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- Title
- OYSTER REEF RESTORATION: IMPACTS ON INFAUNAL COMMUNITIES IN A SHALLOW WATER ESTUARY.
- Creator
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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
- INVESTIGATING THE QUANTITY AND TYPES OF MICROPLASTICS IN THE ORGANIC TISSUE OF OYSTERS AND CRABS IN THE INDIAN RIVER LAGOON.
- Creator
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Waite, Heidi, Walters, Linda J., University of Central Florida
- Abstract / Description
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Microplastics are widespread and abundant. Few studies have examined the diversity and abundance of microplastics in wild organisms. This study determined the microplastic quantity and types in the organic tissues of the eastern oyster Crassostrea virginica and Atlantic mud crab Panopeus herbstii from the Indian River Lagoon (IRL). This study also investigated whether location affected the microplastic abundance and variety. Organisms were collected from three sites across Mosquito Lagoon in...
Show moreMicroplastics are widespread and abundant. Few studies have examined the diversity and abundance of microplastics in wild organisms. This study determined the microplastic quantity and types in the organic tissues of the eastern oyster Crassostrea virginica and Atlantic mud crab Panopeus herbstii from the Indian River Lagoon (IRL). This study also investigated whether location affected the microplastic abundance and variety. Organisms were collected from three sites across Mosquito Lagoon in the northern IRL. Oysters were frozen after collection. Crabs were placed in containers for 5 days before freezing. The soft organic tissue was chemically digested using hydrogen peroxide, filtered, and examined for microplastics. Water samples collected from each study site had an average of 23.1 microplastic pieces per liter and fibers were the most common type. There was a significant interaction for microplastic type and site for both oysters and crabs (p
Show less - Date Issued
- 2017
- Identifier
- CFH2000157, ucf:46042
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000157
- 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
- RECOVERY AND RESTORATION OF THE SEAGRASS HALODULE WRIGHTII AFTER BOAT PROPELLER SCAR DAMAGE IN A POLE-TROLL ZONE IN MOSQUITO LAGOON, FLORIDA.
- Creator
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Grablow, Katherine, Walters, Linda, University of Central Florida
- Abstract / Description
-
This study combined documentation of four boat propeller scar types in Halodule wrightii seagrass beds in Mosquito Lagoon, Florida with manipulative field experiments to document scar recovery times with and without restoration. Scar types ranged from the most severe scar type (Type 1) with trench formation which had no roots or shoots in the trench, to the least severe (Type 4) scars that had no depth, intact roots and shoots shorter than the surrounding canopy. For 110 measured existing...
Show moreThis study combined documentation of four boat propeller scar types in Halodule wrightii seagrass beds in Mosquito Lagoon, Florida with manipulative field experiments to document scar recovery times with and without restoration. Scar types ranged from the most severe scar type (Type 1) with trench formation which had no roots or shoots in the trench, to the least severe (Type 4) scars that had no depth, intact roots and shoots shorter than the surrounding canopy. For 110 measured existing scars, the frequency of each scar type was 56% for Type 1, 10% for Type 2, 7% for Type 3, and 27% for Type 4. In the first manipulative experiment, experimental scars were created to document the natural recovery time of H. wrightii for each scar severity within one year. Type 4 scars recovered to the control shoot density at 2 months, while Types 1, 2, and 3 scars did not fully recover in one year. Mean estimated recovery for H. wrightii is expected in 25 months for Type 1, and 19 months for Types 2 and 3. For the second manipulative experiment, three restoration methods were tested on the Type 1 scars over a 1 year period. Restoration methods included: (1) planting H. wrightii in the scar trench, (2) filling the trench with sand, and (3) filling with sand plus planting H. wrightii. There was complete mortality of all transplants at 2 months and only 25% of scars retained fill sand after 1 year. With dense adjacent seagrass beds, natural recovery was more successful than any of my restoration attempts. Thus, I suggest that managers should concentrate on preventing seagrass destruction rather than restoration.
Show less - Date Issued
- 2008
- Identifier
- CFE0002457, ucf:47708
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002457
- Title
- THE ECOLOGY OF DRIFT ALGAE IN THE INDIAN RIVER LAGOON, FLORIDA.
- Creator
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Liss, Julie Lynnae, Walters, Linda J., University of Central Florida
- Abstract / Description
-
To gain an understanding of the ecology of drift algae in the Indian River Lagoon system along the east coast of central Florida, four questions were addressed: 1) What is the composition and rate of accumulation of drift? 2) How much movement and turnover occurs within drift accumulations? 3) Do growth rates differ for drift versus attached algae? 4) Is there a difference in photosynthetic performance in drift versus attached algal species? Manipulative field and laboratory experiments were...
