2 

Background 

As described in the proposed federal rule, on January 14, 2009, EPA determined under CWA 

section 303(c)(4)(B) that new or revised water quality standards (WQS) in the form of numeric 

nutrient water quality criteria are necessary to meet the requirements of the CWA in the State of 

Florida. Florida’s currently applicable narrative nutrient criterion provides, in part, that “in no 

case shall nutrient concentrations of a body of water be altered so as to cause an imbalance in 

natural populations of aquatic flora or fauna,” Florida Administrative Code (F.A.C.) 62-302-

530(47)(b). EPA determined that Florida’s narrative nutrient criterion alone was insufficient to 

ensure protection of applicable designated uses. 

In August 2009, EPA also entered into a Consent Decree with Florida Wildlife Federation, Sierra 

Club, Conservancy of Southwest Florida, Environmental Confederation of Southwest Florida, 

and St. Johns Riverkeeper, committing to propose numeric nutrient criteria for lakes and flowing 

waters in Florida by January 14, 2010, and for Florida's estuarine and coastal waters by January 

14, 2011. Under the Consent Decree, final rules will need to be issued by October 15, 2010 for 

lakes and flowing water. On June 7, 2010, EPA and Plaintiffs filed a joint notice with the Court 

extending the deadlines for promulgating numeric nutrient criteria for Florida's estuaries, flowing 

waters in south Florida (including canals), and the downstream protection values for flowing 

waters into estuaries. The new deadlines are November 14, 2011 for proposing the estuarine 

criteria, and August 15, 2012 for publishing a final rule for these three categories. This will 

allow EPA time to have proposed criteria peer-reviewed by the SAB. The original deadline of 

October 15, 2010 remains in place for EPA to finalize numeric nutrient criteria for Florida's 

lakes and other flowing waters (streams and springs), outside of south Florida. 

Current Federal Action

In accordance with the determination and EPA’s Consent Decree, EPA has proposed numeric 

nutrient criteria for Florida’s lakes and flowing waters. EPA’s determination did not apply to 

Florida’s wetlands, and as a result, Florida’s wetlands will not be addressed in this rulemaking or 

in EPA’s forthcoming rulemaking involving estuaries and coastal waters. EPA’s Biological 

Evaluation addressed the January 14, 2010 proposed numeric nutrient criteria for lakes and 

flowing waters, and subsequent information provided in a supplemental Notice of Data 

Availability (NODA; 8/3/2010) 

In developing these proposed numeric nutrient criteria for rivers and streams, EPA also evaluated 

their effectiveness for assuring the protection of downstream lake designated uses pursuant to the 

provisions of 40 CFR 130.10(b), which requires that WQS must provide for the attainment and 

maintenance of the WQS of downstream waters. For rivers and streams in Florida, EPA must 

ensure, to the extent that available science allows, that its nutrient criteria take into account the 

impact of near-field nutrient loads on aquatic life in downstream lakes. Regarding numeric 

nutrient criteria for springs, EPA is proposing a nitrate-nitrite criterion for springs based on 

experimental laboratory data and field evaluations that document the response of algae and 

periphyton to nitrate-nitrite concentrations. 
3 

Additionally, EPA is including in this notice a proposed approach for deriving Federal sitespecific alternative criteria (SSAC) based upon State submissions of scientifically defensible 

recalculations that meet the requirements of CWA section 303(c). Total Maximum Daily Load 

(TMDL) targets submitted to EPA by the State for consideration as new or revised WQS could 

be reviewed under this SSAC process. Because SSAC will likely be adopted after the 

promulgation of the final nutrient criteria rule, the SSAC will be subject to future consultation on 

a site-specific basis as EPA approves the SSAC in the future. 

Action Area 

This action includes all the waters of the United States within the jurisdiction of the State of 

Florida. More specifically, the criteria proposed in this rulemaking apply to lakes and flowing 

waters, including springs and canals in the State of Florida, with the exception of flowing waters 

in South Florida. EPA’s proposal defines “lakes and flowing waters” to mean inland surface 

waters that have been classified as Class I (Potable Water Supplies) or Class III (Recreation, 

Propagation and Maintenance of a Healthy, Well-Balanced Population of Fish and Wildlife) 

water bodies pursuant to Rule 62-302.400, F.A.C., excluding wetlands, and which are 

predominantly fresh waters. 

