Viability and Variability of Seagrass Communities in the Loxahatchee Estuary and Associated Reach of the Lagoon 1998, 2000, 2002

September 2003

Mary S. Ridler, Richard C. Dent and Lorene R. Bachman WildPine Ecological Laboratory Loxahatchee River District

Introduction

The southernmost portion of the consists of the Loxahatchee River estuary, the Jupiter Inlet and an approximate five-mile reach of the running from the Jupiter Inlet northerly toward Hobe Sound. Figure #1 presents a map of the study area. This area is unique because it fosters an environment where temperate conditions to the north mix with tropical conditions from the south, making the area very productive for recreational and commercially important finfish and shellfish. In part, the productivity is due to the interaction of faunal species with Submerged Aquatic Vegetation (SAV). SAV is recognized as one of the most important habitats within the Lagoon, yet its’ health and vitality are issues of continuing concern. For the purpose of this report SAV will be referred to as seagrass. Seagrass habitats continue to play a critical role in providing sediment stabilization, nutrient cycling, detridal food sources and a nursery for juvenile fish.

In 1998 and 2000, the Loxahatchee River District conducted in-depth evaluations of the seagrass communities in the southernmost portion of the Indian River Lagoon and the Loxahatchee River. Reports were issued that documented distribution, density and composition of seagrasses (Ridler, Dent, Bachman, Distribution, Density and Composition of Seagrasses in the Southernmost Reach of the Indian River Lagoon, 1998. Ridler, Dent, Bachman, An evaluation of Seagrass Communities in the Southernmost Reach of the Indian River Lagoon, 2000.). Between 1998 and 2000 moderate changes were observed in all sections of the study area. In the summer of 2002, the study area was revisited and transects were replicated from the previous two studies to assess for any further changes.

The overall goal of the current research effort is to compare previous SAV information from 1998 and 2000 to current conditions in 2002. The objectives were: to characterize

the density of seagrass within the study area, to record information on species identification and composition and to compare the data with information gathered in 1998 and 2000.

Description of Study Area

The study area has been divided into four research segments each of which characterizes a portion of the study area based predominantly on distance from the Jupiter Inlet. Each segment supports three or four sampling stations and each station consisted of two to five research transects. Figure #1 presents a map of the study area showing the Jupiter Inlet, the eastern portion of the Loxahatchee River estuary and an approximate five mile reach of the Intracoastal Waterway extending northerly from the inlet channel. Figure #2 shows the research segments and the fourteen stations. The following paragraphs discuss the research segments, sampling stations and research transects. Figures #3,4,5 and 6 show the sample stations and the research transects in each segment.

Jupiter Inlet / Loxahatchee Estuary Segment … stations #1, #13 and #14

There are three seagrass monitoring stations located in this segment. Station #1 is located on the south side of the Jupiter Inlet near DuBois Park. Station #1 experiences extreme water velocity changes due to the close proximity to the Jupiter Inlet. The linear transects used for monitoring extend out from the shoreline an average distance of 65 meters and terminate in 2 meters of water. Station #13 is one mile west of the inlet, located on the south shore between the U.S. Highway One Bridge and the Alt. A1A Bridge. Station #13 has a mangrove-fringed shoreline and the two transects were extended from shore and average of 50 meters and terminated in 2.4 meters of water. Station #14 is located one and a half miles west of the inlet on the west side of the Alt. A1A bridge and the FEC railroad bridge. Five transects were evaluated at this station. All transects ran from the north shore out into the Loxahatchee Estuary. Transects at this station were an average of 170 meters and ended in 1.6 meters of water. Station #14 has a sand bar that runs east to west.

Jupiter Narrows Segment ……… stations #2, #3, #3E and #4

The Narrows segment is directly north of the Jupiter Inlet in the Lagoon portion of the Intracoastal Waterway and contains four seagrass monitoring stations. Station #2 is located on the east shore just north of the SR 707 Bridge approximately one mile north of the inlet. The four transects established for monitoring are each 70 meters in length with an ending water depth of less than 2.0 meters. This station is subject to extensive recreational use. On the western shore of the Lagoon, station #3 is approximately one- half mile north of station #2. The two transects at station #3 start from a residential shoreline and extend out 100 meters to an ending depth of 2.5 meters. Station #3E is

on the east shore diagonally across from station #3. This station is protected from the shore by a fringe of mangrove and two transects extend from the mangroves nearly 70 meters and end in 2.0 meters of water. Station #4 is a half-mile north of station #3 and located on the west side of the Lagoon. Each of the two transects at this station run 100 meters and conclude in 2.6 meters of water depth.

Jupiter Sound South Segment ……… stations #5, #6, #7 and #8

The stations of the southern half of Jupiter Sound are all located north of the Narrows segment and are all located on the western side of the Lagoon. Stations #5 and #6 are on opposite sides of a land jetty approximately two miles north of the Jupiter Inlet. Each station had two transects that extended out 100 meters and ended in a water depth of 2.0 meters. Station #7 is located one-half mile north of station #6 and is situated behind a small sand bar, creating a protected cove. Recreational boaters have used station #7 because a sand bar forms at low tide. The two linear transects at this station run an average of 150 meters from a residential shoreline into 2.0 meters of water. Station #8 is located a quarter of a mile further to the north and is adjacent to a small marina. At this station, only one transect exists and extends out approximately 100 meters and terminates in 3.0 meters of water.

Jupiter Sound North Segment ……… stations #9, #10 and #11

The three stations in this segment are the northernmost stations sampled in this study. All three stations have transects extending from the west side of the Lagoon. Station #9 is 3.7 miles north of the inlet near an upland that consists of low density commercial and residential land uses. The station is located in front of a jet ski rental business and the three transects extend an average of 80 meters and end in over 2.5 meters of water. Station #10 is located 4.5 miles north of the inlet and possesses two transects that are 50 meters in length and terminate in over 3.0 meters of water depth. The station is protected by a mangrove shoreline. Station #11 is the northernmost seagrass sampling location and is approximately five miles north of the Jupiter Inlet, just south of the Hobe Sound Wildlife Refuge. This station is adjacent to one of the long-term seagrass stations sponsored by the St. John’s River Water Management District (SJRWMD). The two transects at station #11 extend out 75 meters and end in 2.5 meters of water. Each of the transects run parallel to a sand bar with fairly steep slopes.

Methodology

The study started in May of 2002 and data collection continued through August of 2002. The two steps involved in the study were: in-situ ground truthing for evaluation of overall seagrass density, distribution and species composition, and comparison of data with prior studies.

In-Situ Ground-Truthing and SAV Measurements

Similar to 1998 and 2000, all fourteen sampling stations were evaluated using the point transect method. The point transect technique involves the placement of a linear transect line perpendicular from the shore out to the deepest edge of the grass bed. Once the transect line was laid on the bottom, researchers swam the length of the line recording observations, every half meter, on what the line was hitting, either sand or vegetation. Observations also included species identifications for overall community composition.

