Life Sciences Commons^™

Conservation Genetics And Systematics Of Several Turtles Species In The Southeastern United States, Joshua Robert Ennen

Dissertations

Chelonians (i.e., turtles) are an imperiled group of reptiles with about 66% of the recognized species listed as threatened by the IUCN. Most chelonian species have a unique set of life history traits (i.e., longevity, delayed sexual maturity, and low juvenile survivorship), which makes their populations exceedingly sensitive to increases in adult and juvenile moralities. With numerous anthropogenic effects (e.g., habitat alteration, exploitation, and over harvesting) negatively influencing mortality rates, chelonians have experienced global precipitous declines and extinctions.

This dissertation focuses on species within two chelonian genera, Gopherus and Graptemys. Although these two genera are vastly different ecologically, they are …

Remote Sensing Of Harmful Algal Blooms In The Mississippi Sound And Mobile Bay: Modelling And Algorithm Formation, Dan Martin Holiday

Dissertations

The incidence and severity of harmful algal blooms have increased in recent decades, as have the economic effects of their occurrence./The diatom Pseudo-nitzschia spp. caused fisheries closures in Mobile Bay during 2005 due to elevated levels of domoic acid. In the previous 4 years Karenia brevis counts of >5,000 cells L"1 have occurred in Mobile Bay and the Mississippi Sound. Population levels of this magnitude had previously been recorded only in 1996. Increases in human populations, urban sprawl, development of shoreline properties, sewage effluent and resultant changes in NP ratios of discharge waters, and decline in forest and marsh lands, …

Experimental Population Dynamics Of Amyloodiniumocellatum In The Spotted Seatrout, Cynoscion Nebulosus, And The Red Snapper, Lutjanus Campechanus, Ignacio Masson

Dissertations

Amyloodinium ocellatum is a parasitic dinoflagellate that infects warm water marine bony fishes and causes high mortalities in aquaculture settings. It has three life history stages: the feeding trophont, the reproductive tomont, and the infective dinospore. This dissertation describes the characteristics of A. ocellatum infections in juvenile spotted seatrout, Cynoscion nebulosus, and red snapper, Lutjanus campechanus, studies the survival and fecundities of the stages in the life cycle of the parasite and presents a population model for A. ocellatum.

At 25°C and 33 ppt, the peak of trophont detachment occurred on day 2 postinfection in spotted seatrout and day 3 …

Sensitivity Of The Carbon Cycle In The Arctic To Climate Change, A. David Mcguire, Leif G. Anderson, Torben R. Christensen, Scott Dallimore, Laodong Guo, Daniel J. Hayes, Martin Heimann, Robie W. Macdonald, Nigel Roulet

Faculty Publications

The recent warming in the Arctic is affecting a broad spectrum of physical, ecological, and human/cultural systems that may be irreversible on century time scales and have the potential to cause rapid changes in the earth system. The response of the carbon cycle of the Arctic to changes in climate is a major issue of global concern, yet there has not been a comprehensive review of the status of the contemporary carbon cycle of the Arctic and its response to climate change. This review is designed to clarify key uncertainties and vulnerabilities in the response of the carbon cycle of …

A Method Of Successive Corrections Of The Control Subspace In The Reduced-Order Variational Data Assimilation, Max Yaremchuk, Dmitri A. Nechaev, Gleb Panteleev

Faculty Publications

A version of the reduced control space four-dimensional variational method (R4DVAR) of data assimilation into numerical models is proposed. In contrast to the conventional 4DVAR schemes, the method does not require development of the tangent linear and adjoint codes for implementation. The proposed R4DVAR technique is based on minimization of the cost function in a sequence of low-dimensional subspaces of the control space. Performance of the method is demonstrated in a series of twin-data assimilation experiments into a nonlinear quasigeostrophic model utilized as a strong constraint. When the adjoint code is stable, R4DVAR's convergence rate is comparable to that of …

Remote Sensing And Mapping Of Tamarisk Along The Colorado River, Usa: A Comparative Use Of Summer-Acquired Hyperion, Thematic Mapper And Quickbird Data, Gregory A. Carter, Kelly L. Lucas, Gabriel A. Blossom, Cheryl L. Lassitter, Dan M. Holiday, David S. Mooneyhan, Danielle R. Fastring, Tracy R. Holcombe, Jerry A. Griffith

