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Pensacola Bay

Pensacola Bay

Pensacola Bay

By Lisa Schwenning,1 Traci Bruce,1 and Lawrence R. Handley2

Background during the early to mid-1950s (Northwest Water Management District, 1991). The system (fig. 1) has historically Predominant land uses within the riverine watershed supported a rich and diverse , productive fisheries, and include forestry, agriculture, military, and public conservation considerable recreational opportunities. It has also provided and recreation, as well as residential and other urban land uses an important resource for commercial shipping and military around several communities. Much of the economic base of activities and has enhanced area aesthetics and property this area is provided by the extraction of natural resources, values. Unfortunately, for many years, point and nonpoint primarily timber and agriculture, but there are also indirect source pollution, direct habitat destruction, and the cumulative economic benefits provided by military activities and the impacts of development and other activities throughout service sector. Major public landholdings include portions the watershed have combined to degrade the health and of Eglin Air Force Base, Blackwater State Forest productivity of much of the Pensacola Bay system (Northwest (Northwest Florida Water Management District, 1997), and Florida Water Management District, 1997). water management district lands along the Escambia and During the 1800s and early 1900s, extensive logging Blackwater . of hardwood trees occurred on entering the Population growth and development apply the greatest Pensacola Bay system (Rucker, 1990). Historically, it is pressure to the environment of Florida’s coastal areas. likely that the timber industry adversely impacted the upper As population increases, so do the demands on coastal bays of the system. Blackwater Bay and lower reaches of the resources. Over 75% of Florida’s residents live in coastal Blackwater River and Creek were covered with sawdust counties, and a 50% increase is estimated by 2020 (Florida from mills in Bagdad, Fla. Sawn timber and sawdust are Department of Environmental Protection, 1998). In the three rich in turpines and other toxic substances. During logging counties included in the Florida portion of the Pensacola Bay operations, turbidity, nutrient concentrations, biological watershed, there has been a 220% increase in population since oxygen demand, and chemical oxygen demand were probably 1960. As a result of the population increase, there has been a high, and dissolved oxygen levels were probably low. Benthic dramatic change in land use of the Pensacola Bay area from communities may have been scarce or nonexistent while the agricultural to urban. Escambia County alone lost 13,247 ha mills were operating at peak levels (Northwest Florida Water (32,732 acres) of agricultural lands between 1992 and 1997; Management District, 1991). during the same time, the county gained approximately 6,071 Barge traffic and log from tributaries to the Port ha (15,000 acres) of urban land use. of Pensacola unquestionably resuspended fine in areas of the system. Fairly extensive dredging of the Blackwater River was authorized and completed in 1916 Scope of Area by the U.S. Army Corps of Engineers (1990). Moskovits (1955) reported general silting problems in Pensacola Bay The Pensacola Bay system consists of about 50,992 ha during 1949–50, as well as settlement of fouling organisms (126,000 acres), including its coastline of 885 km (550 mi) (barnacles, serpulid worms, hydroids, bryozoans, sponges, and open surface waters of about 373 km2 (144 mi2). The jingle shells, and Mytilus sp.) on artificial substrata. watershed covers nearly 18,130 km2 (7,000 mi2). The final These organisms tend to settle in relatively clear water, outlet for the system is the at the mouth of so the presence of these animals suggests that suspended Pensacola Bay. The watershed of the Pensacola Bay system loads were not sufficient to inhibit the settlement includes many different counties, cities, and incorporations. of zooplankton and that water quality may have been better Approximately 65% of the entire watershed is located outside of Florida State lines; Alabama counties—including portions of Covington, Escambia, Conecuh, Butler, Crenshaw, Pike, 2 1 Florida Department of Environmental Protection, Northwest District. Bullock, Montgomery, and Coffee—make up 11,632 km 2 U.S. Geological Survey. 130 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002

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Figure 1. Watershed for the Pensacola Bay system. Methodology Employed To Determine and Document Status 131