Density

For the purpose of this study, the density of seagrass is defined as the percent of seagrass or macroalgae observed along a defined linear transect. Researchers recorded either sand or seagrass presence in one-half meter increments along each transect. Thus, a seagrass density of 40 percent would indicate that vegetation was encountered at four out of ten sampling points along the transect and sand was recorded for the remaining points.

This study described seagrass density using the same scale that was employed in the previous work done in 1998 and 2000. This scale is divided into four categories. This scale is comparable to the measurements used by St. John’s River Water Management District (SJRWMD) in their studies of other sections of the Indian River Lagoon. The scale is described below.

Sparse = less than 24 percent seagrass Patchy = 25 to 50 percent seagrass Dense = 51 to 75 percent seagrass Dense Continuous = greater than 76 percent seagrass

Distribution

Distribution is considered the spatial extent of seagrass communities, regardless of density. Unlike previous studies where digital map series were developed, the maps could not be developed in 2002 because of lack of aerial photographs of the study area. In 1998, base GIS maps of the study area were developed. Using the field information obtained during the summer of 2002, a new series of digital maps was created. Figures #3-#6 are a series of digital maps that report information on where the individual transects were located at each station.

Species Identification and Community Composition

Five species of seagrasses were identified within the study area:

Halodule wrightii shoal grass Syringodium filiforme manatee grass Thallassia testudinum turtle grass Halophila johnsonii Johnson’s seagrass Halophila decipiens paddle grass

Also noted are species of macroalgae, which, for this report, were all grouped and referred to as algae.

All seagrass beds are made up of several species of seagrass or algae. The relative presence of one species to another can be used to describe the composition of the community. The mixture of seagrass species depends upon many environmental factors, predominantly wave action, water clarity, water depth and salinity.

Comparison of Data

The information generated in 2002 was compared with data gathered in 1998 and 2000. The four individual segments were analyzed for relative differences in density and composition. Distribution could not be evaluated in this study because aerial photographs were not taken. Overall distribution changes were documented only by observations of the researchers. The 2002 data will be compared only to density and composition information from previous studies.

In addition to comparing seagrass coverage’s, environmental conditions have been evaluated for the 1998, 2000 and 2002 sample years. Water quality data was compiled for the six months preceding the sampling events for each study. The parameters included in water quality monitoring consisted of: dissolved oxygen, salinity, clarity, turbidity, pH, fecal coliform, chlorophyll a and others. Water quality is an issue that plays a major role in the overall health of seagrass.

Conditions of the Study Area

The hydrology of the southernmost portion of the Indian River Lagoon is strongly influenced by tidal exchanges through the Jupiter Inlet. Research has shown that on an incoming tide water is diverted rather evenly with approximately 45 percent of the marine water flowing northerly into the Lagoon and a similar percentage moving inland into the Loxahatchee estuary (Chiu, T.Y., 1975. Evaluation of Salt Intrusion in the Loxahatchee River, . University of Florida). The remaining ten percent is channeled south to the Lake Worth Lagoon. This tidal influence assures that the waters of the entire study area are well flushed and the substrate is bathed with saline waters

on a routine basis. The 250 square mile watershed of the Loxahatchee River estuary, west of the Alt. A1A Bridge, is substantially larger than the drainage basin for the lower Lagoon. Therefore, a greater freshwater influence is exerted on the water of the estuary. This influence varies seasonally and in other respects, but typically results in modified physical and qualitative characteristics of the water leaving the estuary on an outgoing tide. In contrast, the effect of tidal flushing along the Lagoon is much more constant.

The Loxahatchee River District’s WildPine Ecological Laboratory, as a part of its long- range monitoring program, conducted the water quality sampling. A comprehensive expression of water quality is the Florida Water Quality Index (FWQI), which is a blended measure of water clarity, dissolved oxygen, organic demand, nutrients, bacteria and biological integrity. Index values range from 0 to 90 with lower values reflecting superior water quality conditions. The FWQI scale sets a value of less than 45 as reflecting ‘good’ water quality, values from 45 to 59 as indicators of ‘fair’ water quality and values above 60 as a ‘poor’ water quality measure. A second measure important to seagrass productivity is the Trophic State Index (TSI). This index combines secchi disc measurements, chlorophyll a concentrations, and nutrient values. A TSI number from 0-49 indicates ‘good’ trophic water quality. The Loxahatchee River District develops and publishes the FWQI and TSI values, along with more detailed information on over 20 individual perimeters, for the area twice annually. With infrequent exception, during and after large rainfall events, the quality of water in the study area is consistently good.

Figure #7 summarizes the general water quality characteristics for four representative stations in the study area. Stations #1, #14, #2 and #11 support long-term water quality monitoring stations. The water quality characteristics recorded at these stations are believed to be representative of the research segments in which the stations are found. Values shown represent the 6-month period during and immediately preceding the sampling events of 1998, 2000 and 2002 and are believed to be representative of existing conditions.

At stations #1 and #14 (Inlet/Estuary Segment) salinity averages about 33 ppt. Turbidity averages 1.5 mg/l, pH is at a value of 7.8 and dissolved oxygen levels average 6.9 mg/l. One major difference between the inlet and the estuary is color with significantly higher levels observed in the estuary. The composite index for water quality, FWQI, is within the good range between 18 and 21. The TSI index is also in the good range of 16 to 31. Station #2 (Narrows Segment) salinities average 34 ppt, with very low turbidity, color and nutrients. Dissolved oxygen levels are high, averaging above 7.1 mg/l and levels of organics are relatively low. The composite FWQI at station #2 is very good at 18, the best index value in the study area. Likewise. The TSI index is quite good displaying a value of 15. Station #11 (Sound North Segment) salinity averages above 33 ppt with only occasional drops below 20 ppt., turbidity is near 3.5 mg/l and pH levels and the mean concentration of dissolved oxygen is similar to other

water quality observations in the study area. Water quality is ‘good’ with an average FWQI number of 20 and an average of TSI 35. Light transmittance at station #11 drops 45 percent from one meter to two meters of depth, total suspended solids average of 7.3mg/l and transparency, as measured by secchi disc depth, averages less than 2 meters.

Rainfall can also play a role in the density and composition of seagrasses. Rainfall was evaluated for the eight months prior to each of the studies and 1998 had the most rainfall recorded with 44 inches. Prior to 2000 there were drier than normal conditions recorded with only 19 inches of rain recorded. In 2002 rainfall was 29 inches, still a bit below normal but higher that rain in 2000. As shown in Figure #7, most stations in 2002 had higher salinity readings than both 1998 and 2000. However, in 2002 there were higher turbidity readings at all stations. Turbidity plays an integral part of seagrass growth.

