St. Andrew Bay

By Michael S. Brim1 and Lawrence R. Handley2

1

 U.S. Fish and Wildlife Service.

2

 U.S. Geological Survey.

Background

St. Andrew Bay has a watershed of approximately 

297,576 ha (735,300 acres, or 1,149 mi2) (Beck and others, 

2000) (fig. 1). The bay is almost entirely within Bay County, 

an area of over 2,590 km2 (1,000 mi2), which has a resident 

population of more than 148,000 (U.S. Census Bureau, 2002). 

Panama City is the largest of seven municipalities surrounding 

the bay. Much of the county, however, is unincorporated land 

traditionally supporting silviculture.

The primary industries in Bay County are tourism and the 

military, with Tyndall Air Force Base playing a dominant role 

in the community. The U.S. Navy’s Coastal Systems Station 

and the U.S. Coast Guard also share the bay’s shoreline. 

Most tourist activity occurs on Panama City Beach or upon 

bay waters. Other significant industries include the SmurfitStone Container Corporation paper mill, Arizona Chemical, 

Port Panama City, the Panama City-Bay County International 

Airport, and the Gulf Power Lansing Smith generation plant.

St. Andrew Bay has a rich history. The bay undoubtedly 

received its name from some of the early Spanish navigators 

who explored the northeast gulf coast in the 16th century, 

between 1516 and 1558 (West, 1922). Archaeological 

evidence supports that the first Native Americans in the area 

found food in the bay and shelter along its shores. A skirmish 

took place within the bay during the Civil War. In 1836, James 

Watson built a sawmill on what is now Watson Bayou (West, 

1922). In 1931, International Paper constructed Florida’s first 

paper mill on the site. The mill (currently owned by SmurfitStone Container Corporation) is still in operation. In 1938, 

the U.S. Army Corps of Engineers (USACE) constructed 

the main entrance channel by excavating through a barrier 

peninsula to create a rock-jettied inlet some 9.7 km (6 mi) 

west of the historical East Pass entrance that was once used by 

the Spanish explorers. In about 1950, USACE constructed the 

Gulf Intracoastal Waterway connecting western St. Andrew 

Bay with Choctawhatchee Bay and connecting eastern St. 

Andrew Bay with Lake Wimico and with St. Joseph Bay via 

the Gulf County Canal. In the 1960s, a dam was constructed 

across a portion of North Bay to create Deer Point Lake.

St. Andrew Bay is unique because of its wealth of 

biological diversity. Keppner (2002) documented the diversity 

associated with the bay and compared it with surveys of 

Indian River Lagoon, Fla., which has been touted as the most 

biologically diverse estuary in North America. His report 

documents 2,913 species of plants and animals associated with 

St. Andrew Bay, nearly 400 more species than found in 

the lagoon.

The bay is, however, a fragile ecosystem. Because 

of its high-salinity waters, the depths of the bay, the lack 

of significant freshwater inflow from land drainage, and 

the minimal tidal regime, the bay is highly susceptible to 

becoming polluted or contaminated. Chemicals and nutrients 

are not readily flushed from this bay, and the nature of the 

deep sediments (rich in fine clays, silt, and organic carbon) 

is such that they could easily become reservoirs for metals 

and organic-compound contaminants. While several pointsource discharges occur in the bay, the greatest future threat 

to water and sediment quality (and thus to the diverse biota) is 

urbanization and its associated stormwater runoff.

Additional and more detailed descriptions of St. 

Andrew Bay and its resources can be found in the ecosystem 

management plan (Keppner and Keppner, 2001) and the State 

Surface Water Improvement and Management (SWIM) 

Plan for the bay (Northwest Florida Water Management 

District, 2000).

Scope of Area

St. Andrew Bay covers an area of about 27,714 ha 

(68,480 acres, or 107 mi2). It is unique among gulf coast 

estuaries for several reasons. Waters are deep and clear 

because little fresh water flows into the bay (Saloman and 

others, 1982), the primary source being Econfina Creek, which 

has an average discharge of just 15.3 m3/s (538 ft3/s) (U.S. 

Geological Survey, 1990). The total discharge of all natural 

surface-water sources entering this estuary is probably less 

than 28.3 m3/s (1,000 ft3/s) (Brim, 1998). By comparison, the 

average flow of the Apalachicola River into Apalachicola Bay 

to the east is about 707 m3/s (25,000 ft3/s). Because of the 

absence of a large river emptying into St. Andrew Bay, there 

is little sedimentation and associated turbidity in this bay, a 

situation contrary to that of most “true” estuaries, which have 
10 

km 0 5 10 15 20 

mi 0 3 6 9 12 

Callaway 

Lynn Haven 

Panama City 

St. Andrew

Bay

Tyndall Air Force Base 

Interstate Highway 

River 

Gulf Intracoastal 

Waterway 

County line 

St. Andrew Bay 

Watershed boundary 

City 

Gulf of Mexico

N

Figure 1. Watershed for St. Andrew Bay.

