Site-Specific Information 

in Support of Establishing 

Numeric Nutrient Criteria for 

the Southeast Florida 

Coastal Reef Tract

Division of Environmental Assessment and Restoration

Standards and Assessment Section

Florida Department of Environmental Protection

Tallahassee, FL 32399

August 24, 2010 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft ii August 2010

Table of Contents

Executive Summary ............................................................................................................... 1

Geographic and Physical Description ..................................................................................... 4

Extent and Overview of Area .........................................................................................................4

Designated Uses............................................................................................................................5

Climate and Weather Patterns.......................................................................................................5

Watershed, Land Use, and the Coast..............................................................................................6

Biological Summary............................................................................................................... 9

General Characteristics of Reef and Hardbottom Communities.......................................................9

Southeast Florida Coral Reef Tract Monitoring.............................................................................12

Water Quality Studies ......................................................................................................... 17

Ground Water and Upwelling......................................................................................................18

Coastal Water Quality Monitoring...............................................................................................19

Water Quality Summary ...................................................................................................... 29

Nutrient Enrichment and Adverse Biological Effects .....................................................................31

Waters on the 1998 303(d) List............................................................................................ 33

Numeric Nutrient Criteria for the Protection of Coral Communities...................................... 35

Hawaii and Australia’s Criteria To Protect Corals..........................................................................35

Criteria Based on Nutrient Dosing Experiments............................................................................36

Development of Criteria To Maintain Healthy Conditions of the Southeast Coral Community ........36

Background on the Components of Water Quality Criteria ................................................... 37

Methodology ..............................................................................................................................37

Duration and Frequency ..............................................................................................................38

Summary of the Proposed Criteria....................................................................................... 39

Proposed Criteria ........................................................................................................................39

References .......................................................................................................................... 41

Appendix A. Coral Reef Data-Gathering Activities Summary and Acronyms from 

Collier et al. 2008. .................................................................................................. 44
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft iii August 2010

List of Tables

Table 1. Checklist of nutrient enrichment symptoms in the Southeast Florida Coastal Reef Tract. ............ 2

Table 2. Stony coral species presence/absence for the 12 standard SECREMP sites in Broward, 

Miami-Dade, Palm Beach, and Martin Counties for 2008 (Gilliam 2009). ...............................15

Table 3. Treated wastewater outfall data (Carsey et al. 2010b). ..............................................................17

Table 4. Calculated nutrient fluxes from the wastewater treatment plant outfalls (Carsey et al. 

2010b).......................................................................................................................................18

Table 5. Summary of FACE field studies (Carsey et al. 2008).....................................................................22

Table 6. Net mass (kg] of nutrients into the coastal ocean for eight ebb tide (outflowing) pulses 

(from Carsey et al. 2007). .........................................................................................................24

Table 7. Nutrient concentrations at Broward County sampling stations (Nancy Craig – Broward 

County)......................................................................................................................................29

Table 8. Background values for nutrients (ug/L) on the southeast coast (μg l-1) (Carsey et al. 

2010; Broward County unpublished data)................................................................................30

Table 9. Effluent bloom threshold concentrations (Tichenor 2004b).........................................................32

Table 10. Impaired waters for nutrients, DO, and/or chlorophyll a...........................................................34

Table 11. Comparison of Hawaiian (HI) and Great Barrier Reef (GBR) nutrient criteria (in μg l-1) 

with sample values from a Broward County station in southeast Florida (Station OS-3; 

see Figure 18 for exact location) (HAR 11-54, Moss et al. 2005)..............................................36

Table 12a. Proposed numeric nutrient criteria for TP (ug/L) for the Southeast Florida Coastal 

Reef Tract.................................................................................................................................. 39

Table 12b. Proposed numeric nutrient criteria for TN (ug/L) for the Southeast Florida Coastal 

Reef Tract.................................................................................................................................. 39

Table 12c. Proposed numeric nutrient criteria for chlorophyll a (ug/L) for the Southeast Florida 

Coastal Reef Tract.....................................................................................................................40

Table 12b. Proposed numeric nutrient criteria for DIN (ug/L) for the Southeast Florida Coastal 

Reef Tract.................................................................................................................................. 40

List of Figures

Figure 1. Southeast Coastal Basin Groups and Coastal Basins Planning Units. The black lines 

indicate the extent of area under consideration. ....................................................................... 5

Figure 2. South Florida drainage (after Kelble et al. 2010).......................................................................... 6

Figure 3. Ocean currents of continental southeast Florida (courtesy of K. Banks, Broward 

County)........................................................................................................................................ 8

Figure 4. General coastal ocean circulation sample retention times (Courtesy of R. Smith, NOAA 

AOML)......................................................................................................................................... 9

Figure 5. The reefs of the continental shelf of southeastern Florida (Banks 2010)....................................11

Figure 6. SECREMP sites in relation to southeast Florida counties (SECREMP 2007). ...............................14

Figure 7. Proportion of different biological communities on the southeast Florida reef tract 

(Gilliam 2007). ..........................................................................................................................16
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft iv August 2010

Figure 8. Stony coral species richness for Broward County (BC), Miami-Dade County (DC), Palm 

Beach County (PB), and Martin County (MC) sites, 2003–08 (Gilliam 2009)............................16

Figure 9. Map of inlet and outfall locations in southeast Florida (FACE 2010)..........................................17

Figure 10. Map of cruise sampling locations and coast locations (Proni et al. 2009)................................21

Figure 11. Boynton Inlet nutrient concentrations over two complete tidal cycles for September 

2007 (Carsey et al. 2007)..........................................................................................................24

Figure 12. Location of sampling stations during the FACE SC monitoring cruises in 2007 and 2008 

(Carsey et al. 2010a). The red star indicates the location of the South Central (SC) 

ocean outfall. ............................................................................................................................25

Figure 13. Mean station concentration of N+N with distance (km) north (positive) and south 

(negative) of the SC outfall (Carsey et al. 2010a). ....................................................................26

Figure 14. Mean station concentration of NH4 with distance (km) north (positive) and south 

(negative) of the SC outfall (Carsey et al. 2010a). ....................................................................26

Figure 15. Mean station concentration of P with distance (km) north (positive) and south 

(negative) of the SC outfall (Carsey et al. 2010a). ....................................................................27

Figure 16. TP at the Hillsboro Inlet site, 1981–97 (BCDPEP 2001). The dashed line shows the 

Broward County estuarine TP standard of 0.05 mg L- 1(BCDPEP 2001). ...................................28

Figure 17. TN at the Hillsboro Inlet site, 1981–97 (BCDPEP 2001). The dashed line shows the 

Broward County estuarine TN standard of 1.5 mg L-1(BCDPEP 2001). .....................................28

Figure 18. Location of stations sampled by Broward County (courtesy of Nancy Craig – Broward 

County)......................................................................................................................................29

Figure 20. Map of stations and corresponding NH4 concentrations at sites sampled during the 

Boynton-Delray cruises (Carsey et al. 2010).............................................................................30

Figure 19. Map of stations and corresponding NH4 concentrations at sites sampled during the 

Boynton-Delray cruises (Carsey et al. 2010).............................................................................30

Figure 20. Location of the South Central (Delray) outfall and the Gulf Stream Reef (Tichenor 

2006).........................................................................................................................................33
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 1 August 2010

Executive Summary

This report was prepared by the Florida Department of Environmental Protection (FDEP), in cooperation 

with local scientists, to support the development of numeric nutrient criteria for the Southeast Florida 

Coastal Reef Tract. The primary purpose of the proposed numeric nutrient criteria is to protect healthy, 

well-balanced natural populations of flora and fauna from the effects of excess nutrient enrichment. 

The southeast Florida coast, as defined here for numeric nutrient criteria development, includes the 

Atlantic coastal waters from the northern border of Biscayne National Park (BNP) in Miami-Dade County 

to the St. Lucie Inlet in southern Martin County, extending approximately three miles (4.83 km) offshore 

(Figure 1). The entire area is Class III, with a designated beneficial use of “Recreation, Propagation, and 

Maintenance of a Healthy, Well-Balanced Population of Fish and Wildlife”. 

The hard bottom and coral reef system that occurs in the southeast coastal waters is the most 

prominent and diverse marine community in the area, and is considered to be the northern end of the 

Florida Reef Tract. The ecosystems that flourish on and around reefs are some of the most productive in 

the ocean, supporting extensive benthic and pelagic communities. More than 3,000 animal species can 

coexist on a large reef tract. Because of the potential for nutrient inputs to stimulate macroalgal 

growth, which could subsequently physically damage this community, the hard bottom and coral reef 

community is considered to be the most sensitive indicator of nutrient enrichment. Additionally, 

experimental evidence suggests that moderate additions of inorganic nitrogen may be associated with 

chronic effects on corals (reductions in calcification and healing rates).

While benthic macroalgal growth has occurred in the offshore waters of the reef tract, the Southeast 

Florida Coral Reef Evaluation and Monitoring Project determined that the community composition and 

coral cover within the project’s thirteen monitoring sites was stable, and that diseases did not appear to 

be a major factor affecting stony corals at these sites. This information supports the position that the 

condition of the coral reef and hard bottom communities at these sites is generally healthy. 

As part of a multiple lines of evidence approach, FDEP examined nutrient criteria for corals developed by 

Hawaii and Australia and results from experiments involving nutrients and coral, and then compared 

these values with the nutrient concentrations that occur in portions of the Southeast Coastal Reef Tract

beyond human influences. The existing southeast coast nitrogen concentrations were similar to the 

established Australian and Hawaii protective criteria, while the existing southeast coast phosphorus 

values were lower than Australian and Hawaii criteria. Experimental evidence suggests that Dissolved 

Inorganic Nitrogen levels of 14 μg/L would be protective of coral health (Renegar et al. 2008), while 

ambient data from the southeast coast indicates surface and bottom Dissolved Inorganic Nitrogen (DIN) 

values are near this protective level. These observations, in conjunction with the overall health of the 

reef, indicate that existing nutrient and chlorophyll a levels are protective of the designated use.

Table 1 provides a checklist of nutrient enrichment symptoms and describes whether each symptom has 

been historically or is currently observed in the Southeast Coastal Reef Tract. 

The proposed recommendation for the protection of a healthy, well-balanced aquatic community in the 

Southeast Coastal Reef Tract, as well the annual limits for the area, are provided at the end of this 

report (in Tables 12 a through 12 d).
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 2 August 2010

Table 1. Checklist of nutrient enrichment symptoms in the Southeast Florida Coastal Reef Tract. 

- = Empty cell/no data

Response variable Observed 

historically 

or 

currently?

Explanation Source

Low dissolved oxygen 

(DO) (hypoxia/anoxia)

No Low DO not observed. Carsey et al. (2006, 2007, 

2008, 2009, 2010a)

Reduced clarity No While nearshore turbidity has been associated with 

beach renourishment, and inlets are a potential source 

of color and turbidity, no turbidity increases at the reef 

have been quantitatively linked to human discharges.

Proni et al. (2009)

Increased chlorophyll 

a concentrations

No No trends in chlorophyll a have been observed, including 

down-gradient of potential nutrient sources.

Carsey et al. (2010b)

Phytoplankton blooms 

(nuisance or toxic)

No Phytoplankton is not an issue (consistently very low 

chlorophyll a).