Faculty Publications

Tamarisk (Tamarix spp., saltcedar) is a well-known invasive phreatophyte introduced from Asia to North America in the 1800s. This report compares the efficacy of Landsat 5 Thematic Mapper (TM5), QuickBird (QB) and EO-1 Hyperion data in discriminating tamarisk populations near De Beque, Colorado, USA. As a result of highly correlated reflectance among the spectral bands provided by each sensor, relatively standard image analysis methods were employed. Multispectral data at high spatial resolution (QB, 2.5 m Ground Spatial Distance or GSD) proved more effective in tamarisk delineation than either multispectral (TM5) or hyperspectral (Hyperion) data at moderate spatial resolution (30 m …

Detecting Proteins In Highly Autofluorescent Cells Using Quantum Dot Antibody Conjugates, Karen M. Orcutt, Shanshan Ren, Kjell Gundersen

Faculty Publications

We have applied quantum dot (Qdot) antibody conjugates as a biomolecular probe for cellular proteins important in biogeochemical cycling in the sea. Conventional immunological methods have been hampered by the strong autofluorescence found in cyanobacteria cells. Qdot conjugates provide an ideal alternative for studies that require long-term imaging of cells such as detection of low abundance cellular antigens by fluorescence microscopy. The advantage of Qdot labeled probes over conventional immunological methods is the photostability of the probe. Phycoerythrin bleaches in cyanobacterial cells under prolonged UV or blue light excitation, which means that the semiconducting nanocrystal probe, the Qdot, can yield …

Morphological Deformities As Biomarkers In Fish From Contaminated Rivers In Taiwan, Peter Lin Sun, William E. Hawkins, Robin M. Overstreet, Nancy J. Brown-Peterson

Faculty Publications

Tilapia (Oreochromis spp.) were collected seasonally from four contaminated rivers in southwestern Taiwan for studies of morphological deformities that could be used as biomarkers of contamination. Morphological deformities found in tilapia were separated into 15 categories. Overall, the prevalence of deformities such as split fins, lower lip extension and gill deformities were significantly related to various water quality parameters, including low DO and high ammonium, lead and zinc concentrations. The persistence of tilapia in polluted waters and the development of a suite of morphological deformities suggest that tilapia can be used as sentinels of non-point source pollution in rivers.

Bridging Functional Genomics And Toxicogenomics Through Dna Microarrays In A Fish Model, Shuzhao Li

Dissertations

In a case study of finding gene expression signatures for environmental stressors in Cyprinodon variegatus, this dissertation examines several important issues of applying DNA microarray technology to fish toxicogenomics. The most relevant disciplines, fish toxicogenomics and computational systems biology are reviewed in Chapter 1. Chapter 2 reviews major aspects of DNA microarray technology.

On DNA microarrays, even for probes that target the same transcript, large variations are seen in the probe signals. These variations are partly dependent and partly independent on probe sequences. Chapter 3 estimates the sequence independent variation by combining experimental and computational approaches. Chapter 4 and …

Factors Influencing The Environmental Quality Of The Bay Of Saint Louis, Mississippi And Implications For Evolving Coastal Management Policies, Pradnya Ankush Sawant

Dissertations

The Bay of St. Louis, MS is a small northern Gulf of Mexico estuary that has been identified by the Mississippi Department of Environmental Quality (MDEQ) as an impaired waterbody for its designated uses, mainly due to the presence of pollutant pathogens. A systematic study of this estuary was important to understand the behavior and responses of the bay to several natural and anthropogenic forcing factors. A 14- month long study (bimonthly sampling) to evaluate its environmental quality was undertaken from April 2003 to May 2004. Environmental quality was defined as "the health of an ecosystem characterized in terms of …

Chemical And Isotopic Characterization Of Size-Fractionated Organic Matter From Cryoturbated Tundra Soils, Northern Alaska, Chunhao Xu, Laodong Guo, Chien-Lu Ping, Daniel M. White, Thomas D. Lorenson

Faculty Publications

Recent studies indicate a second layer of organic matter often accumulates in the lower active layer and upper permafrost in arctic tundra soils as a result of cryoturbation. In this study, cryoturbated organic matter was characterized using a combination of physical size fractionation and modern analytical techniques for elemental composition (C and N), stable isotopes (delta(13) C and delta(15)N), radiocarbon content (Delta(14)C), and molecular fingerprinting (pyrolysis-gas chromatography/mass spectrometry, Py-GC/MS). The results indicated that cryoturbated organic matter could be highly bioavailable. Soil organic matter (SOM) associated with fine sand particles was considered to be the organic carbon pool most sensitive to …