156 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
robust rivers draining into them. Bay depths of 12 m (40 ft) are 

not uncommon, and seagrasses flourish because of the clear, 

high-salinity waters. Furthermore, tidal flushing is minimal, 

with spring tides having a vertical amplitude of only about 

0.67 m (2.2 ft) and neap tides often only 0.06 m (0.2 ft).

The St. Andrew Bay system lies in the Coastal Plain 

physiographic province, has a surface stratigraphy composed 

largely of post-Pleistocene sands, and is classified as coastal 

integrated drainage because of the set of small local streams 

draining its coastal regions (Young and others, 1987; Wolfe 

and others, 1988; Fernald and Purdum, 1992; Hydroqual, Inc., 

and Barry A. Vittor and Associates, Inc., 1993). The sediment 

composition within the bay varies, but several studies have 

revealed a positive correlation of increased silt and clay 

content as distance from the inlet increases. Deepwater 

sampling stations within the bay that were farthest from the 

jettied inlet, in the vicinity of Dyers Point and Bear Point, had 

sediments containing 67%–68% fine material (silts and clays) 

(U.S. Army Corps of Engineers, 1994).

St. Andrew Bay, which surrounds the Panama City 

metropolitan area on three sides, is about an equal distance 

(160 km, or 100 mi) from Pensacola to the west and 

Tallahassee to the east. The study area for this vignette extends 

from approximately 290

 57’ to 300 18’ N. latitude and from 

850

 24’ to 850 51’ W. longitude. The gulf’s coastline at this 

location is a northwest/southeast axis.

The study area is divided into five logical segments (fig. 

2): St. Andrew Bay (specifically the lower bay area); East 

Bay, North Bay, and West Bay (the three named arms); and 

St. Andrew Sound (a separate lagoonal embayment to the 

southeast). Information about the size and volume of these 

segments is taken from McNulty and others (1972).

St. Andrew Bay Segment

The first segment constitutes that southern portion of the 

bay between the two major bridges (Hathaway and DuPont) 

and extending south to the gulf inlets. The bay has two inlets: 

the recently reopened historical East Pass at the eastern end 

of Shell Island and the rock-jettied West Pass, which serves as 

the entrance for commercial vessels. Shell Island is an 11-km 

(7-mi) barrier island separating the lower bay from the gulf. 

The St. Andrew Bay segment covers 10,607 ha (26,209 acres), 

with a mean high water (mhw) volume of 5 x 108

 m3 (405,512 

acre-feet).

West Bay Segment

West Bay is defined as the bay water northwest of an 

imaginary line connecting West Bay Point with Shell Point. It 

covers 7,113 ha (17,576 acres), with a mhw volume of 1.7 x 

108

 m3 (136,135 acre-feet). Freshwater inflow comes primarily 

from two small creeks: Burnt Mill and Crooked Creeks. 

The Gulf Intracoastal Waterway enters West Bay on its west 

side. Botheration Bayou enters the bay at its southeast end. 

The municipally treated effluent discharge from the City of 

Panama City Beach enters West Bay on the southern shoreline.

North Bay Segment

North Bay is east of West Bay and north of the Hathaway 

Bridge. It covers 2,702 ha (6,676 acres) and has a mhw 

volume of approximately 68 million m3

 (55,189 acre-feet). 

It is primarily characterized by the presence of Deer Point 

Lake at its northeast end. The lake, a reservoir constructed in 

1961, was once the most estuarine portion of St. Andrew Bay, 

the point at which Econfina Creek flowed into the system. 

Deer Point Dam impounded approximately 2,226 ha (5,500 

acres) of estuarine area (Barkuloo, 1963); eventually the 

reservoir became a freshwater lake, which now serves as the 

potable water source for Bay County and its municipalities. 

North Bay’s east shoreline is highly urbanized and is also the 

location of the Panama City-Bay County International Airport. 

Sixteen bayous are found along the North Bay shoreline.

East Bay Segment

East Bay extends southeast of the DuPont Bridge. It 

covers 7,551 ha (18,659 acres) and has a mhw volume of 2.9 

x 108

 m3 (231,705 acre-feet). East Bay is characterized by the 

presence of Tyndall Air Force Base, which includes almost 

all of the bay’s southern shoreline. Two creeks, Sandy and 

Wetappo, enter the bay’s eastern end, and 10 bayous are found 

along the shoreline. The Gulf Intracoastal Waterway enters 

East Bay along an alignment that cuts through the Wetappo 

Creek historical pathway. East Bay’s northern shoreline has 

extensive residential development to the west and moderate or 

sparse to the east.

St. Andrew Sound Segment

St. Andrew Sound is a lagoon not connected with St. 

Andrew Bay. The sound is approximately due south of East 

Bay. This lagoon extends along a northwest/southeast axis, 

is roughly 16 km (10 mi) long and 1.6 km (1 mi) wide, and 

covers an area of 1,905 ha (4,707 acres). The area features 

Tyndall Air Force Base, which covers approximately 95% 

of the shoreline, including the two barrier peninsulas which 

separate the sound from the gulf.