The Clean Water Act defines waters of the United States as: (a) All waters which are currently 

used, were used in the past, or may be susceptible to use in interstate or foreign commerce, 

including all waters which are subject to ebb and flow of the tide; (b) All interstate waters, 

including interstate “wetlands;” (c) All other waters such as intrastate lakes, rivers, streams 

(including intermittent streams), mudflats, sandflats, “wetlands,” sloughs, prairie potholes, wet 

meadows, playa lakes, or natural ponds the use, degradation, or destruction of which would 

affect or could affect interstate or foreign commerce including any such waters: (1) Which are or 

could be used by interstate or foreign travelers for recreational or other purposes; (2) From which 

fish or shellfish could be taken and sold in interstate or foreign commerce; (3) Which are used or 

could be used for industrial purposes by industries in interstate commerce; (d) All impoundments 

of waters otherwise defined as waters of the United States under this definition; (e) Tributaries of 

waters identified in paragraphs (a) through (d) of this definition; (f) The territorial sea; and (g) 

“Wetlands” adjacent to waters (other than waters that are themselves wetlands) identified in 

paragraphs (a) through (f) of this definition. [40 CFR § 122.2 Waters of the United States or 

waters of the U.S.] 

 
4 

Action Agency Effect Determinations for Relevant Federally Listed Species and Critical 

Habitats 

Lakes 

The following table summarizes the aquatic dependent listed species expected to be found in the 

lakes portion of the action area, EPA’s determination of effects from the action, and a brief 

explanation of why this determination was made. 

 Species in Action Area Determination of Effects Reason for determination 

West Indian manatee ABC 

(Trichechus manatus)

NLAA Beneficial - enhance habitat; reduction 

in cyanobacteria blooms 

Everglade snail kite BC 

(Rostrhamus sociabilis 

plumbeus)

NLAA Discountable – effects extremely 

unlikely to occur 

Whooping crane BC 

(Grus americana)

NLAA Discountable – effects extremely 

unlikely to occur 

Wood stork ABC 

(Mycteria americana)

NLAA Discountable – effects extremely 

unlikely to occur 

American crocodile C 

(Crocodylus acutus)

NLAA Discountable – effects extremely 

unlikely to occur 

A –Panhandle, B- North Florida, C- South Florida, NLAA-Not Likely to Adversely Affect 

Springs 

The following table summarizes the aquatic dependent listed species expected to be found in the 

springs portion of the action area, EPA’s determination of effects from the action, and a brief 

explanation of why this determination was made. 

 Species in Action Area Determination of Effects Reason for determination 

West Indian manatee ABC 

(Trichechus manatus)

NLAA Beneficial – enhance habitat; reduction 

in cyanobacteria blooms 

Everglade snail kite BC 

(Rostrhamus sociabilis 

plumbeus)

NLAA Discountable – effects extremely 

unlikely to occur 

Whooping crane BC 

(Grus americana)

NLAA Discountable – effects extremely 

unlikely to occur 

Wood stork ABC 

(Mycteria americana)

NLAA Discountable – effects extremely 

unlikely to occur 

A –Panhandle, B- North Florida, C- South Florida, NLAA-Not Likely to Adversely Affect 

 
5 

Streams and Rivers 

The following table summarizes the aquatic and aquatic dependent listed and candidate species 

expected to be found in the rivers and streams portion of the action area, EPA’s determination of 

effects from the action, and a brief explanation of why this determination was made. 

 Species in Action Area Determination of Effects Reason for determination 

West Indian manatee ABC 

(Trichechus manatus)

NLAA Beneficial - enhance habitat; reduction 

in cyanobacteria blooms 

Everglade snail kite BC 

(Rostrhamus sociabilis 

plumbeus)

NLAA Discountable – effects extremely 

unlikely to occur 

Whooping crane BC 

(Grus americana)

NLAA Discountable – effects extremely 

unlikely to occur 

Wood stork ABC 

(Mycteria americana)

NLAA Discountable – effects extremely 

unlikely to occur 

American crocodile C 

(Crocodylus acutus)

NLAA Discountable – effects extremely 

unlikely to occur 

Gulf sturgeon AB 

(Acipenser oxyrinchus 

desotoi)

NLAA Beneficial – sensitive to poor water 

quality and low DO 

Okaloosa darter A 

(Etheostoma okaloosae)

NLAA Beneficial – water quality may affect 

competition with similar species 

Shortnose sturgeon BE 

(Acipenser brevirostrum) 

