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- Title
- Quantifying the impacts of oyster reef restoration on oyster coverage, wave attenuation and seagrass fragment retention in Mosquito Lagoon, Florida.
- Creator
-
Garvis, Stephanie, Walters, Linda, Weishampel, John, Virnstein, Robert, University of Central Florida
- Abstract / Description
-
The goal of this project was to determine the effects of oyster reef restoration on oyster coverage, wave height dissipation and seagrass recruitment. First, to assess the current versus historical coverage of natural, dead and restored oyster reefs within Mosquito Lagoon, aerial photographs from 2009, provided by Saint Johns River Water Management District, were digitized using ArcGIS software. Live reefs, restored reefs and dead reefs were screen digitized using a reef 'signature' in order...
Show moreThe goal of this project was to determine the effects of oyster reef restoration on oyster coverage, wave height dissipation and seagrass recruitment. First, to assess the current versus historical coverage of natural, dead and restored oyster reefs within Mosquito Lagoon, aerial photographs from 2009, provided by Saint Johns River Water Management District, were digitized using ArcGIS software. Live reefs, restored reefs and dead reefs were screen digitized using a reef 'signature' in order to estimate the area of each type of reef. The 2009 maps were used as a guide to digitizing the historical aerial photographs (1943, 1951, 1967, 1971, 1984, 1995, 2006). Dead reefs increased both in number and aerial extent during the study period (1943 (-) 2009), with 2009 having over 10 acres of dead reef coverage. Dead reefs were more likely to be found along major boating channels. Several dead reefs exhibited migration into the mangrove islands located landward of the 1943 footprint, with some dead reefs completely washing up into the shoreline. Restoration of dead reefs added 0.5 acres of live oysters to the Mosquito Lagoon area as of January 2009. Second, I examined how different oyster reef types (natural reef, restored reef, dead reef) reduced wave height. To determine wave height attenuation on each reef type, experiments were conducted in a 9 meter long wave tank using sensors that measured changes in wave height. For each reef type, replicate reefs were created in the wave tank. Shoreline sediment without oysters was used as a control. Using the wave generator, wave heights similar to Mosquito Lagoon boat wakes were created. Restored reefs reduced the incoming wave height by 25% compared to sediment without oysters. Lastly, I examined the potential link between oyster reef restoration and recruitment of seagrass fragments. Monthly surveys were performed to quantify the number of seagrass fragments encountering the three oyster reef types: dead reefs, natural reefs and restored reefs. The quantity of seagrass fragments was found to be similar on the three different reef types, but did show a significant trend of seasonality, which corresponds with the growing season of Halodule wrightii. Next, I tested retention of experimentally manipulated seagrass fragments on five natural and five restored reefs. Restored reefs retained seagrass fragments for significantly longer than natural reefs. I also measured seagrass fragment entanglement on each reef type inside the wave tank. I found that seagrass fragments were significantly more likely to become entangled and retained on restored reefs compared to dead and natural reefs. Overall, these metrics are important for determining the success of long-term oyster restoration project in Mosquito Lagoon, Florida. This project has found that oyster restoration is increasing the area of oyster habitat as well as providing important ecosystem services.
Show less - Date Issued
- 2012
- Identifier
- CFE0004538, ucf:49250
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004538
- Title
- RESTORATION OF INTERTIDAL OYSTER REEFS AFFECTED BY INTENSE RECREATIONAL BOATING ACTIVITY IN MOSQUITO LAGOON, FLORIDA.
- Creator
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Barber, Andrea, Walters, Linda, University of Central Florida
- Abstract / Description
-
In recent years, intertidal reefs of Crassostrea virginica (eastern oyster) along central Florida's east coast have suffered extensive losses due to wakes from recreational boats. These wakes have caused extensive shell movement and sediment resuspension which results in large piles of disarticulated shells along the seaward edges of reefs. Dead margins extend up to one meter above mean high water. The creation and enforcement of "no wake" zones in the area are unlikely. Thus, there is an...
Show moreIn recent years, intertidal reefs of Crassostrea virginica (eastern oyster) along central Florida's east coast have suffered extensive losses due to wakes from recreational boats. These wakes have caused extensive shell movement and sediment resuspension which results in large piles of disarticulated shells along the seaward edges of reefs. Dead margins extend up to one meter above mean high water. The creation and enforcement of "no wake" zones in the area are unlikely. Thus, there is an urgent need for an alternative restoration strategy before these oyster reefs decline any further. The goal of this project was to develop a scientifically-based restoration technique that minimized wake damage from recreational vessels on intertidal reefs in Canaveral National Seashore. To accomplish this, I tested a range of restoration measures to identify a design that best increased: 1) oyster recruitment, 2) three-dimensional structure of the intertidal reefs, and 3) biodiversity and abundances of sessile and motile species associated with reefs. As a starting substrate in all treatments, I used restoration mats, which were created by affixing 36 drilled oyster shells to 0.4 x 0.4 m pieces of black mesh (Vexar). Five mats were deployed on the fore-reef, midreef, and backreef areas of each reef. In my experiment, I manipulated two habitat conditions: 1) leveling of existing dead margins to bring the top of the dead margin below mean high water to facilitate settling of larvae, and 2) deploying artificial seagrass seaward of the mats to act as a wake buffer. All combinations of these variables and all appropriate controls were replicated on six oyster reefs each, for a total of thirty reefs. Reefs that were leveled were significantly reduced in height and this difference was maintained throughout the 1 year study. Unleveled reefs actually increased in mean height over the 12 months. Tracking loose shells covering our restoration mats over time likewise documented that shell movement was minimal on control reefs lacking dead margins and significantly greater on reefs with dead margins. Midreef areas on reefs with dead margins were almost completely buried by loose shells. Quarterly monitoring of the number of spat settling on all restoration mats allowed for comparisons between treatments and locations on oyster reefs. After determining that overall water flow on the fore reef areas of all treatments was similar, I tested the null hypothesis that all treatments had similar recruitment of oyster larvae. My first alternative hypothesis was that artificial seagrass would increase oyster recruitment if the grass was a successful wake buffer and minimized sediment resuspension known to be lethal to newly settled oyster or prevented disarticulated oyster shell from moving and reforming mounds. My second alternative hypothesis was that the leveling of the dead margins would increase the total reef surface area available to larval oyster recruitment and thus lead to an increase in the number of recruits and eventually 3-dimensional reef structures (when oysters grow in close proximity and affix themselves together). Statistical analyses showed the artificial seagrass did not decrease the negative impacts caused by recreational boat wakes. Hence, it is not a recommended method for reef restoration. Recruitment of oysters significantly increased over time and significantly differed on various regions of the reefs. Recruitment was always highest on the fore-reef regions and lowest on back-reef regions. Although overall recruitment did not differ among treatments, it was significantly lower on midreef regions of the impacted reefs. This suggests that the leveling of the oyster reefs would increase the surface area available for future oyster recruitment. To look at biodiversity, I tested the hypothesis that all treatments would have similar biodiversity on a month by month basis. Alternatively, biodiversity should always be greatest on leveled reef with artificial seagrass due to increased 3-dimensional structure nearby and longer submersion times. To enumerate biodiversity, two lift nets were placed on each reef, one contained a restoration mat and the other contained only mesh (control). In most months, the four experimental treatments were similar according to the biodiversity measures analyzed. However, biodiversity was always higher in lift nets with restoration mats when compared to lift nets with mesh only. This result again suggests that the mats as designed are important restoration tools. Overall, my results show that placing seagrass in front of oyster reefs may not help to better restoration efforts. However, leveling dead margins on reefs and using the restoration mats is beneficial to oyster reef habitat restoration efforts. As a result of my research, restoration mats, in combination with leveling dead margins, are currently being used in a large-scale, community-based oyster reef restoration project within Canaveral National Seashore boundaries.