Show moreTo gain an understanding of the ecology of drift algae in the Indian River Lagoon system along the east coast of central Florida, four questions were addressed: 1) What is the composition and rate of accumulation of drift? 2) How much movement and turnover occurs within drift accumulations? 3) Do growth rates differ for drift versus attached algae? 4) Is there a difference in photosynthetic performance in drift versus attached algal species? Manipulative field and laboratory experiments were conducted to address these questions with the green macroalga Codium decorticatum and the red macroalga Gracilaria tikvahiae. Changes in pigment concentration and biomass were used as indicators of acclimation from an attached to drift state in Gracilaria tikvahiae and Codium decorticatum. Short-term physiological changes as demonstrated by electron transport rate (ETR) were also used as indications of acclimation from an attached to drift state in C. decorticatum. Composition and rate of accumulation of drift varied by season. While both transport and turnover of drift occurred, turnover within drift accumulations occurred at low rates and was significantly lower in the spring during decreased flow rates. There were no significant differences in growth or pigment concentrations in drift versus attached G. tikvahiae or C. decorticatum. In addition, there were no apparent physiological acclimations to a drift state in C. decorticatum.
Show less - Date Issued
- 2004
- Identifier
- CFE0000112, ucf:46198
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000112
- Title
- PREDATION ON THE EASTERN OYSTER CRASSOSTREA VIRGINICA ON INTERTIDAL REEFS AFFECTED BY RECREATIONAL BOATING.
- Creator
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Stiner, Jennifer, Walters, Linda, University of Central Florida
- Abstract / Description
-
Widely regarded as a keystone species and ecosystem engineer, the eastern oyster Crassostrea virginica plays a vital role in estuarine environments. Complex, three-dimensional oyster reefs act as havens for biodiversity and contribute to ecological processes. Recently, concern for this resource has arisen in Mosquito Lagoon, Florida, the southernmost limit along the Atlantic coast for undisturbed, intertidal reefs of C. virginica. Since the 1990s, intense recreational boating activity has...
Show moreWidely regarded as a keystone species and ecosystem engineer, the eastern oyster Crassostrea virginica plays a vital role in estuarine environments. Complex, three-dimensional oyster reefs act as havens for biodiversity and contribute to ecological processes. Recently, concern for this resource has arisen in Mosquito Lagoon, Florida, the southernmost limit along the Atlantic coast for undisturbed, intertidal reefs of C. virginica. Since the 1990s, intense recreational boating activity has caused atypical dead margins (mounds of disarticulated shells) to emerge on the seaward edges of oyster reefs located along major navigational channels. Once dead margins are formed, little is known about their influence on biotic composition and interactions on oyster reefs. This study focused on the affect of dead margins on: (1) mobile species biodiversity and distribution, (2) reef architecture, and (3) the affect of structural variables on predation of juvenile oysters. To determine if dead margins influenced the biodiversity of mobile species on oyster reefs, lift nets (1 m2) were deployed within Mosquito Lagoon for one year (June 2004 - June 2005). These nets (5/site) were deployed on the back-reef areas of six reefs (3 reference reefs and 3 reefs containing dead margins). To simulate reef habitat, one and a half liters of live oysters were placed within each net. Lift nets were checked monthly and surveyed for all mobile species. The resulting data were assimilated into a species inventory containing 65 species of fishes, mollusks, crustaceans, worms, and echinoderms. The two most abundant species present on reefs in Mosquito Lagoon were the big-claw snapping shrimp Alpheus heterochaelis, a filter-feeder, and the flat-back mud crab Eurypanopeus herbstii, a predator of oyster spat. Contrary to expections, analyses of community metrics showed that dead margins did not significantly affect the biodiversity of back-reef areas on oyster reefs. Modified lift nets (0.25 m2) were placed on six different oyster reefs (3 reference reefs and 3 containing dead margins) to test if dead margins affected the distribution of mobile species inhabiting oyster reefs. Nine nets were arranged to cover three separate areas of each reef: the fore-reef (3 nets), mid-reef (3 nets), and back-reef (3 nets). Half a liter of oyster shells were placed inside each net. These nets were checked weekly, for five weeks and species richness, density, and biomass were recorded. Analyses revealed that all community metrics were significantly higher on reference reefs than reefs affected with dead margins. Further, a significant drop in all three metrics was seen on the mid-reef area of affected reefs. The absence of species on this area is hypothesized to be due to a lack of water, shade, and habitat