Methodology Employed To Determine 

and Document Current Status

The most current mapping study of seagrass coverage 

for the St. Andrew Bay area was conducted more than 10 yr 

ago by the U.S. Geological Survey (USGS) National Wetlands 

Research Center (NWRC) by using natural-color aerial 

Methodology Employed To Determine and Document Current Status 157
1

2

3

4

5

km

mi 4

4 0

0 8

8

Gulf of Mexico

West Bay

East Bay

North Bay

St. Andrew Bay

Panama City-Bay CountyInternational Airport

Panama City

Deer PointLake

Deer PointDam

BaileyBridge

Hathaway

Bridge

Botheration Bayou

ShellPoint

West Bay

Courtney Point

Tyndall Air Force Base

DuPontBridge

St. Andrew Sound

Panama City Beach

Study area

N

Florida

Segment

Gulf Intracoastal Waterway

West Bay

North Bay

St. Andrew Bay

East Bay

St. Andrew Sound

1

2

3

4

5

Figure 2. Caption will appear here and will be constrained to a single line.

Figure 2. Scope of area for the St. Andrew Bay vignette.

158 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
photography taken in 1992 at a 1:24,000 scale as part of the 

northeastern Gulf of Mexico seagrass mapping project.

The mapping protocol for the project consisted of 

stereoscopic photointerpretation, cartographic transfer, and 

digitization in accordance with strict mapping standards and 

conventions. Other important aspects of the protocol included 

the development of a classification system, groundtruthing, 

quality control, and peer review.

The primary data source was 1:24,000-scale natural 

color aerial photography flown by the National Aeronautics 

and Space Administration (NASA) Stennis Space Center in 

fall 1992. In those cases in which the data were inadequate or 

incomplete, contemporary supplemental data were acquired 

from other sources and used to complete the photographic 

coverage. The information derived from the photography was 

subsequently transferred by using a zoom transfer scope onto 

a stable medium overlaying USGS 1:24,000-scale quadrangle 

base maps. 

The seagrass classification system that was developed 

consisted of two classes of open water habitats—RIV 

(riverine, fresh water) and EST (estuarine or marine open 

water)—and five classes of seagrass habitats (see appendix 1 

for full description). One seagrass habitat class is continuous 

seagrass, CSG, for which no density distinction was made. 

The other four classes are patchy seagrass based on percent 

ground cover of patches in 5% increments: PSG1 (0%–10%, 

very sparse), PSG2 (15%–40%, sparse), PSG3 (45%–70%, 

moderate), and PSG4 (75%–95%, dense).

The groundtruthing phase included the participation of 

field staff from the U.S. Fish and Wildlife Service and the 

Florida Department of Environmental Protection. Draft maps 

were sent out to these agencies for review and comments. All 

comments received were incorporated into the final maps.

Methodology Employed To Analyze 

Historical Trends

From 1995 through 1998, the NWRC produced a series 

of historical seagrass maps for the U.S. Fish and Wildlife 

Service’s Panama City Ecological Services and Fisheries 

Resources Office to use in producing a trend analysis for St. 

Andrew Bay. Black and white photography from 1953 at a 

1:20,000 scale, black and white photography from 1964 at a 

1:20,000 scale, and natural color photography from 1980 at a 

1:24,000 scale were used to develop the trend analysis. Each 

group of aerial photography was analyzed with stereoscopic 

visual equipment; seagrasses were delineated onto Mylar® 

(DuPont Teijin Films) 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 the 

Wetland Analytical Mapping System (WAMS) and converted 

into ArcInfo (Environmental Systems Research Institute, Inc., 

Redlands, Calif.) format files. All groups of photography were 

of good to high quality for delineating seagrasses.

Classification of the seagrass for the trend analysis 

followed the same protocol as the development of the 

northeastern Gulf of Mexico seagrass mapping using the 

1992 aerial photography (see appendix 1). The seagrass 

classification system consisted of two classes of open 

water—RIV (riverine, fresh water) and EST (estuarine or 

marine open water)—and five classes of seagrass habitats. 

One seagrass habitat class is continuous seagrass, CSG, for 

which no density distinction was made. The other four classes 

are patchy seagrass based on percent ground cover of patches 

in 5% increments: PSG1 (0%–10%, very sparse), PSG2 

(15%–40%, sparse), PSG3 (45%–70%, moderate), and PSG4 

(75%–95%, dense).

Draft maps were sent out to the U.S. Fish and Wildlife 

Service for review and comments. All comments received 

were incorporated into the final maps. Although there was 

some limited groundtruthing in 1982–83 by NWRC and the 

U.S. Environmental Protection Agency (EPA) of the 1980 

aerial photography, no groundtruthing took place for historical 

seagrass delineation.

