Re-establishment of Fringing Mangrove Habitat in the Indian River Lagoon

Shoreline Restoration Project

2007-2008 Final Report

Prepared for: St. Johns River Water Management District

525 Community College Parkway, S.E. Palm Bay, FL 32909

(Contract # 24860 and Grant # FC397)

Lisa K. Johnson and Laura W. Herren Florida Department of Environmental Protection Office of Coastal and Aquatic Managed Areas

Southeast Aquatic Preserves Field Office 3300 Lewis Street

Fort Pierce, FL 34981 (772) 429-2995

October 30, 2008  

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TABLE OF CONTENTS LIST OF TABLES………………………………………………………………………………………….2 LIST OF FIGURES…………………………………………………………………………………….…..3 LIST OF ACRONYMS…………………………………………………...…………………………..……4 PROJECT BACKGROUND ELC………………………………………………………………………………...………………5

FDEP CAMA……………………………………………………………………………..………18 OBJECTIVES………………………………………………………………………………………….….18 TASK IDENTIFICATION AND DELIVERABLES………………………………………………..……19 INTRODUCTION……………………………………………………………………………………...…21 METHODS Design…………………………………………………………………………………………….22 Elevation…………………………………………………………………………………….……25 Nursery and Mangrove Propagation……………………………………………………………..25 Planting Methods………………………………………………………………………………....26 Sampling Strategy…………………………………………………………………………….…..28 Site selection……………………………………………………………………………….……..28 Monitoring……………………………………………………………………………………..…30 RESULTS ELC sites………………………………………………………………………………………….31 FDEP sites………………………………………………………………………………………..40 One-month monitoring……………………………………………………………………………43 Education and Public Outreach………………………………………………...………………...46 DISCUSSION Survival and Growth…………………………………………………………………………...…50 Re-vegetation vs. Restoration…..………………………………………………………………...51 Resiliency…………………………………………………………………………………………52 Future Direction……..…………………………………………………………………………....54 2008 PROJECT SUMMARY……………………………………………………………………………..56 REFERENCES……………………………………………………………………………………………57 APPENDICES Appendix 1. City of Cocoa Beach Planting Summary…………………………………………...60 Appendix 2. Walton Scrub Planting Summary……………………………………………….…..64 Appendix 3. Rotary Park at Suntree Planting Summary……………………………………...…70 Appendix 4. IR36 Planting Summary ………………………...……………………………….…73 Appendix 5. SL3 Planting Summary……………………………………………………………..76 Appendix 6. Fisherman’s Landing Planting Summary…………………………………………..79 Appendix 7. FY 08-09 Potential SRP SitePhotographs………………………………………….83 Appendix 8. ELC SRP E Site Photographs………………………………………………………87 Appendix 9. ELC SRP Unsuccessful Site Photographs……………………………...…………129

Appendix 10. ELC Planting, Monitoring, and Public Outreach……………………………..…141 Appendix 11. Managing Entities of Existing SRP Sites………………………...………….……154

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LIST OF TABLES 1. Shoreline Restoration Project Coordinators (1995-2006)………………………………………….…..8 2. 2008 SRP Advisory Committee members…………………………………………………...………..23 3. Florida nurseries with east coast mangroves stock………………………………………………...…29 4. Mangroves purchased in FY 0708……………………………………………………………………29 5. Established SRP sites (1995 to 2006)………………………………………………………………....38 6. SRP planting sites assessed in FY 07-08………………………………….…………………………..42 7. SRP sites established by FDEP in FY 07-08……………………………………………………….…42 8. Monitoring schedule for FDEP FY 07-08 SRP sites………………………..……………………...…44 9. One-month monitoring results - City of Cocoa Beach……………………………………………......44 10. One-month monitoring results - Walton Scrub……………………………………………………….45

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LIST OF FIGURES 1. The Riley Encasement Method…………………………………………………………...………..5 2. Successful plantings using a modified encasement method…………………………………….…6 3. A modifided PVC encasement method with extensions……………………………………….....10 4. A modifided PVC encasement method with windows……………………………………….…. 11 5. Survivorship graphs……………………………………………………………………………....14 6. ELC educational sign placed at SRP sites………………………………………………………..16 7. FDEP experimental grid design…………………………………………………………………..24 8. Setup at the City of Cocoa Beach site…………………………………………………………….25 9. A hydrologically-pressurized planting system ………………………….………………………..27 10. Existing SRP sites in Brevard and Indian River Counties……………………………………..…32 11. Exisiting SRP sites in St. Lucie, Martin, and Palm Beach Counties……………………………..33 12. Unsuccessful SRP sites in Brevard and Indian River Counties…………………………………..34 13. Unsuccessful SRP sites in St. Lucie, Martime, and Palm Beach Counties……………………....35 14. Percent survival by year planted………………………………………………………………….36 15. Root structure of dead mangroves when removed from the PVC encasement…………………...37 16. Mangrove trimming and potential effects on stability……………………………………………39 17. Plant exposure at low versus high tides…………………………………………………………..43 18. Volunteer education and outreach……………………………………………………………….. 47 19. Hometown News article ………………………………………………………………………….48 20. Public awareness sign developed by FDEP…………………………………………………….. .49 21. Recruitment challenges at Walton Scrub…………………………………………………………52 22. Resiliency to disturbances………………………………………………………………………...53 23. Natural recruitment along an artificially-created shoreline at SL15……………………………...55

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LIST OF ACRONYMS AC Advisory Committee for SRP BC Brevard County CAMA Office of Coastal and Aquatic Managed Areas ELC Environmental Learning Center on Wabasso Island ESA Environmental Science Academy at SRHS EPA U.S. Environmental Protection Agency FDEP Florida Department of Environmental Protection FIND Florida Inland Navigation District FWC Florida Fish and Wildlife Conservation Commission FWS U.S. Fish and Wildlife Service IRC Indian River County IRL Indian River Lagoon IRLNEP Indian River Lagoon National Estuary Program JNROTC Junior Naval Reserve Officers Training Corps at SRHS MEM Modification of the Riley Encasement Methodology MRC Marine Resources Council PBC Palm Beach County PVC Poly-vinyl-chloride SRP Shoreline Restoration Project SRC Shoreline Restoration Coordinator SJRWMD St. John’s River Water Management District SFWMD South Florida Water Management District SWIM Surface Water Improvement Program REM Riley Encasement Methodology S.E. standard error of the mean SLC St. Lucie County SP State Park SRHS Sebastian River High School SSRPSP St. Sebastian River Preserve State Park

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PROJECT BACKGROUND Records obtained from the Environmental Learning Center (ELC) in 2008 were reviewed for project history, planting methods, site selection criteria, and lessons learned. History A PVC encasement methodology thought to improve the success of mangrove plantings was brought to the attention of St. Johns River Water Management District (SJRWMD or District) staff Bob Day and Ron Brockmeyer Jr. in 1995. The Riley encasement method (REM) was developed to facilitate planting along high wave energy shorelines, overcoming limitations of conventional planting methods (Riley and Kent 1999) (Figure 1). This is especially important at sites placed at lower elevations (Riley and Kent 1999). Large-scale plantings with the REM have been successful outside the United States (Sato et al. 2005 and Bob Riley personal communication). When used at elevations where mangroves typically recruit, limited success (establishment of mature trees) has been documented in the Indian River Lagoon (Bob Riley personal communication) (Figure 2). The Environmental Learning Center was approached in 1995 to administer a Lagoon-wide mangrove restoration program implementing the REM with multi-agency support and funding. A total of $110,500 was originally requested from seven sources: U.S. Fish and Wildlife Service (FWS), Indian River Lagoon National Estuary Program (IRLNEP), SJRWMD, South Florida Water Management District (SFWMD), Florida Inland Navigation District (FIND), and Florida Department of Environmental Protection (FDEP). A total of $52,750 was granted in the first year, and a subsequent range from $38,800 to $53,000 annually from 1995 to 2000, from SJRWMD, SFWMD, and FWS. In 2001, SRP was partially funded with $14,400 by the National Oceanic and Atmospheric Association (NOAA) through the Community-Based Restoration Program (Award Number NA17FZ1510). All three species of mangrove found in the IRL have been successfully planted using the REM (Riley and Kent 1999), but red mangroves have been the focus of the Shoreline Restoration Project (SRP). Records obtained by FDEP from ELC in 2008 indicate that 104 plantings were established in 57 locations from 1995 to 2006.   

Figure 1. Riley encasement methodology (Riley and Kent 1999). Sediment is filled to elevation level where propagules would naturally recruit on the shoreline, supporting mangrove growth in high wave energy areas (Diagram from Cassler 2002).    

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  Figure 2. Successful red mangroves planted in 1996 by the ELC using a modified PVC encasement method at (a) Fisherman’s Landing and (b) Sebastian Riverview Park. Photographs were taken in 2008.

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ELC SRP Project Goals The original goal of the program was to, “establish and maintain a long-term shoreline re-vegetation project benefiting the Indian River lagoon through the restoration or establishment of fringing mangrove habitat.” It was acknowledged that obtaining this goal would require cooperation and coordination between a broad spectrum of entities including government at all levels, private sector, academia and the general public. It was suggested that public officials should generate program support to achieve the long-term sustainable programmatic funding goal. In subsequent years, project goals were modified to: 1) re-establish and maintain fringing mangrove habitat along the high-energy shorelines of the IRL where traditional methods of planting were unsuccessful and 2) educate the public and increase awareness about the benefits of mangroves. To reach these goals, seven project objectives were set:

1. Plant six sites during the 1st fiscal year (1995). 2. Plant > 10 in subsequent fiscal years. 3. Monitor all planted sites according to strategies developed from Florida Marine Research

Institute (FMRI). 4. Develop, implement, and evaluate alternative planting materials and methods. 5. Evaluate potential for spoil island rehabilitation work. 6. Secure long-term support for the program to increase benefits to the IRL. 7. Provide educational opportunities and involve the public in activities which directly benefit the

IRL. A grant-funded Shoreline Restoration Coordinator (SRC) position was created and based out of the ELC. A position announcement from 2005 indicated the SRC is required to:

1. Plan, design and organize planting efforts. 2. Monitor success and growth rates of plants. 3. Deliver public presentations to community groups. 4. Work under the direction of a 10 person advisory committee. 5. Recruit and coordinate large groups of volunteers, from school-age children to adults to assist

with plantings and monitoring. 6. Communicate technical information to the volunteers and ensure that technical directions are

accurately followed. 7. Collect mangrove propagules, and maintain and care for seedlings in a nursery setting 8. Prepare grant proposals related to the project.

In addition, self-motivation, physically-fit, well organized, good communication skills, degree in biology or related field, and computer skills in data management were all required with desired skills in environmental education, horticulture, native or wetland plant cultivation, or plant nursery operations; first aid; experience with small boat operations.