(4,491 mi2) of the Pensacola Bay system (Florida Department of Environmental Protection, 1998). Approximately 857 km2 (331 mi2) (45%) of Escambia Santa Rosa Sound is oriented west to east and connects County form the western portion of the Pensacola Bay Choctawhatchee and Pensacola Bays. It is bordered on the watershed. Nearly all of the 2,631 km2 (1,016 mi2) of south by Santa Rosa Island and on the north by the Gulf Santa Rosa County, located to the east, are included in the Breeze Peninsula. watershed. Seventy-five percent of Okaloosa County (1,940 km2, or 749 mi2) lies in the watershed. Within Okaloosa County are the Yellow and Shoal Rivers, their tributaries, and the other half of Santa Rosa Sound. Only 648 km2 (250 mi2) Methodology Employed To Determine (20%) of Walton County drain into the Pensacola Bay system and contain a portion of the Shoal River and tributaries. and Document Current Status The western portion of the basin is predominantly urban, whereas the eastern portion is primarily low density, rural, The most current mapping study of seagrass coverage for and undeveloped. the Pensacola Bay area was conducted more than 10 yr ago The Pensacola Bay system has been divided into five by the U.S. Geological Survey (USGS) National segments: , East Bay, Pensacola Bay proper, Big Research Center (NWRC) by using natural-color aerial Lagoon, and Santa Rosa Sound (fig. 2). photography taken in 1992 at a 1:24,000 scale as part of the northeastern Gulf of Mexico seagrass mapping project. The mapping protocol consisted of stereoscopic Escambia Bay photointerpretation, cartographic transfer, and digitization in accordance with strict mapping standards and Escambia Bay may be the most vulnerable of the Pensacola Bay segments. It is located north of the line conventions.Other important aspects of the protocol between Garcon Point to the east and Magnolia Point to the included the development of a seagrass classification west. Escambia Bay is commonly divided into upper and system, groundtruthing, quality control, and peer review. lower parts, with Interstate 10 delineating the boundary. This The information derived from the photography was dividing line falls in an area that divides species between subsequently transferred by using a zoom transfer scope the dominant brackish water plant water celery (Vallisneria onto a stable medium overlaying USGS 1:24,000-scale americana) in the upper bay and the dominant seagrass shoal quadrangle base maps. The primary data source was grass (Halodule wrightii) in the lower part of the bay. 1:24,000-scale natural color aerial photography flown by the National Aeronautics and Space Administration Stennis East Bay Space Center in fall 1992. In those cases where the data were inadequate or incomplete, contemporary supplemental East Bay is located east of the line between Garcon Point data were acquired from other sources and used to complete and Redfish Cove. East Bay, like Escambia Bay, is commonly the photographic coverage. divided into upper and lower segments, but with Robinson The seagrass classification system that was developed Point delineating the boundary. The area north of Robinson (see appendix for full discussion) consisted of two classes of Point harbors all brackish water submerged aquatic vegetation. open water—RIV (riverine, fresh water) and EST (estuarine The area south of Robinson Point, or East Bay proper, contains or marine open water)—and five classes of seagrass habitats. shoal grass and turtle grass (Thalassia testudinum). One seagrass habitat class is continuous seagrass, CSG, for which no density distinction was made. The other four classes Pensacola Bay are patchy seagrass based on percent ground cover of patches in 5% increments: PSG1 (0%–10%, very sparse), PSG2 Pensacola Bay is west of the . (15%–40%, sparse), PSG3 (45%–70%, moderate), and PSG4 Escambia and East Bays drain into Pensacola Bay, along with (75%–95%, dense). Texar, Chico, and Grande. Pensacola Bay empties into The groundtruthing phase included the participation of the Gulf of Mexico at the . field staff from Gulf Islands National Seashore, U.S. Fish and Wildlife Service, Dauphin Island Sea Lab, Mississippi Big Lagoon State University, Alabama Department of Conservation and Natural Resources, and Florida Department of Environmental Big Lagoon is oriented west to east and connects lower Protection. Draft maps were sent out to these agencies Perdido and Pensacola Bays. It is bordered on the south by for review and comments. All comments received were Perdido Key and on the north by Pensacola Naval Air Station. incorporated into the final maps. 132