BCDPEP (2001), Carsey et 

al. (2006, 2007, 2008, 

2009, 2010a)

Problematic epiphyte 

growth 

No See SAV. SAV are naturally sparse in the area and local 

scientists did not consider SAV to be suitable for criteria 

development.

Collier et al. (2008)

Problematic 

macroalgal growth

Yes Lyngbya and Codium growths have periodically affected 

portions of the reef, however, no relationship between 

these growths and human nutrient inputs has been 

definitively established.

LaPointe et al. (2005a, 

2005b), Tichenor (2003, 

2004a, 2004b, 2006)

Submerged aquatic 

vegetation (SAV) 

community changes or 

loss

No SAV is naturally sparse in this area and not considered, 

by local experts, to be a suitable endpoint for nutrient 

criteria development.

Collier et al. (2008)

Emergent or shoreline 

vegetation community 

changes or loss 

No While mangroves have been adversely affected in 

lagoons (covered by other reports), the southeast coast 

shoreline consists of sandy beach.

Banks et al. (2005)

Coral/hard bottom 

community changes or 

loss 

Yes Lyngbya and Codium growths have periodically affected 

portions of the reef, however, no relationship between 

these growths and human nutrient inputs has been 

definitively established.

Collier et al. (2008).

Impacts to benthic 

community

N/A Benthic communities consist of the coral reef, covered 

above.

- 

Fish kills No None reported. - 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 3 August 2010
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 4 August 2010

Geographic and Physical Description

Extent and Overview of Area 

The southeast Florida coast, as defined here for numeric nutrient criteria development, includes the 

Atlantic coastal waters from the northern border of Biscayne National Park (BNP) in Miami-Dade County 

to the St. Lucie Inlet at the southern end of the Indian River in Martin County, and extends

approximately three miles (4.83 km) offshore (Figure 1). Coastal waters are defined as those occurring 

between mean high water and the shelf break. The total aerial extent is approximately 627 km2

. 

Often called the “gold coast” because of the color of the beach sand (consisting largely of crushed shell), 

the area includes approximately 130 km of sandy beaches and occasional rock outcrops on the coast in

four counties (Martin, Palm Beach, Broward, and Miami-Dade). The southeast coast is a high energy 

coast, exposed to greater wave action and vertical mixing than in the Keys (Wagener et al. 2008; Collier

et al. 2008). 

The continental shelf here is fairly narrow (3-4 km) and generally bounded on the east by a branch of the 

Gulf Stream called the Florida Current. The current travels very close to the shore, and the area is 

subject to a fairly constant movement of oceanic water. As a result, water quality in this area is highly 

influenced by open ocean conditions with naturally low nutrient levels. A prominent habitat feature is a 

series of coral reefs and hard bottom communities roughly parallel to the shoreline. 

Note that this report concerns the coastal waters, and that the main natural estuaries in the area 

(Biscayne Bay on the southern end, Lake Worth Lagoon, Loxahatchee River, and St. Lucie River on the 

northern end) are covered in other individual reports. 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 5 August 2010

Figure 1. Southeast Coastal Basin Groups and Coastal Basins Planning Units. The black lines indicate 

the extent of area under consideration. 

Designated Uses 

The entire area is Class III, with a designated beneficial use of “Recreation, Propagation, and 

Maintenance of a Healthy, Well-Balanced Population of Fish and Wildlife”. The area is well known for 

the high quality of recreational use in and on the water (which occurs year-round), which is generally 

associated with biological resources of the estuaries or reefs. 

Climate and Weather Patterns

The climate of the southeast coast is defined as Tropical Savanna (using the Köppen Climate 

Classification System). The area is subject to a pronounced dry season (from November to March), 

during which precipitation is usually less than 40 cm. During the wet season (from June to September), 

the area receives 70% of its annual rainfall, resulting in a total annual precipitation of 152 cm (Banks et 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 6 August 2010

al. 2008). Hurricanes, which generally occur from June to November, can significantly influence 

biological communities (including the coral reefs). Hurricanes can physically damage coral reefs, but can

also benefit coral communities by facilitating asexual recruitment of some coral species and removing

macroalgal and bacterial overgrowth from corals (Banks et al. 2008). 

This part of the coast is somewhat protected from strong easterly winds of the Atlantic by the Bahama

Bank, a factor which may have contributed to formation of the reefs that form the hard bottom 

community and may also influence current coral recruitment and reef formation along the coast (Banks 

et al. 2007). 

Oceanographic texts describe this area as the “Caribbean coastal oceanic region” in the southern three 

counties, shifting to the “South Atlantic oceanic region” in northern Palm Beach County (Gross et al. 

1982). This shift can be seen in the near shore biota, as the continental shelf widens in the vicinity of

northern Palm Beach and Martin Counties, where a slightly broader range of oceanic and land 

temperatures occur. The “frost line”, below which winter freezing temperatures are uncommon, is 

around Palm Beach. Overall, ocean temperatures range between 18.3 -30.5 °C on the reefs (Banks et al.

2007), which includes the cooler temperature range of most tropical reef corals. 

Watershed, Land Use, and the Coast

The hydrology of south Florida has been highly altered by man’s efforts to manage water for water 

supply and flood control (Figure 2). The southeast coast lies within three major coastal basin groups: 

the northern half of the Southeast Coast-Biscayne Bay, the Lake Worth Lagoon-Palm beach Coast, and 

the southern quarter of the St. Lucie-Loxahatchee watersheds. 

Figure 2. South Florida drainage (after Kelble et al. 2010).

Much information has been compiled on the history of the hydrological changes in south Florida, and 

these are briefly described here to frame the discussion of coastal characteristics. Beginning in the late 

1800’s, two major hydrologic changes occurred in southeast Florida, significantly changing the historical

hydrodynamics and the timing and quantity of water that is delivered to the coast: 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 7 August 2010

1. Several large canals and levees were created to assist in draining and directing 

the water from areas around Lake Okeechobee and the Everglades. The water is 

now sent to the coast during wet times (or in anticipation of wet weather), and 

retained during drier times, for flood protection and irrigation, respectively; 

2. The coastal lakes, lagoons, and estuaries were connected to each other by the 

creation of the Intracoastal Waterway (ICWW) that runs the length of the east 

coast from the Georgia line through Biscayne Bay. It also crosses the state 

through Lake Okeechobee. The ICWW is generally maintained at a depth of 12 

feet of seawater (fsw) for purposes of navigation, commerce, and safe 

recreation. Associated with the ICWW is the creation and maintenance of 

permanent inlets that allowed the runoff from land to go more directly to the 

sea.

The land between the ocean and the historical Everglades is highly urbanized. Martin, Palm Beach, 

Broward, and Miami-Dade Counties combined contain over thirty percent of Florida’s estimated 18.5

million people (U.S. Census, 2009). 

Hundreds of miles of canals have been built to allow more and more immediate water access for the 

population. The ICWW connects the remaining natural estuaries, and while the ICWW includes habitats 

such as salt marsh and mangroves, they occur in limited amounts compared to the linear miles of 

bulkheaded seawalls. Mangrove forests are common in two contiguous State parks in the southeast 

part of Broward County (John U. Lloyd, and West Lake). In the four county coastal area, water from the 

canals, estuaries, remnant (including some formerly freshwater) coastal lakes, and the ICWW, eventually 

discharge to the Atlantic Ocean by way of stabilized inlets. 

There are three major ports in the coastal watershed, located at Palm Beach, Port Everglades, and 

Miami. Cruise ships, commerce vessels and recreational boats frequent these ports and use the coastal 

waters for transportation and/or recreation. The near shore hard bottom and reefs systems close to the 

ports have been physically modified over time to accommodate the vessels and to minimize safety 

hazards associated with navigating through narrow passes or over shallow reefs.

Nine inlets are maintained in the area covered in this summary. From south to north, Government Cut 

and Baker’s Haulover Inlets allow exchange of water from Biscayne Bay onto the coastal shelf. Port 

Everglades, Hillsboro, Boca Raton, South Lake Worth (Boynton), and Lake Worth exit to the narrowest 

portions of the shelf. At the north end, Jupiter and St. Lucie Inlets allow exchange of water from the 

Loxahatchee and St. Lucie estuaries to the coast.

The inlets are armored to secure their position from natural meandering that would otherwise occur, 

and are periodically dredged to prevent sand deposition. Most of these inlets require regular 

maintenance dredging to transfer sand from the north side of the inlet to the south side, and 

occasionally to maintain depth. 

Between the inlets, there are numerous public beaches that are a highly used recreational resource. 

Several of the beaches are “renourished” over time by the addition of sand either from inlets or from 

offshore. The renourishment is generally on a 10-15 year cycle (Banks et al. 2008). Inlet maintenance 

and beach renourishment creates relatively short-lived turbidity events that can affect the near shore 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 8 August 2010

resources by re-suspending finer particles and potentially exposing reefs to turbidity and sediment 

deposition (Banks et al. 2008).

Hydrodynamics—Currents and Circulation Patterns

Figure 3 shows the generalized currents affecting the southern part of the state. As the Gulf Stream

moves west across the Atlantic and Caribbean, and turns northward across the Bahamas, a branch called 

the Florida Current continues westward toward Florida and then northward along the southeast coast ). 

The Florida Area Coastal Environment (FACE) program has documented that there is a northward 

current along the coast approximately 85% of the time. The Florida Current is the primary driver of 

currents along the southeastern part of the coast. The lowest monthly average velocity is 1.0 m/sec in 

November, and the highest monthly average is 2.3 m/sec in July (Banks et al. 2008). 

Figure 3. Ocean currents of continental southeast Florida (courtesy of K. Banks, Broward County).

On the western side of the Florida peninsula in the Gulf of Mexico, there is a clockwise flowing portion 

of the Gulf Stream called the Loop Current. The Loop Current extends its range northward in the Gulf 

during the summer and can entrain waters from the Mississippi drainage before flowing across the SW 

shelf of Florida, east through the Florida Straits, and into the Florida Current (Wagener et al. 2008). Lee 

et al. (1994) and Wagener et al. (2008) describe the Florida Current as connecting the Loop Current with 

the Gulf Stream. 

Figure 4 shows the main gyres in the Keys, their approximate residence times, and their movement in 

relation to the Loop and Florida Currents. The gyres are important because they are part of a complex

current interaction with the continental shelf and appear to bring cooler, naturally nutrient-rich waters 

from depth onto the continental shelf in the central and northern Keys (FACE 2009). These Keys coastal 

gyres may drift northward, potentially affecting the nutrient balance of the waters farther north along 

the southeast coast. The gyres are much shorter-lived as the southeast shelf narrows and the waters 

are more quickly mixed. 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 9 August 2010

Figure 4. General coastal ocean circulation sample retention times (Courtesy of R. Smith, NOAA 

AOML).

Tides in the region are semi-diurnal with amplitudes of approximately 0.8 m, and tidal plumes influence 

water circulation near navigation inlets. Factors affecting coastal circulation include inlet dimensions, 

shelf width at the inlets, offshore distance of the Florida Current, tidal plume constituents, and salinity. 

The salinity of the plumes from the inlets is significantly different in the wet season (June–September) 

than the dry season (October–May). Salinity stratification in the plumes may influence local circulation

patterns (Banks et al. 2008). 