From 1995 to 2006, there were eight SRC (Table 1). The SRP Advisory Committee (AC) was formed in 1995 with individuals representing entities such as FWS, SJRWMD, SFWMD, FIND, FDEP, Florida Fish and Wildlife Conservation Commission (FWC), The Nature Conservancy (TNC), Florida SeaGrant, and community members. Quarterly meetings were held with the AC and recommendations for the direction the project were made.

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Table 1. Shoreline Restoration Coordinators employed through the Environmental Learning Center from 1995-2006.

ELC SRC Years Camille Sewall 1995-1997 Chandra Salgado 1997-1998 Joe Acaba 1998-2000 Jacob Morton 2000-2001 Constance Cassler 2001-2003 Kadrin Fowler 2003-2004 Vincent Michault 2004-2005 Justin Teall 2005-2006

Site Selection Sites were located along shorelines in the Indian River Lagoon in Brevard (SR520 being the northern boundary), Indian River, St. Lucie, Martin and Palm Beach Counties (Waterway Park and Donald Ross Bridge, south of Jupiter Inlet, being the southern boundary).

SRP AC identified the following site selection criteria:

1. Public lands (a few private sites were planted until the intent was made clear in 2000). 2. Waterfront parks or refuges, spoil islands, canal banks, impoundment areas. 3. High energy areas susceptible to erosion. 4. Areas easily accessible by volunteers. 5. Areas critical to listed species. 6. Areas with support from the managing entity.

Records show that selected sites were not limited to high energy areas (e.g., Dale Wimbrow Park). St. Lucie County Mosquito Control District requested assistance stabilizing lower-energy shorelines surrounding portions of SLC mosquito impoundments. In 1998, it was decided that sites planted on the St. Sebastian River (e.g., Dale Wimbrow Park) would not be expanded as it was thought that the red mangroves would likely be out-competed by freshwater plants. In 1996, the AC recommended that no armored shorelines (e.g., rock and seawalls) be selected for planting sites and that the project focus site selection on only ″natural shorelines.″ Further, it was recommended that plants be established in 1 ft water no farther than 3-4 ft from ″high shoreline edge″, existing shoreline be followed, and not plant on previous shoreline that had eroded. The AC recommended that plantings be located close to existing vegetation when possible. By the end of the first year (in 1996), it was recommended that plants be replanted once a month for first three months if mortality occurred. Sites were to be discontinued if they required replanting more than three times, experiences vandalism, or have extreme wave energy. After two years of the SRP (1995-1997), it was estimated that 5,115 m of shoreline was re-vegetated.

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Nursery Initially, un-rooted propagules were collected and planted as quickly as possible, as recommended by Riley and Kent (1999). There was a verbal agreement from Brian Pool with FDEP in 1997 that propagules were allowed to be collected from trees, but only in impoundments. Unrooted propagules were no longer used after 1997, however, when HBOI donated a greenhouse to the ELC. It was thought the rooted seedlings would have a better survival rate than un-rooted propagules and that they would be available for year-round planting. Collected propagules were used promptly or kept in the greenhouse for up to six months. Rooted propagules were grown by several methods, in soil in nursery trays, in brackish water (similar salinity to that found at the transplantation site) in buckets, and in water in nursery trays. By 2000, it was found that in water in nursery trays was the best method that resulted in the least amount of disturbance to the root system when transplanted in the PVC encasements. Planting Methods A detailed description of PVC encasement preparation, planting instructions, monitoring sheets, site characteristics, area measurements, and monitoring can be found in Appendix 10. Once the PVC is installed, enough sediment is poured into the encasement to create the ″artificial bottom″ described by Riley and Kent (1999), whereby the seedling is brought up to the level of natural seedling recruitment (Figure 1).

The nursery donated in 1997 supported stock by March 1999. This facilitated year-round planting events. The best time to plant mangroves was documented to be from February to June, following potential freezing events and before hurricane season.

In 1995, four to six inches of pipe was left above mean high water and the plant was planted two inches below the top of the encasement. The portion of pipe above mean high water was intended to keep debris from entering the pipe at high tide. In August 1997, a two-piece encasement revision to the REM was used to offer more protection to the seedlings (Figure 3). The SRC reverted to the one piece design after October 1998 when most of the upper segments were lost to vandalism. Some of the plantings were placed in deeper water than specified by the REM or were planted in encasements that were prepared differently from the standard method. One of the purposes of this program was to test the limits of this method and to determine what kinds of modifications might improve results (Cassler 2002).  

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Figure 3. PVC encasement method with extensions. Photo taken at HBOI in 2008. In October 1997, the AC recommended that Spartina alterniflora and other vegetation be planted along with the mangroves when possible to hold the soil until the mangroves grow. A test planting with S. alterniflora on MC1 (Martin County Boy Scout Island) in 1998 was unsuccessful. In 1999, two additional planting methods were used on MC1 other than PVC encasements: individual propagules and clusters of propagules were planted. FDEP does not have specific details on this alternative planting, (e.g., how many and whether propagules were rooted or unrooted, other than what was mentioned in AC meeting minutes). By the end of 1999, AC meeting minutes indicated that most propagules plantings disappeared and/or washed away. In 2003, S. alterniflora plugs, 20 “pot-grown” red mangroves, and one black mangrove were planted at Fisherman’s Landing. Potted mangroves were observed by FDEP at the Coral Cove (north) planting site in Palm Beach County during the 2008 monitoring with the plastics pots in the ground still around the plant. Bamboo encasements were planted on Pelican Island National Wildlife Refuge (NWR) in 1996. The encasements were regularly used by cormorants as loafing sites. High nutrient concentrations and acidity (from guano) led to unsuitable conditions for the seedlings and no mangroves survived past the nesting season. Two sites (Sebastian A1A #2 and Malabar) were established in 1997 by Chandra Salgado-Kent as part of her Master’s thesis study with Dr. Lin in the Department of Biological Sciences at the Florida Institute of Technology (FIT). These sites were used to compare the success of bamboo encasements vs. PVC

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encasements. Her conclusion was that the bamboo was too dark and the plants did not get enough light (Salgado-Kent and Lin 1999). Dr. Lin expressed interest in the project and offered to be available to answer any questions about design and statistical analyses. In March 1999, a small amount of 18-6-12 slow release fertilizer was added at the time of planting to help the propagules through the initial adjustment from greenhouse to shoreline. This practice was discontinued in fall 2000 because the uncertainty of its benefit. Sometime after 2002, PVC plantings were arranged in a cluster design. Each circular cluster consisted of 10 encasements with one in the middle and nine around the outside. Plants in each cluster were on three-foot centers. There was a four-foot gap between clusters to allow for foot traffic (Appendix 10). Site Maintenance and Monitoring Site Maintenance: It was suspected that the PVC encasements were negatively affecting the growth and survival of the mangroves. To address this concern, encasement alleviation techniques were tested. Windows were cut in encasements at some sites to allow more light to penetrate and to give growing prop roots extra room to extend down to the sediment rather than having to wait to grow down once reaching above the top of the encasement (Figure 4). In August 2000, it was decided that the encasements were to be trimmed six inches after one year in the field. This was done to allow the prop roots to grow lower on the trunk, ultimately, shortening the distance that they needed to grow before reaching sediment. In 2001, encasements were trimmed at the SFWMD Seawall and Fisherman’s Landing sites. A horizontal cut at six inches from the top of the encasement was made to prevent the trees from leaning. After being trimmed, the SRC documented stunted growth and evidence of prop root mortality that was attributed to extensive barnacle and mussel settlement. Although concern was raised about the restriction of the roots below the ground by the encasement, it was not possible to remove the encasement below the waterline. Cassler (2002) suggested that lowering the top of the encasement in later years may also stimulate greater growth. This was corroborated at the Fisherman’s Landing site, where mangroves with large canopies (0.1 m3) grew faster following encasement removal.   Figure 4. Windows were cut in some encasements to provide extra light. Photo was taken at the Barrier Island Center/Pepper Cove Impoundment site (established in 2002) in 2008.

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Once individual mangroves become established, meaning that they have sufficient prop roots penetrating the soil to stabilize the tree without the aid of the encasement, the PVC was removed above the waterline. Originally, it was anticipated that the trees would be established in three to five years. Results from the SRP indicate that most mangroves take at least five years to reach this definition of established when grown in PVC encasements. It was recommended that the encasements be removed during the early part of the year after the winter storms have past. This schedule allows for additional root growth, thus improving stabilization, prior to hurricane season. A battery-operated Dremel® tool with a cutting guide was used to carefully remove the above-water portion of the encasements from the tree without damaging the roots. No underwater cutting tool was used. Monitoring: When the project began in 1995, monitoring included measurements of main stem length, leaf length and width and internode distance. The number of prop roots was also recorded along with the length and basal diameter of each prop root. Canopy volume and distance to the top of encasement (TOE) were measured. The status of prop roots was recorded annually to determine when the tree was ready for encasement removal. Other observations, such as wash out, fallen pipes, animal infestations, and vandalism, were also included during monitoring (Appendix 10). In March 1999, it was decided that canopy measurement was a good indication of project success. It was also particularly useful in assessing progress towards the SRP goal to establish and maintain a long-term shoreline revegetation project benefiting the Indian River lagoon through the restoration or establishment of fringing mangrove habitat. Canopy provides habitat for roosting and nesting birds, produces propagules, and is an important source of detritus that fuels the food web in the IRL. A lower percent survival was thought to be acceptable (60-70%) if canopies are large and increased habitat is the outcome. In August 2000 it was decided that canopy volume would be monitored using a random sample of trees within zones at each location. Calipers were developed and used to measure canopy volume starting in February 2001 (Appendix 10). Later, the SRC decided to measure of the canopy of each tree rather than use a random sample. In October 1999, the AC suggested that the number of propagules per tree be counted. In August 2000, a ″field notes″ section was added to the data sheet and the SRC recorded the time it took to monitor each site. Annual photographs were also taken at the same location at each site to provide a visual record of change. FDEP currently does not have these annual photographic records, except for new site establishment photos included in annual reports. By 2001, monitoring procedures were streamlined to include only measurements relating to the success or failure of each site (Appendix 10). This specifically included # live, # dead, and # pulled for initial monitoring. For advanced monitoring, measurements included tree #, distance to top of encasement (positive or negative), # roots in shoreline, # roots 0-30 cm above shoreline, total # live roots, # dead roots, max canopy height, max canopy width, min can width, and canopy volume (calculated). Results In October 1998, a goal of 80% survival was established. This goal was based on survival requirements typically set for restoration or mitigation plantings. According to annual reports and AC meeting minutes, there was a average 26% success in 1999, 28% in 2001, and 27% in 2006. The average percent survival of plantings after the first year was between 50-60% from 1995 to 2006. Average percent survival on a per county basis did not show an increase from north to south. No margins of error were reported. By 2005, more than 10,000 red mangrove (Rhizophora mangle) trees were planted and 79.4 m3 of total mangrove canopy added to IRL shoreline.