NLAA Beneficial – sensitive to poor water 

quality and low DO 

Chipola slabshell mussel A 

(Elliptio chipolaensis) 

NLAA Beneficial – sensitive to poor water 

quality 

Fat threeridge mussel A 

(Amblema neislerii) 

NLAA Beneficial – sensitive to poor water 

quality 

Gulf moccasinshell mussel A 

(Medionidus penicillatus) 

NLAA Beneficial – sensitive to poor water 

quality 

Ochlockonee moccasinshell 

mussel A 

(Medionidus simpsonianus) 

NLAA Beneficial – sensitive to poor water 

quality 

Oval pigtoe mussel AB 

(Pleurobema pyriforme) 

NLAA Beneficial – sensitive to poor water 

quality 

Purple bankclimber mussel A 

(Elliptoideus sloatianus) 

NLAA Beneficial – sensitive to poor water 

quality 

Shinyrayed pocketbook mussel

A (Lampsilis subangulata) 

NLAA Beneficial – sensitive to poor water 

quality 

Choctaw bean D 

(Villosa choctawensis) 

NLAA Beneficial – sensitive to poor water 

quality 

Round ebonyshell D 

(Fusconaia rotulata) 

NLAA Beneficial – sensitive to poor water 

quality 

Southern kidneyshell D 

(Ptychobranchus jonesi) 

NLAA Beneficial – sensitive to poor water 

quality 
6 

The following table summarizes the aquatic and aquatic dependent listed and candidate species 

expected to be found in the rivers and streams portion of the action area, EPA’s determination of 

effects from the action, and a brief explanation of why this determination was made. 

Fuzzy pigtoe D 

(Pleurobema strodeanum) 

NLAA Beneficial – sensitive to poor water 

quality 

Narrow pigtoe D 

(Fusconaia escambia) 

NLAA Beneficial – sensitive to poor water 

quality 

Tapered pigtoe D 

( Quincuncina burkei) 

NLAA Beneficial – sensitive to poor water 

quality 

Southern sandshell D 

(Lampsilis australis) 

NLAA Beneficial – sensitive to poor water 

quality 

A –Panhandle, B- North Florida, C- South Florida, D-Candidate Species, E-Under the 

Jurisdiction of the National Marine Fisheries Service, NLAA-Not Likely to Adversely Affect 

Species-specific analyses of nutrient effects, Analysis of the species and critical habitat that 

may be affected (Supporting references found in Appendix A) 

West Indian Manatee 

The species recovery plan for the West Indian manatee states that the species is “dependent upon 

the health of its entire habitat” and that the manatee’s presence or absence can often be a sign of 

the health of other species that share the same habitat (Service 1999). Numerous human 

activities, including eutrophication, have detrimental effects to manatees’ habitats, and therefore, 

on the health of manatee populations. The recovery plan adds information from the Marine 

Mammal Commission’s 1991 report to congress saying that “Siltation, eutrophication, other 

forms of water pollution, ... degrade the coastal and riverine communities. This degradation 

reduces manatee food supplies and eliminates the secluded areas that are used by manatees to 

mate, calve, and nurse” (Service 1999). Increased nutrient inputs may also affect manatees by 

contributing to harmful algal blooms, such as Lyngbya sp. These species bloom when excess 

nutrients are available and out-compete native seagrasses, such as those that are consumed by 

manatees. Additionally, the toxins produced by Lyngbya are associated with ulcerative 

dermatitis in manatees (Harr et al.2008). Reduction of nutrient inputs through numeric criteria 

could aid in decreasing the frequency or magnitude of Lyngbya blooms, which in turn would 

increase habitat for the manatee’s primary food source, and decrease manatee exposure to the 

cyanobacterial toxins. Whether reducing cyanobacterial blooms or reversing degradation of 

coastal and riverine habitats, the reduction of nutrient loading in Florida waters would be wholly 

beneficial to the West Indian manatee. 

The EPA determined the proposed inland nutrient criteria are “not likely to adversely affect” the 

West Indian manatee. Based on our analysis (as discussed in Appendix B), the Service concurs 

with EPAs determination. We will reconsider effects to this species during the development of 

the South Florida Region inland nutrient criteria and the statewide estuarine nutrient criteria. 

