Seasonal overbank flooding in systems like the Atchafalaya River Basin (ARB) provides the opportunity for fishes in the mainstem to access off-channel areas on the floodplain. Typically, newly inundated floodplain habitats allow adult fishes to add biomass, avoid predation, and potentially, to reproduce. However, in systems like the ARB, the timing, duration, and magnitude of flooding infrequently coincides with known reproductive periods of many fishes assumed to be floodplain-dependent. To quantify the level of floodplain-exploitative fish reproduction in the ARB, I collected larval and juvenile fish with a variety of sampling gear that allowed estimates in both ultra-shallow (< 2-m) and continuously-inundated habitats (headwater lakes, canals, and bayous). A suite of water quality parameters, river stage, flow, and hours of daylight were used to gauge the influence of environmental phenomena on age-0 abundance during both inundation and drawdown. The results of the 19-month study suggest that many taxa do not rely on the floodplain to ensure high survivorship. Interestingly, the reproductive ecologies of many ARB fishes appeared to be largely independent of widespread connectivity. Although an increasing hydrograph appeared to enhance reproductive output, the interannual timing and intensity of spawning showed limited variability. Larval densities were also contrasted with the microcrustacean zooplankton (copepods and cladocerans) population to assess if a potential food limitation existed in the weeks and months following hatching. During the study, increased zooplankter abundance was typically preceded by elevated river-floodplain connectivity. Conversely, as floodwaters receded during the summer, zooplankton abundance declined to lowest levels observed during the study. Overall, there was limited synchronous overlap between the hatchlings of most fish taxa and their zooplankter prey. This could have potentially resulted in starvation and reduced annual recruitment. Yet, my analysis of the factors that regulate larval fish abundance in the ARB suggest that the density of zooplankton was highly significant although high numbers of larvae and zooplankton rarely coincided. Finally, I compared the intraday (morning vs. afternoon) density and mean length of larval fish at fixed sample sites. The results suggest that once-daily ichthyoplankton collections may fail to provide accurate density and length measurements for young fish populations.

Greater structural complexity is often associated with more diverse and abundant species assemblages. Biogenic reefs formed by the eastern oyster (Crassostrea virginica) are structurally complex in nature and have been recognized for their potential habitat value in estuarine systems along the Atlantic and Gulf of Mexico coasts. To determine how the structural complexity of newly created oyster reefs may influence the abundance and distribution of species, three objectives were established. First, to examine spatial and temporal patterns of nekton use at newly created oyster reefs, as well as the impact of wave exposure, six paired oyster reef and mud-bottom treatments at low and medium wave energy shorelines were sampled quarterly, from June 2009 to March 2010, at Caillou (Sister) Lake, Louisiana, using gill nets, seine, and substrate trays. Transient species showed seasonal shifts with no evidence of habitat preference. Resident species were consistently more abundant at oyster reefs than mud-bottom treatments. There were no patterns in nekton use that could be directly attributed to wave exposure. Second, to determine how changes within the structural complexity of newly created oyster reefs may influence nekton use, oyster reef treatments of various complexities were created and sampled using a drop sampler. The presence of oyster reefs per se was the most important factor determining nekton assemblages; newly created oyster reefs provided habitat for nekton assemblages, but there was little difference between reef treatments. Lastly, to determine how oyster reefs mediate predator foraging success, treatments of various complexities were created and trials executed in a laboratory setting using wild red drum (Scianops occelatus) and grass shrimp (Palaemonetes pugio). Foraging success was negatively correlated to the structural complexity of oyster reefs, indicating there may be a point above which increased complexity no longer increases the refuge value of the reef. These results show that oyster reefs may support a high abundance and diversity of resident nekton, but that after structure is introduced, further increasing structural complexity does not automatically increase species abundance and diversity, or the amount of refugia provided.