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Growth measurements and the process of numbering individual trees at each site began in 1998. In 2001, average (± S.E.) tree growth after one year was 21.0 ± 13.3 cm, second year growth was 12.0 ± 7.4 cm, and third year growth was 13.5 ± 4.6 cm (Cassler 2002) (Figure 5). Canopy volume measurements began in 2001. Average reported volume at 24 locations was 0.051 m3. Total canopy volume added to IRL shoreline was 49.7 m3. In the FY 05-06 report, the ELC reported an average canopy volume of 0.1461 m3 and a total volume of 125.2 m3. In 2001, flowers and fruit were observed on at least 1% of trees in six locations. In 2006, reproductive structures were observed on trees at 15 different sites. It was not noted in ELC annual reports what years plantings had been established, i.e. how many years plantings took to produce flowers and fruit. Prop roots extending to and penetrating the soil were documented at four sites in 2005 and 10 sites in 2006. Public Outreach and Education The second goal of the project, “to educate and promote awareness of mangrove habitats” remained central to the project with the ELC from 1995 to 2006 with volunteers donating a total of 4,823 hours. Volunteers included Girl Scouts, Eagle Scouts, Middle School Students, church groups, and community members. Volunteers assisted with encasement preparation, propagule collection, plant care in the greenhouse, mangrove plantings, and site monitoring. The SRC also prepared and delivered presentations to special interest groups including, but not limited to, Rotary Club, P.E.O. Women’s Group, and Lagoon House Brown Bag Lunches. Informational signs were developed and posted at each planting location (Figure 6). The signs production was funded through FIND. FDEP currently has 31 of these signs obtained from the ELC. A slide show was developed in 1995. The presentation was delivered to 77 groups from 1995 to 2001 (Cassler 2002). The four topics covered were:

1. An introduction and history of the IRL. 2. A description of the types of mangroves found in Florida. 3. An explanation of how the mangroves are important to the ecology of the IRL. 4. A description of the SRP.

A portable display board was also created to inform people about the project during public events such as festivals and conferences. The display was presented 25 times at international and local conferences and environmental festivals. Pamphlets describing the project were developed and distributed at public events and talks (Appendix 10). Other media coverage of SRP included one radio program, eight television programs and 20 newspaper articles from October 1995 to December 2001. A description of the SRP was posted on the ELC’s website along with information about mangroves and the IRL.

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Figure 5. (a) Percent survival (solid lines) of red mangroves (planted in 1998) and average total tree growth (dotted lines) three years after planting. (b) shows that percent survival for all sites was inversely proportional to canopy volume (figure from Cassler 2002).

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Alternative Materials Interest in researching and testing alternative materials to PVC for encasements began in 1996. The hope was to find a biodegradable material as durable as the PVC, easier to remove, and as cost effective. Two test sites in 1996 (Sebastian Inlet State Park and Malabar) and one site in 1997 (Pelican Island NWR) were used to investigate the potential to replace PVC with bamboo. Results indicated that the bamboo did not allow enough light to reach the plants and that it was difficult to install. Another PVC alternative, a material termed the “wattle” was the most promising (Taylor 1998). The two categories of materials researched by Taylor (1998) were “manufactured” and “hand-made”. According to the ELC, no options explored proved better than PVC for being strong, long-lived and cost effective ($0.21/ft) (Cassler 2002). In January 1999, using colored PVC was suggested so that the pipes would be less visible to the public. Due to potentially negative effects on water quality, painting the encasements was ruled out. Bob Riley (Mangrove.org) has recently worked with PVC manufactures to create gray-colored PVC that may be both less visible and improve mangrove success. This product, however, is currently available only to project managers that attend an extensive REM training course taught by Mr. Riley through mangrove.org.

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Figure 6. Sign (18 x 24 inches) posted at several ELC mangrove planting sites.

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Recommendations by the ELC for planting red mangroves with PVC encasements

1. Select propagules without insect holes.

2. Use seedlings less than one year old, otherwise they may lack essential nutrients after being grown in a nursery.

3. Plant along natural shorelines, avoiding seawalls or rock revetments unless water recedes 15 cm

or less for part of the year. Sites that continuously have deep water have much slower growth rates and the roots tend to be soft (SFWMD Seawall). Sometimes the sediment gets washed out of PVC leaving the roots suspended in the pipe (Kiwanis Park at Geiger Point).

4. Select remote areas with less human activity for the planting sites. People using these areas

sometimes pull up encasements (Memorial Island) or use them for other purposes (John Jorgensen’s Boat Ramp, MC1 Boy Scout Island).

5. Avoid planting near drainage pipes or in areas where currents are extreme. During periods of

heavy rains the increased current can wash away pipes (Old Fort). The same can happen near inlets where tidal currents are strong (Coon Island).

6. Avoid areas adjacent to birds roosts or rookeries (Sewall’s Point, Pelican Island NWR). Guano

can affect the leaves and perching birds can break small tree limbs.

7. Select relatively stable spoil island sites. Highly dynamic spoil islands may erode before the plants are established (SL19A).

8. Plant on public lands. If private property is planted and there are changes in ownership, the new

owners may restrict access for monitoring or remove trees illegally (Greylight).

9. Select sites that are not adjacent to or in front of a steep slope. Heavy rain may cause soil to slide down-slope and bury encasements or water may gain enough momentum to wash soil away from encasements.

10. Donate used encasements to bait/tackle shops, local nurseries, and citrus groves.

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FDEP CAMA In FY 07-08, Florida Department of Environmental Protection (FDEP), Office of Coastal and Aquatic Managed Areas (CAMA) jointly utilized funding from the St. Johns River Water Management District (SJRWMD) Indian River Lagoon National Estuary Program (IRLNEP) for the administration of the Shoreline Restoration Project (SRP). The grant contract between SJRWMD and FDEP was executed on February 7, 2008. The project was jointly managed by the East Central Aquatic Preserves (ECFAP) and the Southeast Florida Aquatic Preserves (SEFLAP) field offices. The SRC, Lisa Johnson, was hired and began working on May 16, 2008. This report represents efforts of FDEP administering the SRP from February 7, 2008 to September 30, 2008. FY 07-08 OBJECTIVES

a. Review historical records to maintain consistency, develop new methodology, and determine the best methodology for planting mangroves for each recruitment-limiting parameter. Interview groups performing shoreline restoration and review the literature for the most successful methodologies to incorporate for the future.

b. Assess a minimum of 12 sites per year in the IRL to identify hydrological (tidal influence, fetch, boat wake, potential wave energy), substrate parameters, planting elevations, latitude, potential for vandalism or wildlife effects and prioritize sites based on the criteria accordingly. Select at least 6 sites for plantings per year.

c. Remove exotic vegetation when necessary from the shoreline in the selected priority sites.

d. Plant the treated shoreline with black mangrove (Avicennia germinans), red mangrove (Rhizophora mangle), white mangrove (Laguncularia racemosa), cordgrass (S. alterniflora) and other available native wetland plant species as appropriate.

e. Monitor and maintain new and the remaining 75 previously restored areas as described in

Task 3.

f. Continue to educate the public on the importance of mangrove habitat, propagation and planting techniques, and encourage stewardship of resources through volunteer participation and outreach events.

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FY 07-08 TASK IDENTIFICATION AND DELIVERABLES

Task 1: Collect and Care for Mangrove Tree Seedlings (year round) • Propagule collection is performed during the months of August through

November. • In order to maintain a continuous seedling source, propagules will be grown

in the nurseries located at the Environmental Learning Center (when feasible), the St. Sebastian River Preserve State Park, and by volunteers (year round).

• Purchase 5, 10, and 25 gal black, white, and red mangrove trees for use as ″established mangrove strands″ and purchase plugs of Spartina alterniflora.

Task 2: Educate the Public on the value and importance of mangroves and shoreline plantings at festivals, boat shows, and local events (year- round)

• Using educational displays and distributing pamphlets, in addition to hands-on demonstrations and presentations.

• Recruit volunteers and establish a volunteer network with trained and experienced volunteers.

• Coordinate field activities with other CAMA activities such as Island Enhancement Program workdays or other volunteer based groups.

Task 3: Monitor and Maintain New and Existing Sites Until Encasements Are Removed (year-

round). 100 total sites were planted between 1995 and 2005; currently there are 75 existing sites.

• Monitoring activities to assess survival and growth. • Immediately following initial planting distance (inches) is measured from the

top of the mangrove seedling to the top of the encasement, then once a month for three months. Additional measurements take place six, nine and twelve months after planting. Percent survival is calculated after monitoring sessions within the first three months, seedlings that die are replaced with viable seedlings.

• Survival is recorded on a quarterly basis for the first year, semiannually in the second year, and annually after the third year.

• Trees are measured during monitoring events for growth, height and canopy volume. Number of reproductive structures is recorded.

• Number, measurement and classification of the stabilizing prop roots of red mangrove trees are assessed and the degree of progression toward the substrate is recorded

• Trees are cleaned of debris and soil added if needed during every monitoring event and emergency monitoring events after severe storms.

Task 4: Assess for Shorelines along the IRL that can benefit from Restoration (year-round).

• Contact local or governmental agencies or non-profits to inquire about unvegetated shorelines they are managing and visit suggested sites.

• Identify islands managed by CAMA and coordinate with CAMA staff. Task 5: Contact Volunteers and Government Agencies to assist in plantings

(Winter-Spring). Coordinate activities with the Aquatic Preserves planned Island Enhancement workdays.

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• Typically school groups, scout troops and community, boating, and environmental clubs.

• Staff from the East Central Florida Aquatic Preserves, Southeast Florida Aquatic Preserves, and other agencies when possible will assist in plantings and may assist with logistics when boats are required to transport volunteers to island sites.

Task 7: Prepare encasements and tools for each planting event (Winter-Spring)

• Order PVC and cut to REM specifications. • Purchase and/or create tools.

Task 8: Environmental Education conducted for Planting and Monitoring Volunteers (November

- June) • Slide show stresses importance of the mangrove ecosystem and explains the

methodology of ″Riley Encasement″ technique. Task 9: Conduct Plantings (November -June)

• Install encasements and plant with mangrove seedlings. • Perform a minimum of 6 plantings in the Federal F.Y. 07-08. • Utilize adult mangroves and Spartina alterniflora plugs sites where

appropriate.

Task 10: Status Reports Prepared Quarterly July 30, 2008 Status Report Task 12: Shoreline Restoration Advisory Committee Meetings held quarterly November 19, 2007 SRP Committee Meeting at Environmental Learning Center May 7, 2008 SRP Committee Meeting at Environmental Learning Center June 24, 2008 SRP Conference Call to discuss experimental design Task 13: Annual Reports Submitted to Funding Agencies

• Prepared within 30 days of the end of the fiscal year. Task 14: Site History - Future Objective

• Document the data collected by the Shoreline Restoration Project and submit for publication in the appropriate scientific journals.