 The NWRC currently holds the aerial photography, the 

interpreted overlays, and the Mylar® overlays for the 1953, 

1964, and 1980 maps.

Status and Trends

Status and trends for the study area and segments will be 

described by using just two density classifications, continuous 

and patchy, except where specific conditions warrant a more 

detailed description. 

Entire Study Area

As of 1992, the study area contained 1,710 ha (4,225 

acres) of continuous beds and 2,269 ha (5,607 acres) of patchy 

beds (table 1). Table 1 reveals a trend which ends with a total 

loss (of both types of coverage) amounting to 816 ha (2,011 

acres) between 1953 and 1992, an 8% decrease. Furthermore, 

between 1980 and 1992, the system experienced a 592-

ha (1,463-acre) loss of continuous coverage, while patchy 

coverage increased by 448 ha (1,107 acres). Both the areal 

extent and the robustness of the seagrasses in the study area 

have declined significantly.

St. Andrew Bay Segment

The St. Andrew Bay segment comprises 10,607 surface 

hectares (26,210 acres). Table 2 reveals the same general trend 

of seagrass areal loss and robustness in the St. Andrew Bay 

segment as that which is typical for the overall study area.

While total seagrass coverage is almost the same for 

1953 and 1992, there was a loss of about 102 ha (250 acres) 

of total coverage between 1964 and 1992. Also, the decline 

Status and Trends 159
in seagrass robustness between 1980 and 1992 amounted to a 

loss of nearly 157 ha (400 acres) of continuous beds. In that 

same period, a total loss of 63 ha (157 acres) of any type of 

coverage occurred.

Specifically, conditions appear to have improved in the 

beds behind Shell Island but have declined along the west 

shoreline south of the Hathaway Bridge, from the bridge to 

Courtney Point, and also along the shoreline from Redfish 

Point to Davis Point. Most of this change appears to have 

occurred between 1980 and 1992.

East Bay Segment

The East Bay segment comprises 7,551 surface 

hectares (18,659 acres). This segment appears to have 

experienced an increase in overall bed robustness from 

263 ha (650 acres) of continuous-type coverage in 1953 to 

660 ha (1,631 acres) in 1992 (table 3). In that same period, 

the total coverage of seagrass (both coverage types) has 

remained nearly unchanged.

North Bay Segment

The North Bay segment comprises 2,702 surface hectares 

(6,677 acres). The seagrasses in this segment have declined in 

total coverage from 1953 to 1992 by 55 ha (134 acres) (table 

4). This decline appears to be due to a shift in robustness, with 

continuous beds declining from 455 ha (1,123 acres) in 1953 

to 400 ha (988 acres) by 1992. Patchy coverage, at 355 ha 

(877 acres), is identical for those same two years. Most of the 

decline was lowest in 1980, with some recovery by 1992. 

West Bay Segment

The West Bay segment comprises 7,113 surface hectares 

(17,576 acres). This segment has suffered the greatest seagrass 

loss in the St. Andrew Bay system (table 5). Continuous beds, 

which peaked in 1980 at 543 ha (1,343 acres), dropped to just 

92 ha (227 acres) by 1992, an 83% decline in 12 yr. Patchy 

beds, which peaked in 1953 at 1,229 ha (3,037 acres), steadily 

declined to a 1992 total of 698 ha (1,725 acres), a 43% decline. 

Total loss of seagrass coverage (both categories) occurred in 

a steady downward trend, with a net loss of seagrass coverage 

between 1953 and 1992 of 750 ha (1,853 acres).

St. Andrew Sound Segment

The St. Andrew Sound segment comprises 1,905 surface 

hectares (4,707 acres). Seagrass coverage in this segment has 

not varied much over the 39-yr study span (table 6). Total 

coverage has ranged from a minimum of 336 ha (832 acres) 

to a maximum 370 ha (914 acres). The most notable shift 

appears to be a peak in seagrass robustness, with a tripling 

of the occurrence of continuous beds from 1964 to 1980. By 

Coverage 1953 1964 1980 1992

Continuous 263 

(650)

643 

(1,589)

510 

(1,260)

660 

(1,631)

Patchy 778 

(1,922)

504 

(1,245)

403

(996)

360

(890)

Total 1,041 

(2,572)

1,147 

(2,834)

913 

(2,256)

1,020 

(2,520)

Table 3. Seagrass coverage for the East Bay segment for 4 

individual years of evaluation.

[Values are in hectares (acres)]

Coverage 1953 1964 1980 1992

Continuous 491 

(1,213)

567 

(1,401)

693 

(1,712)

536 

(1,324)

Patchy 543 

(1,342)

580 

(1,433)

415 

(1,025)

509 

(1,258)

Total 1,034 

(2,555)

1,147 

(2,834)

1,108 

(2,738)

1,045 

(2,582)

Table 2. Seagrass coverage for the St. Andrew Bay segment for 

4 individual years of evaluation.