Show less - Date Issued
- 2007
- Identifier
- CFE0001785, ucf:47270
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001785
- Title
- SITE PREPARATION METHODS FOR RESTORATION OF NON-NATIVE PASTURELANDSTO NATIVE UPLAND HABITAT.
- Creator
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Kosel, Krisann, Stout, Jack, University of Central Florida
- Abstract / Description
-
The flatwoods ecosystem of Florida has been heavily depleted over time but remains one of the most important systems to many threatened and endangered species. Areas that have been converted into non-native pastures may be restored to provide not only this invaluable ecosystem but also restore connectivity of the surrounding ecosystems. The pasture areas on The Disney Wilderness Preserve in central Florida were surveyed, and a conceptual plan for restoration was written in 1996. That same...
Show moreThe flatwoods ecosystem of Florida has been heavily depleted over time but remains one of the most important systems to many threatened and endangered species. Areas that have been converted into non-native pastures may be restored to provide not only this invaluable ecosystem but also restore connectivity of the surrounding ecosystems. The pasture areas on The Disney Wilderness Preserve in central Florida were surveyed, and a conceptual plan for restoration was written in 1996. That same year a pilot study was developed to assess five methods for removing non-native pasture grasses. The treatments studied were single herbicide, single disc, multiple herbicide, multiple disc, and single herbicide with two disc treatments. All plots were monitored once a year for three years along non-permanent transects. Percent cover was estimated for seven variables and a species list was developed for each plot. The triple herbicide treatment had the best overall success in removal of non-natives and establishment of native species characteristic of flatwoods communities. This treatment also had the highest species richness. The results of this study were used to develop the long term restoration plan for the remaining pasture areas of the preserve. This information may also be useful to restore pastures that connect other important ecosystems being purchased and protected throughout Florida and the Southeastern United States.
Show less - Date Issued
- 2005
- Identifier
- CFE0000709, ucf:46600
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000709
- Title
- The Restorative Effects of Color and Environment Type on Cognitive Functioning.
- Creator
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Michaelis, Jessica, Smither, Janan, Kincaid, John, Beidel, Deborah, Mcconnell, Daniel, University of Central Florida
- Abstract / Description
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Although individuals have limited directed attention capabilities, it has been shown that exposure to natural environments elicit cognitive restoration (i.e. Berman, 2008). It has also been shown that individuals prefer blue and green colors because they are relaxing and prompt happy feelings (Guilford (&) Smith, 1959; Mahnke, 1996; Wexner, 1954). The question however, is what aspects of nature elicit these effects: is it the natural colors, the environmental setting, or both? The present...
Show moreAlthough individuals have limited directed attention capabilities, it has been shown that exposure to natural environments elicit cognitive restoration (i.e. Berman, 2008). It has also been shown that individuals prefer blue and green colors because they are relaxing and prompt happy feelings (Guilford (&) Smith, 1959; Mahnke, 1996; Wexner, 1954). The question however, is what aspects of nature elicit these effects: is it the natural colors, the environmental setting, or both? The present experiment will examine the effects of color (Blue, Green, Black and White, (&) Natural) and environmental setting (Urban, Foliage, (&) Aquatic) on measures of attention, short term memory, and mood. Additionally, this study was designed to replicate the findings of Berman et.al 2008, all while rigorously controlling for the pictorial content of its manipulation. Due to the exploratory nature of this study, no specific hypotheses were made. However, the goal of this research was to (")tease apart(") the effects of color and environment on the restoration of cognitive abilities. One hundred and nineteen non-color blind individuals completed pre and post tests for the State Trait Anxiety Inventory (Form Y-1), Backwards Digit Span, and the Attention Network Task and viewed one of the twelve color/environmental setting picture sets between the pre and posttests. Results of the 2x3x4 Mixed ANOVAs do not support past research which suggests that natural environments are restorative in nature.
Show less - Date Issued
- 2013
- Identifier
- CFE0004892, ucf:49665
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004892
- Title
- RECRUITMENT AND RESTORATION OF THE OYSTER CRASSOSTREA VIRGINICA IN AREAS WITH INTENSE BOATING ACTIVITY IN MOSQUITO LAGOON, FLORIDA.
- Creator
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Wall, Lisa Michele, Walters PhD, Linda J., University of Central Florida
- Abstract / Description
-
Productivity, diversity and survival of estuaries are threatened by explosive coastal population growth and associated recreational activities. One major area of recreational growth has been the number of small pleasure craft motoring in shallow waters at high speeds. On the east coast of Central Florida in the Indian River Lagoon system, intense boating activity occurs year-round and intertidal reefs of the eastern oyster Crassostrea virginica with dead margins (piles of disarticulated...