Figure # 7: General Water Quality Characteristics of the Study Area

Station Inlet Station (1) Narrows Station (2) Sound N. Station (11) Lox. Estuary (14)

1998 2000 2002 1998 2000 2002 1998 2000 2002 1998 2000 2002

Temperature (C) 23.3 24.2 24.5 23.39 24.33 24.65 22.08 23.84 24.96 23.43 4.31 24.87 pH (standard units) 7.9 7.8 7.9 8.0 7.8 7.9 8.0 7.8 7.9 8.0 7.8 7.9 Alkalinity (mg/L) 125 116 122 127 116 121 119 120 123 122 120 127

Turbidity (NTU) 2.2 1.3 2.6 1.7 1.0 2.9 2.4 4.0 5.1 1.9 1.9 4.0 Transparency (m) 2.2 3.1 1.7 2.1 CTB 1.5 0.8 1.5 1.3 1.1 1.6 1.2 Color (Pt/Co units) 12 7 8 12 7 7 12 10 7 12 8 10 TSS (mg/L) 4.2 5.0 5.2 5.4 6.7 4.3 7.0 7.1 4.8 5.7 6.8 4.0

Salinity (ppt) 32.4 34.5 35.5 32.6 34.8 36.7 31.8 34.2 36.0 31.6 33.9 33.3 Conductivity 49333 52282 53753 49733 52738 55177 48700 51849 54163 48267 51602 50837 (umho/cm)

Dis. Oxygen (mg/L) 7.24 6.95 6.30 7.16 7.24 6.27 6.95 7.22 6.37 7.37 7.06 6.24 Dis. Oxygen (% Sat) 103 100 94 103 101 93 97 99 96 105 100 90 B.O.D. (mg/L) 0.8 0.7 1.0 0.7 0.9 1.6 0.9 0.8 0.9 1.0 1.0 1.0

Total N (mg-N/L) 0.67 0.81 0.68 0.73 0.66 0.67 0.67 0.73 0.84 0.54 0.73 0.75 Total Phos (mg-P/L) 0.020 0.004 0.014 0.020 0.006 0.009 0.027 0.015 0.019 0.026 .014 0.018 CHL A (mg/L) 2.2 0.7 2.8 1.8 0.7 1.8 3.5 2.9 3.6 2.0 1.9 4.3

F-Coli (cfu/100ml) 3.2 1.0 4.7 3.3 2.0 8.0 2.2 1.0 8.0 2.3 1.0 4.3 Florida Water (FWQI) Quality Index 20 18 22 22 18 26 31 20 25 22 21 25

Trophic State Index 32 16 36 33 15 32 39 35 43 38 31 44 (TSI)

Another measure commonly used in seagrass studies is light transmittance, or specifically the amount of photosynthetic active radiation (P.A.R) available to the vegetation. An evaluation of the quantity of light reaching various depths was conducted at four of the seagrass monitoring stations for 1998, 2000 and 2002. On days without significant cloud cover, readings well above 1,000 umols were observed at the water surface. Figure #8 provides a review of the percentage of light reaching various depths in the water column for all three sample years. Two out of the four stations sampled for light were shown as having a decrease in light transmittance. This decrease may be due to a number of variants including cloud cover. The light meters work well on clear sunny days, however, cloud cover has a dramatic effect on the readings. Future evaluations of light transmittance must eliminate, the cloud cover variable so that this measure can provide greater insight. Based on research in the Indian River Lagoon and adaptations done by the WildPine Lab, PAR of greater than 53% at 1 meter has been established for a light transmittance target for the study area.

Figure # 8 Light Transmittance at Four Representative Stations 110

100 1 meter (1998) 1 meter (2000) 90 1 meter (2002) 80

70

60

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40 % Light Transmittance 30

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0 Jupiter Inlet Jupiter Narrows Jupiter Sound N. Loxahatchee Estuary Sample Stations

General Findings and Results 2002 Results

The remaining sections of this report outline the specific information within the study area, organized into overall distribution, density and composition and then into observations within the individual research segments. Figure #9 represents overall SAV densities as percent bottom cover for all sample stations in 2002. Figures #10, #11, #12 and #13 contained in the subsequent comparison section of this report, show overall density changes in the research segments.

Overall Distribution

Distribution throughout the five-mile northern stretch of the Lagoon is nearly complete along both shorelines. Similar to the previous studies, the western shoreline showed more extensive spatial distribution possibly due to the shallower water depths. The western shoreline gradually slopes toward the main channel whereas the east shoreline has a steeper slope. Conversely, within the Loxahatchee estuary, seagrass distribution is not complete with only limited areas of vegetative growth when compared to the Intracoastal Waterway segments. Even less spatial area is covered by seagrass within the Jupiter Inlet area where velocity and depth extremes may be limiting.

Overall Density

In general, in 2002, seagrass is observed in densities from 55 to over 90 percent, thus falling into either the dense or dense continuous category. Figure #9 shows the presence of seagrass as a percent of bottom cover at each of the fourteen sampling stations for 2002. In 2002, seven stations (#2, #3, #5, #6, #8, #11 and #14) had dense seagrass coverage. The other half of the nine stations (#1, #13, #3E, #4, #7, #9, and #10) had dense continuous seagrass coverage. No stations within the study area displayed sparse or patchy coverage’s. There are sparse areas within the study area, but most can best be described as sand bars or shoals.

Overall Species Composition

In general terms, S. filiforme is the species found most often in the study area. The second most abundant species of seagrass was H. wrightii. S. filiforme and H. wrightii, constituted over half of the total seagrass found in 2002.

In 2002, there were substantial areas found within the study area, Stations #1, #13 and #14, that had populations of H. johnsonii. At these stations H. johnsonii was found growing intermixed with H. wrightii. H. johnsonii is a species of special concern because it is currently considered threatened within the Indian River Lagoon.

At three sites, H. wrightii or H. johnsonii were observed living closest to shore, where tidal fluctuations and wave action occur. These species tend to be more tolerant of harsher conditions. As the shoreline slopes into deeper water, S. filiforme, and T. testudinum tend to be more dominant. Further out toward deeper water, S. filiforme and T. testudinum disappear and H. wrightii, H. johnsonii reappear and H. decipiens is observed.

One species that has limited representation in the study area was T. testudinum. In 2002, T. testudinum was found at only 4 stations. T. testudinum was seen in the study area, at stations #2, #3 and #4 and small concentrations at station # 14. It was also observed to be living among S. filiforme. While both T. testudinum and S. filiforme

tend to occupy similar depths, T. testudinum, is generally less pollution tolerant and/or more light dependent. Another species that had limited representation was H. decipiens. This species was found in small concentrations at three sampling stations, all of which are in the northern segment of the study area.

Figure # 9 SAV Denisities as a Percent Bottom Cover

100 2002 % SAV 90

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% Submerged Aquatic Vegetation 10

0 Station # 1 Station # 2 Station # 3 Station # 4 Station # 5 Station # 6 Station # 7 Station # 8 Station # 9 Station #14 Station #10 Station # 13 Station # 11 Station # 3E Inlet Segment Narrows Segment Sound S. Segment Sound N. Segment Sampling Stations

The following paragraphs outline 2002 results for the individual research segments. Please refer to Figures #3 through #6 for maps showing individual transects at sample stations. Figures #10, #11, #12 and #13 in the comparison section, show overall SAV densities in each segment. Figures #14, #15, #16 and #17 display the relative abundance, in percent, of the individual species that characterize the seagrass communities observed in each of the four study segments. These figures show the relative percentages of seagrass species only and do not include sand bottom coverage’s. Appendix A, lists information on the individual transects at each sample station.