High wave action, especially when combined with spring tides, can result in greater ebb flows from the 

inlets, potentially causing more sediment suspension and turbidity than an average hurricane because of 

the relatively short time duration of hurricanes (USACE 1996 in Banks et al. 2008).

Biological Summary 

Based on information from local scientists, coral/hard bottom is the most nutrient-sensitive community, 

and therefore, should be the focus for numeric nutrient criteria development. Although SAV may be 

sporadically found, SAV coverage is generally sparse because of the significant currents and wave action 

associated with this area.

General Characteristics of Reef and Hardbottom Communities

Most of the US Atlantic and Gulf Coast continental shelf is flat and sandy, with little rock or natural reef 

on which communities can build or pelagic populations can find shelter (Cole et al. 1982). Where there 

are firm substrates, benthic organisms, such as hard and soft corals, can colonize and form reefs. A reef 

develops when benthic organisms build a rigid, wave-resistant structure on the bottom. The reef 

provides a shallow water environment that is favorable to many organisms, where nutrients are readily 

recycled. As sessile organisms colonize, ecological succession occurs and a reef grows until it reaches a 

balanced state (Cole et al. 1982). 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 10 August 2010

Coral reefs occur mainly in tropical and subtropical oceans warmer than 18 °C, where carbonates 

precipitate readily. Reef building coral builds calcareous skeleton, which multiple subsequent 

generations colonize (Cole et al. 1982). 

Unicellular symbiotic algae, zooxanthellae, provide photosynthetic products directly to the coral in 

return for nutrients and CO2. Zooxanthellae photosynthesis, which requires significant sunlight, greatly 

increases the coral’s ability to extract CaCO3 from seawater to produce the carbonate skeleton (Cole et 

al. 1982).

While corals are the most conspicuous contributors to the framework of a reef, encrusting algae 

(crustose red algae) are also important cement depositors at shallow depths. In addition, beneficial red 

and green calcareous algae produce much of the loose carbonate sediment incorporated in the crevices 

in the reef mass, which is a complex, shallow water benthic environment. The ecosystems that flourish 

on and around reefs are some of the most productive in the ocean, supporting extensive benthic and 

pelagic communities. More than 3,000 animal species can coexist on a large reef tract. Competition for 

firm surface space, rather than lack of food, probably limits the population of filter-feeding benthos, at 

least above 200 meters depth (Cole et al. 1982). 

Characteristics of the Southeast Florida Reef Tract 

The reef tract adjacent to the southeast Florida coast is generally regarded as the northern end of the 

Florida Reef Tract. Recent research suggests that the reef tract system from Biscayne Bay north may 

have a slightly different origin and underpinning than the reef system from Biscayne Bay southward, but 

the relationship is unclear (Banks et al. 2007). Regardless, the coral reef system in southeastern Florida 

is a high-latitude system near the environmental threshold for significant reef growth (Banks et al.

2008). These reefs represent the most northward extension of tropical reefs on the east coast of the 

United States, and transition into worm reef/limestone habitat near the Jupiter Inlet (Jaap and Hallock 

1990). Reefs on the southeast coast lie at the northernmost thermal boundary for reef development in 

the Caribbean, exposing the reef system to greater temperature fluctuations than other Caribbean reefs 

(Chiappone and Sullivan 1994, Wagner et al. 2008). 

From south to north, the southeast Florida reef system tracks the relatively narrow continental shelf. 

This narrow shelf affects the hydrodynamics of oceanic waters, and the Florida Current and deeper 

waters found along this coast provide a relatively narrow range of salinity change and moderate the 

temperature year-round, which provides stability to the reef /hard bottom community.

Comparatively, southeast Florida reefs generally have similar stony coral species richness but reduced 

stony coral cover compared to the Dry Tortugas or Florida Keys coral reefs. Benthic cover by octocorals 

is similar throughout the Florida reef system, while macroalgae appears to contribute less cover and 

sponges appear to contribute more cover off southeast Florida (Callahan et al. 2007). 

The reefs and ridges comprising the current coral/hard bottom community in this area are roughly 

parallel to the existing shoreline, and based on underlying geology (Banks et al. 2007). From shore to 

30-40 m in water depth, the regions’ coral/hard bottom habitat appears to have 5 different areas based 

on reef and coastal morphology. The reef system consists of relict Holocene reefs and lithified sand 

ridges that formed in response to sea-level changes. The current reef system consists of a series of 

three main linear reefs paralleling the shore in an almost due north-south orientation (Figure 5). From 

the shore seaward, the inner reef crests in 3-4 m of water, the middle reef in 6-8 m, and the outer reef, 

which is a relic acroporid-framework reef, crests in 15-21 m of water (Banks et al. 2008). A series of 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 11 August 2010

ridges occur on the shoreward side of the inner reef areas (Collier et al. 2008). Banks et al. (2007) 

describe the underlying geomorphology of this reef system in detail, and also describe the deeper, outer 

reef as one of the longest continuous reef structures in the western Atlantic. 

Figure 5. The reefs of the continental shelf of southeastern Florida (Banks 2010).

Different reef organisms characterize the type of habitats found along southeast Florida reefs, typically 

transitioning from a cover of algae and small octocorals near shore to numerous octocorals and varied 

hard coral populations at the outer reefs

(http://www.dep.state.fl.us/coastal/programs/coral/sefcri.htm).

Inner reefs are characterized by macroalgae and numerous small octocorals living on a substrate of relict 

reef of Anastasia Formation limestone and worm reef (Phragmatopoma spp.), with breaks and sediment 

pockets within the reef (Collier et al. 2009). Typical sessile organisms are lesser starlet coral (Siderastrea 

radians) and colonial zoanthids (Palythoa mammilosa and P. caribaeorum). In the past few years, 

vigorous recruitment of staghorn coral (Acopora cervicornis) has occurred, and some extensive 

aggregations are now present generally inshore of inner reefs in Broward County (Collier et al. 2008). 

Here, monospecific stands of coral form significant habitats (Vargas-Angel et al., in prep.).

Octocorals are most conspicuous on the middle reef, which is characterized by more relief, dissecting 

channels, and octocoral densities of up to 30 colonies per m2

. Abundant stony corals include great star 

coral (Montastraea cavernosa), massive starlet coral (Siderastrea siderea), and mustard hill coral (Porites 

astreoides) (Gilliam et al. 2003). 

The outer reef system often has stronger vertical relief and exhibits the highest diversity and abundance 

of sessile reef organisms. Octocorals and large barrel sponges (Xestospongia mula) are most 

conspicuous, and stony corals are somewhat larger than those located on the middle reef (Collier et al.

2008). 

The reef system at St. Lucie Inlet Preserve State Park (05’ to 27 09’N) is the northern limit for subtropical 

coral reefs on the east coast of Florida. The topography is composed of Anastasia Formation limestone 

that is covered with reef biota. Diploria clivosa forms very large pancake-like colonies and provides the 

majority of the cover. Montrastraea cavernosa also attains large sizes. The other species present, 

including Siderastrea radians, Isophyllia sinuosa, Solenastrea bournoni, and Oculina diffusa, are not 

large. Stony corals account for 3-5% of benthic cover at two 100m transects (Herren 2004).
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 12 August 2010

Southeast Florida Coral Reef Tract Monitoring

Prior to 2004, southeast Florida coral reef monitoring and management activities were limited and led 

primarily by local county agencies (Collier et al. 2008). In 2004, the Southeast Florida Coral Reef 

Initiative (SEFCRI) was developed with guidance from the U.S. Coral Reef Task Force to assist in 

coordinating federal, state, local and non-governmental reef-related efforts. The FDEP Coral Reef 

Conservation Program, which manages the implementation of SEFCRI, coordinated a “State of the Coral 

Reef Ecosystems of Southeast Florida” report in 2008 that summarized various management and 

monitoring efforts (Appendix A).

The Southeast Florida Coral Reef Evaluation and Monitoring Project (SECREMP), a SEFCRI local action 

strategy project, is an expansion of offshore monitoring by the Coral Reef Evaluation and Monitoring 

Project (CREMP) intended to document changes in reef resources throughout the Florida reef tract from 

the Dry Tortugas northward. In 2003, ten sites in Miami-Dade, Broward, and Palm Beach counties were 

added to the original CREMP, which was initiated in the Florida Keys National Marine Sanctuary in 1996. 

Three additional sites were added in Martin County in 2006 (Collier et al. 2008). The SECREMP is 

designed to assess coral coverage, monitor stony coral condition, and archive biotic attributes of coral 

reef ecosystems nationwide (Gilliam 2009). To a large extent, coral cover throughout the southeast 

Florida reefs has been poorly defined and there are few long-term data sets on abundance and/or cover 

for benthic components. This has made it difficult to scientifically determine status and trends for the 

system (Gilliam 2009). 

Figure 6 shows the SECREMP sites in relation to the reefs, and Table 2 lists the coral species identified at 

each of the twelve standard SECREMP sites. The mean number of species identified per site was twelve. 

Figure 7 shows the stony coral species richness by year for the different stations. Over the period of 

monitoring, 2003-2008, there was little change on the reef system (Gilliam 2009). Stony coral richness 

and cover were similar between years. The incidence of disease in 2008 was less than that in 2007, and 

disease did not appear to be a major factor affecting stony coral condition or cover (Gilliam 2009). 

Figure 8 shows the relative percent of bottom cover for the different benthic biological communities 

(Gilliam 2007). In general, the status of the southeast reef system has changed little from 2003 to 2008, 

but there were a few site specific changes. For instance, coral cover was reduced at site PB1 following 

burial by sand between 2004 and 2005. In addition, there was an increase in coverage by the 

cyanobacteria Lyngbya spp. at site DC3 in Miami-Dade County, which may have contributed to a slight 

decline in octocorals and sponges at this particular site (Gilliam 2009). In Broward County however, an 

area of Lyngbya growth seen in previous years (2004) appeared to be in decline from 2005-2008. 

Octocorals and macroalgae remained the two benthic functional habitats with the highest cover for the 

region (Gilliam 2009). 

In 2009, SECREMP assessed the condition of stony corals at their sampling sites. With six years of data 

(2003-2008), the community composition and coral cover was stable, and diseases did not appear to be 

a major factor affecting stony corals at the sites. The SECREMP report states that “Other than the 

reduced cover for the site PB1 following burial between the 2004 and 2005 sample events, there do not 

appear to be any consistent regional trends in temporal changes in functional group cover between 

2003 and 2008. Macroalgae and octocorals remain the two (non-substrate) benthic functional groups 

with the highest cover for the region.” This information supports the position that the overall existing 

condition of the coral reef and hard bottom communities is healthy, although the potential for localized 

stress remains. 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 13 August 2010

Although the limited available monitoring data to date shows little change in the southeast coast coral 

community, there is concern that intermittent benthic algal growth (e.g., Lyngbya), which may be 

related to nutrients associated with natural upwelling, NPDES outfalls, and/or freshwater inputs 

discharged through the inlets, may impact the reef system. In fact, partly as a response to concern 

about potential adverse near-field effects on Gulf Stream Reef, the Delray Beach NPDES outfall has 

ceased open ocean wastewater discharges, except during emergencies, prior to a Legislativelymandated 2025 deadline. By 2025, all domestic wastewater facilities discharging to the southeast

coastal area via ocean outfalls are to be eliminated as primary disposal methods. Also in response to 

these general concerns, the SEFCRI developed a Land-based Sources of Pollution Technical Advisory 

Committee to focus attention on potential anthropogenic nutrient effects. 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 14 August 2010

Figure 6. SECREMP sites in relation to southeast Florida counties (SECREMP 2007).
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 15 August 2010

Table 2. Stony coral species presence/absence for the 12 standard SECREMP sites in Broward, MiamiDade, Palm Beach, and Martin Counties for 2008 (Gilliam 2009). 