Seeding survival has been a continuing problem since the start of the commercial pine plantation in 1950s. The first-year survival of bare-root loblolly pine seedlings at intensively prepared sites in Louisiana has reached a survival plateau of 75 to 85 % with an average of almost 80 %. The major hypothesis of this research was that the survival plateau is a function of the interaction between the frequency distribution of seedling quality and the frequency distribution of microsite quality. This study examined bare-root seedlings and microsite variation, and analyzed the possible options to increase the first-year seedling survival. The study was approached with simulation and field studies. In simulation study, twenty hypothetical seedling and microsite quality distributions were paired in a manner that simulated 400 plantings. In field study, caliper, stem height, shoot-root ratio, leaf area, and xylem pressure potential were measured for a bale of nursery seedlings and the quality distribution was computed from the seedling volume. Similarly, the microsite variables soil penetration, bed height, moisture content, total mineral nitrogen, and texture were measured and the quality distribution of 8 Weyerhaeuser planting sites was generated from the height increment of associated seedlings. The distributions were combined to predict the first year survival from the assumptions about proportional survival for each pairing. The simulation results provided initial support to the hypothesis that consistent survival results from random pairing of initial seedling and site quality distributions. The average caliper was 4.22 mm for the seedling sample obtained from a local nursery. The sample contained at least 31 % inferior quality seedlings and, the planting sites contained 21 % adverse microsites. Analysis showed that the significant proportion of inferior seedlings and adverse microsites would result in lower average survival based on assumed survival matrix. The elimination of seedlings below 5 mm caliper of the nursery stock increased the survival to 90 % at the cost of 40.9 ¢ per seedling, an increase of 37 ¢ per seedling.

This research assessed the current conditions of water quality in a shallow subtropical lake, influenced by a highly developed urban environment. Specifically, the research focused on the dynamics of phosphorus, nitrogen, and dissolved oxygen, as well as the effects of stormwater runoff on lake water quality. Furthermore, the research quantified gross primary production, net primary production, and respiration in order to discern seasonal variation in lake metabolism. A water quality monitoring platform with multi-parameter probes was deployed in the center of University Lake on the Louisiana State University campus. A series of lake water quality parameters including dissolved oxygen (DO) concentration, temperature, pH, specific conductivity, and cyanobacteria were recorded continuously at a 15-min interval from July 2008 to October 2009. In addition, water samples were collected monthly as well as after major rain events during the study period to determine changes in total phosphorus (TP), nitrate (NO3-), nitrite (NO2-), and total Kjeldahl nitrogen (TKN) concentrations. Results show a monthly average concentration of 0.286 mg/L TP (min max: 0.167 - 0.621 mg/L), 0.053 mg/L NO3-N (below detection 0.24 mg/L), 0.045 mg/L NO2-N (below detection 0.012 mg/L), and 2.5 mg/L TKN (below detection 5.12 mg/L). Mean storm event loading of 28.1 kg (7.5 47.8 kg) caused an immediate increase in total phosphorus within the water column by 14.1%. This resulted in a mean TP lake concentration of 0.383 mg/L. A similar trend was observed in a lesser degree in NO3-N and TKN. Phosphorus loads in the lake were correlated with runoff volume (r2 = 0.71), suggesting runoff volume is the most important factor effecting lake TP concentration after a storm event. Analysis of metabolism rates found a mean annual gross primary productivity value of 4.41 g O2/m2/day, a mean annual net primary production value of 2.13 g O2/m2/day, and a mean annual respiration value of 5.90g O2/m2/day. Annually, 1610 g O2/m2 were produced while the annual sum of respiration was 2150 g O2/m2. Respiration rates were mostly equal to or greater than productivity rates throughout the year, indicating that this shallow subtropical urban lake was net heterotrophic throughout most of the year.

Few studies have examined the effectiveness of timber harvesting Best Management Practices (BMPs) in water quality protection of widely-spread, low-gradient, and highly intermittent headwaters on the Gulf Coastal Plain. Also, a spatial disparity exists between the plot-scale water quality benefits afforded by BMP implementation and the watershed-scale with which most watershed stewardship programs are managed. In this thesis research, paired-watershed and Before-After-Control-Impact (BACI) designs were utilized to quantify plot- and watershed-scale changes in streamflow, as well as baseflow and stormflow Total Suspended Sediment (TSS) concentration and yield for 27 months after clearcut harvesting with and without BMPs in a low-gradient, forested, 3rd-order watershed of north-central Louisiana. Based on analyses of post-harvest baseflow, stormflow, stage-discharge relationships, TSS concentration, and sediment yield, low-intensity (2-8% disturbance of sub-watershed drainage area), clearcut harvesting adjacent to streams and with BMP implementation did not impact streamflow or sediment transport at the plot- or watershed-scale. No difference was found between treatment periods for monthly baseflow discharge measurements or in peak water level response to storm events. Flow duration curve analysis showed that baseflow decreased during the post-harvest period, possibly due to differences in the timing of precipitation between treatment periods. Changes in the stage-discharge relationship were observed downstream of harvesting without BMPs, indicating harvest-induced changes to stream geomorphology. Baseflow and stormflow TSS concentration (mg L-1) and yield (kg ha-1 mo.-1) were similar between treatment periods and were on the lower end of published results for Coastal Plain sites. Post-harvest TSS yield increased downstream of harvesting without BMP implementation when high flow events were included in yield calculations. These results indicate that current Louisiana BMPs for timber harvesting are effective in mitigating sediment runoff at the plot- and watershed-scale for conditions similar to the monitored sites, which include an abundance of beaver/debris dams and highly intermittent streamflow. These natural conditions may have further improved sediment reduction from BMP implementation through ponding and reduction of flow rate and carrying capacity. The potential exists for future studies to determine the intermittency and beaver dam impacts to streamflow and sediment transport as forest disturbance increases throughout the watershed.