On The Mechanisms Of Episodic Salinity Outflow Events In The Strait Of Hormuz, Prasad G. Thoppil, Patrick J. Hogan

Faculty Publications

Observations in the Strait of Hormuz (26.26 degrees N, 56.08 degrees E) during 1997-98 showed substantial velocity fluctuations, accompanied by episodic changes in the salinity outflow events with amplitude varying between 1 and 2 psu on time scales of several days to a few weeks. These events are characterized by a rapid increase in salinity followed by an abrupt decline. The mechanisms behind these strong pulses of salinity events are investigated with a whigh-resolution (similar to 1 km) Hybrid Coordinate Ocean Model (HYCOM) with particular reference to the year 2005. In accordance with the observations, the simulated salinity events are …

Oceanic-Atmospheric Modes Of Variability And Their Effect On River Flow And Blue Crab (Callinectes Sapidus) Abundance In The Northcentral Gulf Of Mexico, Guillermo Humberto Sanchez-Rubio

Dissertations

Oceanic-atmospheric modes of variability occur on interdecadal, multidecadal, decadal, and interannual timescales and their influence on climate around the world has been confirmed. The present study investigates Mississippi River and Pascagoula River flows in response to the influence of one or more of the four oceanic-atmospheric modes of variability: the Pacific Decadal Oscillation (PDO), the Atlantic Multidecadal Oscillation (AMO), the North Atlantic Oscillation (NAO), and the El Nino Southern Oscillation (ENSO). These modes of variability are present in phases: PDO warm (PDOw) and cold (PDOc), AMO warm (AMOw) and cold (AMOc), NAO positive (NAOp) and negative (NAOn), and ENSO warm …

The Effects Of Climate Variability On The Structure Of The Phytoplankton Community In Tumaco Bay, Colombia, Ingrid Garcia-Hansen Honkala

Dissertations

Spatiotemporal variability in the diatom and dinoflagellate community structure and chlorophyll a (chl a) concentrations in Tumaco Bay during the 1993-2005 period was related clearly to seasonal and interannual variability in environmental conditions due to the migration of the Inter-tropical Convergence Zone (ITZC) and the influence of El Nino Southern Oscillation (ENSO) events. A total of 134 species of diatoms that belong to 57 genera, and 78 species of dinoflagellates that belong to 25 genera were identified during the survey. The diatom community was the dominant group in the waters of the bay, being the most abundant with the greatest …

Historical Account Of The Two Family-Group Names In Use For The Single Accepted Family Comprising The "Fish Blood Flukes", Stephen A. Bullard, Kirsten Jensen, Robin M. Overstreet

Faculty Publications

The family-group name for the "fish blood flukes" is unstable, with both "Aporocotylidae Odhner, 1912" and "Sanguinicolidae von Graff, 1907 "in use for the single family. Although "Sanguinicolidae von Graff, 1907" (or "Graff, 1907") has been a widely-accepted family-group name for the fish blood flukes subsequent to Yamaguti's 1954 and 1958 synoptical publications ("Systema Helminthum"), a critical examination of the relevant literature, much of it published in German during 1900 through 1926, reveals that "Aporocotylidae Odhner, 1912" is the earliest available family-group name for these flukes. The name Aporocotylidae, moreover, was in wide usage by alpha taxonomists before 1954 and …

Satellite-Detected Fluorescence Reveals Global Physiology Of Ocean Phytoplankton, Michael J. Behrenfeld, T.K. Westberry, Emmanuel Boss, R.T. O'Malley, D.A. Siegel, Jerry D. Wiggert, B.A. Franz, G.C. Feldman, S.C. Doney, J.K. Moore, G. Dall'olmo, A.J. Milligan, I. Lima, N. Mahowald

Faculty Publications

Phytoplankton photosynthesis links global ocean biology and climate-driven fluctuations in the physical environment. These interactions are largely expressed through changes in phytoplankton physiology, but physiological status has proven extremely challenging to characterize globally. Phytoplankton fluorescence does provide a rich source of physiological information long exploited in laboratory and field studies, and is now observed from space. Here we evaluate the physiological underpinnings of global variations in satellite-based phytoplankton chlorophyll fluorescence. The three dominant factors influencing fluorescence distributions are chlorophyll concentration, pigment packaging effects on light absorption, and light-dependent energy-quenching processes. After accounting for these three factors, resultant global distributions of …

