Marine and atmospheric sciences.

Chair: Stephen Howden, University of Southern Mississippi

Vice-chair: Zikri Arslan, Jackson State University 

FRIDAY MORNING

Bost Auditorium North

10:30 Poster Session

MEASUREMENTS OF SOLAR IRRADIANCE WITH A MULTIFILTER ROTATING SHADOWBAND RADIOMETER (MFRSR)

R.Suseela Reddy, Sridhar Kota*, Umesh Remata, Rush Lockhart, Harene Natarajan, and R.Karim, Jackson State University, Jackson, MS 39217

The Jackson State University Meteorology Program (JSUMP) recently installed a Multifilter Rotating Shadowband Radiometer (MFRSR) through a collaborative effort with the NOAA Center for Atmospheric Sciences (NCAS) at Howard University. The MFRSR is currently in operation and measures global, diffuse and direct normal components of Spectral Solar Irradiance, in six narrow bands approximately 10 nm wide. The data resulted from the measurements were used in the computations of aerosol, water vapor, and ozone optical depths. The data for Solar Irradiance were considered for clear day (Oct. 9th, 2006) as well as cloudy day (Oct. 2nd, 2006) skies to study the effect of clouds on Radiation. The results indicated that no atmospheric effects were observed in the variation of total solar irradiance during clear skies. During cloudy skies the atmospheric effects were observed due to clouds. Validation of data with satellite measurements will be discussed. JSU will continue measurements of solar and atmospheric radiation and aerosols for climate studies and for long-range monitoring of Aerosol Radiation Network (AERADNET).

CHRONIC ACCUMULATION PROFILE OF CADMIUM, LEAD, AND MERCURY IN GOLDFISH

Cristina Nica (1*) 1, Zikri Arslan (1), Anthony J. Bednar (2), (1) Jackson State University, Jackson MS 39217 and (2) US Army Engineer Research and Development Center (ERDC), Vicksburg, MS 39180

Mercury, lead and cadmium are among the most toxic heavy metals. Under chronic exposure, fish accumulate these metals to higher levels in the internal organs. The magnitude of stress induced by each individual metal is not only dependent on the relative toxicity of the metal ion, but also the target organ impacted. In this study, the uptake profile and relative toxicity of Cd, Pb and Hg were studied using goldfish. Goldfish were exposed to individual metals for ten days in glass tanks. Two different concentrations of the metals were administered individually: low level (20 [micro]g/L for Hg and 100 [micro]g/L for Cd and Pb) and high level (50 [micro]g/L for Hg and 250 [micro]g/L for Cd and Pb). Lethal effects were observed for fish exposed to Cd and Hg within the first two days. Toxicity of Pb was less pronounced compared to that of Cd and Hg. Internal organs, including the liver, gill, kidney, and muscle tissue were removed from exposed fish and digested in teflon vessels by nitric acid. Two different Certified Reference Materials, dog fish liver (DOLT-1) and lobster hepatopancreas (TORT-2) were digested using the same procedure for quality control. Samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The magnitude of accumulation was higher in fish exposed low levels of metals. Levels of Cd were consistently high in the kidney, while mercury accumulated in the gills, and lead in gills and muscles to higher levels.

FALL POST-LARVAL PENAEID SHRIMP IMMIGRATION INTO A MISSISSIPPI ESTUARY

Ryan Knobf (1*), Ricky Greer (1), John Anderson (2), and Harriet Perry (2), (1) Mississippi Gulf Coast Community College, Gautier, MS 39553, National Aeronautics and Space Administration, Stennis Space Center, MS 39522, (2) Gulf Coast Research Laboratory's J.L. Scott Marine Education Center (MEC), and Center for Fisheries Research and Development, Ocean Springs, MS 39564

The purpose of this project is to monitor the migration of postlarval penaeid shrimp into a Mississippi estuary during the fall season. Samples were taken with a beam plankton trawl at a single station along the marsh edge in Davis Bayou, Jackson County. Weekly sampling was conducted from mid-October through January. Water temperature, dissolved oxygen, salinity, depth, and weather conditions were recorded at the time of each sample. Penaeid shrimp were sorted, identified to species, and the length, weight, total number, and total biomass of each shrimp species recorded. While extensive research has been conducted on the spring immigration of brown postlarval shrimp into estuaries, little research has been done on postlarval recruitment into estuaries during the fall. Brown postlarval shrimp migration into estuaries peaks in the spring, but the postlarvae continue to recruit to the estuary until winter. White postlarval shrimp usually peak in the summer, but also continue to immigrate until winter. Pink postlarval shrimp recruit to the estuary in fall until the winter. Abundance of postlarvae is sometimes used to estimate predictions of commercial landings.