Coldwater r e Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002 River iv r R ate w ck Bla Escambia er iv R w llo R 2 Ye iv e r Robinson 1 Point

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Figure 2. Scope of area for the Pensacola Bay vignette. Status and Trends 133

Methodology for Historical Table 1. Seagrass area for the Pensacola Bay system. Trend Mapping [Values are given in hectares (acres)] Santa Escambia Pensacola Big In 1999, the NWRC produced historical seagrass maps East Bay Rosa Bay Bay Lagoon from 1:20,000-scale black and white aerial photography Sound from 1964 for the U.S. Fish and Wildlife Service’s Panama 105 476 372 271 2,634 1960 City Ecological Services and Fisheries Resources Office to (259) (1,175) (918) (670) (6,508) use in the development of a trend analysis for Pensacola and 24 99 55 236 1,489 Escambia Bays, Santa Rosa Sound, and Big Lagoon. These 1980 seagrass maps for 1964 and the previously described seagrass (60) (245) (137) (582) (3,680) maps from 1992 were used to develop the trend analysis. The 178 165 114 218 1,140 1992 aerial photography from 1964 was analyzed with stereoscopic (441) (408) (282) (538) (2,816) visual equipment; seagrasses were delineated onto Mylar® overlays by using a zoom transfer scope and USGS 1:24,000- scale topographic quadrangles as the base maps. The overlays were digitized by using ArcInfo (Environmental Systems Research Institute, Inc., Redlands, Calif.) and converted into The Murdock report clearly linked the loss of seagrasses in Arc format files. The black and white aerial photography was Escambia Bay with industrial discharges into the drainage of good to high quality for delineating seagrasses. basin (Hopkins, 1973). Classification of the seagrasses for the trend analysis During the 1940s, seagrass was sparse in lower Escambia followed the same protocol as that followed in the Bay. Transient beds, usually small, appeared, disappeared, development of the northeastern Gulf of Mexico seagrass and reappeared several times during the 50 yr of survey. For mapping using the 1992 aerial photography (see appendix 1). example, a recession and disappearance of most of Escambia Draft maps were sent out to the U.S. Fish and Wildlife Bay’s true seagrass occurred from 1950 to 1975. In 1960 (fig. Service for review and comments. All comments received 4; table 2), Escambia Bay had approximately 105 ha (259 were incorporated into the final maps. No groundtruthing acres) of seagrass. Attempts in the 1970s to reestablish shoal took place for the historical seagrass delineations for 1964. grass in lower Escambia Bay were not successful. Seagrass The NWRC currently holds the aerial photography, the beds were believed to have disappeared completely by 1976. interpreted overlays, and the Mylar® overlays for the By 1980 (fig. 5; table 3), it was found that 24 ha (60 acres) of 1964 maps. mostly patchy beds were present. A greater reestablishment of several small beds was observed in the late 1980s, and by 1992 (fig. 6; table 4), patchy beds were observed, mostly around the Status and Trends mouths of bayous, totaling approximately 178 ha (441 acres).

Seagrass beds that were extensive in 1949 were documented in 1975 as having receded or disappeared in most areas of the Pensacola Bay system (Northwest Florida Water Management District, 1997). In the 1940s and early 1950s, 7,000 seagrass was abundant in all segments of the system, but less 6,000 than 5%–10% of these levels remain. Figures illustrating these 1960 documented losses in all segments are available in chapter 5,000 1980 12 of Environmental and Recovery Studies of Escambia Bay 1992 4,000 and the Pensacola Bay System, Florida (U.S. Environmental Protection Agency, 1975). 3,000

Seagrass Coverage 2,000

Escambia Bay 1,000

The loss of seagrass in Escambia Bay may be the most 0 Escambia East Bay Pensacola significant in the system, affecting the biological quality Bay Big Lagoon Bay Santa Rosa of the entire Pensacola Bay system (table 1; fig. 3). The Sound earliest documented assertions of seagrass bed loss were in a 1955 report to the Florida State Board of Conservation by Murdock (1955) after an industrial plant began operating and Figure 3. Summary of seagrass coverage in the Pensacola Bay discharging under permit into the Escambia River. system, 1960, 1980, and 1992. 134

Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002 Land Seagrass, continuous Seagrass, patchy Water

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Figure 4. Distribution of seagrass in the Pensacola Bay system, 1960. Causes of Change 135

Table 2. Seagrass area in the Pensacola Bay system for 1960. In Big Lagoon, seagrass beds declined slightly from 271 ha (670 acres) in 1960 (fig. 4; table 2) to 236 ha (582 acres) [Values are given in hectares (acres). CSG = continuous seagrass; PSG = patchy seagrass] in 1980 (fig. 5; table 3). Seagrass beds declined even further in 1992 (fig. 6; table 4) to 217 ha (538 acres). In contrast to Segment Class Area the previously mentioned segments, Big Lagoon has not had Escambia Bay CSG 4 (10) dramatic losses but has had steady, continued decline in its PSG 101 (249) seagrass meadows. Santa Rosa Sound, like Big Lagoon, has experienced a East Bay CSG 45 (110) steady decline from 1960 (fig. 4; table 2), when it had 2,634 ha PSG 431 (1,065) (6,508 acres), to 1980 (fig. 5; table 3), when there were 1,489 ha (3,680 acres). There was a further decline by 1992 (fig. 6; Pensacola Bay CSG 44 (108) table 4), when 1,139 ha (2,816 acres) were mapped. PSG 328 (810)

Big Lagoon CSG 107 (265) PSG 164 (405) Causes of Change Major causes of seagrass loss were and Santa Rosa Sound CSG 1,247 (3,081) industrial waste discharges, dredge and fill activities, PSG 1,387 (3,427) beachfront alteration, and changing watershed and land-use characteristics. In the Pensacola Bay system, many factors East Bay have affected the entire system, with certain factors having From 1950 to 1975, East Bay experienced a decline an increased local effect. Along the southern shore of East similar to that in Escambia Bay (Northwest Florida Water Bay, bulkheads and groins likely caused changes in nearshore water movements and energy; of seagrass beds likely Management District, 1991). In 1960 (fig. 4; table 2), 476 ha occurred as a result. Industrial caused the loss of (1,175 acres) of seagrass were present. This area declined by vegetation in the northeast section of Escambia Bay since 21% by 1980 (fig. 5; table 3) to 99 ha (245 acres); however, by these remained near the shore in that area. For 1992 (fig. 6; table 4), 165 ha (408 acres) were mapped in instance, the loss of seagrass around the sewage treatment East Bay. plant there was caused first by the laying of a discharge pipe directly through the bed and later by sewage effluents (U.S. Pensacola Bay Environmental Protection Agency, 1975). Although seagrass loss is thought to have occurred According to the U.S. Environmental Protection Agency in the early 1900s, no data have been found to support the (1975), the disappearance of several small beds near the north hypothesis. Two activities occurred in the area that could have end of the Pensacola Bay Bridge was documented in 1951 and caused loss. One possible impact was the dredging of the Gulf was likely attributable to dredging. In 1960 (fig. 4; table 2), Intracoastal Waterway in Pensacola in 1910. A continuous 372 ha (918 acres) of seagrass were mapped. In that same year, 3 by 31 m (9 by 100 ft) was completed between the was enlarged, which involved extensive Apalachicola River in Florida and New Orleans, La., in 1936. dredge and fill activities. Additional dredging was done to the In 1942, the dimensions of the channel were increased to 4 m port in 1967. Most beds declined along the southern shore of deep by 38 m wide (12 ft deep by 125 ft wide). The expansion Pensacola Bay and East Bay and disappeared by 1974. Based of the waterway may account for increased traffic, providing on historical data, seagrasses in Pensacola Bay declined from indirect effects over a longer period of time. 372 ha (918 acres) in 1960 to 56 ha (137 acres) in 1980 (fig. 5; Pensacola Bay waters have been impacted by numerous table 3). In 1992 (fig. 6; table 4), seagrass beds had increased sources of pollution, resulting in a system that does not have to 114 ha (282 acres). the natural biodiversity and productivity expected of a system of this complexity. The massive quantities of point source waste previously discharged into the Pensacola Bay system Big Lagoon and Santa Rosa Sound between 1955 and 1964 have been significantly reduced. Based on surveys by the U.S. Environmental Protection Seagrass disappearance has not been quite as dramatic Agency and its predecessor agencies, the combined quantity in Big Lagoon or Santa Rosa Sound; however, seagrasses of waste discharged by the several major dischargers into have gradually decreased over the years in some areas of the Escambia Bay drainage area was reduced by 40% for Big Lagoon and southwestern portions of Santa Rosa Sound biological oxygen demand, 71% for total nitrogen, and 96% along the Gulf Breeze Peninsula (Northwest Florida Water for total phosphorus by 1975 (U.S. Environmental Protection Management District, 1991). Agency, 1975). 136

Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002 Land Seagrass, continuous Seagrass, patchy Water

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Figure 5. Distribution of seagrass in the Pensacola Bay system, 1980. Monitoring for Seagrass Health 137

Table 3. Seagrass area in the Pensacola Bay system for 1980. mouth of the Blackwater River. Big Lagoon and Santa Rosa Sound have the last two remaining stands of turtle grass and [Values are given in hectares (acres). CSG = continuous seagrass; PSG = patchy seagrass] shoal grass in the Pensacola Bay system. Santa Rosa Sound holds, in addition, a few patches of manatee grass and star grass. Segment Class Area Though shoal grass is a pioneering species and is usually Escambia Bay CSG 4 (10) the first to colonize an area, no historical data have been found PSG 20 (50) supporting transition from one species to another.

East Bay CSG 12 (30) PSG 87 (215) Monitoring for Seagrass Health Pensacola Bay CSG 10 (24) PSG 46 (113) In 1974, the Escambia Bay Recovery Study Team obtained photographs from the Florida Department of Big Lagoon CSG 193 (477) Transportation (FDOT) and used them to develop maps of PSG 43 (105) the seagrass beds. Their FDOT file of aerial photographs of Escambia and Santa Rosa Counties dated back to 1949. The Santa Rosa Sound CSG 860 (2,126) study team project personnel also conducted aerial surveys in PSG 629 (1,554) 1974. These overflights of the bays were made sporadically and occurred more frequently over areas of greater highway While it is true today that point sources have decreased construction. (Refer to U.S. Environmental Protection Agency, significantly, nonpoint sources such as runoff 1975, to see these maps.) are increasing, and pollution continues to degrade water and In 1996, a study was conducted by Heck and others sediment quality throughout much of the system. Santa Rosa (1996) for the Gulf Islands National Seashore within Big Sound and Big Lagoon are two of the few remaining bodies Lagoon and Santa Rosa Sound, where two of the last stands of of water within the Pensacola Bay system that still harbor seagrass within the Pensacola Bay system remained. Annual seagrass beds. groundtruthing, inventory of the seagrass community types, 3 Livingston and others (1972) reported that 784,428 m and water-quality parameters were monitored. The study 3 (1,025,933 yd ) of sediments were dredged from Mulatto suggested a significant decline in seagrass meadows in the in 1965 during construction of the Interstate 10 area. The investigators of this study hypothesized a light- bridge across upper Escambia Bay. Additional dredging attenuation problem caused by an increase in turbidity in these occurred in 1970 when finger were created for housing water bodies (Kirschenfeld, 1999). developments and a narrow channel was dug to open the In 1999, the Florida Department of Environmental southern portion of the bayou to Escambia Bay. Livingston Protection was awarded a seagrass monitoring grant from and others (1972) made a compelling case that the creation the U.S. Environmental Protection Agency’s Gulf of Mexico of deep borrow pits within the bayou and the new narrow Program to determine the extent of the problem. Seagrass entrance to the bay were nutrient traps that reduced circulation monitoring, combined with water-quality and light-attenuation and flushing of the bayou and depressed oxygen availability. monitoring, was conducted over 2 yr, resulting in the In addition, it has been reported that seagrass beds in Mulatto publication of the Seagrass Management Plan for Big Lagoon Bayou were replaced by sludge deposits containing hydrogen and Santa Rosa Sound (Florida Department of Environmental sulfide as a result of dredging (Northwest Florida Water Protection, 2001). Management District, 1991). The seagrass monitoring component of this study involved measurements of the depth of growth, percent cover, epiphytic coverage, Braun-Blanquet density (the second Species Information year), species composition, and canopy height (for more information on the Braun-Blanquet density, see http://chla. The Pensacola Bay system contains four species of library.cornell.edu/cgi/t/text/text-idx?c=chla;idno=2917578). true seagrasses—turtle grass, manatee grass (Syringodium The monitoring parameters (Hach Environmental, Loveland, filiforme), star grass (Halophila engelmannii), and shoal Colo.) measured were temperature, pH, conductivity, salinity, grass—and two brackish water species, water celery and and dissolved oxygen. Water samples were also taken from wigeon grass (Ruppia maritima). each monitoring site once a month to measure turbidity, color, The upper portion of Escambia Bay contains mostly chlorophyll a, total suspended solids, total Kjeldahl nitrogen, water celery, with a few patches of wigeon grass; the lower ammonia, nitrate + nitrite, total phosphorus, orthophosphorus, portion has lost all seagrass. East Bay has lost all seagrass and algal growth potential. The Seagrass Management Plan with the exception of a few areas in upper East Bay around the for Big Lagoon and Santa Rosa Sound (Florida Department of 138

Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002 Land Seagrass, continuous Seagrass, patchy Water

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Figure 6. Distribution of seagrass in the Pensacola Bay system, 1992. Mapping and Monitoring Needs 139

Table 4. Seagrass area in the Pensacola Bay system for 1992. attenuation. Results of water-quality monitoring for the parameters of chlorophyll a, color, and turbidity suggest [Values are given in hectares (acres). CSG = continuous seagrass; PSG = patchy seagrass] eutrophication over the past 2 yr. The summer months of July and August normally show seasonal trends of increased chlorophyll a and color compared to other months of the same Segment Class Area year. Not only is this trend now evident in the data, but those Escambia Bay CSG 36 (88) seasonal highs have also increased over the last 2 yr. PSG 143 (353)

East Bay CSG 5 (13) Light-attenuation Monitoring PSG 160 (395) Photosynthetically active radiation (PAR) is the part of Pensacola Bay CSG 13 (33) the spectrum of sunlight, between 400 and 700 nanometers PSG 101 (249) (nm), that plants use for energy. Seagrass requires about 25% of the surface PAR for photosynthetic production. For Big Lagoon CSG 99 (245) example, if the PAR is 9.5 Moles per square meter per second 2 PSG 119 (293) (M/m /s) just below the surface of the water, then the seagrass requires 2.4 M/m2/s of PAR for optimal survival. Underwater Santa Rosa Sound CSG 796 (1,968) vegetation is less likely to receive sufficient PAR to sustain PSG 343 (848) growth when light reaching the plants is reduced because of water turbidity and algal blooms. In this study, light-attenuation monitoring suggested Environmental Protection, 2001) contains an overview of the that, immediately after a heavy rainfall, stormwater input results from the entire monitoring effort. inhibits the amount of PAR available to the seagrass. Figure 7 illustrates light attenuation at the deep edge of a seagrass bed Epiphytic Coverage in 1.4 m (4.5 ft) of water. Although the monitored storm event lasted only 1 d, the inhibited PAR persisted for several days In summary, 17 out of 20 sites monitored in 2001 after the rainfall because of increased turbidity and nutrient indicated an increase of epiphytic coverage compared to the enrichment from stormwater runoff. previous 2 yr, with the most dramatic increase in Big Lagoon. This change suggests that there may have been an increase in the amount of nutrients over the past 2 yr. If eutrophication has taken place, there should be more indications of this in Mapping and Monitoring Needs other areas of monitoring, such as in water quality (Florida Although historical data documenting extensive losses Department of Environmental Protection, 2001). of seagrass in Pensacola Bay are available, recent (post- 1992) data are scarce. Turtle grass and shoal grass are nearly Water-quality Monitoring absent from Pensacola and Escambia Bays; only water celery and wigeon grass are surviving in limited areas of upper Water-quality monitoring was conducted every month Escambia Bay. These species are also doing well in portions of at each of the 20 monitoring sites. The data were categorized Blackwater Bay, and shoal grass, turtle grass, manatee grass, into two sets of parameters, Hydrolab and laboratory. The and star grass are surviving in portions of Santa Rosa Sound Hydrolab parameters were measured on site with a water- (Northwest Florida Water Management District, 1997) and quality meter and included temperature, dissolved oxygen, pH, Big Lagoon. and salinity. Secchi depth was also included with the Hydrolab Furthermore, standardized mapping of seagrass beds at parameters. Laboratory parameters required chemical analysis appropriate temporal and spatial scales should be made every and included turbidity, color, conductivity, nonfiltered residue, 5–10 yr. Groundtruthing is recommended for verification of ammonia, Kjeldahl nitrogen, nitrate + nitrite, total phosphate, those mapping initiatives. and chlorophyll a. Continuation of a strategic long-term monitoring Algal growth potential was measured every other month. program that includes biotic and abiotic parameters of the Algal blooms and excessive turbidity in the water column community is needed. Such parameters include, but are can reduce the amount of sunlight available to seagrass for not limited to, areal coverage, shoot length, epiphyte load, photosynthesis. One indication of increased algae caused percent coverage, density, and water- and sediment-quality by excessive nutrients is an increase in both chlorophyll a indicators. This monitoring should determine causes of and color. When turbidity increases but chlorophyll a and changes in health, seagrass species composition, density, color remain low, however, stormwater runoff or some other and distribution including total loss or gain. Shoot density stirring mechanism (i.e., boating) may be the cause of light and faunal communities should be measured to determine 140 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002