Show moreProductivity, diversity and survival of estuaries are threatened by explosive coastal population growth and associated recreational activities. One major area of recreational growth has been the number of small pleasure craft motoring in shallow waters at high speeds. On the east coast of Central Florida in the Indian River Lagoon system, intense boating activity occurs year-round and intertidal reefs of the eastern oyster Crassostrea virginica with dead margins (piles of disarticulated shells) on their seaward edges are commonly found adjacent to major boating channels. The cause(s) of the dead margins is unclear. However, the disarticulated shells may be reducing reef sustainability if these surfaces are unavailable for larvae. Recruitment trials were run on eight reefs (4 with dead margins, 4 without) in three 8-week trials in 2001/2002. Significant differences were found for location on reef and season. For survival of recruits, significant differences were found for reef type, location on reef, and season. Sediment loads, percent silt/clay, and relative water motion were all found to be significantly higher on impacted reefs. Spring months were found to be the optimal time for larval recruitment to increase larval set and survival and to also decrease the effects of sedimentation and water motion. Based on these results, experimental restoration began May 2003 to develop an ecologically and economically feasible restoration protocol for this intertidal region. Four different densities of shells (0, 16, 25, 36) were attached to vexar mesh mats (45 X 45 cm) displaying shells perpendicular to the substrate. 360 mats were randomly deployed at one of six identified optimum recruitment locations. Recruitment increased through June and was significantly higher on mats with 36 shells. This was followed by a large, expected decline in recruitment and survival in July/August, due to competition, predation and/or extreme high temperatures. Total live oysters on the restoration mats significantly increased during October 2003 through February 2003. These newly-created oyster reefs are moveable and provide optimal substrate and larval set to be transported post-recruitment to areas resource managers have slated for restoration to aid in reef sustainability. To determine the potential negative effects of flow and sediment levels on oyster larval settlement, which may be associated with an increase in boating actitivity, laboratory experiments were conducted. Eighteen trials, with competent oyster larvae, nine in flowing-water and nine in still-water were run at three sediment levels: no sediment, low sediment, and high sediment loads. Larval settlement was significantly higher in the still-water trials and both high and low sediment loads significantly reduced larval settlement.
Show less - Date Issued
- 2004
- Identifier
- CFE0000113, ucf:46181
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000113
- Title
- GENETIC DIFFERENTIATION AMONG FLORIDA POPULATIONS OF DIADEMA ANTILLARUM.
- Creator
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Chandler, Luke M, Hoffman, Eric, University of Central Florida
- Abstract / Description
-
This project used molecular genetic markers (microsatellites) to determine the amount of genetic diversity within populations and whether significant differentiation exists among Florida populations of the long-spined sea urchin, Diadema antillarum. Specifically, this project aimed to (1) compare genetic diversity of D. antillarum from six populations in south Florida ranging from Biscayne Bay, the Florida Keys, and Dry Tortugas, and (2) determine whether two broodstock populations of D....
Show moreThis project used molecular genetic markers (microsatellites) to determine the amount of genetic diversity within populations and whether significant differentiation exists among Florida populations of the long-spined sea urchin, Diadema antillarum. Specifically, this project aimed to (1) compare genetic diversity of D. antillarum from six populations in south Florida ranging from Biscayne Bay, the Florida Keys, and Dry Tortugas, and (2) determine whether two broodstock populations of D. antillarum contain variation indicative of native Florida populations. Together, these questions can address whether broodstock populations contain the genetic variation necessary to meet the Florida Fish and Wildlife Conservation Commission�s (FWC�s) genetic policies for reintroduction throughout south Florida. Global FST among native populations was 0.0004 with a highest pairwise FST of 0.0025 between the Upper Keys and the area west of Key West, showing an overall trend of little natural differentiation between populations. Global FST for all populations inclusive of the broodstock samples was 0.0019 with a highest pairwise FST between a native population and broodstock of 0.0066 between Dry Tortuga and Mote�s broodstock, indicating little differentiation resulting from captive breeding. Average allelic richness and heterozygosity ranged from 22.6�24.4 and 0.937�0.956, respectively, for each population. Two-way ANOVAs comparing genetic diversity between native and broodstock populations showed no statistical difference in allelic richness (F= 3.892, p= 0.0535) or heterozygosity (F=1.43, p=0.237). The computer program STRUCTURE estimated the most likely number of genetic clusters to be k=1, inclusive of broodstock populations, further indicating a lack of differentiation either among native populations or between native and broodstock populations. These data suggest that captive-bred individuals of D. antillarum could be used for reintroduction as part of a plan to re-establish healthy urchin populations throughout the Florida Keys.
Show less - Date Issued
- 2016
- Identifier
- CFH2000044, ucf:45558
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000044
- Title
- Hydrodynamic Limitations and the Effects of Living Shoreline Stabilization on Mangrove Recruitment along Florida Coastlines.
- Creator
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Pilato, Christian, Walters, Linda, Kibler, Kelly, Quintana-Ascencio, Pedro, University of Central Florida
- Abstract / Description
-
The recruitment success of mangroves is influenced by a variety of factors, including propagule availability, desiccation, herbivory, and hydraulic habitat limitations. Hydrodynamic forces (waves and currents) act as obstacles to mangrove recruitment, restricting the successful colonization of mangrove species. We evaluated the biological and physical limitations to mangrove recruitment through monthly shoreline surveys and lateral pull-tests. Surveys followed mangroves from propagule release...
Show moreThe recruitment success of mangroves is influenced by a variety of factors, including propagule availability, desiccation, herbivory, and hydraulic habitat limitations. Hydrodynamic forces (waves and currents) act as obstacles to mangrove recruitment, restricting the successful colonization of mangrove species. We evaluated the biological and physical limitations to mangrove recruitment through monthly shoreline surveys and lateral pull-tests. Surveys followed mangroves from propagule release through recruitment along the shorelines of De Soto National Memorial (Bradenton, FL), capturing differences in propagule availability and recruitment along natural areas and across differing forms of shoreline stabilization ((")living shorelines(") and revetments). Propagule densities were highest along (")living shorelines("), followed by natural areas and revetments. Seedling densities were similar across treatments, mirroring densities found in disturbed mangrove systems in the Philippines ((<)1 seedling per m2). Pull-tests, simulating wave forces, quantified the physical thresholds for uprooting Rhizophora mangle and Avicennia germinans seedlings in both the greenhouse and field. Uprooting susceptibility significantly decreased with increased seedling biomass and age. A. germinans displayed a lower force to removal than R. mangle, but showed a greater increase in uprooting force with increases in size. Surrounding vegetation and canopy cover were not found to significantly affect the uprooting force of either species. Pull-test results were used in conjunction with drag coefficients from the literature to calculate flow velocities where mangroves would become susceptible to dislodgement from hydrodynamic forces. Seedlings tested would become susceptible at velocities of 7.33 (&)#177; 2.07 m/s for A. germinans and 5.40 (&)#177; 1.59 m/s for R. mangle. The rapid increase in force to removal shows the importance of disturbances, such as erosion, driving seedling dislodgment at the local scale. This research strengthens our understanding of the physical conditions conducive to successful recruitment under hydrodynamic stressors and provides insight into how a common restoration method can influence mangrove recruitment.