THE POTENTIAL OF MISSISSIPPI MESONET DATA TO DETECT CERTAIN TYPES OF FOG BASED ON MULTIPARAMETER PROXIES

Loren White* and Brandon DeShields, Jackson State University, Jackson, MS 39217

Synoptic reports of fog or mist are routinely reported primarily for FAA flight rules determination, by ASOS and AWOS stations sited at medium to large sized airports. The primary criterion for definition of fog or mist is according to the horizontal visibility range (0.5 statute mile or less for fog; 7 statute miles or less for mist). Since fog or mist is normally associated in Mississippi with relative humidity very near 100% and specific conditions of surface layer static stability and wind, it is hypothesized that sufficient relation to these ancillary parameters will enable the creation of a usefully robust proxy for fog/mist based on Mesonet-observed data. In order to develop such a proxy, we have identified events in which a sufficient number of ASOS/AWOS stations near a Mesonet station have reported fog/mist that a widespread fog event can be assumed (thus including the Mesonet site). By compositing and correlating Mesonet parameters for such cases at the five currently operating Mesonet stations, we can determine the feasibility and potential value of such a proxy fog product. For daytime cases, the probable existence of fog at the site can further be confirmed by visible satellite imagery.

MAPPING A NEW ENERGY SOURCE

Leigh Ann Eddins (1), Jason King (1), Hunter Lightsey (1*), Jeff Rotman (1), Mississippi State University, Starkville, MS 39762

Over the past two decades, researchers have studied gas hydrates extensively because of the energy potential of the gases occluded. Gas hydrates are present everywhere in the world, and a large amount of gas hydrates are present in the Gulf of Mexico. The U.S. Geological Survey estimates that gas hydrates possess more carbon than oil reserves. If a safe and an economical process is developed to aquire the energy of gas hydrates, the United States could obtain more fossil fuels locally. Due to the Gulf of Mexico Energy Security Act of 2006 (S.3711), states such as Mississippi, Alabama, and Louisiana will receive royalties from any harvesting of natural gas or oil up to one hundred miles off their respective shores. This recently passed bill has hefty financial implications for these three southern states which depend especially on a method for finding and harvesting gas hydrates. However, locating gas hydrates is a difficult task, so this project explores a unique probability technique for locating gas hydrates. In this project, documented discovery of gas hydrates, documented bottom simulating reflections of gas hydrates, and documented oil reserves are combined with Google Earth [c] software in order to locate areas of gas hydrate concentration.

AGE AND GROWTH OF BOTTLENOSE DOLPHIN (TURSIOPS TRUNCATUS) IN MISSISSIPPI AND ADJACENT GULF OF MEXICO WATERS

Kenneth Brookins (1*), Maria Begonia (1), Delphine Vanderpool (2), Keith Mullin (3) and Moby Solangi (2), (1) Jackson State University, Jackson, MS 39217, (2) Institute for Marine Mammal Studies, Gulfport, MS 39502, and (3) National Marine Fisheries Service, NOAA, Pascagoula, MS 39567

The bottlenose dolphin is one of the most well known cetaceans, because of its widespread use in marine parks and research facilities. However, there is still a strong need for information on growth rates of the species in order to better understand its ecology and population status. The objective of this study is to obtain biological data to elucidate the growth patterns of the bottlenose dolphin, Tursiops truncatus, in the Mississippi Sound and adjacent waters of the northern Gulf of Mexico. Teeth were collected from bottlenose dolphins stranded on the mainland coast of Mississippi and the adjacent barrier islands. The midsection of each tooth was cut into a 2-mm section using an isomer saw with a diamond-embedded blade. The section was then fixed in formalin overnight, rinsed with tap water and decalcified in a decalcifying acid mixture. Once decalcified, the sections were cut into thin, 25 um sections using a sliding microtome equipped with a freezing stage. These sections were then stained in Mayer's hematoxylin stain, rinsed in water before and after a weak ammonia rinse, and mounted on slides in glycerin. The number of growth layer groups (GLG) was read at least 3 times under a stereo microscope. Results revealed that the dolphins varied in ages based on the number of the GLG layers counted. The collection of information such as age and growth structure and other parameters are crucial to understanding the population dynamics and hence to successful management and conservation of the bottlenose dolphin.