Key: A, 1, 2 3 = sites with species present; 0=species absent.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 16 August 2010

Figure 7. Proportion of different biological communities on the southeast Florida reef tract (Gilliam 

2007).

Figure 8. Stony coral species richness for Broward County (BC), Miami-Dade County (DC), Palm Beach 

County (PB), and Martin County (MC) sites, 2003–08 (Gilliam 2009).
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 17 August 2010

Water Quality Studies

Sources of both natural and anthropogenic nutrients to the Southeast Coastal Reef Tract include 

stormwater runoff discharged at inlets, outfalls from wastewater treatment plants (WWTP), upwelling, 

groundwater seepage, and atmospheric deposition. Runoff from land and discharge of treated 

wastewater are the most direct fresh water influences to this system. Figure 9 shows a map with the 

location of inlets and outfalls in the Southeast Coastal Reef Tract area.

There are six domestic wastewater treatment facilities that are permitted to discharge to the study area 

via ocean outfalls, with a combined permitted capacity of over 280 mgd. The facilities provide 

secondary treatment and basic disinfection (FACE 2008). The outfall depth and locations were sited so 

that the discharges would be to the outside edge of the outer reef system and directly influenced by the 

Florida Current to minimize possible effects on the recreational beaches. Table 3 shows the general 

characteristics of the outfalls including permitted flow, depth, length, and diameter, and Table 4 shows 

the calculated nutrient loads from each of the wastewater treatment plant outflows.

Figure 9. Map of inlet and outfall locations in southeast Florida (FACE 2010).

Table 3. Treated wastewater outfall data (Carsey et al. 2010b).

Name Outflow (MGD) Depth (m) Length (km) Diameter (m) Ports

South Central 12.3 27.4 1.6 0.8 1 

Boca Raton 10.7 27.4 1.6 0.9 1 

Broward – N 36.5 32.6 2.2 1.4 1 

Hollywood 39.5 28.3 3.1 1.5 1 

Miami Dade – N 80.6 32.9 3.6 2.3 12

Miami Dade – C 104.6 30.5 5.7 2.3 5 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 18 August 2010

Table 4. Calculated nutrient fluxes from the wastewater treatment plant outfalls (Carsey et al.

2010b). 

1 Mass output computed from concentrations and averaged monthly flows from Koopman et al. (2006).

Name TN (kg day-1 N) NH4 (kg day-1 N) N+N (kg day-1 N) TP (kg day-1 P)

South Central 871 545 191 79

Boca Raton 685 425 134 28

Broward – N 2,045 Nr Nr 180

Hollywood 2,482 1779 179 164

Miami Dade – N 5,339 Nr Nr 634

Miami Dade - C 6,652 Nr Nr 634

Legislation passed in 2008 (SB 1302) will decrease significantly the discharge from ocean outfalls. The 

legislation requires that: 

• New construction or expansion of wastewater ocean outfalls is prohibited, and 

facilities are limited to the permitted capacity in effect on July 1, 2008. 

• Discharge of domestic wastewater through ocean outfalls must meet advanced 

wastewater treatment and management requirements by December 31, 2018, 

unless the facility reduces its baseline loadings of total nitrogen and total 

phosphorus by an amount equivalent to advanced wastewater treatment 

requirements or the facility meets 100% reuse for domestic wastewater discharge by 

the same date. 

• All facilities are required to achieve, at a minimum, 60% reuse of the facilities actual 

annual flow by December 31, 2025.

• Discharge through ocean outfalls beyond December 31, 2025, are prohibited, unless 

as a backup to the functioning reuse system.

In addition to outfalls, inlets may contribute significant amounts of nutrients to the southeast coastal 

area. Estimates of fluxes or concentration from the Boynton, Hillsboro, and Port Everglades Inlets have 

been quantified, and are discussed in the coastal water quality monitoring section, but estimates of 

nutrients from the other inlets are unknown. 

Ground Water and Upwelling

Groundwater seepage is known to be an important contributor of nutrients (especially nitrate) in some 

regions of Florida (Carsey and Stamates 2009). Seepage may transport these materials to the coastal 

ocean, but the contribution to the southeast coastal region has not been adequately evaluated (Carsey 

and Stamates 2009). 

Another contributor of nutrients to the coastal ocean is oceanic upwelling of deep, cooler water that is 

enriched in nutrients. Upwelling has been observed off the coast of southeast Florida (e.g., Smith 1983), 

however, the quantity, duration, and seasonality of the upwelled nutrient contribution has not been 

determined (Carsey and Stamates 2009).
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 19 August 2010

Coastal Water Quality Monitoring 

Florida Area Coastal Environment (FACE) Program

The FACE program was established in 2004 to gather a broad range of data needed for understanding 

Florida’s coastal environment. Data are used for evaluating potential anthropogenic impacts, for 

guidance in the operation and development of water and sewer infrastructure, and for the formulation 

of science-based regulation. The FACE program includes nutrient, stable isotope, sediment, algal, coral, 

physical oceanographic, chemical, meteorological, genetic and microbiological measurements. The 

primary area sampled includes the coastal ocean off southeast Florida and adjacent waters and 

groundwater. In the southeast coastal area, the FACE program has sampling sites at the Boca Raton 

outfall and inlet, the Broward, Hollywood, north and central Miami outfalls, and the Hillsboro, Port 

Everglades and Haulover inlets. Table 5 shows a summary of field studies performed along the coast 

that included sampling in inlets and outfalls. 

Brief Summaries of Several FACE Studies

Hollywood Tracer: A tracer study was conducted on the Hollywood outfall in June 2004 by injecting 

sulfur hexafluoride (SF6) gas into the discharging outfall pipe over the course of six days (Wanninkhof et 

al. 2005). Transportation and dispersion of the plume depends on the physical oceanographic 

conditions during the discharge. Sampling was performed continuously by towing a “fish” containing 

sampling equipment from the side of the vessel at a 2-m depth with periodic sampling at deeper depths 

to aid in defining the plume. The sampling track was irregular within 17 km of the outfall terminus and 

proceeded in a systematic zigzag pattern northward crossing the tracer path. The surface SF6 

concentrations indicated the discharged water flowed northward parallel to the coast in a broadening 

plume, reaching about 3 km width at the farthest point sampled, 66 km from the outfall (Wanninkhof et 

al. 2005). In the experiment, the outfall discharge, which was positively buoyant, generally rose to form 

a seawater-effluent surface layer at about one third of the water depth (Wanninkhof et al. 2005). The 

effluent was transported as a near surface plume until the density contrast was eroded by dilution with 

surrounding water. Depth profiles of SF6 indicated that vertical mixing of the discharged waters 

occurred within 13 km of the outfall. The dilution of the treated wastewater (Dilution = 212 times

distance (km) from outfall) (Wanninkhof et al. 2005) was consistent with earlier outfall studies in the 

area.

Outfall Surveys: From October 6-19, 2006 the treated wastewater plumes in the southeast coastal area 

were surveyed as part of the FACE outfalls survey cruise (Carsey et al. 2010b). Figure 10 shows the 

locations of the outfalls and cruise sampling locations. Samples collected during the cruise were 

analyzed for N+N, NO2, NH4, ortho-P, and Si. Samples were collected near surface, mid-depth, and near 

bottom. Samples were also collected on east-west transects at locations inshore of the boil, near the 

boil, and offshore from the boil. The ephemeral nature of the rising plume and boil was the 

predominant feature observed, with the downcurrent plume irregular and variable in shape (Carsey et 

al. 2010b). 

In general, the surface samples had the highest nutrient concentrations compared to those collected at 

depth, and surface samples near the boil had higher nutrient concentrations than samples farther away. 

Water was rapidly diluted by a factor of 10 within 300 m of the boil (Carsey et al. 2010b). There was no 

obvious relationship with the nutrient patterns and chlorophyll a concentrations. Nutrient 

concentrations agreed with reported outfall fluxes from discharge reports (Table 4). The treatment 

plant outfalls differed considerably in their flow and nutrient output and this was also reflected in the 

receiving water concentrations.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 20 August 2010

Seagrass samples and organic sediments were also collected from various locations near the six outfalls. 

The samples were analyzed for stable N and C isotopes to detect signals of anthropogenic N enrichment. 

There were no differences among sites in the isotopic signatures of either algae or sediment and thus no 

indication of anthropogenic enrichment (Carsey et al. 2010b).

Boynton Intensive: The Boynton Inlet was created in 1917 to improve tidal circulation and provide 

flushing to the south end of the Lake Worth Lagoon, which itself receives input from three canals (C-16, 

C-17, and C-51), several cities, and other nonpoint sources (Carsey et al. 2007). The inlet is 

approximately 200 ft wide and 12 ft deep, with a mean tidal range of 2.5 ft. It is estimated that it takes a 

single day to replace 50% of water in this area of the Lagoon. At the Boynton Inlet, nutrient and flow 

measurements were taken during two 48-hour studies in June and September, 2007 (Carsey et al. 2007). 

The studies were designed to collect water samples over two complete tidal cycles and quantify the flux 

of nearshore source entities into coastal waters. Samples were analyzed for Si, PO4, NH4, NO3+NO2, N 

isotopes, biological indicators, and other physical parameters. 

Nutrient concentrations in incoming tides were nearly zero, while concentrations in outgoing tides were 

much higher (Figure 11). The large volume of water in the outgoing flow from the Boynton Inlet means 

that there are large quantities of nutrients transported out into the coastal ocean. Table 6 provides the 

net mass (in kg) of nutrients discharged during ebb tide pulses.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 21 August 2010

Figure 10. Map of cruise sampling locations and coast locations (Proni et al. 2009).
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 22 August 2010

Table 5. Summary of FACE field studies (Carsey et al. 2008). 

- = Empty cell/no data

Study Name Goals Study 

Area

Platforms Notes Dates Source

Hollywood 

Tracer

Define HW outfall 

plume 10-66 km

HW outfall R/V Coral 

Reef II

Rhodamine 

dye SF6

June 7-9 2004 Wanninkhof et 

al. 2005

Outfalls 

Survey 1

Survey of all six 

TWWP outfall 

plumes

All outfalls R/V N. 

Foster

Nutrients, 

multibeam, 

microbio

October 6-19 

2006

Carsey et al.

2010b

Outfalls 

Survey 2

Survey of all six 

TWWP outfall 

plumes

All outfalls R/V N. 

Foster

Nutrients, 

biology, 

isotopes

February 8-16 

2008

- 

FOCITE-1 SC plume, 

Boynton Inlet 

tracer exp.

SC plume 

Boynton 

Inlet

R/V Coral 

Reef II

Winter February 19-

22 2007

- 

FOCITE-2 SC plume, 

Boynton Inlet 

tracer exp.