Show less - Date Issued
- 2019
- Identifier
- CFE0007899, ucf:52748
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007899
- Title
- If a Virtual Tree Falls in a Simulated Forest, is the Sound Restorative? An Examination of the Role of Level of Immersion in the Restorative Capacity of Virtual Nature Environments.
- Creator
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Michaelis, Jessica, Smither, Janan, Mcconnell, Daniel, Beidel, Deborah, Harris, Paul, University of Central Florida
- Abstract / Description
-
Stress and cognitive fatigue have become a pervasive problem, especially in Western society. Stress and cognitive fatigue can have deleterious effects not only on performance, but also on one's physical and mental health. This dissertation presents a study in which the aim is to investigate the effects of virtual nature on stress reduction and cognitive restoration. Specifically, this study assessed the effects of Immersion (Non-immersive, Semi-immersive, Fully-immersive) and Exploration ...
Show moreStress and cognitive fatigue have become a pervasive problem, especially in Western society. Stress and cognitive fatigue can have deleterious effects not only on performance, but also on one's physical and mental health. This dissertation presents a study in which the aim is to investigate the effects of virtual nature on stress reduction and cognitive restoration. Specifically, this study assessed the effects of Immersion (Non-immersive, Semi-immersive, Fully-immersive) and Exploration (Passive vs Active) on stress reduction and cognitive restoration. Additionally, restoration from the most effective virtual nature environment was compared to that of taking an active coloring break. Eighty-three university students with normal color vision, depth perception and good visual acuity participated in this study. The overall findings of the study suggest that virtual nature is able to reduce stress and anxiety, generally the more immersive and interactive the better. Moreover, though both the those in the passive VR nature condition and those in the coloring condition reported a reduction in stress, only those in the passive VR nature condition exhibited the physiological changes indicative of stress reduction.
Show less - Date Issued
- 2019
- Identifier
- CFE0007687, ucf:52516
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007687
- Title
- Recidivism Measurement and Sanction Effectiveness in Youth Diversion Programs.
- Creator
-
Maroney, Thomas, Wan, Thomas, Sanborn, Joseph, Wolf, Ross, Zhang, Ning, University of Central Florida
- Abstract / Description
-
With the rapid growth of juvenile offender diversion programs, which use many non-traditional sanctions, the effectiveness of sanction combinations in juvenile diversion programs and in each individual program needs to be evaluated. Those making sanctioning decisions currently do so based on intuition rather than using an evidence- or theory-based approach. Considerable research has examined the relationship between offender risk factors and recidivism (who is more likely to reoffend?) and...
Show moreWith the rapid growth of juvenile offender diversion programs, which use many non-traditional sanctions, the effectiveness of sanction combinations in juvenile diversion programs and in each individual program needs to be evaluated. Those making sanctioning decisions currently do so based on intuition rather than using an evidence- or theory-based approach. Considerable research has examined the relationship between offender risk factors and recidivism (who is more likely to reoffend?) and between offender risk factors and sanctions (who is more likely to receive what sanctions?), but little is known about the relationship between sanctions and recidivism (which sanctions best reduce recidivism and for whom?). Furthermore, recidivism studies vary drastically in how they measure or quantify recidivism. This variability of approach makes comparing studies difficult and provides a less-than-complete picture of recidivism in general. The present study used data from one specific youth diversion program to test certain hypotheses of sanctioning by developing and testing a model for assigning sanction combinations to certain offenders on the basis of their individual characteristics. The study first developed measurement models for Offender Risk Propensity, Multiplicity of Sanctions, and Recidivism using structural equation modeling (SEM). Then predictive models were developed to test specific relationships. Understanding the effectiveness of certain sanction packages on certain offenders can form the basis for effective sanctioning in youth diversion programs. This study sought to answer three research questions: What is the best way to measure recidivism? Does completion of a restorative justice program reduce recidivism? Which sanctions, if any, reduce recidivism for specific offender types? To answer the first question: a multi-indicator latent construct of recidivism did a very good job of measuring variation in recidivism. Multiple indicators analyzed simultaneously produced a robust tool that can be used in other recidivism studies and help to reduce comparability issues between studies. The recidivism construct, when tested as a function of completion of the restorative justice program, was seen to produce a significant model having an overall good fit with the data. Thus to answer the second research question: offenders' completion status for the restorative justice program was shown to be a significant predictor of the latent construct of recidivism at the 0.05 level (two-tailed), with those who failed to complete (or chose not to participate) having higher recidivism than did those who completed the program. To answer the third research question: the assignment of specific sanctions (both those suggested by research and theory and those traditionally assigned by this and similar programs) on the entire data set (and on various subsets) of this study have no statistically significant impact on recidivism at the 0.05 level (two tailed).The findings suggest many policy implications. Consistency is all but nonexistent in recidivism measurements in the academic literature and in program review studies. A multi-indicator latent construct of recidivism, such as the one proposed and proven effective in this study, provides a more complete picture than simply conceptualizing recidivism by one dummy variable. This recidivism model can be used as the endogenous variable to evaluate programs and their practices and could reduce the problem of study comparability. This could lead to a better understanding of program characteristics and their impact on offender success. This study also found that completion of the Neighborhood Restorative Justice Program was a significant predictor of recidivism, yet none of the eleven most commonly assigned sanctions were seen to have a significant impact on recidivism for any subgroup. Proponents of restorative justice argue that it is the programs' characteristics and not their specific activities that make the programs successful. Reintegrative Shaming Theory and Labeling Theory support this claim and suggest the best approach to address youth criminal behavior is to admonish the act and not the actor, have the offender and community agree on a plan to make the community whole after that criminal act, and prevent repeated interaction with the formal criminal justice system which encourages the youth to see themself as a deviant and engage in further deviant behavior. These characteristics should be further examined and widely employed if confirmed.
Show less - Date Issued
- 2012
- Identifier
- CFE0004406, ucf:49392
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004406
- Title
- A Multiagent Q-learning-based Restoration Algorithm for Resilient Distribution System Operation.
- Creator
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Hong, Jungseok, Sun, Wei, Zhou, Qun, Zheng, Qipeng, University of Central Florida
- Abstract / Description
-
Natural disasters, human errors, and technical issues have caused disastrous blackouts to power systems and resulted in enormous economic losses. Moreover, distributed energy resources have been integrated into distribution systems, which bring extra uncertainty and challenges to system restoration. Therefore, the restoration of power distribution systems requires more efficient and effective methods to provide resilient operation.In the literature, using Q-learning and multiagent system (MAS...