COMPARISON OF SAMPLE DISSOLUTON METHODS FOR ANALYSIS OF SOIL AND SEDIMENTS FOR HEAVY METALS

Domingos D. A fonso (1*), Zikri Arslan (1*), and Anthony J. Bednar (2), (1) Jackson State University, Jackson MS 39217 and (2) US Army Engineer Research and Development Center (ERDC), Vicksburg, MS 39180

Accurate information of the heavy metals in soil and sediments is critical for better understanding the health issues of heavy metal contamination. Determination of the metals from soil and sediments is, however, a challenging task due to difficulties associated with sample dissolution and instrumental analysis. While complete dissolution of silicate may cause matrix interferences, incomplete dissolution and/or extraction of the metals may yield lower values. Volatility differences may also cause inaccuracies if the elements of interest are lost during high-temperature digestion/extraction. It is therefore essential to develop an analytical procedure to achieve complete extraction of the trace metals into solution by minimizing the analyte loss and dissolution of matrix elements. In this study, we investigated the analytical performance of four different sample dissolution procedures for analysis of soil and sediment samples for As, Cd, Cr, Hg, and Pb. The methods were (a) open-vessel digestion by HN[O.sub.3]+HF, (b) closed-vessel microwave-assisted digestion by HN[O.sub.3]+HF, (c) closed-vessel microwave-assisted extraction by HN[O.sub.3], and (d) ultrasonic extraction in 5% HN[O.sub.3]. The first two methods resulted in complete dissolution of the soil and sediment samples. However, Hg was completely lost in Method (a). Matrix interferences were highest in Method (b) due to the silicate matrix. The heavy metals were extracted by Method (c) without significant dissolution of the silicate matrix. Method (d) was also an effective means of extracting the metals to solution. This method also affords preparation of samples at room temperature rapidly that virtually eliminates analyte loss and minimizes contamination.

COMPARATIVE EVALUATION OF METAL CONCENTRATIONS IN VARIOUS PONDS IN MISSISSIPPI

Sunil Manohar Katta (*1), Zikri Arslan (1), Maria Begonia (1), Pao-Chiang Yuan (1), Anthony J. Bednar (2), (1) Jackson State University, Jackson, MS 39217 and (2) US Army Engineer Research and Development Center (ERDC), Vicksburg MS 39180

The metal concentrations in various ponds in Mississippi were measured to understand if the levels pose any health and environmental risks. The ponds studied include Lake Hico, Crossgates Lake, Stonegates Lake, Lake Catherine, Lakeland, Windsor Hill, Northlake Avenue, Belhaven Lake, Grand Tunica, Swan Lake, and Shadow Lake. These are ponds are actively used for fishing and watering crops, therefore, it is important that possible metal contamination by toxic metal is monitored regularly to avoid adverse health problems and for sustainability of aquatic life. For this purpose, water samples were collected in two sites of each individual pond. Samples were acidified to 0.1% nitric acid (pH~1.8) immediately, and filtered in the laboratory by 0.45-[micro]m membrane filters. Determinations were made by ICP-MS. The accuracy of the elemental results from pond waters was validated by simultaneously running standard water reference sample (SRM 1643e). The results produced with YSI instrument showed pH was neutral between 7.5-8.5, temperature was moderate (30-32 [degrees]C), salinity was low (0.1-0.3%), and dissolved [O.sub.2] (DO) was at 7-8.5 mg/l. Results from elemental analysis of SRM by ICP-MS analysis showed agreement with the certified values. Most of theses ponds showed low levels of metal concentrations (compared to safe drinking water standards EPA) except with some metals (e.g., lead, chromium nickel, cadmium). Crossgates, Grand Tunica, Swan Lake, North Lake Avenue, Windsor Hill, Lake Catherine, Shadow Lake, Stonegates showed high concentrations of iron, manganese, and arsenic.