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INTRODUCTION Fringing mangrove habitat is a vital resource to tropical estuarine systems such as the Indian River Lagoon. Mangroves serve as nurseries and provide refuge for protected and economically-important species, stabilize existing and accreting sediments, absorb wave energy during storm events, and promote nutrient cycling (Tomlinson 1994). Mangrove habitat utilization by faunal species has been well documented (Mumby et al. 2004; Taylor et al. 1998; Sheridan 1997; Thayer 1987). Telemetry studies conducted in 2007 and 2008 demonstrate the importance of red mangroves in the daily migration patterns of gray snapper Lutjanus griseus from mangrove fringe to the seagrass beds in the Central Embayment of the Loxahatchee River (Dr. Albrey Arrington personal communication). Since the mid-1900s, mangrove habitat in the Indian River Lagoon (IRL) has declined following large-scale impoundment of wetland areas for mosquito control (Brockmeyer et al. 1997) and coastal development (Steward et al., 2002). Since then, management efforts (management plans and the Mangrove Trimming and Preservation Act) have been approved by Florida’s Governor and Cabinet to protect this valuable habitat. The IRL Comprehensive Conservation and Management Plan (IRLNEP 2008) lists as an objective to “Preserve, protect, restore and enhance the wetland resources of the Indian River Lagoon region.” The 1990 Indian River Lagoon – Jensen Beach to Jupiter Inlet Aquatic Preserve Management Plan Objective A.3.1 is “To identify suitable unvegetated and disturbed shoreline areas as restoration sites.” Task A.3.1.1. in this plan states that “All suitable shorelines will be re-vegetated with mangroves and/or marsh grass plantings.” The 2002 Surface Water Improvement Management (SWIM) lists as Goal II, “To attain and maintain a functioning macrophyte-based ecosystem which supports endangered and threatened species, fisheries and wildlife.” Coastal Wetland Objectives includes “Restore function of impounded and other impacted marshes” and “Create new marshes” (Steward et al. 2002). The legislative intent of the 1996 Mangrove Trimming and Preservation Act is to “protect and preserve mangrove resources valuable to our environment and our economy from unregulated removal, defoliation, and removal” (403.9323 F.A.C.). The Federal Emergency Management and Assistance program (FEMA Title 44) lists as one of its requirements for the National Flood Insurance Program (NFIP 60.3 e7) to, “Prohibit man-made alteration of sand dunes and mangrove stands within Zones V1-30, VE, and V on the community's FIRM which would increase potential flood damage.” A new economic study by Hazen & Sawyer (2008) has estimated the total value of the IRL in its 2007 state to be $3.7 billion. While the annual value of mangrove habitats as it contributes to the overall value of the IRL was not estimated in this study, seagrass habitats were estimated around $329 million per year, or $4,600 per year per acre of seagrass as it contributes to local fisheries. Based on similar ecosystem functions of mangroves and seagrasses (Hogarth 2007), mangrove habitat in the IRL could be estimated at a similar value. Despite the ease of growing red mangroves in a nursery, literature reviews indicate mixed success of plantings using traditional using nursery-raised plants (Lewis 2005; Ellison 2000; Cintron-Molero 1992). The Riley PVC encasement method was developed as a mangrove planting method to use in high energy areas where traditional methods have failed (Sato et al. 2005; Riley and Kent 1999). Studies reviewing mangrove restoration projects in Florida have also concluded that species composition and biomass of successfully-restored ecosystems are different than natural ecosystems (McKee & Faulkner 2000; Proffitt & Devlin 2005; Shafer & Roberts 2008). Because of their long prop roots, which allow for the plants’ partial submergence, red mangroves (Rhizophora mangle) have often been the only species of focus with restoration plantings. Naturally-recruiting black (Avicennia germinans) and white (Laguncularia racemosa) mangrove species have been found in succession more than fifteen years following red mangrove plantings in 10 restoration sites in south Florida (Shafer & Roberts 2008). The transition

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between emergent marsh and mangrove swamp habitats has also been documented ten years following Spartina alterniflora plantings (Shafer & Roberts 2008). In a review of mangrove ecosystem restoration efforts in the U.S. by Cintron-Molero (1992), general features of ideal mangrove restoration sites are listed: 1) low elevation and minimal immersion time, 2) tidal flushing for dispersal of propagules, 3) nutrients, freshwater inputs, and salinity 5-10 ppt, 4) moist, wet environments, 5) sheltered environments, 6) terrestrial sediment input and/or source of inorganic nutrients. For mangrove restoration projects, Lewis and Streever (2000) identify five critical steps to achieve success:

1. Understand individual species ecology of the mangrove species at the site; in particular the patterns of reproduction, propagule distribution, and successful seedling establishment.

2. Understand the normal hydrologic patterns that control the distribution and successful establishment and growth of targeted mangrove species.

3. Assess modifications of the original mangrove environment that currently prevent nautral mangrove establishment.

4. Design the restoration program to restore hydrology of an area and then, if possible, utilize naturally-recruited mangrove propagules for plantings.

5. Only plant mangroves after steps a-d have been assessed and it is determined that natural recruitment alone will not be sufficient to achieve the objectives of the restoration project.

In 2008, FDEP reviewed project records obtained from the Environmental Learning Center (ELC), visited restoration sites established from 1995 to 2005, and established six new mangrove planting sites using an experimental design to test relative success of three planting methods at three elevation elevations. MATERIALS & METHODS Design With the assistance of AC members and other participants that provided advice during a conference call held on June 24, 2008 (Table 2), FDEP established a 3 * 3 grid design that compares three elevation levels and three planting methods: 1) PVC encasements, 2) multi-stem pots, and 3) mature individuals. Each elevation level is 1.5 m apart and contains one individual from each of the 3 planting methods randomly placed on 1.5 m centers (Figure 7). To allow for 1.5 m on each side, the total dimensions of each grid are 6 m x 6 m. The length of shoreline in need of restoration (total available shoreline) at each site was separated into one meter increments. Each grid was randomly placed along the total available shoreline using a random number table. The number of grids placed at each site was dependent on the available shoreline length. The sampling design requires that all sites be selected and available shoreline measured prior to randomly placing the grids and planting (see sampling design in Figure 7). Individual sites planted in FY 07-08 were selected on a site by site basis and were intended to be part of a pilot study to allow CAMA staff time to improve the design and to plan for future restoration projects. All sites in FY 08-09 will be selected and placement of grids will be randomly decided prior to planting at any site.

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Table 2. List of 2008 SRP Advisory Committee Members.

Name Affiliation

1 Amber Hoffmann Volusia County 2 Sharon Tyson ECFAP 3 Dr. Mayra Ashton ECFAP 4 Jeanene Bengoa ECFAP 5 Bob Day SJRWMD 6 Christopher Lindo MRC 7 Dr. Donna Devlin FAU 8 Dr. Ed Proffit FAU 9 Dr. Elizabeth Irlandi FIT 10 Laura Herren SEFLAP 11 Jeff Beal FWC 12 Mark McGee SEFLAP 13 LeRoy Creswell Florida SeaGrant 14 Mark Crosely FIND 15 Michelle Webster Volusia County 16 Mike Renda TNC 17 Mike Yustin Martin County 18 Ricardo Zambrano FWC 19 Troy Rice SJRWMD

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Figure 7. Grid design that shows the three planting methods and the three elevation levels.

 

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Elevation At this time, elevation is defined by SRP as the distance from high tide line. Surveyed measurements for shoreline elevation gradients are currently beyond the scope of the SRP. Three general elevation levels, 1.5 m width, were examined. Prior to planting each site, grids were measured and marked with surveying flags starting at the annual high water line. The high water line was identified by wrack line in late August and September and using standard wetland delineation procedures by identifying natural recruitment of mangroves and the prevalence of hydrophytic vegetation typically adapted for saturated soil conditions (ACOE 1987). Each elevation level extends waterward every 1.5 m from the high water line (Figure 8).

Figure 8. Setup along the high water line at the City of Cocoa Beach site in August 2008. Nursery and Mangrove Propagation Mangroves used for planting are kept at the St. Sebastian River Preserve State Park (SSRPSP) where staff have provided nursery space to store and propagate plants used for the SRP (Clinton “Ed” McKenzie personal communication). All SRP plants stored at the nursery are maintained by the SRC, FDEP staff, and volunteers. At the nursery red, black, and white mangroves and Spartina alterniflora are partially submerged in holding ponds placed on tables under shade cloth. Since seedlings should not be allowed to dry out, pond

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construction was a top priority for the nursery in FY 07-08 (MRC 1998). Twenty-four 55″ x 41″ holding ponds were constructed by SRC and SEFLAP staff with 2 x 4 pieces of wood purchased with project funds. Four additional ponds were made by volunteers from 2 x 9 pieces of scrap wood. Ponds are lined with plastic sheeting and filled with fresh water. To reduce osmotic stress associated with transplantation, mangroves are conditioned in salinity of 5-10 ppt at least two weeks prior to planting, then 10-15 ppt one week prior to planting. A 500 gal plastic holding tank was purchased to store brackish water pumped from the IRL at the nursery. Salinity is measured with a refractometer purchased with project funds. Nursery vendors located on the east coast of Florida were contacted for purchasing mature red, white, and black mangroves and S. alternifloa (Table 3). Red mangroves were not commercially available above three gallon and black mangroves were not available above one gallon from any vendor on Florida’s east coast at the time plants were purchased in September 2008. Plants (from Sebastian stock) grown by Bates Nursery in Ft. Pierce were purchased and delivered to the SSRPSP nursery (Table 4). The long term plans for the mangrove nursery at SSRPSP include propagating future stock for SRP. In FY 08-09, S. alterniflora plugs will be potted in 1 gal pots. Propagules collected during the fall 2008 drop will be used for both future multi-stem and mature plantings and potted in one gallon pots. Some three gallon red mangroves purchased from Bates nursery will re-potted in several gallon pots. Vehicle Transportation A 1998 Chevrolet Blazer was acquired by SEFLAP for SRP use. A 10´ by 5´ trailer was purchased with project funds for transportation of mangroves to the sites. For transportation to Spoil Islands and water-access sites, the SRP 15´ aluminum Jon boat with Johnson engine was obtained from ELC. FY 07-08 project funds were used for Jon boat maintenance. Planting Methods  Three planting methods were used in 2008: 1) modified Riley Encasement Methodology (MEM), 2) multi-stem, 3) mature single-stem. PVC encasement: The PVC encasement method used by FDEP was a slightly modified version of the Riley Encasement Method (MEM) (Riley and Salgado-Kent 1999; Salgado-Kent and Lin 1999). The REM uses thin-walled, and ultra violet (uv) resistant PVC (in the process of being patented by Bob Riley) that has been scored such that the PVC will break into 1/3 pieces as the mangrove grows. The MEM PVC encasements used by FDEP are also thin walled 160 psi (11.25 kg/cm2), 1½″ diameter, but lack the scores and special uv-resistant coloration of the REM encasements. Both the REM and MREM are five feet tall and have straight longitudinal slits to allow for water exchange and growth of the mangrove, and one end cut at a 45° angle, to allow for ease during installation. No encasements that were warped, curled, or cut at angles other than 45° angle were used in the project. The five-foot encasements were driven about 2.5 ft into the ground such that the top was above the seasonal high tide mark. Two methods were used to drive the PVC: 1) small pile-driver and 2) a hydrologically-pressurized pump system developed by SEFLAP staff (Figure 9). The hydrologic system is driven by a one inch transfer pump, max pressure 50 psi max flow 1742 gph with a submerged snorkel in the water. The pump brings water in through the intake valve, pressurizes it, and sends it through the export hose to a planting wand with a pressurized shut-off valve. The wand, made of ¾″ PVC reduced through a ½″ tip, is inserted into the PVC encasement where pressurized water sent through the wand liquefies the sediment, allowing the casing to sink into the ground to the desired depth. This system worked well for planting potted plants as well. The pressure from the wand liquefies sediment and allows the root ball to sink intact into the sediment.