SC plume R/V Walton 

Smith

Summer June 10-13 

2008

- 

Boynton 

Intensive 1

Water, chemistry, 

and biology flux 

through Boynton 

Inlet

Boynton 

Inlet

ADCP 4 ebb tides 

and 4 flood 

tides

June 3-4 2007 Carsey et al.

2007

Boynton 

Intensive 2

Water, chemistry, 

and biology flux 

through Boynton 

Inlet

Boynton 

Inlet

ADCP 4 ebb tides 

and 4 flood 

tides

September 

26-28 2007

Carsey et al.

2007

Boynton Inlet 

flows

1-year 

measurement of 

Boynton Inlet 

flows

Boynton 

Inlet

ADCP Horizontal 

ADCP

February 2007 

to October 

2008

- 

GSR-ADCP 1-year 

measurement of 

ocean current at 

GSR

GSR reef ADCP Vertical 

ADCP

April 2007 to 

July 2008

- 

SC 

Monitoring 

Cruises

WQ sampling 

program around 

SC outfall

SC outfall R/V Cable Six 

bimonthly 

cruises

June, August, 

& October 

2007; 

February, 

Carsey et al.

2010
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 23 August 2010

May, & July 

2008
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 24 August 2010

Figure 11. Boynton Inlet nutrient concentrations over two complete tidal cycles for September 2007 

(Carsey et al. 2007).

Table 6. Net mass (kg] of nutrients into the coastal ocean for eight ebb tide (outflowing) pulses (from 

Carsey et al. 2007).

South Central Monitoring Cruises: The South Central (SC) monitoring cruises collected samples from 

the surface, middle and near bottom of the water column at 18 locations during June, August, and 

October 2007 and February, May, and July 2008 (Figure 12; Carsey et al. 2010a). The cruise went from 

approximately 5 km south of the SC outfall to just north of the Boynton Inlet. Samples were analyzed 

for various parameters, including NH4, N+N, orthophosphate, Si, DOC and chlorophyll a. 

Nutrient concentrations around the outfall site showed significantly elevated concentrations in surface 

samples, but were much less elevated in the middle or bottom samples. For N+N, NH4, and P there was 

a rapid decrease in surface concentration, and little to no increase in middle or bottom sample 

concentrations, with no discernable effect from the outfall at > 3 km from the outfall (Carsey et al.

2010a). Figures 13 through 15 show the decrease in nutrient concentration with distance north 

(positive) and south (negative) from the SC outfall. Concentrations in the figures are means for each 

sampling station over the 6 cruises.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 25 August 2010

Figure 12. Location of sampling stations during the FACE SC monitoring cruises in 2007 and 2008 

(Carsey et al. 2010a). The red star indicates the location of the South Central (SC) ocean outfall.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 26 August 2010

Figure 13. Mean station concentration of N+N with distance (km) north (positive) and south 

(negative) of the SC outfall (Carsey et al. 2010a).

Figure 14. Mean station concentration of NH4 with distance (km) north (positive) and south (negative) 

of the SC outfall (Carsey et al. 2010a).
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 27 August 2010

Figure 15. Mean station concentration of P with distance (km) north (positive) and south (negative) of 

the SC outfall (Carsey et al. 2010a).

Samples collected from stations within Lake Worth Lagoon (Station #s 16-18; see Figure 12) had higher 

nutrient, chlorophyll a, and TSS concentrations and lower pH and salinity than the coastal stations 

(Carsey et al. 2010a). Inlet concentrations tended to fall intermediate between the lagoon and coastal 

stations. 

Broward County Environmental Monitoring 

The Broward County Department of Planning and Environmental Protection has conducted water quality 

monitoring at estuarine sampling stations in the Intracoastal Waterway (ICWW), Hillsboro and Port 

Everglades Inlets, beginning at a subset of stations in 1973 (BCDPEP 2001). The county water quality 

monitoring study was conducted to determine water quality conditions, both long-term and current at 

each sampling site. Nitrogen values at the Hillsboro Inlet were generally within compliance with 

Broward County standards, 1.5 mg L1, but phosphorus values were frequently above the TP standard of 

0.05 mg/ L. The source of TP is likely land use and secondary canal discharges upstream. The water 

quality near the Hillsboro Inlet was better than the canals due to the influence of the Atlantic Ocean. 

Figures 16 and 17 show the annual mean TN and TP for the Hillsboro Inlet site. The influence of the 

estuarine water from the Hillsboro Inlet to the offshore reef system is unknown.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 28 August 2010

Figure 16. TP at the Hillsboro Inlet site, 1981–97 (BCDPEP 2001). The dashed line shows the Broward

County estuarine TP standard of 0.05 mg L- 1(BCDPEP 2001).

Figure 17. TN at the Hillsboro Inlet site, 1981–97 (BCDPEP 2001). The dashed line shows the Broward 

County estuarine TN standard of 1.5 mg L-1(BCDPEP 2001).

The Port Everglades Inlet is located at the boundary of the Central ICWW, which receives freshwater 

inputs from the C-13, Middle River, North New River Canal and New River Canal systems, and the 

southern ICW, which receives freshwater inputs from the Dania Cutoff. Land use in the central ICWW 

area is highly developed, but there are also some undeveloped mangrove forests in the southern ICWW 

of Broward County (BCDPEP 2001).

Broward County EPGMD implemented a targeted water quality monitoring program in the spring of 

2006 to determine ambient water quality over the reefs and in the water exiting through the Port 

Everglades Inlet. Four stations were sampled on a monthly basis (Figure 18). Samples were collected at 

the surface and near bottom on an outgoing tide. Water column parameters measured included TN, TP, 

TDN, TDP, NO3, NH4, SRP, TOC, DOC, Si, chlorophyll a, and turbidity.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 29 August 2010

Figure 18. Location of stations sampled by Broward County (courtesy of Nancy Craig – Broward 

County).

Data indicate that water exiting through the Port Everglades Inlet has higher nutrient, chlorophyll a and 

turbidity concentrations compared to offshore stations (Table 7). However, the extent to which this less 

saline, higher nutrient surface water mixes down to the reef community is unclear. 

Table 7. Nutrient concentrations at Broward County sampling stations (Nancy Craig – Broward 

County).

Parameter OS1 PE1 PE1 (surface) PE1 (bottom) OS2 OS3

TN (μg N L-1) 118.5 120.89 138.41 105.28 116.4 108.00

DIN (μg N L-1) 9.35 17.09 24.64 11.77 9.24 9.76

NH4(μg N L-1) 3.65 5.25 6.08 4.52 3.3 3.33

NOx (μg N L-1) 5.30 9.55 14.86 6.09 5.34 5.58

TP (μg P L-1) 7.04 8.43 9.84 7.17 6.94 6.75

Chl a (μg L-1) 0.71 1.21 1.84 0.80 0.81 0.64

Turbidity (NTU) 0.24 0.49 0.72 0.33 0.25 0.22

Water Quality Summary

Water quality is generally affected by nutrient inputs from both outfalls and inlets only in the immediate 

vicinity of the nutrient source. At a short distance from both inlets and outfalls, the nutrient 

concentrations drop back to lower “background” levels. For instance, nutrient concentrations fell to 

background at the surface within 3 km of the SC outfall (Carsey et al. 2010a). 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 30 August 2010

Figure 19 shows a map of the Boynton Delray sampling stations on the left and the corresponding

average station NH4 concentrations on the right by depth (surface, middle, and bottom). There are 

elevated NH4 concentrations near the outfall at the surface (Stations 3 through 5) and near the inlet and 

in Lake Worth Lagoon (Stations 13 and 16 through 18), but values are near background between the 

outfall and inlet (map and data for figure from Carsey et al. 2010a). Table 8 shows nutrient 

concentrations for several parameters at stations outside of the direct influence of either inlets or 

outfalls from the recent FACE and Broward County sampling efforts. 

Figure 20. Map of stations and corresponding NH4 concentrations at sites sampled during the 

Boynton-Delray cruises (Carsey et al. 2010).

Figure 19. Map of stations and corresponding NH4 concentrations at sites sampled during the 

Boynton-Delray cruises (Carsey et al. 2010).

Table 8. Background values for nutrients (ug/L) on the southeast coast (μg l-1) (Carsey et al. 2010; 

Broward County unpublished data).

Program Station N+N NH4 Ortho-P TN TP CHLA

FACE BD-7 3.22 7.66 0.001 - - 0.497

FACE BD-8 1.43 8.71 0.001 - - 0.275

FACE BD-9 1.59 5.61 0.002 - - 0.317

FACE BD-10 1.25 6.77 0.002 - - 0.387

Broward County OS-3 - 3.33 - 108.00 6.75 0.64

0 10 20 30 40

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

NH4 ug/l

Station

Surface

Middle

Bottom
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 31 August 2010

Nutrient Enrichment and Adverse Biological Effects

Many stressors associated with human activity could potentially affect the southeast Florida reef tract, 

including inlet dredging and port channel deepening, boating and fishing activities, grounding or 

anchoring of ships on reefs, and/or installation of fiber optic cables across reefs (Gilliam 2009; Collier et 

al. 2008). In addition, temperature can play a role. Extreme or sudden cold temperatures (e.g., climate 

or unusual upwelling events) can result in expulsion of zooxanthellae, and possible coral bleaching. 

Warming temperatures associated with climate change may lead to coral bleaching, although mass 

bleaching events similar to those reported in the Caribbean have not been reported off southeast 

Florida (Collier et al. 2008). 

Establishing a relationship between anthropogenic nutrient inputs and coral health has proven to be 

difficult. During the past decade in southeast Florida, benthic macroalgal growth has occurred in the 

offshore waters of Palm Beach County, and benthic cyanobacterial mats (Lyngbya confervoides) have 

occurred on portions of the middle reef tract offshore of Broward County (Banks et al. 2005). Excess 

growth of Codium and Caulerpa has been associated with physical smothering and mortality of some 

reef biota (Lapointe 1997; Lapointe et al. 2005b). Growth of Codium isthmocladum was first observed in 

1989 on deep (27-45 m) reefs off northern Broward and Palm Beach Counties (Collier et al. 2008). The 

Codium was adapted to low light levels and developed seasonally in the late spring and summer 

(Lapointe 1997). Tichenor (2004) also reported the occurrence of Codium on the Gulf Stream Reef (GSR) 

in 2003 at 75-90 feet below the surface. 

While some researchers have hypothesized that land based sources of nutrients are associated with

these macroalgal and cyanobacterial growths (e.g., Lapointe et al. 2005a and Tichenor 2004), the algal 

growths generally appear first in deeper offshore waters where upwelling may be a significant nutrient 

source. Other investigators have noted that the effects of land-based nutrient enrichment on reefassociated communities are not entirely understood (Banks et al. 2005). Comparisons of tissue nutrient 

content of C. isthmocladum and water column concentrations between southeast Florida and the 

Caribbean indicate higher P availability in southeast Florida relative to the Caribbean, potentially due to 

natural sources, such as upwelling and sediment, or anthropogenic land based sources (Lapointe et al. 

2005a). Analysis of δ15N values of C. isthmocladum and Caulerpa species collected from shallow, middepth, and deep reefs off the southeast Florida coast found that the δ15N levels were highest near shore 

and decreased with increasing depth. This observation, coupled with higher δ15N values in the southern 

part of the study area (near Boca Raton), prompted Lapointe et al. (2005b) to conclude that land based 

nutrient sources were more influential than natural upwelling for these algae. 