complexity. To document architectural differences, two types of transects were run along five reference reefs and five reefs with dead margins. First, quadrat transects determined the percent of live oysters, the percent of shell clusters, topographic complexity (using chain links), and the angle of shells on each reef type. Transect lines were stretched parallel to the water line and covered all three reef areas (fore-reef, mid-reef, and back-reef). The results showed reference reefs to have approximately four-fold more live oysters, approximately twice as many shell clusters, and significantly greater topographic complexity. Numbers of live oysters and shell clusters were greater on the fore-reef and back-reef areas of both reef types. Second, laser transects were used to record reef profiles and the slope of fore-reef areas. Transect lines were stretched perpendicular to the water line and every 20 cm the distance between the lagoon bottom and reef top was measured. Vertical reef profiles and fore-reef slopes were significantly different between reference reefs and reefs with dead margins. Dead margins compressed reef widths, increased center peaks, and increased slopes on the fore-reef area by two-fold. Lastly, field experiments were conducted to determine the affect of dead margins on the vulnerability of oyster spat to predation. Structural variables (e.g. shell orientation, single versus shell clusters, reef slope) were manipulated and effects on oyster mortality were observed. Three predators were tested: the blue crab Callinectes sapidus, the common mud crab Panopeus herbstii, and the Atlantic oyster drill Urosalpinx cinerea. Structural variables did not have a significant influence on oyster mortality; however, a significant difference was established between predators. Panopeus herbstii consumed the most juvenile oysters, followed by U. cinerea and then C. sapidus. Together, these findings document ecological implications of dead margins on C. virginica reefs and reinforce the urgent need for enhanced regulations and restoration. If the intensity of recreational boating remains unregulated, dead margins will continue to increase. Thus, in order to maintain the diversity and productivity of Mosquito Lagoon, it is crucial to fully understand how dead margins alter the biogenic habitat and biotic communities of oyster reefs.
Show less - Date Issued
- 2006
- Identifier
- CFE0001059, ucf:46790
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001059
- Title
- IS THE EXOTIC BRAZILIAN PEPPER, SCHINUS TEREBINTHIFOLIUS, A THREAT TO MANGROVE ECOSYSTEMS IN FLORIDA?.
- Creator
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Donnelly, Melinda, Walters, Linda, University of Central Florida
- Abstract / Description
-
Mangrove ecosystems are critical to Florida, providing economic resources to humans, and untold ecological resources to estuarine organisms. In Florida's estuaries, mangrove ecosystems have suffered significant losses due to natural and human disturbances; these disturbances potentially leave mangrove communities vulnerable to invasion by the opportunistic exotic, Schinus terebinthifolius (Brazilian pepper). Prior experiments have suggested that Schinus terebinthifolius is unable to survive...
Show moreMangrove ecosystems are critical to Florida, providing economic resources to humans, and untold ecological resources to estuarine organisms. In Florida's estuaries, mangrove ecosystems have suffered significant losses due to natural and human disturbances; these disturbances potentially leave mangrove communities vulnerable to invasion by the opportunistic exotic, Schinus terebinthifolius (Brazilian pepper). Prior experiments have suggested that Schinus terebinthifolius is unable to survive under marine conditions and poses no long term threat to mangrove systems. However, this contradicts field observations where Schinus terebinthifolius was found growing in the intertidal zone of Mosquito Lagoon alongside three native species of mangroves, Rhizophora mangle, Avicennia germinans and Laguncularia racemosa. The purpose of my study was to evaluate competition between the invasive S. terebinthifolius and these three native species of mangroves in the coastal estuarine system along the east coast of Central Florida in Canaveral National Seashore. The effects of competition were evaluated by testing the ability of S. terebinthifolius to: 1) chemically inhibit growth of mangrove propagules, 2) invade new coastal habitats by dispersing seeds in the water, 3) alter species richness and abundance of the flora when present in a mangrove system, and 4) recruit and survive in mangrove habitat. By better understanding the invasibility and impact of Schinus terebinthifolius on mangroves, coastal resource managers will be able to develop the most effective management strategies to prevent this exotic from altering the structure and productivity of the mangrove ecosystem.
Show less - Date Issued
- 2006
- Identifier
- CFE0000998, ucf:46713
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000998
- Title
- PREDICTING RISKS OF INVASION OF CAULERPA SPECIES IN FLORIDA.