[Values are in hectares (acres)]

Coverage 1953 1964 1980 1992

Continuous 1,527 

(3,773)

2,183 

(5,394)

2,302 

(5,688)

1,710 

(4,225)

Patchy 3,268 

(8,075)

2,523 

(6,234)

1,821 

(4,500)

2,269

(5,607)

Total 4,795 

(11,848)

 4,706 

(11,629)

 4,123 

(10,190)

3,979 

(9,832)

Table 1. Seagrass coverage for the entire St. Andrew Bay study 

area for 4 individual years of evaluation.

[Values are in hectares (acres)]

160 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
Coverage 1953 1964 1980 1992

Continuous 455 

(1,124)

514 

(1,270)

483 

(1,193)

400 

(988)

Patchy 355 

(877)

262 

(647)

238 

(588)

355 

(877)

Total 810 

(2,002)

776 

(1,917)

721 

(1,782)

755 

(1,866)

Table 4. Seagrass coverage for the North Bay segment 

for 4 individual years of evaluation.

[Values are in hectares (acres)]

Coverage 1953 1964 1980 1992

Continuous 311 

(768)

437 

(1,080)

543 

(1,342)

92 

(227)

Patchy 1,229 

(3,037)

830 

(2,051)

500 

(1,236)

698 

(1,725)

Total 1,540 

(3,805)

1,267 

(3,131)

1,043 

(2,577)

790 

(1,952)

Table 5. Seagrass coverage for the West Bay segment 

for 4 individual years of evaluation.

[Values are in hectares (acres)]

Coverage 1953 1964 1980 1992

Continuous 7 

(17)

22 

(54)

72 

(178)

22 

(54)

Patchy 361 

(892)

348 

(860)

264 

(653)

347 

(857)

Total 368 

(909)

370 

(914)

336 

(830)

369

(912)

Table 6. Seagrass coverage for the St. Andrew Sound segment 

for 4 individual years of evaluation.

[Values are in hectares (acres)]

1992, however, continuous beds had dropped back to the 1964 

quantity. The shifts in robustness appear to be minor changes 

from continuous to dense patchy (75%–95% coverage) and 

back again (figs. 3, 4, 5, and 6).

Causes of Change

Entire Study Area

Because of the varied nature of the St. Andrew Bay 

complex, being almost five independent bay areas, it is 

difficult to make anything but general observations on 

changes or losses for the entire study area. Each segment has 

experienced different types and degrees of development on 

the adjacent uplands. Thus seagrass impacts related to these 

land uses are best described on a segment basis. There are, 

however, stressors which are of general concern, including 

hurricanes and tropical storms, atmospheric deposition of 

nutrients (not as yet quantified), ubiquitous stormwater runoff 

(but of varied composition), propeller scarring (primarily from 

recreational boats), and algal blooms, light attenuation, and 

turbidity caused by multiple factors.

The overall decrease of total seagrass coverage within 

the bay amounts to an 8% loss over the 39-yr evaluation 

span. Between 1953 and 1964 (11 yr) the bay lost 89 ha (214 

acres) of coverage; between 1964 and 1980 (16 yr) it lost 583 

ha (1,439 acres); and between 1980 and 1992 (12 yr) it lost 

another 144 ha (358 acres). Even though the last five decades 

have seen increased regulatory programs, such losses would 

appear to indicate that somehow regulation, management, 

and education are still not entirely adequate to conserve St. 

Andrew Bay’s seagrass resources.

St. Andrew Bay Segment

The lower bay segment appears to be stable, despite rapid 

urbanization and public use. This stability may be in part due 

to improvements of both industrial and municipal treatment 

processes and to the fact that St. Andrew Bay has not 

undergone any major port or harbor improvements, as other 

bays have. There is no easily perceived cause for the declines 

in seagrass robustness from 1980 to 1992 which appear to 

have occurred on the west shore between the Hathaway Bridge 

and Courtney Point and at the end of the “Tyndall peninsula” 

between Redfish and Davis Points.

East Bay Segment

East Bay also appears to be a fairly stable seagrass 

ecosystem, with only minor variations in total coverage and 

no trend of decline. One factor surely contributing to this 

stability is the undeveloped shoreline along Tyndall Air Force 

Causes of Change 161
Gulf of Mexico

Land 

Seagrass, continuous 

Seagrass, patchy 

Water 

0km 

0 1 2 3 4 5 mi

N

2 4 6 8

Figure 3. Distribution of seagrass in the St. Andrew Bay system, 1953.

162 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
Gulf of Mexico

N

LandSeagrass, continuous Seagrass, patchy Water

km

mi

0 2 4 6 8

0 1 2 3 4 5

Figure 4. Distribution of seagrass in the St. Andrew Bay system, 1964.

Causes of Change 163
Gulf of Mexico

N

LandSeagrass, continuous Seagrass, patchy Water

km

mi

0 2 4 6 8

0 1 2 3 4 5

Figure 5. Distribution of seagrass in the St. Andrew Bay system, 1980.