Jupiter Inlet / Loxahatchee Estuary Segment … stations #1, #13 and #14

Station #1 had a dense continuous coverage of 92.5% SAV. The dominant species at this station was H. wrightii, which constituted over half of the seagrass found at this site. H. johnsonii was also found at this station, present both by itself and in combination with H. wrightii. Station #14 had a dense SAV coverage of 75%. About one-third of the seagrass found at this site was H. wrightii and another third was H. wrightii in combination with H. johnsonii. Station #13 had a dense continuous coverage of 83.6% SAV. At this site H. johnsonii was the most dominant at 21% of the total SAV recorded. H. johnsonii was also found in combination with H. wrightii. Station #13 also had 13% of the total SAV being algae, not seagrasses.

Seagrass distribution in this segment is not complete and is dependent on environmental conditions. The seagrass communities found within this segment are associated with shallow, clear water. Distribution is generally closer to shore because of water velocity and tidal fluctuations.

Jupiter Narrows Segment ……… stations #2, #3, #3E and #4

Two out of the four stations in this segment had dense seagrass the other two stations had dense continuous coverage. Stations # 2 and # 3 recorded seagrasses ranging between 68% to 72%. Stations #3E and # 4 had coverage’s between 86% and 89%.

Spatial distribution within this segment is complete along both the east and west shorelines with the exception of small areas immediately north of the SR 707 bridge. Along the western shore, the seagrass grows a relatively greater distance from the shore primarily due to the greater extent of shallow water. Also, a sand bar running parallel to the western side of the channel serves as a protective barrier and deflects wave action from watercraft.

S. filiforme was the predominant species found at all stations in this segment. Overall, H. wrightii and S. filiforme make-up more than 50% of all seagrass found at all stations in this segment. Other species that were found include: T. testudinum at stations #2, #3 and #4 and H. johnsonii at station #4.

Jupiter Sound South Segment ……… stations #5, #6, #7 and #8

Stations #5, #6 and # 8 have dense coverage of seagrass, ranging from 68 % to 72%. Station #7 has a dense continuous coverage of 83%. At all four stations in this segment S. filiforme was the most prevalent species found. Stations #5, #6 and #7 all had large populations of S. filiforme in combination with H. wrightii. This combination means that S. filiforme and H. wrightii were found living among each other. Station #6 was the only station in this segment observed to support H. decipiens. At station #6, H. decipiens was found to comprise 13% of the seagrass found.

Similar to the Narrows segment, the seagrass distribution in this segment is complete along both shorelines with larger distributions associated with the western shallows. Two land jetties in this segment effectively harbor portions of the substrate and allow expanded growth of seagrass further east into the Lagoon.

Jupiter Sound North Segment ……… stations #9, #10 and #11

Stations # 9 and # 10 had dense continuous seagrass coverage’s ranging from 79% to 81%. Station #11 had a dense coverage of 52%. All three stations were primarily populated by S. filiforme. Each station also had the presence of H. wrightii and most often H. wrightii was found in combination with S. filiforme. H. decipens was found at station # 11 and comprised of 22 % of the total seagrass found.

While seagrass distribution is also complete in this segment, the band of vegetation is narrower and concentrated more so along the shorelines. This segment is the furthest north and the water is more highly colored and more turbid, limiting light penetration to relatively shallow depths. The presence of a sand bar at station #11 is associated with the greater spatial distribution in this limited area.

Comparisons with 1998 and 2000 Results

The final objective of this study was to compare the results of this investigation with the work done in 1998 and 2000. All fourteen stations originally surveyed in 1998 and 2000 were compared to the results from this study. The following sections will compare the stations over the six-year timeframe. Figures #10-#13 provide information on seagrass density. Figures #14-#17 discuss seagrass composition.

Distribution (1998, 2000, 2002)

While digital distribution maps could not be made for 2002, overall seagrass distribution did not change significantly from 1998 to 2002. Seagrass distribution over the six-year timeframe has remained fairly constant with only small changes. Distribution changes mostly occur along the outside edge of the seagrass beds. The edge of bed is described as the area that is the farthest from shore and normally occurs where the channel starts. As the depth of water increases, seagrass presence decreases.

Density (1998, 2000, 2002)

All but three stations demonstrated slight increases in seagrass coverage from 2000 to 2002. Stations #3E, #6 and #11 were the only three stations that saw a slight decrease in density. Station #3E decreased slightly however continued to exhibit a dense continuous overall coverage. Station #6 decreased from 81% in 2000 to 69% in

Figure # 10: SAV Densities in the Jupiter Inlet Figure # 11: SAV Densities in the Jupiter Narrows Segment (1998-2002) Segment (1998-2002) 1998 Avg. 1998 Avg. 100 2000 Avg. 100 2002 Avg. 2000 Avg. 90 90 2002 Avg. 80 80 70 70 60 60 50 50 40 40 % SAV Cover % SAV Cover 30 30 20 20 10 10 0 0 St #1 St #13 St #14 St # 2 St # 3 St # 3E St # 4 Sample Stations Sample Stations

Figure # 12: SAV Densities in the Jupiter Sound South Figure # 13: SAV Densities in the Jupiter Sound North Segment (1998-2002) 1998 Avg. Segment (1998-2002) 2000 Avg. 90 90 2002 Avg. 1998 Avg. 80 80 2000 Avg. 2002 Avg. 70 70

60 60

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40 40 % SAV Cover % SAV Cpver 30 30

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0 0 St # 5 St # 6 St # 7 St # 8 St # 9 St # 10 St # 11 Sample Stations Sample Stations

2002, changing its coverage from dense continuous to dense SAV coverage. Station #11 had a very slight decrease and still has a dense coverage.

Six stations increased in density enough to change their scale rating. Stations #1, #13, #2, #7, #9 and #10 all increased in the scale to the next category either from patchy to dense or dense to dense continuous. Station #1 located closest to the Inlet, was the station that demonstrated the most dramatic change between 2000 and 2002 increasing from patchy to dense continuous seagrass coverage. Refer to Figures #10 - #13 for density information.

Composition (1998, 2000, 2002)

Composition appears similar between 2000 and 2002 as seen in Figures #14-#17. There was a slight decrease in composition from 1998 to 2000 in the number of species. In 2002 the number of species slightly increased at most stations. Two species that developed the largest increase again were, H. johnsonii and the combination of H. wrightii and S. filiforme. T. testudinum also slightly increased from 2000 to 2002. In 2000 three stations had T. testudinum present, which, was down from 1998 and in 2002 four stations recorded T. testudinum. In 2002, many stations documented multiple species of seagrasses living together, this is not a new observation but the percentage of seagrass combinations increased in 2002. For example, station #2 in 2000 had H. wrightii having the highest percentage followed closely by S. filiforme. In 2002, station #2 had S. filiforme as the highest percentage followed by H. wrightii and second highest was S. filiforme in combination with T. testudinum. The decrease in H. wrightii and the increase in both S. filiforme and T. testudinum are important because S. filiforme and T. testudinum are less pollution tolerant. This is important because the literature reflects that these species are more productive in terms of fish recruitment and biological productivity.