- Creator
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Glardon, Christian, Walters, Linda, University of Central Florida
- Abstract / Description
-
Invasions of exotic species are one of the primary causes of biodiversity loss on our planet (National Research Council 1995). In the marine environment, all habitat types including estuaries, coral reefs, mud flats, and rocky intertidal shorelines have been impacted (e.g. Bertness et al. 2001). Recently, the topic of invasive species has caught the public's attention. In particular, there is worldwide concern about the aquarium strain of the green alga Caulerpa taxifolia (Vahl) C. Agardh...
Show moreInvasions of exotic species are one of the primary causes of biodiversity loss on our planet (National Research Council 1995). In the marine environment, all habitat types including estuaries, coral reefs, mud flats, and rocky intertidal shorelines have been impacted (e.g. Bertness et al. 2001). Recently, the topic of invasive species has caught the public's attention. In particular, there is worldwide concern about the aquarium strain of the green alga Caulerpa taxifolia (Vahl) C. Agardh that was introduced to the Mediterranean Sea in 1984 from the Monaco Oceanographic Museum. Since that time, it has flourished in thousands of hectares of near-shore waters. More recently, C. taxifolia has invaded southern Californian and Australian waters. Since the waters of Florida are similar to the waters of the Mediterranean Sea and other invasive sites my study will focus on determining potential invasion locations in Florida. I will look at the present distribution of C. taxifolia - native strain in Florida as well as the distribution of the whole genus around the state. During this study, I address three questions: 1) What is the current distribution of Caulerpa spp. in Florida? 2) Can I predict the location of potential Caulerpa spp. invasions using a set of environmental parameters and correlate them to the occurrence of the algae with the support of Geographic Information System (GIS) maps? 3) Using the results of part two, is there an ecological preferred environment for one or all Caulerpa spp. in Florida? To answer these questions, I surveyed 24 areas in each of 6 zones chosen in a stratified manner along the Floridian coastline to evaluate the association of potential indicators Caulerpa. Latitude, presence or absence of seagrass beds, human population density, and proximity to marinas were chosen as the 4 parameters expected to correlate to Caulerpa occurrences. A logistic regression model assessing the association of Caulerpa occurrence with measured variables has been developed to predict current and future probabilities of Caulerpa spp. presence throughout the state. Fourteen different species of Caulerpa spp. were found in 26 of the 132 sites visited. There was a positive correlation between Caulerpa spp. and seagrass beds presence and proximity to marinas. There was a negative correlation with latitude and human population density. C. taxifolia aquarium strain wasn't found. Percent correct for our model was of 61.5% for presence and 98.1% for absence. This prediction model will allow us to focus on particular areas for future surveys.
Show less - Date Issued
- 2006
- Identifier
- CFE0001041, ucf:46796
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001041
- Title
- NATIVE AND INVASIVE COMPETITORS OF THE EASTERN OYSTER CRASSOSTREA VIRGINICA IN MOSQUITO LAGOON, FLORIDA.
- Creator
-
Boudreaux, Michelle, Walters, Linda, University of Central Florida
- Abstract / Description
-
Populations of Crassostrea virginica within Mosquito Lagoon, Florida have recently undergone significant die-offs, which are a subject of major concern. Restoration efforts within Mosquito Lagoon are focusing on reconstructing the three-dimensional reef habitats. Before effective protocols can be established, however, important questions about the sources of juvenile and adult oyster mortality must be answered. Potential causes of Crassostrea virginica mortality in the Indian River Lagoon...
