and find that turbulent dissipation of inertial modes in planets with smooth density profiles do not give rise to dissipation as strong as the one observed. We also study inertial modes in density profiles that exhibit discontinuities, as some recent models of Jupiter show. We found that, in this case, our method could not produce convergent solutions for the inertial modes. Additionally, we propose a way to observe inertial modes inside Saturn indirectly, by observing waves in its rings that may be excited by inertial modes inside Saturn.

In this study, the structure, depositional system, and the seismic stratigraphy of the VLE 196 area, Block V in Lamar Field were interpreted using 3-D seismic data and well logs to characterize structural and depositional settings of the Guasare-Misoa interval. To demonstrate structural settings of the study area 3-D seismic data were interpreted. Three main seismic reflectors, which are the Late Eocene unconformity, Guasare, and La Luna formations, were picked. The most dominant structure in the area is the VLE 400 Fault which was interpreted as a left-lateral strike-slip reverse fault due to its behaviors as a reverse fault in cross sections and as a strike-slip fault in strike sections. The VLE 400 Fault subdivides the VLE 196 area into two main structural blocks, a downthrown block in the western part and the upthrown block in the eastern part of the field where the hydrocarbons were trapped. Several en echelon normal and reverse faults were located along the both sides of the area. The main importance of these faults are that they fractured the La Luna source rock and created migration pathways through the reservoir layers of the Misoa Formation. To interpret depositional system of the Guasare-Misoa interval, tops of the C4 and C5 intervals and associated C4 layers were picked based on well logs and lithofacies maps were prepared. The results of this part of the study show that the sandstones of the Misoa Formation are delta front and fluvial/distributary channel facies of delta system. The net sand thickness map of the C4 interval also exhibits southeast northwest contour patterns reflecting depositional axes in the area. Shaly units of the C4 interval interpreted as potential seals and are of variable thickness and extend. Seismic stratigraphic interpretation of the area shows that the four main seismic facies are dominant which mainly represent the recent sediments, "C" sands of the Misoa Formation, underlying Colon and Mito Juan shales, and basement respectively. Some distributary eroded channel fill structures were also observed within the Misoa Formation, but they were not continuous through the area because of the intensive faulting.