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Figure 7. The amount of photosynthetically active radiation (PAR) was diminished for several days while turbidity settled after a storm event at Big Lagoon in Florida. October 18 indicates a normal day, with surface PAR around 9.6 Moles per square meter per second (M/m2/s) and underwater PAR (at grass blade depth) around 3.7 M/m2/s. Available PAR to the seagrass bed is about 38% of surface PAR. October 20 indicates a storm event with decreased surface and underwater PAR caused by clouds and rain. Following the storm event, surface PAR returned to normal, while underwater PAR remained inhibited for days because of increased turbidity from stormwater runoff. Available PAR decreased to insufficient levels of around 22%, which persisted for 4 d before returning to normal. References Cited 141 habitat function and productivity. Changes in light quality projects in northwest Florida and throughout the Gulf of and quantity as they affect seagrass health may be related to Mexico coastal area. nutrient loading and stimulation of phytoplankton blooms, The Ecosystem Restoration Section of the Florida epiphytes, and drift macroalgae and should be included in Department of Environmental Protection has initiated many the monitoring program. Assessment of the biogeochemical local shoreline restoration projects involving emergent environment occupied by belowground tissue, such as and submerged vegetation and propeller scar restoration. porewater composition, would also be useful, as would the Restoration sites have included Wayside Park in Gulf Breeze, monitoring of contaminants in , sediment, and the mouth of Bayou Texar, and propeller scarred areas in Big seagrass tissue. All of these monitoring activities, however, Lagoon and elsewhere. The Florida Marine Research Institute would not be able to be accomplished without a large source states that the Pensacola Bay system has, in general, light to of funding. The prioritization of activities would be to study moderate scarring with a few areas labeled as severe. Propeller the parameters related to seagrass health and growth, such as scar restoration is new to the Pensacola Bay system: few areal coverage, density, shoot length, etc. If these attributes restoration attempts have been made within the past 5 yr, but were found to be declining, then other parameters—such as restoration opportunities are becoming more attainable. contaminants in water, sediment, and tissue and light quality Future restoration opportunities should include and quantity—would be useful to measure. experimental research on seagrass bed creation and restoration to determine how donor stocks, including drift grass (detached Studies should address the following: plants), should be selected to achieve maximum success. The research should also determine if there are methods to • effects of boating impacts (trawling and boat traffic, accelerate natural recruitment of seagrasses. including jet skis, motorboats, and sailboats),