Show morePopulations of Crassostrea virginica within Mosquito Lagoon, Florida have recently undergone significant die-offs, which are a subject of major concern. Restoration efforts within Mosquito Lagoon are focusing on reconstructing the three-dimensional reef habitats. Before effective protocols can be established, however, important questions about the sources of juvenile and adult oyster mortality must be answered. Potential causes of Crassostrea virginica mortality in the Indian River Lagoon system include sediment loads, competition, predation, and disease. My research focused on the interactions between oysters and the competitors that may affect the settlement, growth, and survival of Crassostrea virginica. The four objectives of my thesis research were to: 1) identify potential oyster competitors in Mosquito Lagoon, 2) determine if the sessile species recruiting to oyster shells have changed over time, 3) determine how the dominant competitors, barnacles, affect oyster settlement, growth and survival, and 4) determine if oyster or barnacle larvae are better able to settle in increased sediment and flow conditions that are associated with high levels of recreational boating. Lift nets were deployed within Mosquito Lagoon to determine available competing species. I collected species inventory data at six sites to determine the sessile invertebrate species (competitors) present on oyster reefs. Nets were deployed intertidally, just above mean low water, on living oyster reefs. One and a half liters of live and dead oysters were placed within the nets upon deployment. The nets were picked up monthly and surveyed for all fauna. Upon retrieval, all oysters within each net were brought back to the lab where all sessile organisms were immediately identified and returned to the lagoon. This survey began June 2004 and continued for one year. Shells from historic shell middens (up to 15,000 years old) were examined to determine if the sessile species settling on oyster reefs have changed over time. Similar species were found on both shells of historic and extant reefs. One notable exception was the appearance of Balanus amphitrite, an invasive barnacle, on the extant reefs. Balanus amphitrite is thought to have invaded Mosquito Lagoon approximately 100 years ago. This has resulted in a five fold increase in barnacle abundance per oyster shell. Balanus spp. were identified as important potential competitors and thus my research focused on spatial competition between C. virginica and native versus invasive barnacles of the area. Over 300 barnacles, including a native species, Balanus eburneus, and an invasive, Balanus amphitrite, have been counted on a single oyster shell. To determine how Balanus spp. affected settlement, growth, and survivorship of C. virginica, laboratory and field experiments were conducted in which densities of Balanus amphitrite and Balanus eburneus were manipulated. Density treatments included: no barnacles (control), low, medium, and high coverage of barnacles. Laboratory settlement trials with cultured oyster larvae were run in still water and flow (recirculating flume) using all barnacle density treatments. Additionally, all treatments with 7-day oyster spat were deployed in the field to follow oyster spat growth and survivorship. Settlement was counted by microscopy, and growth and survivorship were measured every 3 days for 4 weeks. Settlement of oysters was affected by barnacle presence only in flowing water. Still water trials showed no oyster preference related to any barnacle density or species. The presence of barnacles affected the growth and survivorship of oyster spat. However, there were no species specific differences. Studies suggest that recreational boating activities, especially boat wakes that cause sediment resuspension, may decrease recruitment and this may then provide an advantage to sessile competitors less affected by flow and sediment loads. To address these issues, replicated laboratory trials were run in a laboratory flume to quantify the effects of water motion (0, 5, 10 cm/s) and sediment loads (0, 8, 16 g/ml) on oyster recruitment and the recruitment of an important, relatively new competitor in the system, the barnacle Balanus amphitrite. If B. amphitrite settles in a wider variety of flow rates and sediment conditions, it may have a competitive advantage over the native oyster in this space-limited habitat. I found that high flow and sediment loads reduced larval settlement of C. virginica. Alternatively, settlement of cyprids of B. amphitrite did not differ among treatments. Thus, continuous boat traffic during settlement times should favor recruitment of the invasive barnacle Balanus amphitrite over the native oyster Crassostrea virginica. Determination of the competitive interactions of Crassostrea virginica in Mosquito Lagoon gives us important insights into the ecological conditions necessary for re-establishment of these oyster populations. Crassostrea virginica in Mosquito Lagoon was significantly impacted by barnacles; settlement, growth, and survivorship were all reduced by Balanus spp. This information will help resource managers in planning restoration techniques to minimize oyster and barnacle competitive interactions and increase Crassostrea virgininca success.
Show less - Date Issued
- 2005
- Identifier
- CFE0000780, ucf:46575
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000780
- 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
- UNDERSTANDING THE INVASION OF FLORIDA'S INTERTIDAL CRASSOSTREA VIRGINICA REEFS BY NON-NATIVE MARINE INVERTEBRATE SPECIES.
- Creator
-
Nash, Ethan, Walters, Linda, University of Central Florida
- Abstract / Description
-
Predicting the locations of new biological invasions has become a high priority for biologists as well as trying to predict if newly introduced species will become damaging to native ecosystems. Reefs of the eastern oyster Crassostrea virginica in Mosquito Lagoon, Florida have been highly disturbed in recent years resulting in dead reefs (piles of dead, disarticulated shells) some of which have been restored. I conducted oyster reef surveys for non-native invertebrates to determine if...