Based on a projection of plume dynamics and predicted water column nitrogen concentrations, Tichenor 

(2004b) concluded that the South Central NPDES outfall contributed to Lyngbya growth on a reef 

approximately 5-7 km down-gradient of the outfall, however, no actual water column nutrients on the 

reef were available to substantiate the model predictions. Tichenor (2004a and 2004b) plotted the 

facility’s effluent nutrient concentrations (based on monthly discharge monitoring report data) over 

time, and suggested that an increase in the nutrient effluent concentration was coincident with the 

emergence and spread of the down-gradient Lyngbya growth on Gulf Stream Reef. Based on 

observations in March 2002, Tichenor (2004b) developed a series of maximum effluent nutrient 

concentrations that may be associated with the potential onset of cyanobacteria proliferation (Table 9). 

It is important to note that the effluent nutrient concentrations are not the same as concentrations 

found on the reef, and the actual nutrient levels responsible for the Lyngbya proliferation are not 

known. 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 32 August 2010

Table 9. Effluent bloom threshold concentrations (Tichenor 2004b).

- = Empty cell/no data

- TKN NH4 N+N TP

Threshold concentration (mg l-1) 15.99 10.18 1.07 1.16

In 2005, Palm Beach County Reef Rescue (PBCRR) performed nutrient analyses to establish background 

concentrations and determine the potential for elevated concentrations down current of the South 

Central outfall (Tichenor 2006). The PBCRR noted that down current DIN values were relatively similar

to DIN values predicted by the outfall plume model developed at the Hollywood outfall (Wanninkhof et 

al. 2005). Tichenor (2006) concluded that the location where the Lyngbya proliferation begins, 

approximately 5-7 km down current of the South Central outfall, is likely where downward vertical 

mixing of effluent begins to occur (Figure 20). In contrast, other investigators have found there were no 

differences in the isotopic signatures of either algae or sediment associated with sites up and downgradient of outfalls, and concluded there was no indication of anthropogenic enrichment (Carsey et al.

2010b). 

While a relationship between anthropogenic nutrient inputs from ocean outfalls and coral health has 

not been clearly established, the six domestic wastewater treatment facilities that discharge to the 

Southeast Florida Coastal Reef Tract area via ocean outfalls are legislatively required to eliminate their 

outfalls as the primary disposal method by 2025, in part due to concerns that nutrients in these outfalls 

could exacerbate algal growth on the reef. 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 33 August 2010

Figure 20. Location of the South Central (Delray) outfall and the Gulf Stream Reef (Tichenor 2006).

Waters on the 1998 303(d) List 

Although there are no listings for the coastal waters in this area, there are nutrient-listed waters in the 

estuaries and canals in the coastal basins that ultimately drain to the coast by way of the inlets (Table 

10). 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 34 August 2010

Table 10. Impaired waters for nutrients, DO, and/or chlorophyll a.

- = Empty cell/no data

Planning Unit Waterbody Name WBID Impairment(s)

St. Lucie– 

Loxahatchee 

(Group 2 Basin)

- - - 

North St. Lucie North St. Lucie - DO, nutrients (historical chla)

North St. Lucie Tenmile Creek - DO

North St. Lucie St. Lucie - DO, nutrients (chla)

North St. Lucie Fivemile Creek - DO

C-24 C-24 Canal - DO, nutrients (chla)

C-23 C-23 Canal - DO, nutrients (chla)

South St. Lucie Tidal St. Lucie - Nutrients (chla)

South St. Lucie St. Lucie Canal - DO, nutrients (chla)

South St. Lucie South Fork St. Lucie - DO

South St. Lucie Bessey Creek - DO, nutrients (chla)

Loxahatchee North Fork Loxahatchee - DO, nutrients (chla)

Coastal North Coastal - Nutrients (chla)

Coastal St. Lucie River - Nutrients (chla)

Coastal Manatee Pocket - Nutrients (chla)

C-44 C-44 Canal - DO

Lake Worth Lagoon– 

Palm Beach Coast 

(Group 3 Basin)

- - - 

L-8 L-8 Canal 3233 DO

C-51 C-51 3245 DO, nutrients (chla)

C-51 Lake Clarke 3245B DO, nutrients (TSI)

C-17 PB Stations/D Canals 3242A DO, nutrients (chla)

C-15 Lake Ida 3262A Nutrients (TSI)

Hillsboro Canal E-4 Canal 3264D Nutrients (chla)

Intracoastal Hillsboro Inlet Park 8096B Historical chla

Biscayne Bay– 

Southeast Coast 

(Group 4 Basin)

- - - 

Broward Pompano Canal 3271 DO, nutrients (chla)

Broward C-13E/Middle River 3274 Nutrients (chla)

Broward North Fork New River 3276A DO, nutrients (chla)

Broward South New River Canal 3277A Nutrients (historical chla)

North Dade Snake Creek Canal E 3283 Nutrients (historical chla)

South Dade C-111 Canal 3303 Nutrients (historical chla)
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 35 August 2010

Numeric Nutrient Criteria for the Protection of Coral Communities

After determining that the southeast Florida coastal reef tract coral and hard bottom community is the 

most sensitive biological resource in this region, the FDEP evaluated three different lines of evidence to 

develop numeric nutrient criteria that would be protective of coral communities. The three approaches 

were (1) an evaluation of nutrient criteria developed by Hawaii and Australia to protect their coral reef 

communities, (2) an evaluation of available nutrient dosing experiment studies on corals, and (3) 

development of criteria calculated using available water quality data for the area that would maintain 

the currently healthy conditions of the southeast coral community.

Hawaii and Australia’s Criteria to Protect Corals

Hawaii and Australia, two areas with coral reef systems, have developed nutrient guidelines to protect 

their coral reefs, with combined wet season/dry season values ranges from 110-160 μg/L for TN and 16-

30 μg/L for TP, in open coastal waters (see Table 11). In Australia, guidelines for the Great Barrier Reef 

(GBR) were developed by Moss et al. (2005), using GBR water quality data and consulting the values 

recommended by Hawker and Connell (1989) which was drawn from worldwide literature. While the 

Moss et al. (2005) stated their dissolved inorganic nitrogen values (DIN, ranging from 1-5 μg/L) were 

similar to those of Hawker and Connell (2 μg/L), they also noted that the ortho-phosphate values 

derived (3-8 μg/L) were an order of magnitude higher than the Hawker and Connell guidelines (0.25 

μg/L, and that this was most likely due to Caribbean data used in the earlier research. Caribbean waters 

generally have lower concentrations of phosphate than waters adjacent to reefs in the Indo-Pacific 

(Moss et al. 2005). 

The Hawaiian criteria were also developed to protect the coral reefs from upland sources of nutrients, 

and included criteria for TN, TP and chlorophyll a, expressed as geometric means for wet and dry 

seasons, and criteria not to be exceeded more than 10% and 2% of the time. Chlorophyll a levels in 

Hawaii for both seasons (0.30 μg/L wet season and 0.15 μg/L dry season) were similar to both the GBR 

guidelines (0.5 μg/L wet season and 0.6 μg/L dry season) and those of Hawker and Connell (1989) (0.59 

μg/L, no seasons). Total P criteria in Hawaii (20 μg/L wet season and 16 μg/L dry season) were higher 

than the levels observed in the southeast Florida coastal waters (6.75 μg/L) because the Hawaiian TP 

background levels are naturally higher due to the underlying basalt.

Both Hawaii and Australia divide their coastal waters similarly (i.e. estuary, embayment, etc.) for the 

purposes of nutrient criteria. Waters on the southeast Florida coast are most similar to the “open 

coastal” or “Inshore” categories of Hawaii or Australia respectively. Additionally, both Hawaii and 

Australia established “wet and dry” criteria based on either freshwater input or regional climate. Values 

from Broward County OS-3 station are included in Table 11 for comparison to the criteria for Hawaii and 

Australia. In general, the existing southeast coast nitrogen concentrations were similar to the 

established Australian and Hawaii protective criteria, while the existing southeast coast phosphorus 

values were lower than Australian and Hawaii criteria. 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 36 August 2010

Table 11. Comparison of Hawaiian (HI) and Great Barrier Reef (GBR) nutrient criteria (in μg l-1) with

sample values from a Broward County station in southeast Florida (Station OS-3; see Figure 18 for 

exact location) (HAR 11-54, Moss et al. 2005).

- = Empty cell/no data

- Estuary Embayment (HI) 

or Enclosed 

Coastal (GBR)

Open Coastal 

(HI) or Inshore 

(GBR)

Ocean (HI) or 

Offshore (GBR)

TN HI criteria wet (dry) 200 200 (150) 150 (110) 50

TN GBR criteria 250-300 160-200 145-160 120-135

TN SE FL - - 108 - 

NH4 HI criteria wet (dry) 6 6 (3.5) 3.5 (2) 1 

NH4 GBR criteria - - - -

NH4 SE FL - - 3.33 - 

TP HI criteria wet (dry) 25 25 (20) 20 (16) 10

TP GBR criteria 20-25 20 20-30 10-30

TP SE FL - - 6.75 - 

Chlorophyll a HI criteria 

wet (dry)

2 1.5 (0.5) 0.30 (0.15) 0.06

Chlorophyll a GBR criteria 3-4 2 0.5-0.6 0.3-0.5

Chlorophyll a SE FL - - 0.64 - 

Criteria Based on Nutrient Dosing Experiments

As the second line of evidence, FDEP reviewed the available literature on nutrient dosing experiments 

on corals. While the literature was limited, experimental evidence suggests that Dissolved Inorganic 

Nitrogen levels of 14 μg/L would be protective of coral health (Renegar et al. 2008). Ambient data from 

the southeast coast indicates surface and bottom DIN values are near this protective level, and these 

observations, in conjunction with the overall health of the reef, indicate that existing nutrient and 

chlorophyll a levels are protective of the designated use.

Development of Nutrient Criteria to Support Healthy Conditions on the Southeast Florida Coral Reef 

Community

While benthic macroalgal growth and coral diseases have occurred in the offshore waters of the reef 

tract, the Southeast Florida Coral Reef Evaluation and Monitoring Project determined that the 

community composition and coral cover within the project’s thirteen monitoring sites was stable, and 

that diseases did not appear to be a major factor affecting stony corals at these sites. This information, 

in conjunction with comparisons of nutrient data for the southeast coast to the criteria developed by 

Hawaii and Australia and proposed by Renegar, supports the position that maintaining current levels of 

water quality should maintain the existing healthy condition of the coral reef and hard bottom 

communities. The following section describes the components of water quality criteria and the 

statistical method used to calculate proposed nutrient criteria.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 37 August 2010

Background on the Components of Water Quality Criteria

Methodology 

For consistent application and for providing an appropriate level of protection, water quality criteria 

need to include magnitude, frequency, and duration components. The magnitude is a measure of how 

much of a pollutant may be present in the water without an unacceptable adverse effect. Duration is a 

measure of how long the pollutant may be above the magnitude, and frequency relates to how often 

the magnitude may be exceeded without adverse effects. It is preferred to derive the magnitude 

component of a criterion through a cause-effect relationship (such as those measured through toxicity 

testing). The magnitude would then be set at a level that would protect a majority of the sensitive 

aquatic organisms inhabiting the system. Absent a demonstrated cause-effect relationship, the 

magnitude may be set at a level designed to maintain the current data distribution, accounting for 

natural temporal variability, when the current conditions are protective of the designated uses of the 

waterbody. Since a criterion derived based on the existing data distribution has no direct link to any 

observed cause and effect relationship, it is assumed that maintaining the current data distribution will 

preserve the uses associated with that distribution. 