164 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
Gulf of Mexico

N

LandSeagrass, continuous Seagrass, patchy Water

km

mi

0 2 4 6 8

0 1 2 3 4 5

Figure 6. Distribution of seagrass in the St. Andrew Bay system, 1992.

Causes of Change 165
Base covering almost all of the south shore of East Bay. Other 

factors include the relatively moderate urban development and 

a lack of any significant heavy industry on the north shore. 

Careful management of north shore development will be 

crucial to maintaining the seagrass resources of East Bay.

North Bay Segment

Most seagrass decline in this segment was along the 

south and southwest shorelines of North Bay where urban 

development has occurred.

From Little Oyster Bar Point southward to the Hathaway 

Bridge, seagrass abundance declined from continuous to 

patchy beds between 1964 and 1992 (see figs. 4–6). This is 

an area that was subject to the creation of numerous dead-end 

residential canals which can be seen in figure 6. In addition, 

a treated effluent discharge was once located south of Posten 

Bayou, but that point source has been removed and relocated 

to the lower bay, and effluent treatment levels improved. Only 

future seagrass monitoring will reveal whether or not any 

further decline in bed robustness has taken place since 1992.

Losses of beds and a decline in bed robustness can also 

be observed in North Bay along the south shore between 

the “Bailey” bridge and the dam at Deer Point Lake. The 

municipal sewage effluent once drained into Beatty Bayou and 

could have contributed undesirable nutrients to the bay. This 

outfall has since been relocated, treatment has been improved, 

and this possible source of seagrass stress has been eliminated. 

Other causes of seagrass decline along this shallow shore zone 

may include increased urban runoff associated with moderate 

to heavy urbanization in the Lynn Haven area.

West Bay Segment

In 1953, West Bay had a total coverage of 1,540 ha 

(3,805 acres); this segment lost 750 ha (1,312 acres) of 

seagrass by 1992, when total coverage had been reduced to 

just 790 ha (1,952 acres). The history of West Bay and the 

possible causes for these seagrass losses are complex and 

complicated. The losses are probably the result of cumulative 

stresses from several sources. These currently unquantified 

stresses can only be qualitatively described at this point; 

however, a restoration effort (described later in this vignette) 

may shed light on the most significant causes.

The first consideration within West Bay is the Gulf 

Intracoastal Waterway (GIWW). Over the last four decades, 

increased vessel traffic, larger vessels, and unstabilized 

banks may have adversely affected the West Bay system 

by transporting fine sediments and nutrients into the bay. 

West Bay is connected with Choctawhatchee Bay by a 29-

km (18-mi) long GIWW land cut. At least one incident of 

complete blockage of the land cut occurred in September 

1988 because of sediment runoff and accumulation. In 

addition, the hydrologic interaction between West Bay and 

Choctawhatchee Bay via the GIWW is not well defined. The 

sometimes sediment-laden Choctawhatchee River enters the 

eastern end of Choctawhatchee Bay not far from the GIWW 

land cut leading to West Bay. The long-term hydrologic 

interactions and sediment exchange of this canal have not 

been clearly defined and quantified. The GIWW could be a 

source of stresses which may adversely affect seagrass health, 

even though the land cut connecting the two bays is many 

kilometers long.

In 1970, two events took place that may have 

significantly affected the welfare of seagrass beds in southern 

West Bay. In that year the State of Florida, the USACE, and 

the EPA issued permits for two separate major projects.

The permits for the first project were issued to the City 

of Panama City Beach for the discharge of treated municipal 

effluent into the bay. The city’s effluent enters the bay 

via a 1.6-km-long (1-mi-long) drainage ditch. Discharge 

commenced with an initial volume of about 9.5 million liters/

day (2.5 million gallons/day). Although the treatment level 

of the effluent has been significantly improved since 1970, 

currently the permitted discharge volume to the bay is 26.5 

million liters/day (7 million gallons/day). Plans by the city 

and regulatory agencies are in place to remove the discharge 

from the bay upon or before expiration of the current EPA 

National Pollutant Discharge Elimination System permit. 

Nutrients from this discharge, particularly during the 1970s, 

could have adversely affected seagrass growth by encouraging 

the excessive growth of epiphytic algae on the seagrass 

leaves or by stimulating excessive growth of light-blocking 

phytoplankton on the water surface above seagrass beds.

Permits for the second project were issued in 1970 to a 

company named Marifarms for a commercial shrimp-farming 

operation. A permit and lease allowed the netting-off of 1,012 

ha (2,500 acres) of southern West Bay with a net made of 

mesh with holes less than 1 cm2

 (0.4 inch2), the size required 

to confine raised shrimp to the leased area. The confining 

net was approximately 3 m (10 ft) in depth and 5,500 m 

(18,000 ft) in length (U.S. Army Corps of Engineers, 1970). 