Show morePredicting the locations of new biological invasions has become a high priority for biologists as well as trying to predict if newly introduced species will become damaging to native ecosystems. Reefs of the eastern oyster Crassostrea virginica in Mosquito Lagoon, Florida have been highly disturbed in recent years resulting in dead reefs (piles of dead, disarticulated shells) some of which have been restored. I conducted oyster reef surveys for non-native invertebrates to determine if disturbance on these oyster reefs might assist invasion by two species, Mytella charruana and Perna viridis, recently introduced to the southeastern coast of the United States. Next, I investigated if M. charruana's temperature and aerial exposure tolerance limits may allow for it to establish permanently on intertidal oyster reefs. Temperature and aerial exposure tolerance experiments were conducted and oyster reef temperatures were collected. Oyster reef surveys could not predict if reef disturbance is assisting in the invasion process because only two non-native individuals (P.viridis) were found, one on a restored reef and one on a natural (reference) reef. Tolerance experiments showed that some Mytella charruana survived even after 7 days of 8° C temperatures if the mussels are exposed to air for 4 hours or less per day. Mytella charruana had near 0% survival after 4 hours of 44° C. However, only disturbed reefs reached this temperature in the field. It is likely that M. charruana could survive in the low intertidal zone on restored or reference reefs. This information is important for understanding the introduction of M. charruana in Mosquito Lagoon and also provides a data set of temperature tolerances for better understanding of whether the species might be able to invade other areas.
Show less - Date Issued
- 2011
- Identifier
- CFE0003593, ucf:48889
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0003593
- Title
- RECRUITMENT AND RESTORATION OF THE OYSTER CRASSOSTREA VIRGINICA IN AREAS WITH INTENSE BOATING ACTIVITY IN MOSQUITO LAGOON, FLORIDA.
- Creator
-
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
- INVESTIGATION OF MICROPLASTIC ACCUMULATION IN THE GASTROINTESTINAL TRACT IN BIRDS OF PREY.
- Creator
-
Carlin, Julia, Walters, Linda, Donnelly, Melinda, University of Central Florida
- Abstract / Description
-
Plastic pollution is unavoidable in the natural environment. Consequences of plastic ingestion include exposure to environmental pollutants and toxin accumulation, causing endocrine disruption, inflammatory and physiological stress in organisms. Microplastics have been shown to transfer across food webs, however, limited studies have examined microplastic accumulation across terrestrial food webs. Furthermore, few studies have examined plastic pollution in apex predatory animals. A study was...
Show morePlastic pollution is unavoidable in the natural environment. Consequences of plastic ingestion include exposure to environmental pollutants and toxin accumulation, causing endocrine disruption, inflammatory and physiological stress in organisms. Microplastics have been shown to transfer across food webs, however, limited studies have examined microplastic accumulation across terrestrial food webs. Furthermore, few studies have examined plastic pollution in apex predatory animals. A study was conducted to quantify the abundance of plastic pollution in the gastrointestinal tract in birds of prey. Two species were investigated, one which forages in terrestrial habitats and one which forages in aquatic environments including Buteo lineatus (red-shouldered hawk) and Pandion haliaetus (osprey), respectively. The gastrointestinal tract was necropsied, chemically digested, and examined for microplastic prevalence. Overall, microplastics are significantly more abundant per gram of gastrointestinal (GI) tract tissue in species that forage on small rodents and terrestrial reptiles (B. lineatus) as compared to species that forage on fish and aquatic invertebrates (P. haliaetus). Buteo lineatus averaged 0.81 (+/- 0.15) fibers and 0.14 (+/- 0.04) fragments per gram of GI tract tissue while P. halieatus averaged 0.31 (+/- 0.09) fibers and 0.04 (+/- 0.02) fragments per gram of GI tract tissue. There was a significant interaction between type and color in both B. lineatus and P. haliaetus GI tract tissues. Micro-Fourier-transform infrared spectroscopy ([micro]-FTIR) was run on haphazardly selected samples and found that rayon was the most common polymer identified in both species. The significant difference found between species could be indicative that terrestrial raptors may experience greater bioaccumulation than aquatic species foraging at comparable trophic levels. However, the significant interaction between type and color in both species indicates a potential common source of pollution that affects both environments. Further investigation on the source of polymers is necessary in order to develop conservation and management strategies aimed at decreasing the output of synthetic fibers into the environment. Due to the abundance of polymers found in these species, understanding the potential biological and physiological effects of plastics is essential to informing superior management strategies that can better protect and preserve wildlife from increasing anthropogenic pressures.
Show less - Date Issued
- 2019
- Identifier
- CFH2000501, ucf:45621
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000501
- Title
- Exploring multi-scale variation of fish community diversity in a dynamic coastal estuary.