Research was conducted to implement remote setting technology for the commercial- scale production of oysters on alternative cultch material in Louisiana. Genetic research has created an enhanced oyster stock for commercial cultivation. Since the Louisiana oyster industry relies on natural seed production for product, they are unable to utilize these new advances and are never guaranteed a reliable source of oyster seed. Remote setting is one way of producing a consistent supply of genetically improved oysters. Cultch material for oyster settlement is a limiting resource. Several alternatives to clamshell have been explored. The objectives of this study are: (1) test larval setting success (penetration) using three cultch types in aerated and non-aerated treatments; (2) characterize triploid oyster seed growth and abundance among three cultch types on a commercial oyster lease; (3) characterize ploidy dilution of planted triploid oyster seed by natural diploids among three cultch types on an oyster lease; and (4) document the costs associated with seed bedding. Limestone had significantly less spat set than both whole and crushed oyster shell; spat set significantly less at bottom-depth and mid-depth in non-aerated compared to aerated treatments (objective 1). This shows the importance of aeration for spat settlement distribution among depths. Oyster growth was significantly less on limestone compared to both whole and crushed shell (objective 2). Spat on limestone were limited in two dimensional growing space. Of the fifty individuals sampled from each cultch type for percent triploidy, 2%, 4% and 8% were triploid for crushed shell, limestone and whole shell, respectively; all cultch types showed at least 92% diploid dilution (objective 3). These results are based on one site and season, therefore cannot be used to make conclusions about overall practicality for oyster production in Louisiana. The cost associated with seed bedding is $6.00 per barrel (objective 4). Whole oyster shell had significantly more initial spat set and growth than limestone. There was no significant difference in oyster abundance among all cultch types.

Wildfire has been suppressed in the nations forests for over a hundred years. The accumulation of forest fuels over time has created an urgent need to reduce fuel loads to prevent catastrophic wildfires from occurring, not only in our wildlands, but also in our Wildland/Urban Interfaces (WUIs). The residents who live within the WUI are particularly vulnerable to extreme wildfire events. As cities become more densely populated, increasing numbers of people are moving beyond the suburbs into the WUI. A complex matrix of structures and forested land, developing communities, and impinging forests exists within the WUI. This study utilized a survey instrument to elicit perceptions of wildfire risk and prescribed burning practices from residents within the WUI in the Florida parishes of southeastern Louisiana. Residents within the WUI show increasing interest in learning more about wildfire risk, acceptance for traditional forest management practices, such as prescribed burning, and willingness to interact with and receive education from the forest professionals in their region. The analysis of the data provides statistical support for the conclusion that the overall perception of wildfire risk is low and the acceptance of prescribed burning is high.