• effects of nonpoint pollution sources on seagrass beds,

• socioeconomic values and impacts of management, References Cited on users Florida Department of Environmental Protection, 1998, The • effects of the increase in the human population Pensacola Bay watershed management guide: an integrated (nonpoint nutrient loading, user impacts), ecosystem action plan: Pensacola, Florida Department of • factors involved in repairing propeller scar damage, Environmental Protection, Northwest District, 268 p., 5 appendixes. • dredging effects on light attenuation, and Florida Department of Environmental Protection, 2001, • indirect effects of dredging. Seagrass management plan for Big Lagoon and Santa Rosa Sound: Pensacola, Florida Department of Environmental Protection, Northwest District, 45 p. Restoration and Enhancement Heck, K.L., Jr., Sullivan, M.J., Zande, J.M., and Moncreiff, C.A., 1996, An ecological analysis of seagrass meadows Opportunities of the Gulf Island National Seashore—years one, two, and three: seasonal assessment and inventory, interaction studies Habitat functions and productivity of natural seagrass and assessment/inventory: University of South Alabama, community types should be identified, as well as should Marine Environmental Science Consortium, executive linkages with other habitats to support habitat conservation, summary, 7 p. creation, enhancement, and restoration in the Pensacola Bay system. Hopkins, T.S., 1973, Marine ecology in Escarosa: Tallahassee, The Florida Department of Environmental Protection is Florida Department of Natural Resources, Coastal working with Federal, State, and local agencies and with local Coordinating Council, 100 p. businesses, individuals, and civic organizations to promote and Kirschenfeld, T., 1999, FDEP Northwest District, Ecosystem facilitate a large-scale restoration project. Project Greenshores Restoration Section Gulf of Mexico grant proposal: seagrass is a habitat restoration project designed to restore an area in management plan for Big Lagoon and Santa Rosa Sound, Pensacola Bay that was once lightly populated with seagrass. Pensacola Bay system. This project will attempt to restore between 4 and 8 ha (10 and 20 acres) of oyster reefs and emergent and submerged grasses, Livingston, R.J., Hopkins, T.S., Adams, J.K., Schnitt, M.D., as well as to educate the public on the importance of seagrass and Welch, L.M., 1972, The effects of dredging and communities in estuarine habitats. Seagrasses to be planted eutrophication on Mulat-Mulatto Bayou (Escambia Bay, include turtle grass, shoal grass, and wigeon grass. This Pensacola, Florida): Tallahassee, Florida Department of project will also be used as a template for further restoration Transportation, 180 p. 142 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002

Moskovits, G., 1955, Marine (v. 2), in Literature survey of Lake Charles, La., Gulfport, Miss., Mobile, Al., and Pensacola Fl. (J.P. Barlow, Prog. Dir.): College Station, A&M University, Department of Oceanography, Texas A&M Project 98, 55-34F. Murdock, J.F., 1955, Investigation of the Lee County bay scallop fishery [a report] submitted to Florida State Board of Conservation: Coral Gables, Fla., University of Miami, Marine Laboratory, 101 p. Northwest Florida Water Management District, 1991, Surface Water Improvement and Management (SWIM) Program: the Pensacola Bay system, biological trends and current status: Havana, Fla., Northwest Florida Water Management District, 181 p. Northwest Florida Water Management District, 1997, Pensacola Bay system: Surface Water Improvement and Management (SWIM) Plan: Havana, Fla., Northwest Florida Water Management District, 146 p. Rucker, B.R., 1990, Blackwater and Yellow Pine: the development of Santa Rosa County, 1821–1865 (2 v.): Tallahassee, Florida State University, Ph.D. dissertation, 780 p. U.S. Army Corps of Engineers, 1990, Collection and analysis of bottom sediment samples from upper Escambia Bay, Florida: U.S. Army Corps of Engineers, 26 p. U.S. Environmental Protection Agency, 1975, Environmental and recovery studies of Escambia Bay and the Pensacola- Bay system Florida: U.S. Environmental Protection Agency, EPA 904/9-76-016, 322 p.

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