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Figure 9. A hydrologically-pressurized system of planting can be used for installing PVC encasements and planting underwater. Unrooted propagules were inserted with the thicker (brown) end down and the part of the seed that germinates pointed upward so that it is level with the high water line following recommendations by Riley and Kent (1999). Sediment was placed inside the encasement so that five to eight centimeters of the propagule was covered. The propagules was then flushed with water so that any sediments adhering to the upper portion of the propagule was washed away. Mature: Mature single-stem trees, approximately three feet high growing in three gallon pots, were purchased from Bates Nursery in Ft. Pierce and transferred to the SSRPSP nursery (Table 4). Marine Resources Council (MRC 1998) recommends planting potted mangroves after 2 to 3 yrs, once the plant has developed a healthy root system. The best time of year for planting mature mangrove plants is early spring after the last cold front (MRC 1998). Mature plants were planted at the same or a lesser depth than they had been growing in pots (MRC 1998). Multi-stem: Seedlings from the fall 2007 drop (approximately one year old) were assembled into multi-stem pots with four stems per pot by SRC and volunteers. A mixture of loamy, sandy soil obtained following construction at the ECFAP Office in Cocoa and potting soil from the SLC Jail Nursery were used for repotting.

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Sampling Strategy A Simple Random (sensu Kehler 2005) strategy was used for the IRL Shoreline Restoration Project. The collective network of available shoreline at all six sites was transformed into one continuous line. Sites were selected to reduce the amount of inter-site variability as much as possible, thus creating a homogenous area of interest. An assumption of the sampling strategy is that all shorelines along the IRL are the same and each grid is considered one replicate. From year to year, the same number of replicates (grids) will have to be established. Sampling points will be evaluated at the end of the study to determine the amount (if any) of spatial autocorrelation (repeated pattern) between sampling points. Site Selection Three criteria were used to select each of the 2008 planting sites: 1) had to be on public lands, 2) low potential for vandalism, and 3) planting would enhance surrounding ecosystem function. Site locations range from the northern boundary at SR 520 in the Banana River Aquatic Preserve in Brevard County to the southern boundary at Jupiter Inlet in Palm Beach County in the IRL Jensen Beach to Jupiter Inlet Aquatic Preserve and may include IRL tributaries; Sebastian, St. Lucie, and Loxahatchee Rivers. At most sites selected, exotic vegetation had been removed by the local managing entity prior to planting. The SRC began the certification process for Pesticide Applicator License for exotics removal on Natural Areas, passing the core exam with the Florida Agriculture Extension Services on August 26, 2008. Sites were selected by FDEP staff in consultation with local land-management entities. Permission letters (e.g., email communication, formal letters, research permits, and/or license agreements) were obtained by FDEP prior to planting at each site. Local site management plans were considered, ensuring that the presence of mangroves would not to preclude future recreational development of the sites.

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Table 3. Florida nurseries with east coast mangrove stock.

Table 4. Mangroves purchased from Bates Nursery in Ft. Pierce, FL.

Units Name Description Amount Total

300 Rhizophota mangle Red Mangrove 3 Gallon 12 360025 Avicennia germinans Black Mangrove 1 Gallon 4 10015 Laguncularia racemosa White Mangrove 7 Gallon 25 37515 Laguncularia racemosa White Mangrove 3 Gallon 7 105

200 Spartina alterniflora plugs 0.6 120 Delivery to Fellsmere 100 Total 4,400

Nursery Location Phone Contact Size- Red Size- White Size- Black Mangroves Unlimited Ft. Lauderdale 954-832-0251 Joseph Fulghum 8 ft + trees (hydroponic) No No Marine Resources Council Melbourne 321-725-7775 Chris Lindo 1.5'-2' No 1.5-2' (qty 50 pots) Aquatic Plant Management Venus 954-444-1379 Al Suarez 18-24″ (1 g, 3 g) seeds 8-12″ (liners) Ocean Garden Homestead 305-247-1152 Wayne Christensen 2.5' 6″, 30″ 2.5' Bates Nursery Ft. Pierce 561-358-7480 Chad Bates 8-10″ (1 g), 3 g 8-10″ (1 g), 3 g 8-10″ (1 g) Liner Farm Inc. St. Cloud 800-330-1484 Dave Biggar 4″-6″ 4″-6″ 4″-6″ Plantation Spice Growers Goulds 305-257-2306 Charles Smoleny 6″ 25 g, 45 g 15 g Maple Street Natives Melbourne 321-729-6857 Sharon Dolan 1' + No No

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SRP received four separate donations of red mangrove seedlings, all from fall 2007 seed drop, from citizens (Kay Parker, Wabasso, and Jeremy Neff, Jensen Beach) and supporting entities (St. Lucie County Jail Nursery and University of Florida-SeaGrant Extension Office). St. Lucie County (SLC) Jail Nursery inmates grew more than 500 single-stem mangroves in one gallon pots collected by UF SeaGrant Extension Office. Jeremy Neff donated approximately 3,000 seedlings grown 500 each in five gallon buckets. Floating propagules were collected by the SRC and volunteers after the drop following Tropical Storm Fay on August 20, 2008. Propagules with evidence of herbivory or parasitism were eliminated (Dr. Donna Devlin personal communication). Some of the propagules were inserted into the PVC encasements and others were placed in ponds at the nursery to grow as stock for planting future years. Propagules collected from locations south of Sebastian Inlet are used for plantings south of the Inlet, and those collected from locations north of the Inlet are used for plantings north of the Inlet. When possible, propagules used in the PVC encasements were collected at the site on the day of planting. Monitoring During FY 07-08, all recorded sites established by the ELC were monitored by SRC and SEFLAP staff for survivorship. The number of encasements and the number of living plants were counted and a GPS waypoint was taken with a Garmin® (eTrexH) GPS in decimal degrees. No growth measurements were taken. Unsuccessful sites, sites with no surviving mangroves, were documented and removed from the monitoring list for FY 08-09. New sites established by FDEP were monitored and maintained according to the monitoring schedule proposed by FDEP, and as recommended by SRP Advisory Committee. Monitoring takes place once a month for the first three months, quarterly for the first three years, then annually after three years. New plantings are to be replaced each month for the first three months then again during the 6, 9, 12 month monitoring visits. FDEP aims for 85% success over three years, which is consistent with most restoration projects required for mitigation (some require 100%). Water level was noted at the time of planting and each monitoring visit at each site. Fixed markers were placed on either side of a planting area so that long-term, consistent photographs could be taken. Survivability data, growth [distance to the top of the encasement (TOE)], canopy volume (length * width * height of leaf canopy), and stem success (the number of surviving stems for multi-stem plantings) were collected in FY 07-08 at the new FDEP sites. No encasements were trimmed in FY 07-08. Starting FY 08-09, encasements will be trimmed six inches or more to alleviate constraint and allow prop roots to grow when the encasement is no longer necessary for the survival of the plant and there are sufficient prop roots to maintain stability. According to the ELC, this could be three to five years or more. This was done at Fisherman’s Landing and Sebastian Riverview Park, the two sites with the largest mangrove stands grown by the ELC with the PVC encasement method (Figure 2).

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RESULTS ELC Sites Site monitoring took place from May to September 2008. SRP records obtained from the ELC indicate that 103 sites were established from 1995 to 2006. In many of these sites, however, more than one planting and replanting took place at the same location (e.g., Ft. Pierce Inlet SP # 1 and #2). In most of these cases, no distinctions were made between the different plantings in the site descriptions or at the site. For ease of reporting and future monitoring, FDEP grouped sites located within property boundaries of one managing entity. For example, all eight plantings on the Harbor Branch Oceanographic Institution (HBOI) campus are grouped together as one “site”. Of the 57 sites established by the ELC, 32 sites continue to support mangroves and 25 sites were unsuccessful with no surviving mangroves (Table 5). Toland Seawall site, established in 1997, supports surviving mangroves, however, this is a privately-owned property and monitoring will take place with the owner sometimes during FY 08-09. The Hog Point site, planted by former SRC Vincent Michault when he worked for EEL in 2007, was not established by the SRP with ELC, but it was added to the list of existing sites to maintain consistency with site maintenance and data collected on mangrove planting with the PVC encasement methodology. At Melbourne Beach Pier, empty encasements were removed south of pier, where ELC records indicate the plantings were located. There is one mangrove stand growing in a trimmed PVC encasement and several empty PVC surrounding it north of the pier; however, ELC records indicate all plantings were south of pier. Shapefiles were made of existing sites, which include successful sites and FDEP plantings in FY 07-08, and unsuccessful sites with ArcMap 9.2 and used to generate maps of all existing sites and unsuccessful sites (Figures 10-13). The average survival (± standard error) for the 57 sites (excluding Toland Seawall) is 10% ± 2.1. Because some sites had more than one planting, and no distinctions are able to be made, survival cannot accurately be correlated to the age of site. There does not appear to be any differences in survival based on the year the site was first planted (Figure 14). Encasements were removed from sites in FY 07-08 if they were found floating in the water or easily removed. While removing the PVC the SRC noticed that roots of dead trees pulled from encasements appeared to be constricted (Figure 15). Encasements that were difficult to remove within a reasonable amount of time (e.g., trimmed low to the ground or submerged in high water) will be removed in the FY 2008-2009.

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Figure 10. Existing SRP sites established by the ELC from 1995 to 2006 and FDEP in 2008 in Brevard and Indian River Counties.

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Figure 11. Exisiting SRP sites established by the ELC from 1995 to 2006 and FDEP in 2008 in St. Lucie, Martin, and Palm Beach Counties.

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Figure 12. Unsuccessful SRP sites established by ELC from 1995 to 2006 in Brevard and Indian River Counties.

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Figure 13. Unsuccessful SRP sites established by ELC from 1995 to 2006 in St. Lucie, Martin, and Palm Beach Counties.

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Year Site First Established

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

Aver

age

% S

urvi

val i

n 20

08

0

10

20

30

40

50

60

70

80

90

100

210

4

2 3

56 5

5

4

3

0

1

Figure 14. Comparison of establishment date and the average percent survival (± S.E.) of red mangroves as recorded in in 2008. The number of sites per year is noted above each column.