- Creator
-
Troast, Brittany, Cook, Geoffrey, Walters, Linda, Paperno, Richard, University of Central Florida
- Abstract / Description
-
Examining diversity over multiple spatial and temporal scales affords the opportunity to develop a mechanistic understanding of the factors influencing community diversity dynamics, and how these may shift in a changing world. This thesis first examines multi-decadal fish community diversity metrics across a coastal biogeographic transition zone to quantify changes in species assemblages, assess relationships between fish community diversity and the abiotic environment, and capture potential...
Show moreExamining diversity over multiple spatial and temporal scales affords the opportunity to develop a mechanistic understanding of the factors influencing community diversity dynamics, and how these may shift in a changing world. This thesis first examines multi-decadal fish community diversity metrics across a coastal biogeographic transition zone to quantify changes in species assemblages, assess relationships between fish community diversity and the abiotic environment, and capture potential shifts in the location of a putative biogeographic break. Results of this chapter indicate not only a change in fish community composition, but also a shift in the location of the biogeographic transition zone. If these trends continue, a potential 16-62km shift northward by the year 2100 could occur. Understanding the novel species assemblages these shifts could result in is necessary for the future management of this area. Next this thesis examines diversity on a local scale, assessing the response of the fish community to restoration of oyster reefs and coastal wetlands which act as essential fish habitat. Results support the idea that fish community composition at restored oyster reefs is more similar to those of live reefs than dead reefs, however, results of abundance and diversity analyses were equivocal. Living shoreline analyses produced no differences between control and restored sites before or after restoration. Possible explanations for lack of clear trends in the fish community could be explained by the presence of other essential fish habitats in the area, scale of restoration, and length of monitoring. This thesis explores diversity on a multitude of spatial and temporal scales to better understand how fish communities respond to change and generates fundamental knowledge that can improve our ability to conserve and manage coastal communities and better inform the development of ecosystem-based management strategies.
Show less - Date Issued
- 2019
- Identifier
- CFE0007905, ucf:52753
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007905
- Title
- Hydrodynamic Limitations and the Effects of Living Shoreline Stabilization on Mangrove Recruitment along Florida Coastlines.
- Creator
-
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
- Understanding sediment biogeochemistry and the role of juvenile oysters on recently restored eastern oyster reefs.
- Creator
-
Locher, Bryan, Chambers, Lisa, Walters, Linda, Kibler, Kelly, University of Central Florida
- Abstract / Description
-
In recent decades, goals for the restoration of eastern oyster (Crassostrea virginica) populations along the eastern coast of the United States have shifted from increasing harvestable oyster fisheries to enhancing the range of ecosystem services provided by oyster reefs. By filtering large volumes of water and releasing nutrient-rich feces and pseudofeces, oysters can locally enhance sediment biogeochemical cycling compared to that of unstructured benthic environments. An ongoing restoration...
Show moreIn recent decades, goals for the restoration of eastern oyster (Crassostrea virginica) populations along the eastern coast of the United States have shifted from increasing harvestable oyster fisheries to enhancing the range of ecosystem services provided by oyster reefs. By filtering large volumes of water and releasing nutrient-rich feces and pseudofeces, oysters can locally enhance sediment biogeochemical cycling compared to that of unstructured benthic environments. An ongoing restoration program in Mosquito Lagoon, FL was leveraged to assess the immediate impacts ((<) 1 year) of restoration on sediment biogeochemical properties of oyster reefs. The first study measured both short-term and long-term pools of carbon, nitrogen and phosphorus on dead, natural and restored reefs periodically over one year. The second study investigated one of the contributions to sediment nutrient pools by comparing feeding and feces/pseudofeces nutrient content of juvenile and older oysters. Results show that inorganic nitrogen and phosphorus pools can change within weeks after restoration and total nutrient pools by 6 months post-restoration. Restored reefs experienced a 136 % increase in ammonium, 78 % increase in total nitrogen, 46 % increase in total phosphorus, and 75 % increase in organic matter concentrations after 12 months of restoration. These nutrient increases were all positively correlated with oyster density, shell length and reef height measured on each reef. When standardized to grams of dry tissue weight, juvenile oysters showed significantly higher rates of chlorophyll-a removal, release of ammonium, and biodeposits with higher concentrations of dissolved organic carbon, nitrite + nitrate, and ammonium. The short-term changes to biogeochemical cycling on eastern oyster reefs within the first year of restoration are important to managers seeking to monitor ecosystem service recovery and overall coastal ecosystem health.
Show less - Date Issued
- 2019
- Identifier
- CFE0007671, ucf:52460
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007671
- Title
- Community-based coastal restoration: long term impacts on habitats and people in Volusia County.