Show moreNatural disasters, human errors, and technical issues have caused disastrous blackouts to power systems and resulted in enormous economic losses. Moreover, distributed energy resources have been integrated into distribution systems, which bring extra uncertainty and challenges to system restoration. Therefore, the restoration of power distribution systems requires more efficient and effective methods to provide resilient operation.In the literature, using Q-learning and multiagent system (MAS) to restore power systems has the limitation in real system application, without considering power system operation constraints. In order to adapt to system condition changes quickly, a restoration algorithm using Q-learning and MAS, together with the combination method and battery algorithm is proposed in this study. The developed algorithm considers voltage and current constraints while finding system switching configuration to maximize the load pick-up after faults happen to the given system. The algorithm consists of three parts. First, it finds switching configurations using Q-learning. Second, the combination algorithm works as a back-up plan in case of the solution from Q-learning violates system constraints. Third, the battery algorithm is applied to determine the charging or discharging schedule of battery systems. The obtained switching configuration provides restoration solutions without violating system constraints. Furthermore, the algorithm can adjust switching configurations after the restoration. For example, when renewable output changes, the algorithm provides an adjusted solution to avoid violating system constraints.The proposed algorithm has been tested in the modified IEEE 9-bus system using the real-time digital simulator. Simulation results demonstrate that the algorithm offers an efficient and effective restoration strategy for resilient distribution system operation.
Show less - Date Issued
- 2017
- Identifier
- CFE0006746, ucf:51856
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006746
- Title
- OYSTER REEF RESTORATION: IMPACTS ON INFAUNAL COMMUNITIES IN A SHALLOW WATER ESTUARY.
- Creator
-
Harris, Katherine P, Walters, Linda J., University of Central Florida
- Abstract / Description
-
Oyster reefs are important estuarine ecosystems that provide habitat to many species including threatened and endangered wading birds and commercially important fishes and crabs. Infaunal organisms (i.e. small, aquatic animals that burrow in the sediment) are also supported by oyster reef habitats. Infaunal organisms are critical to marine food webs and are consumed by many important species that inhabit coastal estuaries. However, over the past century 85% of shellfish reef habitats have...
Show moreOyster reefs are important estuarine ecosystems that provide habitat to many species including threatened and endangered wading birds and commercially important fishes and crabs. Infaunal organisms (i.e. small, aquatic animals that burrow in the sediment) are also supported by oyster reef habitats. Infaunal organisms are critical to marine food webs and are consumed by many important species that inhabit coastal estuaries. However, over the past century 85% of shellfish reef habitats have been lost, making restoration of these areas vital. Due to their important role in coastal food webs, infauna is hypothesized to be a strong indicator of habitat productivity to document the transition from a dead to a restored and living intertidal oyster reef. Research was conducted in Mosquito Lagoon of the northern Indian River Lagoon system. Three replicate samples were collected from 12 intertidal oyster reefs (four dead, four live, four restored). Samples were collected one-week pre-restoration and one month and six months post-restoration. Infauna was counted and sorted into six taxonomic categories: polychaetes, amphipods, isopods, gastropods, bivalves, and decapods. Reef infaunal abundance increased following restoration: restored reefs became more similar to live reefs one month following restoration. Six months after restoration restored reefs were also significantly different than dead reefs. Live reefs consistently had high infaunal abundance and dead reefs consistently had low abundance, while restored reefs were intermediate. These data suggest restored reefs are more productive than their dead counterparts, with restoration showing a positive trajectory to impact numerous infaunal species and their associated food webs.
Show less - Date Issued
- 2018
- Identifier
- CFH2000366, ucf:45851
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000366
- Title
- RESPONSES OF SMALL RODENTS TO RESTORATION AND MANAGEMENT TECHNIQUES OF FLORIDA SCRUB AT CAPE CANAVERAL AIR FORCE STATION, FLORIDA.
- Creator
-
Suazo, Alexis, Stout, I. Jack, University of Central Florida
- Abstract / Description
-
Proper habitat management is essential for the survival and reproduction of species, especially those listed under state or federal laws as endangered, threatened or of special concern, and those with small local populations. Land managers use a combination of mechanical cutting and prescribed burning to manage and restore degraded scrub habitat in east central Florida. This approach improves habitat for the endangered Florida scrub-jay (Aphelocoma coerulescens), but little is known about its...
Show moreProper habitat management is essential for the survival and reproduction of species, especially those listed under state or federal laws as endangered, threatened or of special concern, and those with small local populations. Land managers use a combination of mechanical cutting and prescribed burning to manage and restore degraded scrub habitat in east central Florida. This approach improves habitat for the endangered Florida scrub-jay (Aphelocoma coerulescens), but little is known about its effects on other taxa, especially the threatened southeastern beach mouse (Peromyscus polionotus niveiventris). This single species approach may not be beneficial to other taxa, and mechanical cutting and prescribed burning may have detrimental effects on P. p. niveiventris. To evaluate the effects of land management techniques on P. p. niveiventris, I live trapped populations at Cape Canaveral Air Force Station near Titusville, Florida during 2004-2005. I evaluated the relative abundance and related demographic parameters of small mammal populations trapped in compartments under different land management treatments, and investigated the relationship between Florida scrub-jay breeding groups using these compartments and abundance of southeastern beach mice. My results suggest that P. p. niveiventris responded positively to prescribed burning, while the cotton mouse (P. gossypinus) responded positively to the mechanical cutting. Reproduction and body mass of southeastern beach mice were similar across land management compartments. Abundance of Florida scrub-jay breeding groups and southeastern beach mice were positively correlated suggesting that both listed species benefited from the same land management activities. A mosaic of burned and cut patches should be maintained to support small mammal diversity. In addition, adaptive management should be used at CCAFS to understand how small mammals, particularly the southeastern beach mouse, respond to land management activities.
Show less - Date Issued
- 2007
- Identifier
- CFE0001521, ucf:47124
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001521
- Title
- QUANTIFYING THE SUCCESS OF EASTERN OYSTER PILOT REEFS IN BREVARD COUNTY, FLORIDA.
- Creator
-
Anderson, Lacie, Walters, Linda J., University of Central Florida
- Abstract / Description
-
Crassostrea virginica, the eastern oyster, is a native keystone species that inhabits many coastal and estuarine ecosystems along the Atlantic seaboard. Introduction of the eastern oyster into estuarine areas with limited current populations is gaining popularity as a pro-active approach to improve estuarine water quality. In November 2014 and April 2015, a total of five pilot oyster reef treatments were deployed in Brevard County: bagged adult oysters (grown by community members under their...