Tourism industry is one of the main drivers of the global economy and plays a key role in regional development. As negative environmental and socio-cultural impacts of mass tourism became apparent, the appeal of alternative forms of tourism, especially ecotourism, continued to gain a broad recognition. As a result, ecotourism became one of the fastest growing sectors in global tourism during the past decade. Being a fast-developing country with ample natural resources, Sri Lanka can benefit from adopting and promoting ecotourism. At present, Sri Lankas ecotourism resources remain largely under-utilized. With rising demand, ecotourism operators are under pressure to meet expectations of diverse consumers of their products. In this background, the need to define and distinguish ecotourists from other types of tourists has become important. The importance of using a behavioral approach to distinguish true ecotourists from other types of tourists is widely emphasized by tourism scholars. This study developed distinct motivational and behavioral profiles of visitors to forest-based attractions in Sri Lanka. Furthermore, understanding and predicting ecotourist behavior is important for ecotourism operators to better cater their target markets. Many authors have attempted to explain the recreational behavior through various behavioral theories. Based on Ajzen's (1991) Theory of Planned Behavior, this study proposed an ecotourism behavioral model of forest-based recreational areas in Sri Lanka, and incorporated knowledge and satisfaction in predicting ecotourism behavior. The role of previous visits in predicting future behavioral intentions in an ecotourism setting was modeled separately. The results identified four different types of tourists based on their behavioral and motivational characteristics i.e. ecotourists, picnickers, egoistic tourists, and adventure tourists. A typical ecotourist in Sri Lanka represents a relatively young recent high-school or university graduate, or a university student. The segment identified as egoistic tourists seems to be the most lucrative market segment to target from both environmental sustainability and business perspectives. The proposed ecotourism model suggests that knowledge and satisfaction are important determinants of ecotourism behavior. In addition, previous experiences of participating in ecotourism proved to be an important precursor of future behavioral intentions. Broad implications of visitor profiling and behavior modeling are also discussed.

In the 1980s, the term ecotourism emerged as a direct result of acknowledgment and reaction by travelers to global ecological practices. In reality, the concept of ecotourism carries wide applications, particularly for bio-diverse countries with unique natural attractions. Sri Lanka qualified as such a country, presenting a significant tourism resource base, that display natural and cultural phenomena, including forests, waterfalls, mountains, exotic flora and fauna, and a heritage equally as ancient and as rich as the Greeks and Romans. Ecotourism in todays dynamic global environment demands that ecotourism operators face a keenly competitive market in order to present an appealing ecotourism products and services to diverse customers. Therefore, an improved understanding of how tourists acquire knowledge about a destination and its services is important for marketing management decisions, designing of effective communication campaigns, and efficient service delivery. Consumer pre-purchase information search may be identified as one of the most compelling research fields in consumer behavior. However, scant evidence exists on how information is actually processed, prior to making travel decisions. This proposed model examines the causal relationship among information searching, information processing, destination image, and travel-related search outcomes pertaining to forest-based tourism, using a Structural Equation Modeling approach. The proposed model offers special attention to travelers information processing consequently influencing travel related outcomes. In addition, this study identified four distinct market segments, based on ecotourists utilization of external information sources in visiting forest-based tourism destinations in Sri Lanka: impulsive searchers, active seekers, passive seekers and, provider dependents. In the context of ecotourists actual travel related decisions, such as destination choice, estimated expenses and the length of stay at the destination, study findings suggest that provider dependents, followed by impulsive searchers are the most productive segments for destination marketers. Service providers are the primary source of information for provider dependents, while impulsive searchers tend to acquire travel related information through word of mouth communication.

The Gulf killifish (Fundulus grandis) is a topminnow native to the tidal marshes of the Gulf of Mexico. The species is prized by anglers as effective bait for catching popular sportfish and is of interest to aquaculturists and bait dealers due to its hardy nature. Limited seasonal availability and aquaculture of this species due to low fecundity and larval cannibalism of fry has led to increased incentive to improve cultural techniques. The purpose of this study is to determine the influences of temperature, salinity, and air incubation on embryogenesis of the Gulf killifish. Temperature was found to have a negative relationship with time to hatch and size at hatch when F. grandis eggs were incubated in 10 and 20 g/L saline treatments. Temperature did not significantly affect percent hatch at 10 g/L, but percent hatch displayed a positive relationship with temperature at 20 g/L. When incubated in 0.4, 7, 15, and 30 g/L salinity treatments, a negative relationship between salinity and rate of embryogenesis was detected. While larvae incubated in these salinities hatched at about the same size, reduced hatching percentages were reported in the 0.4 and 30 g/L treatments. A positive relationship between the rate of embryogenesis and temperature was observed in air incubated embryos. After reaching a stage of development when embryos are documented to hatch, temperature was observed to have a negative relationship with the extent of time hatch could be delayed. The results of this study can be used to improve culture practices for Gulf killifish. Larval size at hatch, percent hatch, and time to hatch can now be predicted across a range of temperatures and salinities. Warmer temperatures can be used to accelerate embryogenesis of air incubated embryos while colder temperatures can be used to extend the period of time hatch can be delayed.