The other species of seagrass that showed a decline from 1998 to 2000 was, H. johnsonii. H. johnsonii populations increased in 2002. In 2002, H. johnsonii was found at stations #1, #13, #14 #6 and #11 not in combination with other species. Also in 2002, H. johnsonii was found in combination with H. wrightii and constituted a substantial portion of seagrasses at three stations, #1, #14, #13.

Between 2000 and 2002 both overall seagrass density increased and there was also a slight increase in seagrass composition. Conversely between 1998 and 2000 there was an increase in seagrass density but a decrease in species composition. For example, station #14, in 1998 had a good representation of H. wrightii, S. filiforme and H. johnsonii that in 2000 changed to domination by H. wrightii, reduction in S. filiforme, and a reduction in H. johnsonii. This reduction in S. filiforme and H. johnsonii was seen to reverse, showing an increase in 2002. At many of the other stations, species that decreased in the time period between 1998 and 2000 began to increase in 2002. For

Figure # 14 Submerged Aquatic Vegetation Composition at Jupiter Inlet and Loxhatchee River Stations (#1, #13, #14)

% SAV Composition Station # 1 % SAV Composition Station # 13 (1998-2002) (1998-2002) 62.3

23 91.3 29.6 51.9 20.3 25.8 8.5 15 0 0 3.5 0 0 5.3 0 2002 Ave. 4.9 0 1.3 4.9 0 24.8 0 2002 Ave. 15.6 0 0 5.9 0 0 0 2.8 0 0 2000 Ave. 1.8 0 0 0 0 1 0 2000 Ave. 83.9 13.6 0 0 0 0 0 2.49 0 0 1998 Ave. 20.4 0 0 44.2 0 0 0 0 36 0 1998 Ave. % Algae % Algae % H. wrightii filiforme johnsonii % H. wrightii filiforme % S. filiforme johnsonii % S. filiforme testudinum % H. johnsonii % H. decipens testudinum % H. johnsonii % H. decipens % Combination: % T. testudinum % Combination: % T. testudinum % H. wrightii + T. % H. wrightii + S. % H. wrightii + H. % H. wrightii + T. % H. wrightii + S. % H. wrightii + H.

% SAV Composition Station # 14 (1998-2002) 35.1 51.3

14.4 30.1 8.6 10.2 10.9 4.1 0.8 0 0.1 0 2002 Avg. 15.9 9.2 3.6 4.6 0 41.6 0 1.2 0 2000 Avg. 28.9 13.6 6.7 2.5 0 2.7 0 1.6 2.3 1998 Avg. % Algae % H. wrightii filiforme johnsonii % S. filiforme testudinum % H. johnsonii % H. decipens % Combination: % T. testudinum % H. wrightii + T. % H. wrightii + S. % H. wrightii + H. Figure # 15: Submerged Aquatic Vegetation Composition at Jupiter Narrows Stations (#2, #3, #3E, #4)

% SAV Composition at Station # 2 % SAV Composition at Station # 3 (1998-2002) (1998-2002) 39.1 55.2 21.9 35.6 35.7 31.6 7.2 15.3 3.5 7.4 16.7 11.4 10.9 5.9 4.5 4.2 0.4 0 0 0.3 2002 Avg. 35 0 0 0 0 0 0 2002 Avg 4.8 8.5 6 11.2 12 4 5.2 0.6 0.7 0.4 3.5 1.9 38.2 0 0 2000 Avg. 15 33.9 0 0 0 2000 Avg 36 6 24 1.8 18.5 6 2.5 0.6 13.3 0.4 0.3 0.9 0 1998 Avg. 0 0 3 0 0 0 1998 Avg. % Algae % Algae % H. wrightii filiforme % H. wrightii filiforme johnsonii % S. filiforme johnsonii % S. filiforme testudinum % H. johnsonii testudinum testudinum % H. decipens % H. johnsonii testudinum % H. decipens % Combination: % T. testudinum % Combination: % T. testudinum % H. wrightii + T. % H. wrightii + S. % H. wrightii + H. % H. wrightii + T. % H. wrightii + S. % H. wrightii + H. % S. filiforme + T. % S. filiforme % S. filiforme + T. % S. filiforme

% SAV Composition at Station #3E % SAV Composition at Station # 4 58.9 (1998-2002) (1998-2002)

55.5 53.6 13.8 20.1 31.7 69.5 16.2 8.1 7.5 10 0 0 0 0 0 0 0 2002 Avg. 5 0.8 2.5 0 0 2.4 1.2 2002 Avg. 11.6 52.9 9.1 0.4 10.2 37.4 0 1.2 0 0 0 0 0 0 2000 Avg. 5.5 1.2 0.2 0.2 0 3.6 0 2000 Avg. 12.7 3.3 5.7 52.4 7.6 1 0 0 0 0.4 0 0 1998 Avg. 5.7 16.1 0 0 0 4.8 0.83 0 1998 Avg. % Algae % Algae % H. wrightii filiforme % H. wrightii filiforme johnsonii % S. filiforme johnsonii % S. filiforme testudinum testudinum % H. johnsonii testudinum % H. decipens % H. johnsonii testudinum % H. decipens % Combination: % Combination: % T. testudinum % T. testudinum % H. wrightii + T. % H. wrightii + S. % H. wrightii + H. % H. wrightii + T. % H. wrightii + S. % H. wrightii + H. % S. filiforme + T. % S. filiforme % S. filiforme + T. % S. filiforme Figure # 16: Submerged Aquatic Vegetation Composition at Jupiter Sound South Stations (#5, #6, #7 and #8)

% SAV Composition at Station #5 SAV Composition at Station # 6 (1998-2002) (1998-2002)

54.8 22 35.3 67.8 60.7 5.2 2.2 16.4 41.4 18.8 13.7 1.9 0 0 0 0 0 0 0 2002 Avg. 0.3 2.6 1.8 0.4 2.3 0 3.4 2002 Avg. 13.2 5 7.8 2.8 0 0 0 0 2.8 16.4 0 2000 Avg. 0 0.2 1.5 0 0 0 0 2000 Avg. 12.1 17.6 48.8 3.7 57.6 25.5 33.1 0 1.4 0 0 0 0 0 1998 Avg. 0.5 1.4 0 0 0 0 0 0 1998 Avg. % Algae % Algae % H. wrightii filiforme johnsonii % H. wrightii filiforme % S. filiforme johnsonii % S. filiforme testudinum % H. johnsonii testudinum % H. decipens testudinum % H. johnsonii testudinum % H. decipens % Combination: % T. testudinum % Combination: % T. testudinum % H. wrightii + T. % H. wrightii + S. % H. wrightii + H. % H. wrightii + T. % S. filiforme + T. % S. filiforme % H. wrightii + S. % H. wrightii + H. % S. filiforme + T. % S. filiforme