Show moreCrassostrea virginica, the eastern oyster, is a native keystone species that inhabits many coastal and estuarine ecosystems along the Atlantic seaboard. Introduction of the eastern oyster into estuarine areas with limited current populations is gaining popularity as a pro-active approach to improve estuarine water quality. In November 2014 and April 2015, a total of five pilot oyster reef treatments were deployed in Brevard County: bagged adult oysters (grown by community members under their docks through oyster gardening) collected in fall 2014 and spring 2015, bagged clean shell, oyster restoration mats, and empty plots (control). Locations of deployment included a Merritt Island impoundment (Marsh Harbor), Nicol Park (Port St. John), and Scout Island (Melbourne Beach). Prior to deployment, we collected morphometric data (shell length, weight) on all gardened oysters. Abiotic factors including salinity, air and water temperature, and wind speed were collected monthly. During quarterly sampling at each site, morphometric data were collected for all live oysters, surviving and newly recruited. Results show survival of gardened oysters and natural recruitment differed by and depended greatly on the within-site location of each reef. In areas with no recruitment and limited gardened oyster survival, regular deployment of gardened oysters is needed for long term success. In areas with natural recruitment, bagged, clean shell or oyster restoration mats are most successful. Future restoration sites should be tested prior to any large-scale oyster deployments.
Show less - Date Issued
- 2016
- Identifier
- CFH2000059, ucf:45557
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000059
- Title
- DETERMINING FACTORS THAT INFLUENCE SMOOTH CORDGRASS (SPARTINA ALTERNIFLORA LOISEL) TRANSPLANT SUCCESS IN COMMUNITY-BASED LIVING SHORELINE PROJECTS.
- Creator
-
Carrion, Steven A, Walters, Linda J., University of Central Florida
- Abstract / Description
-
Efforts to mitigate shoreline erosion through living shoreline methods along the USA Atlantic seaboard have often incorporated the cultivation and transplantation of smooth cordgrass, Spartina alterniflora. Assessments of these transplants at several sites in the Indian River Lagoon have shown that survival is variable after a year (survival: 10-93%). Lower survival has been attributed to environmental variables such as dislodgement by wave energy, and transplant shock due to salinity changes...
Show moreEfforts to mitigate shoreline erosion through living shoreline methods along the USA Atlantic seaboard have often incorporated the cultivation and transplantation of smooth cordgrass, Spartina alterniflora. Assessments of these transplants at several sites in the Indian River Lagoon have shown that survival is variable after a year (survival: 10-93%). Lower survival has been attributed to environmental variables such as dislodgement by wave energy, and transplant shock due to salinity changes from cultivation to estuarine conditions. To improve living shoreline projects, we examined the effects of cultivation salinity (0 ppt, 15ppt) on transplantation success, and the success of anchoring plants to biodegradable mats (Jute mesh, 5 individuals per 50 cm2) and utilizing oyster bags as breakwaters in facilitating reestablishment of new transplants. Spartina alterniflora individuals were grown under salinity treatments for 20 weeks; plants grown in 15 ppt produced new shoots with significantly greater heights than those grown in freshwater. The plants were then transplanted to two sites in the IRL, and monitored after four weeks. After four weeks there was a greater net increase in stem density and larger decrease in plant height for plants grown in 15 ppt. Jute-mesh mats and oyster bags did not impact growth or survival of transplants. Low-saline (15 ppt) conditions increased shoot growth of the project by 50% in four weeks at a cost of 30 cents per additional shoot produced by an individual. Longer-term monitoring will determine if benefits persist or decrease over time, and if the cost is justified by the benefits.
Show less - Date Issued
- 2016
- Identifier
- CFH2000068, ucf:45538
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000068
- Title
- ASSESSING THE IMPACT OF OYSTER REEF AND LIVING SHORELINE RESTORATION ON MACROINVERTEBRATE COMMUNITY ASSEMBLAGES IN MOSQUITO LAGOON, FLORIDA.
- Creator
-
Searles, Adam, Cook, Geoffrey, University of Central Florida
- Abstract / Description
-
As the world continues to experience substantial rates of habitat loss, habitat restoration has become of prime interest to ecologists worldwide. Restoration has shown to be successful in recovering targeted components of certain ecosystems but it is important to achieve a holistic understanding of the resulting ecological impacts it has on communities. To address this, four oyster reefs and three living shorelines were restored during the summer of 2017. These sites, along with four dead...
Show moreAs the world continues to experience substantial rates of habitat loss, habitat restoration has become of prime interest to ecologists worldwide. Restoration has shown to be successful in recovering targeted components of certain ecosystems but it is important to achieve a holistic understanding of the resulting ecological impacts it has on communities. To address this, four oyster reefs and three living shorelines were restored during the summer of 2017. These sites, along with four dead oyster reefs, four living oyster reefs, and three undisturbed (control) living shorelines, were sampled before restoration and regularly post-restoration for one year using lift nets. Macroinvertebrates were collected and enumerated in the lab. Diversity indices, community composition, and similarity percentages were then calculated and compared across treatments, time, and treatment-by-time. Live reefs displayed significantly higher species richness and Shannon diversity than restored and dead reefs. Simpson diversity did not differ between live and restored oyster reefs but both were significantly higher than dead reefs. Though not statistically detectable, species richness and Shannon diversity on restored reefs were relatively similar to dead reefs before restoration but became increasingly similar to live reefs over the course of the study. Additionally, analyses revealed significantly different community compositions between live reefs and restored reefs, as well as between live and dead reefs. Living shorelines showed no significant differences in diversity indices but did experience similar seasonal fluctuations in diversity across treatments. Just as with oyster reefs, restored and control living shorelines harbored significantly different communities across time. The findings of this study emphasize the need for dedication to thorough monitoring and multi-metric evaluation of success in restoration efforts. This study and future research will equip resource managers with ways to quantify the effects of restoration that will consider several important ecosystem components.
Show less - Date Issued
- 2019
- Identifier
- CFH2000545, ucf:45646
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000545
- Title
- A Study of the Influence of the Restorative Justice Model on Out-of-School Suspensions in a Large Urban School District.
- Creator
-
Agard, Brian, Johnson, Jerry, Doherty, Walter, Baldwin, Lee, Larsen, James, University of Central Florida
- Abstract / Description
-
The purpose of this quantitative study was to investigate whether the Restorative Justice model influenced the number of days that students were suspended out-of-school or the number of out-of-school suspension incidents. In addition, the researcher analyzed whether the Restorative Justice model had different impacts for the subgroups of students qualifying for free and reduced lunch (FRL), English Learners (EL), students qualifying for exceptional student education services (ESE), and three...