FRIDAY AFTERNOON

Hunter Henry Executive Room 12

1:00 TRACE ELEMENT BEHAVIOR IN THE MISSISSIPPI RIVER PLUME AFTER HURRICANES KATRINA AND RITA 

MooJoon Shim (1*), Lyndsie Gross (2), Peter Swarzenski (3), and Alan M. Shiller (2), (1) University of Southern Mississippi, Hattiesburg, MS 39406, (2) University of Southern Mississippi, Stennis Space Center, MS 39529, and (3) US Geological Survey, St. Petersburg, FL 33701

Hurricanes Katrina and Rita caused substantial mixing of waters along the Louisiana Shelf as well as remobilization of shelf sediments. These physical disturbances could have resulted in a significant change in trace element fluxes through this coastal mixing zone. Therefore, samples of Mississippi River delta outflow waters were collected during October 2006 and we report the results of trace element analyses of these samples here. River endmember concentrations for a suit of dissolved trace elements (Co, Cr, Cu, Fe, Mn, Ni, and V) were similar to previous reports for Mississippi River water. Dissolved Ni and Cu showed largely conservative mixing in the plume, also consistent with previous observations. Dissolved Co, Cr, and Mn all showed maximum concentrations at mid-salinities, though the salinity of maximum concentration varied among these elements. These distributions are indicative of input from reducing bottom sediments. There is little previous data for these elements in this region, however, this behavior is not out of line with other estuarine observations.

1:20 SUDDEN NOCTURNAL WARMING EVENTS AS OBSERVED BY THE MISSISSIPPI MESONET

Loren White*, Shari Dixon, and Brandon DeShields, Jackson State University, Jackson, MS 39217

A previously undocumented atmospheric phenomenon of "nocturnal warming events" has been discovered in data from the Mississippi Mesonet meteorological observing network. The phenomenon may be broadly defined as a sudden rise in air temperature during the nighttime hours, without any likely connection with frontal or convective activity. As Mesonet stations have been installed in various parts of Mississippi, variations in frequency and intensity of such events have been noted. A rough attempt has been made to classify the events according to: 1) intensity of temperature increase; 2) existence of a correlated decrease in dewpoint; 3) existence of a later sudden cooling that follows a period of quasi-isothermal temperature; and 4) existence of a significant increase in wind speed. In the most notable events: 1) temperature is strongly anticorrelated with dewpoint; 2) temperature levels off for an hour or two before dropping fairly rapidly; 3) antecedent calm or very weak winds are replaced by wind speeds exceeding 2 m/s; and 4) the near-surface temperature inversion is reduced by 50%. Although nocturnal warming events could plausibly be explained by a variety of interacting mechanisms, most commonly it is believed that suddenly intensified winds mix down warm, dry air from a strong nocturnal radiation inversion. The trigger for reinvigorating the surface winds is unclear, though gravity waves from geostrophic adjustment or distant convection may play a role.

1:40 PERFORMANCE OF COLLISION CELL ICP-MS FOR DETERMINATION OF IRON FROM FISH OTOLITHS

Zikri Arslan* and Stephanie Daniels, Jackson State University, Jackson MS 39217

Iron is an important trace element in otolith microchemistry to gather information about the life histories of fish groups. However, iron occurs at very low concentrations in oceanic and estuarine waters. As a result, the iron concentration in the otoliths of fish is also very low that makes the determination of iron problematic by ICP-MS due to interferences of otolith matrix and spectral overlaps of polyatomic ions on isotopes of iron. Even in most cases the results for iron are not reliable to include in statistical evaluations. In this study, we have investigated the performance of collision cell ICP-MS in simulated otolith solutions. A method was developed to reduce the interferences of calcium on iron. The method is based on the coprecipitation of iron with sodium hydroxide to separate it from the interfering otolith calcium. Because otoliths are predominantly (e.g., 96% CaC[O.sub.3]), optimization of the precipitation conditions were carried out with CaC[O.sub.3] (99.999%). Iron is quantitatively precipitated as hydroxides at pH above 11.8. The precipitation of the calcium was controlled by optimizing the volume of sodium hydroxide solution used. The procedure was validated by analysis of fish otolith reference material by ICP-MS.