The Influence Of Habitat And Fishing On Reef Fish Assemblages In Cuba, Gaspar Gonzalez-Sanson, Consuelo Aguilar, Ivet Hernandez, Yureidy Cabrera, R. Allen Curry

Gulf and Caribbean Research

The abundance of selected fish species was estimated using the stationary visual census technique in the northwestern region of the Cuban shelf. A total of 26,809 individuals of 32 species were counted in 1,172 stationary point censuses made at 10 reef sites along the coast. We found that the abundance patterns were most probably the consequence of the presence/absence of mangroves and seagrass beds in adjacent lagoon areas. A second factor influencing the spatial variation appeared to be overfishing on an east-west gradient, with lower abundances of commercially targeted species near Havana City in the east.

Abundance And Distribution Of Two Species Of Squilla (Crustacea: Stomatopoda: Squillidae) In The Northern Gulf Of Mexico, Jennifer L. Wortham

Gulf and Caribbean Research

Stomatopods (mantis shrimps) are predatory benthic crustaceans. Mantis shrimp in the genus Squilla are frequent bycatch animals unintentionally collected in conjunction with the shrimp fishery in the Gulf of Mexico (GOM). Their carcasses are discarded instead of being retained for human consumption, fish meal, or other protein-based food products. The size, depth, salinity, and temperature distributions of these species, as well as their abundance based on gender, were examined to gain biological information that would be necessary if a fishery were to develop in the GOM. I collected samples (n = 2,854) of Squilla empusa and Squilla chydaea in the …

Seagrass Loss In Belize: Studies Of Turtlegrass (Thalassia Testudinum) Habitat Using Remote Sensing And Ground-Truth Data, Gary R. Gaston, Cole Easson, Greg Easson, Justin Janaskie, M.A. Ballas

Gulf and Caribbean Research

Spatial and temporal change in turtlegrass (Thalassia testudinum) habitat of the South Water Caye Marine Reserve (SWCMR) in Belize were analyzed using satellite images backed up with ground-truth data. We had two pri-mary objectives. First, we wanted to determine areal expanse of seagrass across a large area (~12 km by 3 km) of the SWCMR, and address its change over time. We used paired satellite images taken during 2001 and 2005 to determine coverage by seagrass and measure temporal variables. These analyses recorded an overall seagrass loss of 1.8% (52.3 ha) during the 4 yr period. Secondly, we …

Determining Salinity-Tolerance Of Giant Salvinia Using Chlorophyll Fluorescence, Patrick D. Biber

Gulf and Caribbean Research

Salvinia molesta Mitchell, a floating invasive aquatic plant, is one of the top 10 worst invasive aquatic weeds in the world. It was discovered in the lower Pascagoula River in 2005 and evidence suggests that this non-native species is spreading along the northern Gulf of Mexico. These plants exhibit rapid growth and nutrient uptake rates, allowing them to out compete other plants in similar habitats. Distributional observations suggest that non-native S. molesta is able to survive in salinities of up to 7 ppt in the lower Pascagoula River. The response of S. molesta to three salinity levels (0, 5, 10 …

First Records Of The Seagrass Parasite Plasmodiophora Diplantherae From The Northcentral Gulf Of Mexico, Allison K. Walker, Jinx Campbell

Gulf and Caribbean Research

Plasmodiophora diplantherae is known to occur throughout the pantropical distribution of its host, the seagrass genus Halodule. However, records in the subtropical region are limited to Tampa Bay, FL where it was detected once during an examination of herbar-ium specimens of H. beaudettei collected in December 1951 (den Hartog 1965) and to Fort Pierce, FL where it was collected once infecting H. wrightii (Braselton and Short 1985). This communication represents the first report of this parasite from Mississippi and Louisiana in the northcentral Gulf of Mexico (GOM).

A Comparison Of Fish Populations In Shallow Coastal Lagoons With Contrasting Shoalgrass (Halodule Wrightii) Cover In The Northcentral Gulf Of Mexico, Just Cebrian, Glenn A. Miller, Jason P. Stutes, Adrienne L. Stutes, Mairi E. Miller, Kate L. Sheehan

Gulf and Caribbean Research

A number of studies have examined the effects of reduced seagrass cover on local fish populations (e.g., Heck et al. 1989, Ferrell and Bell 1991, Hughes et al. 2002 and more), but few of those studies have focused on shoalgrass (e.g., Tolan et al. 1997, Rydene and Matheson 2003). We present a preliminary comparison of fish populations in three shallow coastal lagoons in the northcentral GOM that have varying levels of shoalgrass cover. Namely, we compare (1) abundances of individual species and the entire fish population, (2) fish population diversity, and (3) length-frequency distributions of the most abundant species.