Show moreThe purpose of this quantitative study was to investigate whether the Restorative Justice model influenced the number of days that students were suspended out-of-school or the number of out-of-school suspension incidents. In addition, the researcher analyzed whether the Restorative Justice model had different impacts for the subgroups of students qualifying for free and reduced lunch (FRL), English Learners (EL), students qualifying for exceptional student education services (ESE), and three ethnic subgroups (White, Black, and Hispanic) in an urban school district in Central Florida for the sixth-, seventh-, and eighth-grade students for the seven school years from 2010-2011 to 2016-2017. Primary data analysis strategies were descriptive statistics and visual analyses utilizing an interrupted time series design. The findings can be helpful in informing decision makers if the Restorative Justice model is having a positive influence on decreasing out-of-school suspension incidents and/or out-of-school suspension days.
Show less - Date Issued
- 2018
- Identifier
- CFE0007144, ucf:52325
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007144
- Title
- VARIABILITY OF CARBON STOCK IN FLORIDA FLATWOODS ECOSYSTEMS UNDERGOING RESTORATION AND MANAGEMENT.
- Creator
-
Becker, Kathryn, Hinkle, C. Ross, University of Central Florida
- Abstract / Description
-
The global community is struggling with mitigating the effects of widespread habitat loss and degradation; the effects of which are being further magnified in the face of global climate change. Quality natural habitat is becoming increasingly limited and atmospheric carbon levels continue to rise. Therefore, land managers responsible for multiuse management are often faced with the dilemma of managing ecosystems for biodiversity, as well as optimizing ecosystem services such as carbon storage...
Show moreThe global community is struggling with mitigating the effects of widespread habitat loss and degradation; the effects of which are being further magnified in the face of global climate change. Quality natural habitat is becoming increasingly limited and atmospheric carbon levels continue to rise. Therefore, land managers responsible for multiuse management are often faced with the dilemma of managing ecosystems for biodiversity, as well as optimizing ecosystem services such as carbon storage and sequestration. However, some management techniques used to meet these objectives may yield conflicting results, specifically, the management tool of prescribed fire. Fire is crucial in maintaining species composition and structure in many ecosystems, but also results in high carbon emissions. Thus, it is important for land mangers to achieve the most efficient prescribed fire management regime to both preserve plant and animal communities, and optimize carbon storage. A former ranchland at the Disney Wilderness Preserve, Central Florida, USA is being restored to native ecosystems and managed to preserve biodiversity and increase carbon storage. This study quantified the carbon stocks within the aboveground biomass, litter, and top 90 cm of soil in five ecosystems at the Disney Wilderness Preserve, all of which are managed with prescribed fire every two to three years. These carbon stocks were compared in ecosystems in different stages of restoration: bahia grass pasture, pasture in restoration for longleaf pine flatwoods, and restored longleaf pine flatwoods. The carbon stocks were also compared among three restored flatwoods communities: longleaf pine flatwoods, slash pine flatwoods, and scrubby flatwoods. To determine the effects of the current prescribed fire management, carbon stocks were quantified and compared in recently burned areas (burned 4 months prior) and areas burned two to three years prior, in all ecosystems. Soil carbon properties were assessed using 13C isotope analysis. Aboveground biomass and litter carbon stocks were found to increase with higher stage of restoration, and were significantly less in areas with recent fire management. The results of this study did not provide evidence that soil carbon stock was significantly different in different stages of restoration or at different times since fire, but soil carbon stock was found to be significantly different among the flatwoods communities. In un-restored pasture and pasture in restoration sites, the soil was found to be increasingly depleted in 13C with increasing soil depth. This pattern indicated that carbon in the upper, more labile soil carbon pool had been derived from current C4 pasture or native grasses, while carbon in the deeper, more stable carbon pool is a legacy of the historical C3 forest vegetation that existed prior to conversion to pasture. Additionally, a pattern of less depletion in 13C with increasing time since deforestation was noted, indicating an increasing loss of historic forest carbon with increasing pasture age. As the pastures in restoration for longleaf pine flatwoods mature, the isotopic composition of the soil profile in the restored longleaf pine flatwoods may serve as a reference value for the soil profiles of these sites. Overall, the mean carbon stock in the aboveground biomass, litter and top 90 cm of soil in the un-restored pasture was ~13.3 kg C/m2, the carbon stock in the pasture in restoration was ~12.7 kg C/m2, the longleaf pine flatwoods had the highest carbon stock at ~17.7 kg C/m2, the scrubby flatwoods had the smallest carbon stock at ~7.7 kg C/m2, and the slash pine flatwoods had a carbon stock of ~15.8 kg C/m2.
Show less - Date Issued
- 2011
- Identifier
- CFE0003603, ucf:48870
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003603
- Title
- Factors limiting native species establishment on former agricultural lands.
- Creator
-
Weiler-Lazarz, Annalisa, VonHolle, Mary, Quintana-Ascencio, Pedro, Neill, Christopher, Nickerson, David, University of Central Florida
- Abstract / Description
-
Restoration of abandoned, nonnative species-dominated agricultural lands provides opportunities for conserving declining shrubland and grassland ecosystems. Land-use legacies, such as elevated soil fertility and pH from agricultural amendments, often persist for years and can favor nonnative species at the expense of native species. Understanding the factors that limit native species establishment on abandoned agricultural lands can provide important insights for restoration and conservation...
Show moreRestoration of abandoned, nonnative species-dominated agricultural lands provides opportunities for conserving declining shrubland and grassland ecosystems. Land-use legacies, such as elevated soil fertility and pH from agricultural amendments, often persist for years and can favor nonnative species at the expense of native species. Understanding the factors that limit native species establishment on abandoned agricultural lands can provide important insights for restoration and conservation of native species on human-modified lands. I conducted two field experiments on abandoned agricultural lands: a former pasture on Martha's Vineyard, MA and a former citrus grove at Merritt Island National Wildlife Refuge (MINWR) in Titusville, FL. In these experiments I tested how soil chemical properties affect native and nonnative species abundance and how different methods of removing nonnative, invasive species affect native and nonnative species abundance. In the first experiment, specifically I tested how restoration treatments affect competition between existing nonnative agricultural plant species and native plant species that are targets for sandplain grassland restoration on Martha's Vineyard, MA. At MINWR, I examined how lowering soil fertility with carbon additions and lowering soil pH by applying sulfur affects nonnative species richness and cover (in two former citrus groves that were historically scrub/scrubby flatwoods. Overall, I found that biotic factors, such as competition with nonnative species, play a stronger role in limiting native species establishment than soil chemical properties. Likewise, control of nonnative, invasive species is most effective with mechanical treatments to physically reduce cover, rather than altering soil chemical properties.