To ensure confinement, two nets (with a combined total of 

11,000 m (36,000 ft) of netting) were kept in place. The permit 

also allowed the removal of marine fishes within the netted 

area through the application of rotenone. Fish removal was 

necessary to prevent unwanted predation upon the shrimp 

crop. A complaint detailing and challenging the legalities of 

the Marifarms project was filed in the Circuit Court of the 

Second Judicial District on August 3, 1970, by the Organized 

Fishermen of Florida (Circuit Court of the Second Judicial 

District of Florida, 1970).

The Marifarms company operated from 1970 through 

1975, when Hurricane Eloise tore out the netting, and the 

company subsequently went bankrupt. It was not until 1999, 

however, that it was discovered that the netting had been 

treated with an antifouling compound to keep it free of 

the growth of various marine organisms (algae, tunicates, 

hydroids, barnacles, etc.). In that year, the shrimp off-loading 

area and net-treatment location were rediscovered, and paint 

chips from the treatment operation were chemically analyzed. 

166 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
The 25-yr-old paint chips still contained nearly 3% copper and 

0.2% organo-tin (Hemming and others, 2003).

The effects of continuous shrimp harvesting by trawl, 

chemical treatment of the nets, and removal of native fish 

species from the 1,012-ha (2,501-acre) shrimp grow-out 

area may all have had a significant adverse effect on 

seagrass survival.

Other potential causes of the West Bay seagrass losses 

could include less-than-optimal silviculture practices adjacent 

to the bay. Although residential development is still minimal 

along West Bay, future development plans are extensive and 

include the proposed relocation of the international airport to 

north of West Bay, between Crooked and Burnt Mill Creeks. 

For these reasons, extensive and careful management is being 

undertaken to protect and restore the seagrass beds of West Bay.

St. Andrew Sound Segment

The seagrass beds in St. Andrew Sound and their 

health have remained relatively stable over the 39-yr span 

of evaluation, probably because of the almost entirely 

encompassing presence of Tyndall Air Force Base. The 

shoreline around the sound has remained almost completely 

unaltered because of the Air Force presence and management.

The only noteworthy event within the sound during the 

span of study was Hurricane Eloise, which altered the area 

geologically and hydrologically. The storm and its surge 

effects have been documented by Burdin (1976). Prior to 1975, 

the entrance to the sound was an inlet at the northwest end, 

but in September 1975 the hurricane breached the 16-km-long 

(10-mi-long) barrier peninsula at its midpoint. Within 2 yr, the 

northwest inlet had closed. The present-day entrance is at the 

midpoint of the sound. This relocation of the inlet appears to 

have had some moderate effects on seagrass distribution.

Species Information

Several species of seagrasses occur within St. Andrew 

Bay and St. Andrew Sound, and their presence has been 

reported regularly (Saloman and others, 1982; Florida 

Department of Natural Resources, 1991; Fonseca, 1994; 

Koenig and others, 1998).

The dominant seagrass species, undoubtedly providing 

the most valuable seagrass habitat, is turtle grass (Thalassia 

testudinum). This subtidal species grows to depths of 1.8–2.4 

m (6–8 ft) mean low water in the southern bay areas near the 

gulf (St. Andrew Bay segment) and in St. Andrew Sound. 

Light penetration appears to limit maximum growth depths to 

1.2–1.8 m (4–6 ft) in the interior bay segments.

The intertidal and subtidal species shoal grass (Halodule 

wrightii) dominates the shallow and intertidal bay areas. 

These beds are often exposed to the air in winter when north 

winds create “wind tides” and push large amounts of water 

from the bay and in spring when the north winds combine 

with low tide conditions of the solunar spring tide. Manatee 

grass (Syringodium filiforme) can be found scattered within 

turtle grass beds, or sometimes in pure stands thriving near 

the influence of clear, highly saline water entering the bay 

from the gulf. While it is not a dominant species, it provides 

valuable diversity and cover where it is present. Wigeon grass 

(Ruppia maritima) occurs in some of the fresher parts of the 

bay, including areas of some bayous. Finally, the presence of 

star grass and paddle grass (Halophila spp.) has been noted, 

albeit rarely, amongst turtle grass beds of the southern bay.

Monitoring for Seagrass Health

The St. Andrew Bay Resource Management Association, 

in partnership with Gulf Coast Community College and the 

Florida Department of Environmental Protection, initiated 

in 2000 a seagrass monitoring program at three locations 

in the St. Andrew Bay estuarine system. Transects have 

been established at sites near Shell Island, in Grand Lagoon 

(both within the St. Andrew Bay segment), and in West Bay. 

Monitoring is accomplished in fall each year. Data collected 

include species composition, shoot density, percent cover, 

and canopy height. In addition, water-quality data, including 

turbidity and photosynthetically active radiation, are collected 

monthly at each site. The work is supported by a grant from 

the National Oceanic and Atmospheric Administration to 

the Florida Department of Community Affairs. Because the 

program is only 3 yr old, no trends regarding seagrass health, 

gains, or losses have yet been documented.