2:00 DIEL CYCLING IN IRON SPECIATION IN THE PEARL RIVER, MISSISSIPPI 

Peter van Erp* and Alan M. Shiller, University of Southern Mississippi, Hattiesburg, MS 39406 and University of Southern Mississippi, Stennis Space Center, MS 39522

Investigations in the cycling between oxidized and reduced forms of iron in freshwater has mainly been carried out in streams affected by acid mine drainage. This study looks at the existance of an iron diel cycle in the Pearl River, Mississippi. Speciation of iron plays a significant role in the transport of trace metals and/or organic matter. Using filtered (0.2 [micro]m) surface water collected from the Pearl River near Stennis Space Center, Mississippi a series of incubation experiments has been conducted. Initial incubations showed that an iron diel cycle was not significant with [Fe(II)] between 30-80 nM. A subsequent incubation where samples were treated with the Fe(II) chelator bathophenanthrolinedisulphonate (BPDS) showed significant production of Fe(II) up to 2.6 [micro]M. Apparently a diurnal peak of Fe(II) was being prevented due to rapid oxidation of the Fe(II). Further incubations will be conducted to ascertain the mechanism behind this rapid oxidation.

2:20 Break

2:40 DETECTION OF HYPOXIC CONDITIONS IN THE MISSISSIPPI BIGHT IN THE SUMMER OF 2006

Stephan Howden, University of Southern Mississippi, Hattiesburg, MS 39406

Monitoring of coastal waters for hypoxic conditions on the continental shelves of the U.S. has revealed that the development of hypoxia (dissolved oxygen concentrations < 2.0 mg/L) in the summer months is more common that once thought. In the Mississippi Bight, anecdotal evidence for the sporadic recurrence of hypoxia in Mississippi Bight had been recently augmented by summer time measurements conducted by the Mississippi Department of Marine Resources in 2004 at Fish Haven 2 (FH-2) south of Horn Island, and analysis of foraminifer assemblages in surface sediment samples taken in the 1950's near FH-2. Based upon a detection of near-hypoxic waters near FH-2 in late July 2006, two cruises on the R/V Tom Mellwain were conducted in August 2006 to sample a grid of 22 sites south of the barrier islands of Mississippi. The prime objectives were to map the extent of the hypoxic region along with the physical environment (temperature, salinity, and currents). With some exceptions, at each site profiles were measured of dissolved oxygen, temperature, pressure, conductivity, turbidity, and currents. Oxygen was measured using a YSI 6030 probe and a Sea-Bird SBE 43 probe. Salinity and dissolved oxygen values were compared and verified with analysis of discrete water samples using a Guildline Autosalinometer and Winkler analysis, respectively. A hypoxic bottom water region of 7 sites extending seaward to ~20 m water depth near FH-2 and extending along the 10 m isobath from Ship Island to Petit Bois Pass was detected. Winkler analyses confirmed four of these sites, with the other three having values <2.8 mg/L. Dissolved oxygen profiles exhibited large gradients near the seafloor making difficult the match-up between the profile data and the water samples. Eleven of the sites had values <3.0 mg/L. The water column was highly stratified throughout the region, in some cases with several pronounced pycnoclines, consistent with isolation of deep waters from atmospheric refreshment.

3:00 EFFECTS OF SITE, SEASON, AND DEPTH IN SEDIMENT ON THE ABUNDANCE OF LIVE FORAMINIFERA IN TWO NORTHERN GULF OF MEXICO MARSHES

Sondra Simpson, Charlotte Brunner*, and Patricia M. Biesiot, University of Southern Mississippi, Stennis Space Center, MS 39529 and University of Southern Mississippi, Hattiesburg, MS 39406