Show less - Date Issued
- 2012
- Identifier
- CFE0004323, ucf:49462
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004323
- Title
- Determining the impacts of beach restoration on loggerhead (Caretta caretta) and green turtle (Chelonia mydas) nesting patterns and reproductive success along Florida's Atlantic coast.
- Creator
-
Hays, Allison, Weishampel, John, Ehrhart, Llewellyn, Mota, Mario, Hinkle, Charles, University of Central Florida
- Abstract / Description
-
Artificial beach nourishment, the most common method to mitigate coastal erosion in the United States, is also considered the most ecologically friendly alternative for shoreline stabilization. However, this habitat alteration has the potential to impact nesting marine turtles and developing hatchlings. The first objective of this study was to determine how nourishing beaches with two different design templates affects loggerhead (Caretta caretta) and green turtle (Chelonia mydas) nesting...
Show moreArtificial beach nourishment, the most common method to mitigate coastal erosion in the United States, is also considered the most ecologically friendly alternative for shoreline stabilization. However, this habitat alteration has the potential to impact nesting marine turtles and developing hatchlings. The first objective of this study was to determine how nourishing beaches with two different design templates affects loggerhead (Caretta caretta) and green turtle (Chelonia mydas) nesting success, the ratio of nests to the total number of nests and non-nesting emergences, and reproductive success, the ratio of hatched and emerged hatchlings to the total number of eggs deposited. Two types of restoration designs exist along the southern Brevard County, FL coastline, which supports some of the highest density loggerhead and green turtle nesting worldwide. Since 2005, approximately 35 kilometers of beach have undergone 1) full-scale restoration (typically called nourishment), where sand was added above and below the mean high tide line (2005, 2010) or 2) dune restoration, where sand was placed on the dune (2005, 2006, 2008, 2009). To quantify the effects of these restoration types, we used a Before-After-Control-Impact-Paired Series (BACIPS) model, which tests for significance between the difference in nesting success rates at the impact (engineered) and control sites (natural beach) before and after restoration (?). For loggerheads, there was a significant difference in ? after dune restoration during the years of construction (2005, 2006, 2008, and 2009; p(<)0.001) and one year post-construction (2007; p(<)0.05 and 2010; p(<)0.001). After full-scale restoration, there was a significant difference in ? during the years of construction (2005 and 2010; p (<)0.001) and one year post-construction (2006; p(<)0.001). For green turtles, there was a significant difference in ? after dune restoration during two of the four years of construction (2006; p(<)0.05 and 2008; p(<)0.01) and one of the two one-year post-construction years (2010; p(<)0.05). After full-scale restoration, the significant difference in ? lasted every season (2005-2010; p(<)0.001). There were no significant differences in ? for loggerhead or green turtle reproductive success rates after either type of restoration. The second objective was to use the different restoration designs to study what beach characteristics function as loggerhead nesting cues to explain why altering the beach decreases nesting success rates. We examined beach elevation and slope, sand moisture content, sand grain size, beach width, and distance traveled. Logistic regression model selection found all variables were important (R2=0.75). Further examination of trends, with each crawl divided into quarters, found beach slope served as a nesting cue. In all study sites except one, when turtles false crawled, the beach flattened out in the final quarter of the crawl. Conversely, in nesting emergences, the final quarter rose at a steeper slope than the previous quarter. Additionally, model selection found variables important in nest site selection were also important in hatching (R2=0.44) and emergence (R2=0.45) success. These results offer new insight into how and why marine turtle nesting patterns change after artificial nourishment, providing information necessary to nourish beaches in a more (")turtle-friendly(") manner. ?
Show less - Date Issued
- 2012
- Identifier
- CFE0004332, ucf:49447
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004332
- Title
- EFFECTS OF A SHORE PROTECTION PROJECT ON LOGGERHEAD AND GREEN TURTLE NESTING ACTIVITY AND REPRODUCTION IN BREVARD COUNTY, FLORIDA.
- Creator
-
Brock, Kelly, Ehrhart, Llewellyn, University of Central Florida
- Abstract / Description
-
Marine turtle reproductive success is strongly correlated with the stability and quality of the nesting environment. Because females show fidelity to key nesting beaches, the management and physical characteristics of these beaches directly affect future generations of marine turtles and may be essential for the recovery of these threatened and endangered species. The impacts of beach restoration on loggerhead turtles (Caretta caretta) and on green turtles (Chelonia mydas) were investigated....
Show moreMarine turtle reproductive success is strongly correlated with the stability and quality of the nesting environment. Because females show fidelity to key nesting beaches, the management and physical characteristics of these beaches directly affect future generations of marine turtles and may be essential for the recovery of these threatened and endangered species. The impacts of beach restoration on loggerhead turtles (Caretta caretta) and on green turtles (Chelonia mydas) were investigated. Previous studies concerning beach nourishment projects have focused on loggerhead turtles. I compared data between nourished and non-nourished areas and between loggerhead and green turtles. I found, at one season post-nourishment, negative effects on nesting success and no significant effect on reproductive success for both loggerheads and established the same relationships with green turtles. Physical attributes of the fill sand, which did not facilitate acute scarp formation or severe compaction, did not physically impede turtles in their attempts to nest. Instead, the decrease in nesting success was attributed to an absence of abiotic and or biotic factors that cue nesting behavior. The increase in loggerhead nesting success rates during the second season post-nourishment was attributed to the equilibration process of the seaward crest of the berm. After the beach was restored, both species of turtles placed nests significantly farther from the water in the nourished area than in the non-nourished area. Green turtles nested on or near the dune and loggerheads nested on the seaward crest of the berm. The tendency of loggerheads to nest closer to the water resulted in more loggerhead than green turtle nests being "washed out" by erosion during the equilibration process. There was a significant increase in hatching success only for loggerheads when wash outs were excluded, thus illustrating the importance of nest placement and the detrimental effects of the equilibration process to the reproductive success of loggerheads. A decrease in reproductive output occurred during the first season post-nourishment. The reduction in the estimated total number of hatchlings produced (reproductive output) was a consequence of decreased nesting success lowering nest numbers. This reduction demonstrates that, regardless of similar reproductive success rates, marine turtles incurred net losses during the first season following nourishment. These results further reveal the impacts of decreased nesting success and the importance of minimizing excessive non-nesting emergences associated with beach nourishment.
Show less - Date Issued
- 2005
- Identifier
- CFE0000493, ucf:46365
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000493