SAV Composition at Station # 7 SAV Composition at Station # 8 (1998-2002) (1998-2002)

75.7 56.6 71.5 10.6 38.2 19.7 9.8 9.1 4.9 0 0 0 0 0 4.9 4.2 2002 Avg. 0 0 0 0 0 0 4.6 0 2002 Avg. 20 11.5 13.7 33.5 3.3 0 0 0 0 0 0 0 2000 Avg. 0 0 3.7 0 0 0 4.6 0 2000 Avg. 14.2 58.4 35.1 42.3 14 0 0 0 27.5 0 0 0 0.4 0 1998 Avg. 0 0 3.8 0 0 0 5 0 1998 Avg. % Algae % Algae % H. wrightii filiforme johnsonii % S. filiforme % H. wrightii filiforme johnsonii testudinum % S. filiforme % H. johnsonii testudinum % H. decipens testudinum % H. johnsonii testudinum % H. decipens % Combination: % T. testudinum % Combination: % H. wrightii + T. % T. testudinum % H. wrightii + S. % H. wrightii + H. % S. filiforme + T. % S. filiforme % H. wrightii + T. % H. wrightii + S. % H. wrightii + H. % S. filiforme + T. % S. filiforme Figure # 17: Submerged Aquatic Vegetation Composition at Jupiter Sound North Stations (#9, #10 and #11)

% SAV Composition at Station # 9 % SAV Cover at Station # 10 (1998-2002) (1998-2002)

87.7 79.4

92.8 85.8 10.3 7.4 2.9 0 0 0 0 0 0 0 2002 Avg. 4.8 0 0 1.2 4.2 0 0 0 2.4 0 2002 Avg. 7.4 4 0 0 0 0.8 0 0 0 2.4 0 2000 Avg. 5.3 0 0 0 1.5 0 0 0 0 2000 Avg. 11.5 50.3 3.8 8.2 79.2 7.2 29.4 2.6 0 1.2 1.6 0 0.5 0 1998 Avg. 0 3.4 0 0 0 2.1 0 0 1998 Avg. % Algae % Algae % H. wrightii filiforme % H. wrightii johnsonii filiforme % S. filiforme johnsonii % S. filiforme testudinum % H. johnsonii testudinum % H. decipens testudinum % H. johnsonii testudinum % H. decipens % Combination: % T. testudinum % Combination: % T. testudinum % H. wrightii + T. % H. wrightii + S. % H. wrightii + H. % H. wrightii + T. % H. wrightii + S. % S. filiforme + T. % S. filiforme % H. wrightii + H. % S. filiforme + T. % S. filiforme

% SAV Coverage at Station # 11 (1998-2002)

58.9 27.7 21.7 26 13.3 9.7 0 1.9 34 0 0 0 0 2002 Avg. 57.2 6.9 0 28 0 0 0 0 0 0 0 2000 Avg. 9.5 4.3 0 0 0 0 0 0.9 0 1998 Avg. % Algae % H. wrightii filiforme johnsonii % S. filiforme testudinum % H. johnsonii testudinum % H. decipens % Combination: % T. testudinum % H. wrightii + T. % H. wrightii + S. % H. wrightii + H. % S. filiforme + T. % S. filiforme example, from 1998 to 2000, H. wrightii slightly increased but in 2002, demonstrated a slight decrease being replaced by more pollution intolerant species. The increase in less pollution tolerant species may signify that the environmental conditions are improving allowing more seagrass diversity.

The following paragraphs outline the comparison of data for each of the research segments. Figures #10-#13 show overall SAV densities and Figures #14-#17 display the relative abundance, in percent, of the individual species that characterize the seagrass communities in each research segment. Figures#14-#17 show only the percentage of seagrass species exclusive of sand bottom coverages.

Jupiter Inlet / Loxahatchee Estuary Segment … stations #1, #13 and #14

Station #1 was the only station in this segment that had a substantial increase in SAV cover, it went from patchy (less than 50%) to dense continuous. This station is the closest to the Inlet and therefore experiences the most significant fluctuations in water velocity, the increase in seagrass was predominantly H. wrightii. Stations #13 had a slight increase as well and improved from dense converge in 2000 to dense continuous in 2002. Station #14, located in the Loxahatchee Estuary west of the Railroad Bridge, was the only station in this segment that recorded dense coverage. Densities in this segment ranged from 72% to 89%.

The predominant species of seagrass found at station #1 and #14 continues to be H. wrightii since 1998. At Station #13 the predominant species of seagrass has been H. johnsonii since 1998. At each of these stations the percentage of the dominant species has increased since 1998. Since 1998, the percentage of S. filiforme has also increased at both station #14 and #13. A substantial increase in the combination of H. wrightii and H. johnsonii has been seen at all three stations in this segment. The combination of H. wrightii and H. johnsonii in 1998 ranged from 0% to 1.1% and in 2002 ranged from 18.8% to 22.7%.

Overall the seagrasses found within this segment continue to be increasing in density and composition. The density of H. johnsonii has substantially increased in this segment. Composition continues to improve demonstrating that environmental conditions are favorable for multiple species to coexist.

Jupiter Narrows Segment ……… stations #2, #3, #3E and #4

Station #2 and #3 both had dense SAV coverages while station #3E and #4 both were observed to have dense continuous coverages. The density in this segment has increased substantially since 1998. In 1998 SAV coverage ranged from 46% to 69.3%, in 2000 SAV coverage increased to 51.1% to 90.6% and in 2002 SAV coverage again increased to 69.3% to 89.7%. The only station in this segment that had a slight decrease in SAV coverage was station #3E, SAV decreased from 90.6% in 2000 to

88.7% in 2002. Station #3E is located across from Coral Cove Park and has substantial recreational boating activities.

Stations #2, #3 and #3E all have increased populations of S. filiforme since 1998. Also populations of T. testudinum have increased at stations #2, #3 and #4 since 1998. Combinations of S.filiforme and H.wrightii as well as combinations of S.filiforme and T. testudinum have increased since 1998. In 2002 there was a substantial increase in overall SAV density in this segment, however the number of seagrass species decreased from 2000. Since 2000, the number of species has again increased and resembles the species that were seen in 1998, just in greater density.

Overall this segment has substantial seagrass communities that are increasing in density and composition. Composition is one key component to the productivity of seagrass communities. This segment is critical because of its proximity to the Inlet and the key role the seagrass communities play in juvenile fish populations of both commercially and recreationally important finfish and shellfish.

Jupiter Sound South Segment ……… stations #5, #6, #7 and #8

Stations #5, #6, #8 all had dense SAV coverages in 2002. Station #7 improved to a dense continuous coverage in 2002. Since 1998 all four stations have increased in SAV coverage. In 1998 SAV coverages ranged from 19.1% to 79%, in 2000 ranged from 56.6% to 82.2% and in 2002 ranged from 70.7% to 86%. The only station in this segment that decreased from 2000-2002 was station #6, with 82.2% SAV coverage in 2000 to 70.7% coverage in 2002.