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Figure 15. (a) Roots of dead mangroves removed from their encasements appear constricted. Eau Gallie Bridge and (b) Coconut Point Sanctuary (Melon Property).

(a)  (b)

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Table 5. A list of the 57 SRP sites established by the ELC from 1995 to 2006. Successful sites that will continue to be monitored in FY 08-09 are in bold.  

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The manager of Hobe Sound NWR requested that all PVC encasements be removed from mangroves planted by the ELC and that no further plantings be established there in the future. While monitoring the site, six empty encasements were removed and encasements from ten surviving mangroves were cut to a height of six inches above ground. Two encasements were trimmed to approximately 12″ above ground. Several mangroves had prop roots. Those without prop roots began to lean as soon as the encasement was trimmed (Appendix 8). Plantings on the property of Blowing Rocks Preserve had been trimmed by Mike Renda, Restoration Biologist with The Nature Conservancy (Figure 16). He attributed the etiolation (slow growth and “legginess”) to lack of light within the encasements. He also noticed damage from the top rim of the encasements. The ELC stopped collecting growth data in 2005. In 2006, he began pruning 6-12″ inches off of the top of the plant and filing down some of the encasements with a Dremel® tool. Figure 16. Trimming mangroves may enhance growth and stability: (a) Mike Renda (TNC’s Blowing Rocks Preserve) showing height where the mangrove would be trimmed (6″ from top) and (b) Brian Sharpe (SEFLAP staff) pointing out a trimmed mangrove with a trunk that appears thicker than mangroves that have not been trimmed.     

(a)  (b)

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At the Melbourne Beach Pier site, several empty PVC and one surviving mangrove stand with large canopy and prop roots extending beyond the encasement were found north of pier, whereas the records for the site indicate all plantings were established south of the pier. One empty PVC encasement was found south of the pier, and was removed during the site visit on August 24, 2008. Since we do not have record of these plantings, we conclude that PVC encasement plantings north of the pier were not established by the ELC. Plantings established at Hog Point Sanctuary on Brevard County Environmental Endangered Lands (EEL) property were established on July 13, 2008 by former SRC, Vincent Michault while employed with EEL in 2007. This site was added to the SRP list of surviving sites to maintain a continuity of mangrove restoration monitoring data with four other planting sites on EEL-managed properties. At Longpoint Park, there are PVC encasement plantings, but FDEP has no record from ELC of a site established there. Brevard County Parks and Recreation staff at Longpoint Park have notified the SRC that they want PVC encased red mangrove plantings removed, if possible, due to restricted visitors’ access to the water for boat launching and fishing. PVC encasements from what appear to be a SRP planting were found on IR26, but there is no record of the ELC establishing a site there. More research will be done to identify the source and date of the plantings. Fisherman’s Landing and Sebastian Riverview Park were the focus of encasement alleviation efforts by the ELC in 2001. At these sites, several mangroves have outgrown their encasements and have become large, reproductively mature trees (Figure 2). Seven unsuccessful sites were not found: Wildcat Cove, Indian Landing Impoundment, Donald Ross Bridge, Malabar, and Sebastian A1A, Greylight, Plantation Flats. Waypoint locations were approximated based on general area descriptions. Site Selection In FY 07-08, 16 sites were assessed for mangrove planting potential (Table 6). At each site, general features were noted, such as hydric soils, planting elevations, latitude, potential for vandalism or wildlife effects, and hydrological parameters, including tidal influence, fetch, boat wake, and potential wave energy. Six of the 16 sites were selected for planting in FY 07-08 (Table 7). Permission letters and appropriate documentation have been obtained for three planting sites in FY 08-09. FDEP Sites All plantings took place from August to September 2008. Six planting sites were established by FDEP: City of Cocoa Beach, Walton Scrub, IR36, Rotary Park at Suntree, SL3, Fisherman’s Landing. A total of 252 mangroves were planted along 146 m of available shoreline in 24 total replicate grids (Appendices 1-6). Supplemental red mangroves were planted in available shoreline areas outside the grids at some of the sites. A total of 78 total mature and multi-stem red mangroves were planted supplementally. At the City of Cocoa Beach, six Simpson’s Stoppers (Myrcianthes fragrans) were planted. City of Cocoa Beach. Two grids were planted at this site (3 planting treatments * 3 species * 3 elevation levels = 27 plants per grid). Three planting methods with three native mangrove species, white

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(Laguncularia racemosa), black (Avicennia germinans), and red (Rhizophora mangle) were planted on three elevation levels. Rooted seedlings grown in the nursery since the fall 2007 drop planted with the PVC encasement method. The shoreline gradient was steep from erosion (Appendix 1). Project Design Shift Following a shift from joint ECFAP and SEFLAP management of SRP to project management only by SEFLAP on September 1, 2008, the project design changed to three planting methods with one species, red mangroves and three elevation levels. Each grid is 3 planting treatments * 1 species * 3 elevation levels = nine plants per grid (Figure 7). The decision to reduce the design to one species was due to the need to reduce the number of experimental variables and associated cost. Also, natural succession of black and white mangroves following red mangrove restoration plantings has been documented (Shafer and Roberts 2008). Walton Scrub, IR26, Rotary Park at Suntree, SL3, and Fisherman’s Landing were planted with red mangroves. Walton Scrub. Ten grids with nine plants each were planted. The site is located 10 m below Indian River Dr. Articulated Cement blocks and rocks buried under the sandy soil/substrate made the encasement method and digging challenging. This site historically supported mangrove (Kevin Stinette personal communication). The five-person planting team consisted of SRP and Southeast Florida Aquatic Preserve (SEFAP) staff. The high tide water line reached the block wall, and during high tide periods, plants in the first two levels are partially to completely submerged (Figure 17). A total shoreline length of 45 m was available at this site for mangrove planting. This length was divided into three sections (south to north) 17 m (1st transect tape, 9-26 m), 21 m (2nd transect tape, 0-21 m), 7 m (2nd transect tape, 25-32 m). If there was existing native vegetation, the shoreline was not considered available. A supplemental section of 26 multi-stem and 20 single stem reds were planted in an area north of the grids (Appendix 2). Note that matures at this site were not “mature”. These were seedlings from the fall 2007 drop. All other sites were planted with three gallon mature red mangroves purchased from Bates Nursery. IR36. Two grids were planted on the southeast corner of Indian River County spoil island IR36. Wave energy is high at this site. A total of 21 multi-stem and mature red mangroves were planted on available shoreline to the north of the grids (Appendix 3). Rotary Park at Suntree. One grid was planted. Schinus terebinthifolius (Brazilian Pepper) dominated the shoreline at this site. The grid was placed in a felled root structure. SL3. Two grids were planted along the southeast corner of this St. Lucie County spoil island SL3. FDEP SEFLAP is coordinating with SLC to enhance this island in FY 08-09 (Appendix 5). Fisherman’s Landing. Seven grids were planted towards the northern boundary of the property. This is an existing site established by the ELC in 1996. FDEP plantings were to the north and south of a mangrove stand greater than six feet in height (Appendix 6).

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Table 6. Potential SRP planting sites assessed in 2008. FY 07-08 planting sites established by FDEP are noted in bold. Site County Managing Entity Status

1 City of Cocoa Beach Brevard City of Cocoa Beach Public Works Department Planting 08/02/2008

2 Maritime Hammock Sanctuary Brevard Brevard County EEL Program FY 2008-2009, planting scheduled 10/25/08

3 Fisherman’s Landing Brevard Brevard County Parks & Recreation Planting 09/27/2008 4 Rotary Park at Suntree Brevard Brevard County Parks & Recreation Planting 09/06/2008 5 Riverview Park, Melbourne Brevard Brevard County Parks & Recreation Exotic Removal Needed 6 Hubbs Seaworld Brevard Hubbs-SeaWorld Research Institute Initial Site Assessment on 08/24/2008 7 IR 36 Indian River SEFLAP Planting 09/11/2008 8 Veteran’s Memorial Park St. Lucie City of Port St. Lucie Not Available

9 SLC Impoundment 14a, Wilcox Rd. St. Lucie St. Lucie County Mosquito Control Initial Site Assessment on 07/11/2008

10 Walton Scrub St. Lucie St. Lucie County Environmental Resources Planting 08/29/2008

11 Ft. Pierce Inlet State Park St. Lucie FDEP Park Service FY 2008-2009, Research Permit issued 08/29/08 12 SL 3 St. Lucie SEFLAP Planting 09/26/2008

13 Blind Creek St. Lucie St. Lucie County Mosquito Control FY 2008-2009, License Agreement signed 09/26/2008

14 Blowing Rocks Preserve Martin The Nature Conservancy Initial Site Assessment on 08/13/2008

15 Jensen Beach Impoundment, Dutcher Martin Martin County Mosquito Control Initial Site Assessment on 09/16/2008

16 Indian Riverside Park Martin Martin County Parks & Recreation Initial Site Assessment on 09/09/2008 Table 7. SRP sites established by FDEP in FY 07-08.    Site County Managing Entity 1 City of Cocoa Beach Brevard City of Cocoa Beach Public Works 2 Rotary Park at Suntree Brevard Brevard County Parks & Recreation 3 Fisherman's Landing Brevard Brevard County Parks & Recreation 4 IR 36 Indian River SEFLAP 5 SL 3 St. Lucie SEFLAP 6 Walton Scrub St. Lucie St. Lucie County Parks & Recreation

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Figure 17. Mangroves planting in August and September 2008 were (a) exposed during low tide and (b) submerged during high tide. Note: wrack accumulation around plantings at the high water line. One-month Monitoring Water levels were near annual high at sites Lagoon-wide due to the time of year, canal discharge, and stormwater runoff following Tropical Storm Fay on August 20, 2008. One-month monitoring was done at two sites (City of Cocoa Beach and Walton Scrub) prior to the end of FY 07-08 (Table 8). City of Cocoa Beach. Monitoring was done on September 13, 2008 (Table 9). Only presence or absence was noted. No growth measurements were recorded at this time. All encasement plantings were surviving. No plants were replaced following the monitoring visit. Three mangrove species were planted at this site in consultation with ecologists from the City of Cocoa Beach (Sharon Tyson personal communication), and the project shifted focus to only red mangroves following this planting. All subsequent monitoring and replacement of plants in FY 08-09 to achieve 85% success at this site will be done by ECFAP staff in consultation with ecologists with the City of Cocoa Beach (Sharon Tyson personal communication). A total of 30 one gallon black mangroves and 17 three gallon white mangroves purchased from Bates Nursery were transferred from the SRP nursery at SSRPSP to ECFAP to replace those donated by Citizen’s Support Organization for the City of Cocoa Beach planting. Walton Scrub. Monitoring was done on September 29, 2008 (Table 10). Distance to the top of encasement (TOE) for MEM, and canopy volume (length * width * height) for mature and multi-stem, and number of multi-stem with leaves for multi-stem plantings were measured and recorded. Plants were replanted on October 1, 2008. There may be a higher mortality of encasement plantings, as the water level was higher than planted propagules and it was not possible to see growth. Note that matures were not “matures”, and that seedlings from the fall 2007 drop were planted.