Age Estimates Of Two Large Misty Grouper, Epinephelus Mystacinus (Serranidae) From Bermuda With A Comparison Of The Age Of Tropical Groupers In The Western Atlantic, Brian E. Luckhurst, John M. Dean

Gulf and Caribbean Research

Misty grouper are known to attain at least 54 kg and 115 cm total length (TL) (Heemstra and Randall 1993) although a maximum size of 160 cm TL is reported (Appeldoorn et al. 1987, cited in www.FishBase.com). Recently, two specimens (152 and 157 mm TL) were landed by commercial fisherman from the edge of the Bermuda platform, providing documentation of the maximum size which may be attained by this species. There are no age and growth studies on misty grouper (Heemstra and Randall 1993; www.FishBase.com). Therefore, the age data presented here, although not validated, represent the first estimates of maximum …

Macrofauna Associate With Ungrounded Prop Roots Of Rhizophora Mangle In Veracruz And Quintana Roo, Mexico, Kathryn D. Tunnell, Kim Withers

Gulf and Caribbean Research

The prop roots of the red mangrove (Rhizophora mangle) provide a solid substrate for diverse assemblages of marine organisms in areas typically characterized by soft bottoms (Bingham 1992, Farnsworth and Ellison 1996). Macrobenthic communities of mangroves have received little attention compared with other components of the ecosystem, largely due to sampling difficulties (Lee 2008). Mangrove root epifauna are likely used by predatory fish, especially juveniles. Thus, these organisms have the potential of being important links between mangroves and adjacent ecosystems. The fauna associated with red mangrove prop roots along Mexican Gulf of Mexico (GOM) and Caribbean shorelines has …

Genetic Variation For Carcass Quality Traits In Cultured Sea Bass (Dicentrarchus Labrax), Eric A. Saillant, Mathilde Dupont-Nivet, Marie Sabourault, Pierrick Haffray, Stanislas Laureau, Marie-Odile Vidal, Béatrice Chatain

Faculty Publications

Genetic parameters for carcass quality traits were estimated in 27 families of sea bass (3 dams x 9 sires factorial mating design), raised mixed in the same tanks starting before hatching. O. spring parentage was determined a posteriori using 6 microsatellite loci. Carcass quality traits were recorded at 818 days post fertilization (mean standard length: 32.6 +/- 3.1 cm). Genetic parameters were estimated from the sire half sib variance and covariance components. Heritability of body weight (BW) and carcass processing traits (standardized to body weight) percent head weight (Head%), percent viscera weight (Viscera%) and percent visceral fat weight (VisceFat%) were …

Morphological Characteristics Of Early Life History Stages Of The Blue Crab, Callinectes Sapidus Rathbun, From The Northern Gulf Of Mexico With A Comparison Of Studies From The Atlantic Seaboard, Kenneth Stuck, Harriet Perry, Darcie Graham, Richard W. Heard

Gulf and Caribbean Research

Zoeae, megalopae, and early crab stages of Callinectes sapidus Rathbun, 1896 were described from the northern Gulf of Mexico (nGOM). Observations during this study were based on larvae reared in the laboratory through the early crab stages and on megalopae and early crab stages collected in the wild. Gulf of Mexico data are compared with similar information for the southeast Atlantic coast of the United States. Size and setation of C. sapidus larvae reared from nGOM stocks were different than those in published descriptions of larvae reared from Atlantic populations. Seasonal differences in size were noted in both reared and …

Note On The Natural And Cultural History Of Hurricane Balls, Joyce M. Shaw

Gulf and Caribbean Research

Hurricane balls are natural phenomena of tropical storms and hurricane winds and waves and are found along the shoreline. Gunter Library at the Gulf Coast Research Laboratory (GCRL) is home to a small collection of hurricane balls which were found along the shore lines of barrier islands and marsh beaches by GCRL staff over the years. Hurricane balls come in many sizes, and large balls can be slightly larger than a standard basketball of 24.8 cm diameter (USA Basketball 2001). Large balls in the Gunter Library collection range from 34.5 cm diameter (from 1969 Hurricane Camille) to 53.5 cm diameter …