Seagrass composition in this segment continues to show that S. filfiforme is the predominant species of seagrass found. Station #5 and #6 had slight decreases in S. filiforme from 2000 to 2002, however both stations had increases in the combination of S.filiforme and H. wrightii. Station #6 had an overall decrease in SAV density from 2000 to 2002 however the number of species actually increased from 4 species of seagrass and combinations of seagrass in 2000 to 7 associations of seagrass and combinations in 2002. All four stations had increases in the combination of S.filiforme and H. wrightii from 1998 to 2002. T.testudinum also slightly increased in the segment from 2000 to 2002.

In general the viability of seagrasses in this segment have remained similar to 1998. There have been some increases and some decreases in seagrass density but the composition has remained similar between the years. There appears to be a slight increase in species composition between 2000 and 2002, but two years is a fraction of time, more comparisons over the next few years, need to be further analyzed.

Jupiter Sound North Segment ……… stations #9, #10 and #11

Stations #9 and #11 had dense SAV coverages in 2002, while station #10 had a dense continuous SAV coverage. Since 1998 overall SAV coverage in this segment has increased. In 1998 SAV coverages ranged from 43.3% to 67%, in 2000 SAV coverages ranged from 54.9% to 71.8% and in 2002 SAV coverages ranged from 53.6% to 83.3%.

At all three stations S.filiforme continues to be the most dominant seagrass species followed closely by H.wrightii. At stations #9 and #11 the combination of S.filiforme and H.wrightii increased from 2000 to 2002. Station #11 was the only station in this segment that had H.decipens recorded and the population of H.decipens has increased since 1998. Station #9 had no T. testudinum recorded in 2000, however in 2002 it was found in combination with S. filiforme.

Overall seagrass density in this segment has increased from 1998. The composition if seagrasses in this segment remains similar to the composition observed in 1998 and 2000. This segment also continues to be the only one in the study area that has a substantial population of H. decipens.

Future Research:

In the future there are six distinct areas in which this information will prove a valuable tool. These projects are ones that the Loxahatchee River District plans on coordinating in the future.

One project includes returning to the fourteen sampling stations every two years to conduct surveys and compare information. Another project will be to evaluate the study area for T. testudinum. Throughout the study area T. testudinum is one of the species least represented. Started in 2001, the study has established GPS coordinates for most of the T. testudinum beds in the Jupiter Sound South and Inlet areas. In future year’s, comparisons can be drawn regarding the extent of this important species. The fourth project is an evaluation of seasonal variations within the study area. The Loxahatchee River District has and will continue to record information at three stations for the South Florida Water Management District. The fifth evaluation will be to compare the current seagrass information to results of analytical work compiled from sites further north in the Indian River Lagoon. The last project will be to compare the seagrass community information with available data on other biological communities such as benthic macroinvertebrates and juvenile fish.

Summary

The comparison of data from 1998, 2000 and 2002 has fulfilled the initial objective of the research effort. The comments listed below are provided to summarize the major findings of the study and to encourage further evaluations and research efforts.

• The primary objective was to add to current information available on seagrass communities in the southernmost reach of the Indian River Lagoon and the Loxahatchee River estuary.

• The second objective was to compare the 2002 data with information gathered in 1998 and 2000. This was accomplished and the results are displayed in this report.

• While distribution maps could not be generated, it is believed that overall distribution of seagrass communities did not significantly change from 2000.

• Seagrass densities on the average increased by 25.6% from 1998 to 2002.

• In 2002, seven of the representative stations had dense seagrass populations and the other seven had dense continuous coverage’s compared to one sparse, six patchy, six dense and only one dense continuous in 1998.

• Six stations increased in seagrass density and changed their density scale rating, changing from either patchy to dense or dense to dense continuous.

• The two species that increased the most throughout the study area in 2002 were, S. filiforme in combination with H. wrightii and H. johnsonii. The increase of these species, biologically speaking is positive, S. filiforme is a common and very productive seagrass and H. johnsonii is currently listed as a threatened species in the Indian River Lagoon.

• Both density and composition slightly increased in the study area in 2002.

• The species that decreased the most was H. wrightii. This species of seagrass is often found in areas that cannot sustain other more productive seagrass species, so its decrease, means the subsequent increase in more productive species.

• The species or combination that seemed to replace H. wrightii was H. wrightii in combination with S. filiforme and H. wrightii in combination with H. johnsonii. The trend of seagrasses in combination with one another is seen as a good one, because diversity helps sustain healthy faunal (fish and shellfish) associations.

In general, seagrass observations within the study area demonstrate that environmental conditions within the southern Indian River Lagoon and the Loxahatchee estuary are capable of not only sustaining seagrasses, but actually increasing seagrass density and composition. Further evaluations are necessary to ensure that this trend remains the same and is not altered by mans encroachment on these natural resources.

Appendix A Jupiter Inlet / Loxahatchee Estuary Segment

Station # 1 1998 Avg. 2000 Avg. 2002 Avg. Station # 14 1998 Avg. 2000 Avg. 2002 Avg. % Sand 56.9 50.5 7.5 % Sand 69.2 30.5 25.3 % H. wrightii 37 45.2 57.6 % H. wrightii 9.1 35.6 26.4 % S. filiforme 0 0 0 % S. filiforme 2.1 2.5 3.1 % T. testudinum 0 0 0 % T. testudinum 0.53 0 0.58 % H. johnsonii 6 2.9 3.3 % H. johnsonii 13.1 10 6.5 % H. decipens 0 0 0 % H. decipens 0 0 0 % H. wrightii + S. filiforme 0 0 0 % H. wrightii + S. filiforme 0.67 11 7.7 % H. wrightii + T. testudinum 0 0 4.9 % H. wrightii + T. testudinum 0 6.4 8.2 % H. wrightii + H. johnsonii 1.1 1.4 18.8 % H. wrightii + H. johnsonii 0.3 0.83 22.7 % S. filiforme + T. testudinum 0 0 0 % S. filiforme + T. testudinum 0 0 0 % Algae 0 0 0 % Algae 4.3 3.2 0.08 % Combination: 0 0 7.9 % Combination: 0.73 0 0

Station # 13 1998 Avg. 2000 Avg. 2002 Avg. % Sand 61.3 33.6 16.4 % H. wrightii 7.9 10.4 12.6 % S. filiforme 0 1 4.1 % T. testudinum 0 0 0 % H. johnsonii 17.1 19.8 21.6 % H. decipens 0 0 1.1 % H. wrightii + S. filiforme 0 0 4.1 % H. wrightii + T. testudinum 0 0 0 % H. wrightii + H. johnsonii 0 0.5 20.8 % S. filiforme + T. testudinum 0 0 0 % Algae 15.1 34.7 19.3 % Combination: 0 0 0 Appendix A Jupiter Inlet / Loxahatchee Estuary Segment