(a)  (b)

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Table 8. Monitoring schedule for red mangrove planting sites established by FDEP in FY 07-08.

Site Planting Date One Month Two

Month Three Month

Six Month

Nine Month

One Year

1 City of Cocoa Beach 8/2/2008 9/2/2008 10/2/2008 11/2/2008 2/2/2009 5/2/2009 8/2/2009

2 Walton Scrub 8/28/2008 9/28/2009 10/28/2008 11/28/2008 2/28/2009 5/28/2009 8/28/2009

3 Rotary Park at Suntree 9/6/2008 10/6/2008 11/6/2008 12/6/2008 03/06/209 5/6/2009 9/6/2009

4 IR 36 9/11/2008 10/11/2008 11/11/2008 12/11/2008 3/11/2009 5/11/2009 9/11/2009 5 SL 3 9/26/2008 10/26/2008 11/26/2008 12/26/2008 3/26/2009 5/26/2009 9/26/2009

6 Fisherman's Landing 9/27/2008 10/27/2008 11/27/2008 12/27/2008 3/27/2009 5/27/2009 9/27/2009

Table 9. One-month monitoring results from the City of Cocoa Beach site. Red-filled boxes indicate mortality.

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Table 10. One-month monitoring at the SLC Walton Scrub site. Red-filled boxes indicate mortality.

 

Walton Scrub

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Education and Public Outreach A network of volunteers from school groups (JROTC and Environmental Science Academy at Sebastian High School, graduate and undergraduate students at Florida Institute of Technology, and Brevard Community College) and FDEP CAMA’s IRL Spoil Island Project was established for planting, monitoring, and nursery maintenance. Volunteers contributed a total of 695 hours from May to September 2008 towards this project. Staff from the ECFAP and SEFLAP assisted with plantings and logistics for volunteer events. One FY 08-09 planting event at the Brevard County Environmentally Endangered Lands Program Maritime Hammock Sanctuary site is being conducted as a graduate student project for Dr. Elizabeth Irlandi’s Coastal Mitigation & Restoration course (OCN 5601) at the Florida Institute of Technology. Brief presentations outlining the goals and objectives of the SRP, including underlying management principles such as exotics removal, were delivered to volunteer groups prior to each planting event and nursery work day (Figure 18). A Microsoft PowerPoint slide presentation was created for students in Mr. George Anderson’s Environmental Science class with the Environmental Science Academy at Sebastian River High School. The presentation emphasized the role of mangrove habitat to the Indian River Lagoon and explaining the three planting methods being used by the SRP. An article about the SRP was written for the Hometown News in Indian River County and published on October 3, 2008 (Figure 19). Five hundred single stem red mangroves were donated from the SRP stock to Environmental Science Academy (ESA) at Sebastian River High School students. These individuals will be planted as multi-stem pots and cared for by the students in the school’s greenhouse. The ESA students will plant these mangroves at one of the sites established in FY 08-09. Following recommendations by the ELC for measures to reduce vandalism, a ″Mangrove Restoration Site″ sign was designed in coordination with Martin County to place at SRP mangrove planting sites (Figure 20). An informational sign for the red mangrove, designed for the Spoil Island Enhancement Initiative, was placed at the planting site on IR 36.

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Figure 18. (a) Discussion on removal techniques for Brazilian Pepper and other exotics species prior to planting event at Rotary Park at Suntree with undergraduate and graduate students from FIT and (b) Work day at SSRPSP nursery with NJROTC students from Sebastian River High School.

(a) 

(b) 

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Figure 19. Indian River County Hometown News article about the SRP on October 3, 2008.

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Figure 20. Public awareness sign developed by FDEP. Image provided by Martin County.

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DISCUSSION Survival and growth The average (± S.E.) survival of red mangroves planted at 57 sites established by the ELC from 1995 to 2006 was 10% ± 2 in 2008. Overall survival (number of mangroves surviving divided by the total planted) was 6.5%. These percentages are conservative estimates, as at some sites the total number of mangroves planted used to calculate these percentages may be higher, and consequently the percentage of survival may be lower. This is primarily due to incomplete or inconsistent data located in the individual planting site records. For example, the monitoring records for Hobe Sound NWR indicate that there was a 1996 planting event, but there is no indication of how many individuals were planted that year. Margo Stahl, Hobe Sound NWR Manager, confirmed that the 1996 planting event took place. Although there was no recollection of the number of plants associated with the 1996 event, she said that none of the plants survived. In 1999, the site folder indicated 50 mangroves were planted at the same site, so 50 mangroves were used to calculate the overall survival for this site (Table 5). In addition, the SRC regularly provided tables identifying the number of mangroves planted to the AC members. These reporting tables were sometimes not consistent with the planting records in individual site folders. These higher numbers may have been associated with replanting. Therefore, for each site the numbers of mangroves planted reported here are the numbers recorded on informational sheets in each site folder from the ELC. Growth measurements of planted mangroves at ELC-established sites were not taken during 2008 monitoring. At some sites (e.g., Harbor Branch and Ft. Pierce Inlet State Park) it was not clear which tree corresponded to which planting event. Thus, it was not possible to compare 2008 and future growth measurements to annual growth measurements recorded by the ELC. Most labels on encasements (permanent marker) and trees (brass tags) were either not visible or indecipherable. To facilitate future project management, FDEP define the term “site” as all shorelines located within the property boundaries managed by a single entity. For example, all plantings on the Harbor Branch Oceanographic Institution property are combined and considered one site. The definition of “site” was not clear in the records obtained from the ELC. Some locations, such as Harbor Branch, had more than one listing (Harbor Branch 1-8). Other sites, such as Hobe Sound NWR, were replanted, but did not receive a new site number. Sites like Pelican Drive were planted along three shorelines but only two ″sites″ were documented and driving directions only indicate the general location of the plantings. Furthermore, it was not clear from data sheets in individual site folders which planting corresponded to which location. No GPS data were collected by ELC to assist with site relocation. Low overall survival may be generally attributable to one or more of the following:

1. Large number of locations and plantings (103 plantings in 57 locations). 2. High turnover rate with SRC. 3. Insufficient site maintenance. 4. Lack of adherence to site selection criteria recommended by AC (see Site Selction section of SRP

Background). 5. Plantings at different elevations (e.g., Kiwanis Park at Geiger Point in Melbourne and Eau Gallie

Bridge are too waterward). 6. Modifications to the original REM test the boundaries of the methodology. Note: Bob Riley will

provide project advice and sell FDEP his modified PVC for the encasements if the SRC is trained by his company, mangrove.org. The fee would be approximately $3,000.

7. Overwhelming/confounding amount of information without a standardized method of record-keeping.

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8. Focus of massive plantings and replanting vs. conditioning a site for naturally-recruiting mangroves and then perhaps supplementing with plantings.

9. Public education component was extremely strong, however high volunteer involvement and goal to establish 10 sites per year may have outweighed focus of site restoration work.

Cintron-Molero (1992) attributes unsuccessful plantings to three basic factors: 1) failure to recognize factors limiting establishment (need for shelter from wave and wind action, tides and currents), 2) lack of provision for proper hydrologic regime, and 3) failure to provide follow-up, including replacement for mortality and lack of consideration of stand maintenance. Artificial planting efforts associated with permit actions are often hampered by their "one-shot" approach. Given the focus of SRP and the encasement methodology on high wave energy areas where traditional planting methods are unsuccessful, lack of survival could be attributed to a combination of not following methodology, improper hydrology of sites selected, and lack of follow-up. In general, we observed that mangrove planting sites that were maintained by local managers (e.g., Brevard County Environmentally Endangered Lands and The Nature Conservancy’s Blowing Rocks Preserve) tended to have higher survival than sites with low maintenance (Appendix 11). Re-vegetation vs. Restoration The term restoration is used here by FDEP to mean the achievement of long-term sustainable re-establishment of mangrove ecosystems, both physical habitat and function, on available shorelines of the Indian River Lagoon. It has been suggested that the ultimate goal of restoration/creation efforts should be to “conserve landscape diversity and function and compensate for lost ecosystem services” (Cintron-Molero 1992). The shift from re-vegetation to restoration reflects the long term goal of SRP to focus on a more system-wide approach to site restoration, rather than planting one species. The long-term goal will be to understand the natural history of the area, including hydrology, and prepare the identified sites to support natural recruitment, then supplement the area with nursery stock if necessary (sensu Lewis 2005; Lewis 2000). A study by Shafer and Roberts (2008) of 18 mangrove plantings at wetland mitigation sites found that if site elevations are suitable, mangrove planting may be unnecessary in areas with an abundance of mangrove propagules. At most planting sites established by the ELC, there were seed sources, but plantings were done at an inappropriate elevation (too high or too low). In some cases, sites were selected with secured shorelines (Melbourne Beach Pier) or a sharp incline in elevation. The high water line extends up beyond the point where the shoreline is secured, and the natural seed source of the area is unable to naturally recruit where growth would be supported (Figure 21).

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Figure 21. Propagule source at Walton Scrub. Propagules were pushed up and distributed along the shoreline by high water, but the level of water was too far up the articulated block wall where mangroves are unable to recruit. Resiliency Studies have found restoration of mangrove environments to be successful when they take advantage of natural adaptive strategies and recovery processes (reviewed by Cintron-Molero 1992). Mangrove resilience, its ability to absorb or recover from disturbance and change while maintaining its function and service, is imperative in minimizing economic and biological impacts of a future changing climate (Leitholf 2008; McLeod & Salm 2006). Red mangroves have a growth rate potential (shoot-length increase) of six to twelve inches per year in nutrient-rich soils (Barnett and Crewz 1992). Growth rates of restored and disturbed mangroves have been found to be higher than natural mangroves (Proffitt and Devlin 2005). Following disturbance from a hurricane, given suitable conditions, mangroves can regain similar coverage in four to five years (Gene Lamere personal communication). Mangrove restoration through hydrological modification of an area followed by natural volunteer recruitment has been documented on the west coast of Florida (Lewis 2005). Yet, observations of slower growth and etiolation

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have been found in encased plantings established by the ELC. The mangrove used in the REM look physically different and appear to grow slower than naturally-recruited mangroves. Ultimately, mangroves are in competition with the invasive exotic Brazilian Pepper (Schinus terebinthifolius) for shoreline space (Leitholf 2008). The challenges that growing mangroves face will affect the ability of the habitats they will form to survive following disturbances such as rising sea level, intense storm events, herbivory, parasitism, mutations, human impacts, and freezing temperatures in northern counties (Figure 22). Several studies have demonstrated differences in species composition and ecosystem characteristics between natural mangrove forests and those restored with plantings (Proffitt & Devlin 2005; Shafer & Roberts 2008).