The frequency and duration components of the criteria are best established as additional descriptors of 

the reference condition data distribution. Specifically, these components should be part of a statistical 

test designed to determine whether the long-term distribution of data has shifted upward (or in some 

cases, downward) from the reference distribution. This test would then be used to determine whether 

future monitoring data are consistent with the magnitude (long-term average) defined by the reference 

dataset. It is critical to account for the natural variability surrounding the magnitude expression and to 

control for statistical errors. 

The derivation of the magnitude, frequency and duration components of the numeric nutrient criteria 

for the Florida Keys is described briefly below. More details concerning the statistical approaches used 

can be found in the document “Overview of FDEP Approaches for Nutrient Criteria Development in 

Marine Waters” (FDEP 2010).

Magnitude 

The magnitude component can be set at a variety of values based on the frequency and duration that 

will be used to determine compliance. For the “healthy existing conditions” approach, FDEP established 

the magnitude at: a) an adjusted long-term central tendency (geometric mean) of the distribution, 

expressed as a long-term geometric mean never to be exceeded; and b) an annual geometric mean, not 

to be exceeded more than two times over a five-year period. The long-term average condition was 

adjusted to a level that represents an insignificant increase from the baseline. Allowing for an 

insignificant increase accounts for uncertainty in the estimate of the mean and partially addresses the 

fact that the reference based approach fails to identify a threshold of imbalance, and thus is highly 

prone to excessive Type I error. For the purpose of antidegradation evaluations, EPA has established 

that a 10% change in a water quality parameter represents an insignificant departure from the historical 

condition, known as a de minimus change (U.S. Sixth Circuit Court 2008). Therefore, the long-term 

geometric mean limit was derived to allow for up to a 10% increase in the long-term geometric mean, 

which was calculated as the geometric mean of the annual geometric means of the long-term dataset 

for each segment of the waterbody.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 38 August 2010

Because it is not always practical to assess compliance with the criteria on the same long-term basis, 

FDEP also developed criteria expressed as an annual geometric mean so that estuaries could be assessed 

on an annual basis. It should be noted that the duration and frequency components of the criteria must 

be linked to the response timeframe of the sensitive endpoint. Short-term averaging periods (e.g., 1 to 

30 days) might be appropriate for nutrient criteria where a sufficiently robust cause-effect relationship 

has demonstrated that a eutrophic response occurs over such time frames. If however, such a shortterm response cannot be demonstrated, or there is no indication of use impairment, longer averaging 

periods should be used. 

Duration and Frequency

Since the duration and frequency components of the criteria must be consistent with the derivation of 

the magnitude component, the long-term geometric mean target cannot simply be applied as an annual 

mean. Doing so would result in an unacceptability high Type I failure rate (identifying a healthy system 

as being impaired) since approximately 50% of the individual yearly means are expected to be above the 

long-term mean. Therefore, the long-term target must be adjusted to allow for the application to a 

shorter duration with an acceptable Type I error rate of no more than 10%. 

An annual criterion with an approximate 10% Type I error rate for a given frequency was derived by 

appropriately accounting for the annual variability above the mean. This annual target concentration 

was derived as an upper percentile of the distribution of the annual geometric mean concentrations. 

Previous proposals by EPA have utilized 3-year assessment periods to express the duration nutrient 

criteria components. Although it is possible to construct a test that achieves the 10% Type I error rate 

target over a 3-year period, a slightly longer period (5 years) will provide better control for Type II error 

and will more fully capture climatic cycles (e.g., el Niño, la Niña), which tend to be longer than 3 years in 

Florida (and may actually be on a multi-decadal scale). Furthermore, a 5-year period is more consistent 

with both the state’s 5-year 303(d) assessment and NPDES permit renewal cycles.

Given a five year assessment period, FDEP derived criteria expressed as an annual geometric mean by 

using the 75th percentile of the annual geometric means from the long-term dataset. FDEP 

demonstrated that setting the criteria at this percentile results in a magnitude that, when expressed as 

an annual geometric mean not to be exceeded more than twice during a 5-year period, will achieve the 

targeted 10% error rate. The magnitude component of the criteria (not to be exceeded more than twice 

in a 5-year period) was established to allow for 2 separate assessments:

• As an annual geometric mean for a network of stations in a specified segment of the 

waterbody; and 

• As an annual geometric mean for a single station in a given segment. 

The two expressions of magnitude differ in the handling of within-segment spatial variability. The 

network average magnitude was calculated based on the distribution of spatially averaged annual 

geometric means, while the single site magnitude was calculated using the distribution of station annual 

geometric means. Use of the network average magnitude is appropriate for assessing overall segment 

status. However, a network average is only representative of overall segment status if it is relatively 

homogeneous. If the segment is not well mixed, is very large, or contains localized nutrient sources, 

then there is a potential that isolated areas of enrichment may be masked in the network spatial 

average. Therefore, the single station annual geometric mean has the benefit of assessing localized 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 39 August 2010

enrichment patterns. FDEP has not decided whether both expressions of magnitude are needed in all 

cases, and we are seeking additional feedback from local experts and stakeholders.

Summary of the Proposed Criteria

FDEP proposes three sets of potential criteria: (1) a long-term geometric mean concentration; (2) an 

annual geometric mean of values from a network of stations over a given area, not to be exceeded more 

than twice in a five-year period; and (3) an annual geometric mean of values from a single location, not 

to be exceeded more than twice in a five-year period. 

Proposed Criteria

The proposed long-term targets for the protection of a healthy, well-balanced aquatic community in the 

southeast Florida coast are provided in Tables 12a, 12b, 12c, and 12d. The proposed criteria are based 

on a data from sampling locations selected as representative of minimally affected by anthropogenic 

sources. The sites are OS1 and 3 in Broward County (Figure 18) for TP and TN, and BD 1, 2, 7-12, and 15 

from the FACE studies (Figure 12). Data from each of these sites were used to develop chlorophyll a and 

DIN values below. 

Table 12a. Proposed numeric nutrient criteria for TP (ug/L) for the Southeast Florida Coastal Reef 

Tract. 

Note: The criteria are based on 4 years of data from 2 stations. For compliance purposes, the long-term geometric mean shall not exceed the 

long-term limit nor shall the average of all stations in a segment exceed the network average more than twice in a 5-year period. The last 

column shows the value that a single station shall not exceed more than twice in a 5-year period. Note that FDEP is evaluating if the data are 

sufficient to finalize criteria.

Depth Long-Term 

Geometric 

Mean

Long-Term 

Limit

Network 

Average 2 Out 

of 5 Year Annual 

Limit

Assessed as a 

Single Site 

Geometric Mean 2 

Out of 5 Year 

Annual Limit

Surface 7.13 7.85 9.7 9.9

Bottom 6.92 7.61 9.4 9.6

Surface to Bottom 7.04 7.74 9.6 9.7

Table 12b. Proposed numeric nutrient criteria for TN (ug/L) for the Southeast Florida Coastal Reef 

Tract. 

Note: The criteria are based on 4 years of data from 2 stations. For compliance purposes, the long-term geometric mean shall not exceed the 

long-term limit nor shall the average of all stations in a segment exceed the network average more than twice in a 5-year period. The last 

column shows the value that a single station shall not exceed more than twice in a 5-year period. Note that FDEP is evaluating if the data are 

sufficient to finalize criteria.

Depth Long-Term 

Geometric 

Mean

Long-Term 

Limit

Network 

Average 2 Out 

of 5 Year Annual 

Limit

Assessed as a 

Single Site 

Geometric Mean 2 

Out of 5 Year 

Annual Limit

Surface 118 130 164 168

Bottom 112 124 157 161

Surface to 

Bottom

116 127 161 165

 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 40 August 2010

Table 12c. Proposed numeric nutrient criteria for chlorophyll a (ug/L) for the Southeast Florida Coastal 

Reef Tract. 

Note: The criteria are based on 3 years of data. For compliance purposes, the long-term geometric mean shall not exceed the long-term limit 

nor shall the average of all stations in a segment exceed the network average more than twice in a 5-year period. The last column shows the 

value that a single station shall not exceed more than twice in a 5-year period. Note that FDEP is evaluating if the data are sufficient to finalize 

criteria.

Depth Long-Term 

Geometric 

Mean

Long-Term 

Limit

Network 

Average 2 Out 

of 5 Year Annual 

Limit

Assessed as a 

Single Site 

Geometric Mean 2 

Out of 5 Year 

Annual Limit

Surface 0.46 0.51 0.69 0.78

Bottom 0.38 0.41 0.54 0.60

Surface to 

Bottom

0.43 0.47 0.63 0.69

Table 12b. Proposed numeric nutrient criteria for DIN (ug/L) for the Southeast Florida Coastal Reef 

Tract. 

Note: The criteria are based on 4 years of data. For compliance purposes, the long-term geometric mean shall not exceed the long-term limit 

nor shall the average of all stations in a segment exceed the network average more than twice in a 5-year period. The last column shows the 

value that a single station shall not exceed more than twice in a 5-year period. Note that FDEP is evaluating if the data are sufficient to finalize 

criteria.

Depth Long-Term 

Geometric 

Mean

Long-Term 

Limit

Network 

Average 2 Out 

of 5 Year Annual 

Limit

Assessed as a 

Single Site 

Geometric Mean 2 

Out of 5 Year 

Annual Limit

Surface 9.1 10.0 12.6 13.3

Bottom 10.6 11.7 14.0 14.9

Surface to 

Bottom

10.1 11.1 13.5 14.2
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 41 August 2010

References

Wren, K., and S. Blitch. 2010. St. Joseph Bay. Apalachicola public workshop presentation on February 

11, 2010, in support of FDEP numeric nutrient criteria for estuarine and coastal waters. 

Banks, K., C. Beaver, J. Bohnsack, R.E. Dodge, D. Gilliam, W. Jaap, B. Keller, V.R. Leeworthy, T. Matthews, 

R. Ruiz-Carus, D. Santavy, and R. Spieler. 2005. The State of Coral Reef Ecosystems of Florida. pp. 

150-200. In: J. Waddell (ed.), The State of Coral Reef Ecosystems of the United States and Pacific 

Freely Associated States: 2005. NOAA Technical Memorandum NOS NCCOS 11. NOAA/NCCOS 

Center for Coastal Monitoring and Assessment’s Biogeography Team. Silver Spring, MD. 522 pp.

Banks, K.W., B.M. Riegl, E.A. Shinn, W.E. Piller, and R.E. Dodge. 2007. Geomorphology of the southeast 

Florida continental reef tract (Miami-Dade, Broward, and Palm Beach Counties, USA). Coral 

Reefs 26: 617-633.

Banks, K.W., B.M. Riegl, V.P. Richards, B.K. Walker, K.P Helmle, L.K.B. Jordan, J. Phipps, M.S. Shivji, R.E. 