Station # 2 1998 Avg. 2000 Avg. 2002 Avg. Station # 3 1998 Avg. 2000 Avg. 2002 Avg. % Sand 53.8 48.9 30.4 % Sand 41.5 30.7 30.8 % H. wrightii 17.3 18.4 15.2 % H. wrightii 8.7 24.2 4.4 % S. filiforme 16.6 16.3 27.1 % S. filiforme 19.8 24.7 39.5 % T. testudinum 0.8 4.4 5.1 % T. testudinum 14 2.4 10.9 % H. johnsonii 1.1 3.1 0.3 % H. johnsonii 10.7 2.8 0 % H. decipens 0.7 0 0 % H. decipens 0 0 0 % H. wrightii + S. filiforme 6 1.8 4.1 % H. wrightii + S. filiforme 0 2.4 7.5 % H. wrightii + T. testudinum 0.2 0 0 % H. wrightii + T. testudinum 1.7 0 0 % H. wrightii + H. johnsonii 0.1 0.3 3.1 % H. wrightii + H. johnsonii 0 1.3 0 % S. filiforme + T. testudinum 2.8 6.2 11.6 % S. filiforme + T. testudinum 3.5 7.8 7 % Algae 0.4 0.4 0.2 % Algae 0 3.6 0 % Combination: 0 0.2 2.9 % Combination: 0 0 0

Station # 3E 1998 Avg. 2000 Avg. 2002 Avg. Station # 4 1998 Avg. 2000 Avg. 2002 Avg. % Sand 30.7 9.4 11.3 % Sand 33.9 16.5 10.3 % H. wrightii 25.7 28.7 12.1 % H. wrightii 3.7 7.6 6.7 % S. filiforme 36.4 50.3 51.8 % S. filiforme 34.5 58.1 48.4 % T. testudinum 0.7 0 0 % T. testudinum 5 4.6 4.5 % H. johnsonii 2.3 1.1 0 % H. johnsonii 10.6 1 0.7 % H. decipens 0 0 0 % H. decipens 0 0.2 2.3 % H. wrightii + S. filiforme 3.9 10.5 17.7 % H. wrightii + S. filiforme 8.3 0.3 14.6 % H. wrightii + T. testudinum 0 0 0 % H. wrightii + T. testudinum 0 0.2 0 % H. wrightii + H. johnsonii 0 0 0 % H. wrightii + H. johnsonii 0 0 0 % S. filiforme + T. testudinum 0.3 0 7.1 % S. filiforme + T. testudinum 3.2 8.5 9 % Algae 0 0 0 % Algae 0.5 3 2.2 % Combination: 0 0 0 % Combination: 0 0 1.1 Appendix A Jupiter Inlet / Loxahatchee Estuary Segment

Station # 5 1998 Avg. 2000 Avg. 2002 Avg. Station # 6 1998 Avg. 2000 Avg. 2002 Avg. % Sand 45.8 29.5 27.3 % Sand 44.6 17.8 29.3 % H. wrightii 2 3.5 1.4 % H. wrightii 9.6 10.9 13.2 % S. filiforme 31.1 47.8 39.7 % S. filiforme 26.7 50 15.5 % T. testudinum 0 2 0 % T. testudinum 0.2 0 0.2 % H. johnsonii 0.7 0 0 % H. johnsonii 0.7 0.2 1.8 % H. decipens 0 0 0 % H. decipens 0 1.2 9.6 % H. wrightii + S. filiforme 13.8 3.6 30 % H. wrightii + S. filiforme 18.1 13.5 24.8 % H. wrightii + T. testudinum 0 0 0 % H. wrightii + T. testudinum 0 0 1.3 % H. wrightii + H. johnsonii 0 0 0 % H. wrightii + H. johnsonii 0 0 0.3 % S. filiforme + T. testudinum 6.5 2 0 % S. filiforme + T. testudinum 0 0 1.6 % Algae 0 11.5 1.6 % Algae 0 6.4 0 % Combination: 0 0 0 % Combination: 0 0 2.4

Station # 7 1998 Avg. 2000 Avg. 2002 Avg. Station # 8 1998 Avg. 2000 Avg. 2002 Avg. % Sand 21 43.4 14 % Sand 80.9 35 28.3 % H. wrightii 11.2 1.5 4.2 % H. wrightii 6.6 13 7.6 % S. filiforme 45.9 41.6 48.6 % S. filiforme 7.9 24.8 54.3 % T. testudinum 0 0 0 % T. testudinum 0 0 0 % H. johnsonii 0 0 0 % H. johnsonii 0 0 0 % H. decipens 0 0 0 % H. decipens 2.6 21.8 0 % H. wrightii + S. filiforme 21.6 5.5 16.9 % H. wrightii + S. filiforme 0.7 2.4 6.5 % H. wrightii + T. testudinum 0 0 0 % H. wrightii + T. testudinum 0 0 0 % H. wrightii + H. johnsonii 0 0 0 % H. wrightii + H. johnsonii 0 0 0 % S. filiforme + T. testudinum 0 0 4.2 % S. filiforme + T. testudinum 0 0 0 % Algae 0.3 8 8.4 % Algae 1.3 3 3.3 % Combination: 0 0 3.6 % Combination: 0 0 0 Appendix A Jupiter Inlet / Loxahatchee Estuary Segment

Station # 9 1998 Avg. 2000 Avg. 2002 Avg. Station # 10 1998 Avg. 2000 Avg. 2002 Avg. % Sand 56.7 37.7 32 % Sand 33 28.2 16.7 % H. wrightii 12.5 2.5 2 % H. wrightii 5.5 3.8 4 % S. filiforme 21.4 57.8 54 % S. filiforme 53 61.6 72.8 % T. testudinum 1.1 0 0 % T. testudinum 0 0 0 % H. johnsonii 0 0 0 % H. johnsonii 2.3 0 0 % H. decipens 1.6 0 0 % H. decipens 0 0 1 % H. wrightii + S. filiforme 0.5 0.5 7 % H. wrightii + S. filiforme 0 1.1 3.5 % H. wrightii + T. testudinum 0.7 0 0 % H. wrightii + T. testudinum 0 0 0 % H. wrightii + H. johnsonii 0 0 0 % H. wrightii + H. johnsonii 1.4 0 0 % S. filiforme + T. testudinum 5.3 0 5 % S. filiforme + T. testudinum 0 0 0 % Algae 0.2 1.5 0 % Algae 4.8 5.3 2 % Combination: 0 0 0 % Combination: 0 0 0

Station # 11 1998 Avg. 2000 Avg. 2002 Avg. % Sand 53.4 45.1 46.4 % H. wrightii 26.5 0 13.9 % S. filiforme 13 32.4 14.8 % T. testudinum 0 0 0 % H. johnsonii 0 0 1 % H. decipens 4.5 18.7 11.6 % H. wrightii + S. filiforme 2.2 0 5.2 % H. wrightii + T. testudinum 0 0 0 % H. wrightii + H. johnsonii 0 0 0 % S. filiforme + T. testudinum 0 0 0 % Algae 0.4 3.8 7.1 % Combination: 0 0 0