Mapping and Monitoring Needs

Seagrasses within the St. Andrew Bay system and 

St. Andrew Sound have not been mapped since 1992. The 

ecosystem management plan developed by the St. Andrew 

Bay Environmental Study Team (Keppner and Keppner, 

2001), however, includes an action plan (SG1) encouraging 

monitoring of seagrass beds by aerial photography and 

interpretation every 5 yr in partnership with the U.S. Fish and 

Wildlife Service. The action plan also encourages continuing 

the St. Andrew Bay Resource Management Association-Gulf 

Coast Community College seagrass monitoring program in the 

bay. New aerial photography for the Florida Panhandle was 

taken in October 2003, and the resulting maps and geographic 

information system data layers will be made available to 

agencies, participating conservation groups, and county and 

municipal government planning departments in 2005.

The other action plans (Keppner and Keppner, 2001) 

regarding seagrasses are discussed in the following section.

Mapping and Monitoring Needs 167
Restoration and Enhancement 

Opportunities

The Bay Environmental Study Team (BEST) for St. 

Andrew Bay is composed of all users of the bay including 

State, Federal, and municipal governments, industries, 

academic institutions, conservation organizations, commercial 

fishing interests, and the general public. BEST is structured 

very similar to the EPA National Estuary Program and serves a 

similar purpose for St. Andrew Bay.

The BEST ecosystem management plan for St. Andrew 

Bay includes other action plans, besides the previously 

explained SG1 (above), to protect and preserve seagrasses:

SG2, Protection of Seagrass Beds, calls for pursuit 

of additional State, Federal, and local legislation that 

would provide additional protection for the seagrass 

beds in the St. Andrew Bay ecosystem. The action 

plan will also include actions on the bay such as the 

placement of marker buoys and channel markers to 

reduce propeller scarring in seagrass beds.

SG3, Restoration of Lost or Damaged Seagrass 

Beds (anywhere within the bay), includes work for 

inventorying all of the bay, identifying areas of loss, 

and designing and imple menting restoration at any 

sites where such action is appropriate.

SG4, Restoration of Seagrass Loss in West Bay, is 

aimed at the restoration of the lost West Bay seagrass 

beds. Currently BEST is the project sponsor for this 

USACE Aquatic Ecosystem Restoration Project (under 

the authority provided by section 206 of the Water 

Resources Development Act of 1996). The project 

was initially evaluated by the Mobile District Corps 

of Engineers in 2001. In spring 2002, the Preliminary 

Restoration Plan was completed (U.S. Army Corps of 

Engineers, 2002). To date, the scope of work is being 

developed for the Ecosystem Restoration Report, 

a study which should provide critical information 

regarding seagrass stressors and their elimination, as 

well as an optimal strategy for reestablishing 

seagrass beds.

SG5, Education About the Significance of Seagrass 

Meadows in the Ecosystem, involves (1) the 

production of an underwater video depicting the 

importance of seagrass meadows, (2) the production 

of a video about seagrass monitoring, (3) distribution 

of “A Boater’s Guide to St. Andrew Bay,” (4) 

placement of educational signs at boat ramps, and 

(5) the development of an educational display about 

seagrasses for use at conservation meetings and other 

public gatherings.

•

•

•

•

SG6, Innovative Pier and Dock Construction, is aimed 

at developing and encouraging the use of pier and 

dock materials and designs which encourage seagrass 

growth beneath them, are minimally disruptive to 

seagrasses, and are created of materials that are 

chemically compatible (nontoxic) with seagrasses or 

estuarine organisms.

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Field Office, publication no. PCFO-EC 03-01.

•

168 Seagrass Status and Trends in the Northern Gulf of Mexico: 1940–2002
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faunal assemblages of shallow water sand and seagrass 

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565 p.

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Colonel and District Engineer, U.S. Army Corps of 

Engineers, Mobile, Ala.

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of St. Andrew Bay, Florida: Prepared for U.S. Army 

Engineer District, Mobile, Ala., Waterways Experiment 

Station, Coastal Ecology Branch Environmental Laboratory.

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West Bay aquatic ecosystem restoration project, Bay County, 

Florida: U.S. Army Corps of Engineers, Mobile District.

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http://factfinder.census.gov.

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v. 4, Northwest Florida: Report FL-90-4.

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Fla., Panama City Publishing Company.

Wolfe, S.H., Reidenauer, J.A., and Means, D.B., 1988, An 

ecological characterization of the Florida Panhandle: New 

Orleans, La., U.S. Department of the Interior, U.S. Fish and 

Wildlife Service, Minerals Management Service, USFWS 

Biological Report 88(12), OCS Study MMS 88-063, 277 p.

Young, W.T., Butts, G.L., Donelan, L.W., and Ray, D.H., 

1987, Biological and physico-chemical assessment of St. 

Andrew Bay estuaries 1986–1987: Florida Department of 

Environmental Regulation, Northwest District, Biology 

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