The abundance of living foraminifera was documented over one year for two northern Gulf of Mexico salt marshes: one in a high-marsh setting of the Pearl River, and one in a low-marsh setting of the Jourdan River. This study tested the effects of site and season on the distribution of live foraminifera with depth in the sediment. Three sediment cores were taken and combined at each site in each of four seasons. The foraminifera were stained with rose Bengal, sieved at 45 [micro]m, and counted. Statistical analysis consisted of two-way ANOV As and a series of pair-wise comparisons. During the study, 14 taxa were recorded as living. Of these, 11 taxa were found in the low-salinity, high marsh, which was dominated by Trochammina macrescens, Trochammina inflata and Tiphotrocha comprimata, and 13 in the higher-salinity, low marsh, which was dominated by Miliammina fusca. Both site and depth in sediment had significant effects. However, the interaction effect was not significant. Surprisingly, season did not have a significant effect nor was there a significant interaction between site and season. The fauna had a statistically significant preference for depths <5 cm, and several species, including Polysaccammina ipohalina and Trochammina macrescens, had significant abundance peaks in the subsurface from 2.5-5 cm.

3:20 DEPTH-INDUCED VARIATION IN HYPERSPECTRAL REFLECTANCE SIGNALS OF AQUATIC VEGETATION

Melissa A. Larmer (1*), Jonathan R. Jones (1*), Christopher A. May (2), Hyun J. Cho (1), (1) Jackson State University, Jackson, MS 39217 and (2) Grand Bay National Estuarine Research Reserve, Moss Point, MS 39561

Remote sensing of submersed aquatic vegetation (SAV) is often limited due to the water absorption of near infrared radiation. We studied depth-induced variations in the reflectance patterns of common SAV using a GER spectroradiometer to provide a scientific understanding of the effects of depth and turbidity on remote sensing of SAV. Spectral measurements of upwelling energy were taken over Ruppia maritima beds at Grand Bay National Estuarine Research Reserve (NERR) and over outdoor tanks containing Myriophyllum aquaticum. Water level above the plant canopy was controlled by siphoning. Plants were scanned three times at a each depth at the intervals of 5-10 cm. The upwelling energy was converted to reflectance (%). Normalized Difference Vegetation Index (NDVI) values were then calculated for each set of measurements. Due to water absorption, the high plateau that appears in near-infrared regions of terrestrial plants became two individual peaks in submerged plants at approximately 719 and 810nm. NDVI values were approximately 0.3 for emergent SAV; these values decreased as water depth increased. Remote detection of SAV in shallow, coastal and inland waters will be improved if our results are integrated into the current vegetation index. We will apply our results to AISA images of Grand Bay NERR to assess the capability of this technique in identifying SAV beds. Acknowledgements: This research is supported by grants from NOAA-ECSC (No. NA17AE1626, Subcontract # 27-0629-017 to Jackson State University), National Science Foundation-UBM (No. DMS-0531927), MS-AL Sea Grant Consortium, and The Center for University Scholars of Jackson State University.

3:40 GUT MICROBIAL COMMUNITIES IN THE ESTUARINE BIVALVES GEUKENSIA DEMISSA AND CRASSOSTREA VIRGINICA

Dawn Loggans*, Patricia M. Biesiot, and Shiao Y. Wang, University of Southern Mississippi, Hattiesburg, MS 39406

The ribbed mussel Geukensia demissa is a dominant intertidal bivalve commonly found in salt marshes along the east coast of the United States and the Gulf of Mexico; the eastern oyster Crassostrea virginica is subtidal in the same regions. Previous studies have shown that detrital lignocellulose derived from Spartina alterniflora is utilized by G. demissa to meet 26-80% of its carbon requirements whereas C. virginica assimilates < 3%. We hypothesize that differences in the gut microflora of these two bivalves may contribute to the observed variation in digestion of refractory organic detritus. To characterize the gut microbial community in these bivalves, universal primers specific for bacteria were used to PCR amplify the 16S ribosomal RNA gene, which was then cloned. Sequence results from the clone libraries indicate that the two bivalve species do have different gut bacterial communities. Mycoplasma spp. dominate in the gut of G. demissa. Other gut bacteria included Enterococcus faecium, Epulopiscium sp., Streptacidiphilus, Lactobacillus zeae and Synechococcus sp. In contrast, Mycoplasma was not found in C. virginica, although Massilia sp., Salmonella sp., Desemzia incerta, Gaetbulimicrobium brevivitae, Acinetobacter sp., Anaplasma sp., and several uncultured proteobacteria were isolated. Current efforts are focused on determining whether the gut isolates are cellulolytic.

4:00 Divisional Business Meeting