Figure 22. Disturbances such as herbivory (top left), insect attachment and colonization (top right), morphological mutations- propagule on tree at MC2 (bottom left), pigmentation mutation- pink propagule collected in Jensen Beach (bottom right).

      

    There are two schools of thought regarding mangrove restoration. Lewis (2005) has been a strong proponent of understanding the fundamentals of mangrove biology and ensuring the physical parameters of the site support mangrove growth before expensive, time-consuming planting projects are undertaken, and only in the event that plantings are supplementing natural recruitment. On the other hand, it is

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thought by some that physical shoreline environments where mangroves may have existed in the past have been altered by development to the extent that conventional methods of planting no longer work and environmental engineering means are needed to re-introduce species to an area to ensure ecosystem survival (Riley and Kent 1999). In addition to the PVC Riley Encasement Methodology (REM), Mangrove Solutions has begun manufacturing and developing a method for introducing mangroves in high energy areas using concrete reef balls (Krumholz et al. 2008; www.mangrovesolutions.org). Future Direction The FDEP experimental design will test the relative success of three planting methods on shorelines in the IRL: 1) PVC encasements, 2) multi-stem pots, 3) mature. PVC encasements have a low success according to results from the 1995-2006 plantings established by the ELC, but success can be high according to Bob Riley (personal communication). In areas with high wave energy, it is thought that PVC encasements can protect the growing seedling from waves and debris washing onshore. The introduction of PVC into the environment is sometimes a point of contention both aesthetically and environmentally. Encasements have been found floating in the water, and some sites with 0% survival have empty PVC encasements and a SRP sign. The other two planting methods without PVC encasements have been found by non-profit and groups to be successful. Multi-stem plantings are thought to introduce a large and established rootball, increasing chances of success, but the seedlings are still small and unprotected. The mature tree method is thought to have the advantage of age and an established root system. Most mature plants planted by FDEP in FY 07-08 had several sprouting prop roots. Empty PVC encasements will be removed from sites, both successful and unsuccessful, and encasements of surviving mangroves will be monitored and trimmed as necessary to allow prop roots to establish in the sediment outside the encasement, eventually removing as much of the encasement as possible to allow the tree to grow on its own without support. Mortality will be replaced ensuring 85% success will be achieved at all FDEP sites for a period of three years following initial planting. Shorelines are not always the same (e.g., City of Cocoa Beach and Blind Creek, Appendix 1 and Appendix 7). Differences in the physical shoreline may contribute to the relative success of planting methods. In terms of site selection, however, a common misconception about mangroves is that they can create shoreline where there was previously none (Hogarth 2007). Shoreline sites should be selected where previously-occurring erosion is minimal. Mangrove roots can only stabilize existing and accreting sediment, and existing shoreline erosion cannot be mitigated by planting mangroves. The causes of erosion often operate on a faster timescale than relatively slow-growing mangrove trees. To ultimately achieve the long-term goal of long-term sustainable mangrove ecosystem restoration in the IRL, historic aerials should be used to calculate the historic surface area of mangrove habitat in the IRL. With historic coverage information, criteria for site selection may include whether mangroves were located at that site in the first place. If historically present at a site that currently does not support mangroves, then we should try to determine the potential reasons for there disappearance. If mangroves were not historically located at a site, there should be a justification for why mangroves should be planted in a location where they were not historically supported. With statistically-valid comparisons between the three planting methods by FDEP, the focus can then be placed on specific needs of restoration. In addition to the required planting and monitoring events, time should be dedicated to updating the set of site selection criteria for mangrove restoration projects. This includes, but is not limited to, shoreline type, slope, and species history. Mangrove-associated species, such as S. alterniflora will be planted at sites to encourage mangroves to naturally recruit, trapping

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mangrove seedlings and holding them in place (Shafer and Roberts 2008; Lewis 1975). This observation has also been documented on SL15 (Figure 23).

Figure 23. Naturally-recruited red mangroves within Spartina alterniflora on St. Lucie County spoil island SL15 in 2007.

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2008 PROJECT SUMMARY

• SRP history was summarized from files and records obtained from ELC.

• FDEP monitored all recorded sites established by the ELC from 1995 to 2006.

• There are 57 existing sites with surviving mangroves that will continue to be monitored for survival and growth in FY 08-09.

• • The average survival at existing sites established by the ELC is 10 % ± 2 (S.E.)

• Experimental design was established for FDEP plantings.

• A total of 252 red mangroves were planted a six sites established by FDEP (north to south): City of Cocoa Beach, Rotary Park at Suntree, Fisherman’s Landing, IR36, SL3, Walton Scrub.

• One-month monitoring was conducted at City of Cocoa Beach and Walton Scrub. Mangroves were replaced at Walton Scrub where mortality had occurred.

• A 5´ x 10´ trailer was purchased for transportation of plants to sites.

• Public awareness signs were designed and produced for placement at planting sites.

• A system was designed and purchased for conditioning mangroves with brackish water at the nursery.

• A hydrologically-pressurized planting system was designed and purchased to facilitate PVC installation and planting.

• Mangroves were purchased from Bates Nursery in Ft. Pierce and donated mangroves

were acquired from private citizens and local entities.

• A newly-established network of volunteers donated 695 hours for planting, nursery maintenance, and mangrove propagation.

• Sites established during FY 07-08 were considered part of a pilot study for FDEP

staff to learn and improve on the future experimental design and planting methods.

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REFERENCES U.S. Army Corps of Engineers (ACOE). 1987. Corps of Engineers Wetlands Delineation Manual. Wetlands Research Program’s Technical Report Y-87-1. Vicksburg: Environmental Laboratory, Department of the Army. Barnett, M.R. and Crewz, D. (eds.) 1992. Rhizophora mangle L., Red mangrove. SEF-37, Florida Seagrant College Program, Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, University of Florida. Brockmeyer, R.E. Jr., Rey, J.R., Virnstein, R.W., Gilmore, R.G., and Earnest, L. 1997. Rehabilitation of impounded estuarine wetlands by hydrologic reconnection to the Indian River Lagoon, Florida (USA). Wetlands Ecology and Management. 4(2): 93-109. Cassler, C. 2002. Shoreline Restoration Project: A 6 Year Review (1995-2001). Wabasso: Environmental Learning Center. Cintron-Molero, G. 1992. Ch 6: Restoring mangrove systems. In: GW Thayer, ed., Restoring the Nation’s Marine Environment, College Park: Maryland Seagrant. pp 223-277. Ellison, A.M. 2000. Mangrove restoration: do we know enough? Restoration Ecology 8(3): 219-229. Environmental Learning Center (ELC).

• Final Report 04-05 • SFWMD Tag 1998 • SFWMD Tag 2002-2003 • SFWMD Tag 2003-2004 • Annual Report 2002-2003 • Annual Report 2005-2006 • Original 1995 Proposal

Hazen & Sawyer Environmental Engineers & Scientists. August 2008. Indian River Lagoon Economic Assessment and Analysis Update (Contract No. 24706) for the Indian River Lagoon National Estuary Program in cooperation with the St. Johns River Water Management District and South Florida Water Management District. Final Report.

Hogarth, P.J. 2007. Biology of Mangroves and Seagrasses. New York: Oxford University Press.

Indian River Lagoon National Estuary Program (IRLNEP). 2008. Indian River Lagoon Comprehensive Conservation and Management Plan Update 2008 (DRAFT).

Kehler, Dan. 2005. Study Design and Power Analysis. EMAN National Science Meeting, Penticton, BC.

Krumholz, J., Jadot, C., Barber, T., and Williams, H. 2008. Development of a restoration technique for red mangroves (Rhizophora mangle) in high energy environments. Leitholf, S. 2008. Assessing and modeling mangrove forest dynamics along the temperate-subtropical ecotone in Eastern Florida. M.S. Thesis, University of Central Florida.

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Lewis, R.R. and Dunstan, F.M. 1975. Possible role of Spartina alterniflora Loisel in establishment of mangroves in Florida. Pp. 82-100. In R.R. Lewis (ed.) Proceedings of the Second Annual Conference on Restoration of Coastal Vegetation in Florida. 203 pp. Lewis, R.R. 2000. Ecologically-based goal setting in mangrove forest and tidal marsh restoration. Ecological Engineering. 15: 191-198. Lewis, R.R. and Streever, B. 2000. Restoration of mangrove habitat. WRP Technical Notes Collection (ERDC TN-WRP-VN-RS-3.2), U.S. Army Engineer Research and Development Center, Vicksburg, MS. Lewis, R.R., III. 2005. Ecological engineering for successful management and restoration of mangrove forests. Ecological Engineering. 42: 403-418. Marine Resources Council of East Florida (MRC). 1998. A Field Manual for Invasive Plant Removal and Mangrove Restoration: Getting the Community Involved. Rockledge: Library of the Indian River Lagoon. Prepared for the National Marine Fisheries Service, NOAA. McKee, K.L and Faulkner, P.L. 2000. Restoration of biogeochemical function in mangrove forests. Restoration Ecology. 8(3): 247-259. McLeod, E. & Salm, R.V. 2006. Managing mangroves for resilience to climate change. International World Conservation Union (IUCN): Resilience Science Group Working Paper Series- No. 2. Michault, V. and de Seguin des Hons, X. 2006. Shoreline Restoration Project mangroves monitoring of 24 sites in Brevard and Indian River County. Proffitt, C.E. and Devlin, D. J. 2005. Long-term growth and succession in restored and natural mangrove forests in southwestern Florida. Wetlands Ecology and Management. 13: 531-551. Riley, R.W. and Salgado-Kent, C.P. 1999. Riley encased methodology: principles and processes of mangrove habitat creation and restoration. Mangroves and Salt Marshes. 3: 207-213. Salgado-Kent, C.P. and Lin, J. 1999. A comparison of Riley encased methodology and traditional techniques for planting red mangroves (Rhizophora mangle). Mangroves and Salt Marshes. 3: 215-225. Sato, G., Fisseha, A., Gebrekiros, S., Karim, H.A., Negassi, S., Fischer, M., Yemane, E., Teclemariam, J., and Riley, R. 2005. A novel approach to growing mangroves on the coastal mud flats of Eritrea with the potential for relieving regional poverty and hunger. Wetlands. 25(3): 776-779. Shafer D.J. and Roberts T. H. 2008. Long-term development of tidal mitigation wetlands in Florida. Wetlands Ecology and Management. 16: 23-31. Sheridan, P. Benthos of adjacent mangrove, seagrass and non-vegetated habitats in Rookery Bay, Florida, U.S.A. Estuarine, Coastal, and Shelf Science. 44: 455-269. Steward, J.; Virnstein, R.; Haunert, D.; and Lund, F. 2002. (UPDATE) Surface Water Improvement and Management (SWIM) Plan for the IRL. St. Johns River and South Florida Water Management Districts, Palatka andWest Palm Beach, Florida. Taylor, M. 1998. Alternative Materials Research for Mangrove Encasement Planting Technique. Vero Beach: Green Data.

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