- Creator
-
Wimmer, Rachel, Walters, Linda, Donnelly, Melinda, Koontz, Amanda, University of Central Florida
- Abstract / Description
-
Coastal habitats provide invaluable economic and ecosystem services. However, coastlines are eroding at increasing rates due to anthropogenic and climate driven changes. Grey and green infrastructure solutions have been proposed to retard the decay of coastlines, with oysters serving as a popular living shoreline. Three community-based stabilizations that implemented living shorelines and engaged local communities in restoration efforts over the past decade in Volusia County were revisited to...
Show moreCoastal habitats provide invaluable economic and ecosystem services. However, coastlines are eroding at increasing rates due to anthropogenic and climate driven changes. Grey and green infrastructure solutions have been proposed to retard the decay of coastlines, with oysters serving as a popular living shoreline. Three community-based stabilizations that implemented living shorelines and engaged local communities in restoration efforts over the past decade in Volusia County were revisited to determine if they were successful and if they produced positive public perceptions of success. Chicken Island, which was restored after waves, boat wakes, tides, and adverse weather altered the natural shoreline, had significant increases in oyster size and density but an unsuccessful deployment of mangrove seedlings. The Port Orange study site installed living shoreline along existing sea wall and experienced low oyster recruitment, limited success with S. alterniflora propagation, and high cover of bare sediment. The Mosquito Lagoon Marine Enhancement Center had high vegetative cover and biodiversity and decreases in oyster density likely due to the development of healthy, mature oyster reefs. A survey of volunteers who participated in these three restoration projects was also conducted to determine if there is a tie in ecosystem function produced through restoration and community perceptions of restoration success. While there were not enough survey responses to draw conclusions, the responses were indicative of the future research needed to understand volunteer identities and sense of place as they relate to the human-nature system. To improve the long-term success of living shorelines, it is critical to not only select restoration methods appropriate for the specific location of the restoration, but to involve local communities to increase sense of self and investment in restoration efforts.
Show less - Date Issued
- 2019
- Identifier
- CFE0007878, ucf:52781
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007878
- 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
- Effects of harmful algal blooms caused by Aureoumbra lagunensis (brown tide) on larval and juvenile life stages of the eastern oyster (Crassostrea virginica).
- Creator
-
Makris, Panagiota, Walters, Linda, Quintana-Ascencio, Pedro, Scarpa, John, University of Central Florida
- Abstract / Description
-
Harmful algal blooms caused by the marine microalga Aureoumbra lagunensis have been associated with negative impacts on marine fauna, both vertebrate and invertebrate. Within the Indian River Lagoon (IRL) estuary system along Florida's east coast, blooms of A. lagunensis in excess of 1(&)#215;106 cells mL-1 have occurred along with higher than average salinities ((>)35 PSU) during times of peak reproduction and growth for the eastern oyster Crassostrea virginica. Field and laboratory studies...
Show moreHarmful algal blooms caused by the marine microalga Aureoumbra lagunensis have been associated with negative impacts on marine fauna, both vertebrate and invertebrate. Within the Indian River Lagoon (IRL) estuary system along Florida's east coast, blooms of A. lagunensis in excess of 1(&)#215;106 cells mL-1 have occurred along with higher than average salinities ((>)35 PSU) during times of peak reproduction and growth for the eastern oyster Crassostrea virginica. Field and laboratory studies were used to investigate the effects of A. lagunensis and high salinities on early life stages of eastern oysters, late pediveliger to early juvenile. Natural recruitment of C. virginica within Mosquito Lagoon (northern IRL) from 2013 to 2015 was negatively associated with blooms of A. lagunensis ((>)1(&)#215;105 cells mL-1) and high salinities ((>)35 PSU), but recruitment of barnacle competitors was not. Larval settlement, tested using recirculating raceway flumes, was affected both by A. lagunensis and high salinities. Additionally, survival and growth rates of juvenile C. virginica were tested following one-week laboratory exposure to A. lagunensis and subsequent transplantation to the field for four weeks. Survival of juvenile oysters was negatively correlated with A. lagunensis and time (80% survival for A. lagunensis exposure and 90% survival when exposed to Isochrysis galbana control). Our results indicated negative impacts of Aureoumbra lagunensis on larval and juvenile eastern oysters during the term of the experiment. Oyster recruitment and growth continued during and following exposure to bloom concentrations of A. lagunensis, but at reduced rates.
Show less - Date Issued
- 2016
- Identifier
- CFE0006535, ucf:51309
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006535