Spieler, R.E. Dodge. 2008. Chapter 5. The reef tract of continental southeast Florida (MiamiDade, Broward and Palm Beach Counties, USA). Ed. B.M. Riegl, R.E. Dodge, Coral Reefs of the 

USA, Springer Science and Business Media B.V., 2008.

Boynton-Delray Coastal Water Quality Monitoring Plan, 2007. NOAA Atlantic Oceanographic and 

Meteorological Laboratories Ocean Chemistry Division. Miami, Florida.

Broward County Department of Planning and Environmental Protection. 2001. Florida Historical Water 

Quality Atlas, 1972-1997. Technical Report Series 01-03. Water Resources Division and 

Environmental Monitoring Division.

Carsey, T., C. Featherstone, K. Goodwin, C. Sinigalliano, J. Stamates, J-Z. Zhang, J. Proni, J. Bishop, C. 

Brown, M.M. Adler, P.L. Blackwelder, and H. Alsayegh. 2010a. DRAFT Boynton-Delray Coastal 

Water Quality Monitoring Program. NOAA Technical Report, OAR-AOML

Carsey, T., H. Casanova, C. Drayer, C. Featherstone, C. Fischer, K. Goodwin, J. Proni, A. Saied, C. 

Sinigalliano, J. Stamates, P. Swart, and J-Z. Zhang. 2010b. FACE Outfalls Survey Cruise – October 

6-19, 2006. NOAA Technical Report, OAR-AOML, Atlantic Oceanographic and Meteorological 

Laboratory, Miami, Florida.

Carsey, T., J. Bishop, C. Brown, S. Cummings, C. Featherstone, D. Meerhoff, C. Sinigalliano, J. Stamates, 

N. Amornthammarong, F. Bloetscher, J. Craynock, P. Dammann, K. Goodwin, J. Proni, P. Swart, 

and J-Z. Zhang. 2007. Boynton Inlet 48-hour Sampling Intensives, June and September 2007. 

NOAA Data Report AOML-XX.

Carsey, T., K.D. Goodwin, J. Hendee, J.R. Proni, C. Sinigalliano, J. Stewart, J-Z. Zhang, N. 

Amornthammarong, J. Craynock, S. Cummings, P. Dammann, C. Featherstone, J. Stamates, K. 

Sullivan. 2008. A glimpse of the Florida Area Coastal Environment (FACE) program. Proceedings 

of the 11th International Coral Reef Symposium, Ft. Lauderdale, Florida, 7-11 July 2008. Session 

no. 16.

Carsey, T.P. and J. Stamates. 2009. The Florida Area Coastal Environment (FACE) Program. NOAA/AOML. 

Miami, FL. Retrieved on July 28, 2010. 

http://www.aoml.noaa.gov/themes/CoastalRegional/projects/FACE/PDF/FactSheet_31mar09.p

df

Chiappone, M., Sullivan K.M. 1994. Ecological Structure and Dynamics of Nearshore Hard-Bottom 

Communities in the Florida Keys. Bulletin of Marine Science 54(3): 747-756. 
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 42 August 2010

Collier, C., R. Ruzicka, K. Banks, L. Barbier, J. Beal, D. Bingham, J. Bohnsack, S. Brooke, N. Craig, R. Dodge, 

L. Fisher, N. Gadbois, D. Gilliam, L. Gregg, T. Kellison, V. Kosmynin, B. Lapointe, E. McDevitt, J. 

Phipps, N. Poulos, J. Proni, P. Quinn, B. Riegl, R. Spieler, J. Walczak, B. Walker, and D. Warrick. 

2008. The State of Coral Reef Ecosystems of Southeast Florida. pp. 131-159. In: J.E. Waddell and 

A.M. Clarke (eds.), The State of Coral Reef Ecosystems of the United States and Pacific Freely 

Associated States: 2008. NOAA Technical Memorandum NOS NCCOS 73. NOAA/NCCOS Center 

for Coastal Monitoring and Assessment’s Biogeography Team. Silver Spring, MD. 569 pp.

Cook, C.B., E.M. Mueller, M.D. Ferrier, E. Annis. 2002. Chapter 28. The influence of nearshore waters on 

corals of the Florida reef tract. Ed. J.W. Porter, K.G. Porter, CRC Preess, Boca Raton, Florida.

Fabricius, K.E., 2005. Effects of terrestrial runoff on the ecology of corals and coral reefs: review and 

synthesis. Marine Pollution Bulleting 50: 125-146.

FACE. 2010. The Florida Area Coastal Environment Program: An Overview. 

http://www.aoml.noaa.gov/themes/CoastalRegional/projects/FACE/faceweb.htm. Retrieved on 

July 28, 2010.

Furnas, M., A. Mitchell, M. Skuza, J. Brodie. 2005. In the other 90%: phytoplankton responses to 

enhanced nutrient availability in the Great Barrier Reef Lagoon. Marine Pollution Bulletin, 51: 

253-265.

Gilliam, D.S. 2009. Southeast Florida Coral Reef Evaluation and Monitoring Project, 2008 Year 6 Final 

Report. 2007. National Coral Reef Institute, Nova Southeastern University Oceanographic 

Center. FDEP contract number G0099.

Gross, M.G. ed; 1982. Oceanogrpahy.

Hawaiian Water Quality Standards. 2004. Hawaii Department of Health. Amendment and compilation 

of Chapter 11-54 Hawaii Administrative Rules, August 31, 2004.

Jaap, W.C. and P. Hallock. 1990. Chapter 17 Coral Reefs. In: Ecosystems of Flroida. Eds: R.L. Myers, J.J. 

Ewel. Univ. Central Florida Press, Orlando.

Jameson. S.C. and R.A. Kelty. 2004. A review of indicators of land-based pollution stress on coral reefs. 

A background paper for the joint EPA/NOAA/USGA/DOI workshop on Assessing Pollution Stess 

on Coral Reefs, August 310September 2, 2004. Honolulu, HI.

Kleypas J.A., R. W. Buddemeier, D. Archer, J.P. Gattuso, C. Langdon, B.N. Opdyke. 1999. Geochemical 

consequences of increased atmospheric carbon dioxide on coral reefs. Science 284:118–120. 

Lapointe, B.E., P.J. Barile, M.M. Littler, D.S. Littler, B.J. Bedford, C. Gasque. 2005a. Macroalgal blooms on 

southeast Florida coral reefs I. Nutrient stoichiometry of the invasive green alga Codium 

isthmocladum in the wider Caribbean indicates nutrient enrichment. Harmful Algae 4: 1092-

1105.

Lapointe, B.E., P.J. Barile, M.M. Littler, D.S. Littler. 2005b. Macroalgal blooms on southeast Florida coral 

reefs II. Cross-shelf discrimination of nitrogen sources indicates widespread assimilation of 

sewage nitrogen. Harmful Algae 4: 1106-1122.

Moss, A., J. Brodie, M. Furnas. 2005. Water quality guidelines for the Great Barrier Reef World Heritage 

Area: a basis for development and preliminary values. Marine Pollution Bulletin 51: 76-88.

Moyer, R.P., B Riegl, K Banks, RE Dodge. 2003. Spatial patterns and ecology of benthic communities on 

a high-latitude South Florida (Broward County, USA) reef system. Coral Reefs 22: 447-464.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 43 August 2010

Payton, A. 2006. Submarine groundwater discharge: An important source of new inorganic nitrogen to 

coral reef ecosystems. Notes in Limnology and Oceanography 51(1): 343-348. 

Proni, J., M. Adler, D. Meerhoff, N. Amornthammarong, K. Goodwin, J. Bishop, E. Peltola, F. Bloetscher, 

D. Pierrot, T. Carsey, C. Sinigalliano, J. Craynock, P. Swart, S. Cummings, J. Stamates, P. 

Dammann, K. Sullivan, C. Drayer, R. Wanninkhof, C. Featherstone, and J-Z. Zhang. 2009. Final 

Report: An Investigation of the South Central Regional Wastewater Treatment Plant Ocean 

Outfall and Coastal Environment. Florida Area Coastal Environment (FACE) Project.

Proni, J.R. and R.G. Williams. 1997. Chapter 22. Acoustic measurements of currents and effluent plume 

dilutions in the western edge of the Florida Current. In: Acoustic Remote Sensing Applications, 

Ed. S.P. Singal, Narosa Publishing House, New Delhi, India.

Renegar, D.A., P.L. Blackwelder, and A.L .Moulding. 2008. Coral ultrastructural response to elevated 

pCO2 and nutrients during tissue repair and regeneration. Proceedings of the 11th International 

Coral Reef Symposium, Ft. Lauderdate, Florida, Session 25, July 7-11.

Renegar, D.A. and B.M. Riegl. 2005. Effect of nutrient enrichment and elevated CO2 partial pressure on 

growth rate of Atlantic scleractinian coral Acropora cervicornis. Marine Ecology Progress Series 

293: 69-76.

Risk, M.J., B.E. Lapointe, O.A. Sherwood, and B.J .Bedford. 2009. The use of δ15N in assessing sewage 

stress on coral reefs. Marine Pollution Bulletin 58: 793-802. 

Sherwood, O.A., B.E. Lapointe, M.J. Risk, R.E. Jamieson. In press. Nitrogen Isotopic Records of Terrestrial 

Pollution Encoded in Floridian and Bahamian Gorgonian Corals. Environmental Science and 

Technology (accepted Nov 2009).

Smith, J. 1985. Temporal and special characteristics of summer upwelling along Florida’s Atlantic shelf. 

Journal of Physical Oceanography 13: 1715.

Tichenor, E. 2003. The occurrence and distribution of cyanobacteria on Gulf Stream Reef, Boynton 

Beach, Florida. Palm Beach County Reef Rescue. http://www.reef-rescue.org/PDFreports.shtml

Tichenor, E. 2004a. Correlation between waste water treatment plant effluent quality and cyanobacteria 

proliferation on Gulf Stream Reef, Boynton Beach, Florida. Palm Beach County Reef Rescue. 

http://www.reef-rescue.org/PDFreports.shtml

Tichenor, E. 2004b. The occurrence and distribution of cyanobacteria on Gulf Stream Reef, Boynton 

Beach, Florida. Palm Beach County Reef Rescue. http://www.reef-rescue.org/PDFreports.shtml

Tichenor, E. 2006. Examination of effluent plume behavior Delray Beach, Florida ocean outfall. Palm 

Beach County Reef Rescue. http://www.reef-rescue.org/PDFreports.shtml

U.S. Census Bureau 2009. http://www.census.gov

Wagner, D.E., R Kramer, R vanWoeslk; 2010. Species composition, habitat, and water quality influence 

coral bleaching on Southern Florida. Marine Ecology Progress Series 408: 65-78.

Wanninkhof, R., K. Sullivan, W.P. Dammann, J.R. Proni, F. Bloetscher, A.V. Soloviev, and T.P. Carsey. 

2005. Farfield tracing of a point source discharge plume in the coastal ocean using sulfur 

hexafluoride. Environmental Science and Technology 39: 9993-8890.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 44 August 2010

Appendix A. Coral Reef Data-Gathering Activities Summary and Acronyms from Collier et al. 

2008.
Nutrient Criteria Technical Support Document Southeast Florida Coastal Reef Tract

Draft 45 August 2010