EPA did not make an effect determination for manatee critical habitat for the proposed numeric 
7 

nutrient criteria in inland waters. There is no critical habitat for the West Indian manatee in lakes 

in Florida; therefore, none will be affected. Based on the available information (Appendix B), 

the Service believes that the proposed nutrient rule “may affect, but is not likely to adversely 

affect” West Indian manatee critical habitat in Florida inland streams or springs. This letter can 

be used as concurrence of that conclusion. We will reconsider effects to this species’ critical 

habitat during the development of the South Florida Region inland nutrient criteria next year and 

the estuarine nutrient criteria (set for 2012). 

Everglade snail kite 

By implementing numerical nutrient criteria, nutrient levels within the waters of the Everglade 

snail kite’s habitat should decrease, which should allow for a greater abundance of the kite’s 

primary prey species. Excess nutrient supply near input sources has facilitated a shift from a 

marsh community dominated by sawgrass to one that favors cattails. The native sawgrass 

communities provide suitable habitat for apple snails, which are the primary food source of the 

Everglade snail kite. Because increased nutrients allow for a community dominated by cattails, 

setting numeric nutrient criteria should aid in the re-establishment of sawgrass due to reduced 

nutrient input. Increasing sawgrass habitat, which provides habitat for apple snails, should 

increase the primary food source for the Everglade snail kite. Any effects to the snail kite 

directly (not its food source) are discountable. Therefore, a decrease in nutrient loading from the 

implementation of numeric nutrient criteria in the habitat of the Everglade snail kite should not 

harm the species because of the unlikelihood of adverse effects. The primary threat to the 

species is habitat loss or degradation, and nutrients would pose a discountable effect as compared 

to these primary threats. 

EPA has determined that the proposed nutrient criteria will “not likely adversely affect” the 

Everglade snail kite. As a result of our analysis (Appendix B) and the antidegradation policy 

already in place to protect low-nutrient waters (i.e., lower than 40 ppb), and the existing 

phosphorus condition of other waterbodies utilized by kites (greater than 50 ppb), the Service 

concurs with EPA, that the proposed rule “may affect, but is not likely to adversely affect” the 

Everglade snail kite. The Service will reassess potential effects to this species during 

development of EPAs South Florida Region’s inland nutrient criteria. 

EPA did not make an effect determination for snail kite critical habitat. However, based on the 

available information in Appendix B, the Service determines that the proposed rule “may affect, 

but is not likely to adversely affect snail kite critical habitat.” This letter can be used as 

concurrence of that determination. The Service will re-assess the effects to this species’ critical 

habitat when EPA develops their South Florida Region nutrient rule. 

Whooping Crane 

As documented in the Canadian Wildlife Service/FWS’s joint recovery plan for the whooping 

crane, the species’ primary threats include limited genetics, collisions with power lines or other 

structures, loss and degradation of migration stopover habitat and coastal ecosystems, and threat 

of chemical spills in their primary wintering grounds (Canadian Wildlife Service and Service 
8 

2007). No information regarding direct or indirect effects of nutrients on this species could be 

identified, thus the frequency of effects to whooping cranes would be discountable as compared 

to the primary threats to the species. 

EPA determined the proposed numeric inland nutrient criteria “may affect, but are not likely to 

adversely affect” the whooping crane (Grus americana). Due to this species being an 

experimental, nonessential population in Florida, EPA is not required to consult under section 

7(a)2 of the Endangered Species Act for the whooping crane. 

Wood Stork 

As described in the multi-species recovery plan for the wood stork, the major threat to this 

species is loss of habitat from the disruption of natural water flow in swamp areas of south 

Florida (Service 1997). No information regarding direct or indirect effects of nutrients on this 

species could be identified, and thus the frequency of potential effects to wood stork are expected 

to be negligible compared to the primary threats to the species. Wood stork are not directly 

affected by nutrient concentrations. 

The EPA determined the proposed inland nutrient criteria “may affect, but are not likely to 

adversely affect” the wood stork. Based on our analysis, the Service concurs with EPAs 

determination (see Appendix C for further information). We will reconsider effects to this 

species during the development of the South Florida Region inland nutrient criteria and the 

statewide estuarine nutrient criteria. 

American Crocodile 

According to the recovery plan for the American crocodile, the major impacts to the species are 

habitat degradation and fragmentation, changes in hydrologic conditions within their habitat, and 

mortality from both natural (cold, hurricanes) and anthropogenic (vehicle collisions) causes 

(Service 1999). No information regarding direct or indirect effects of nutrients on this species 

could be identified, thus the frequency of potential harm to American crocodiles would be 

discountable as compared to the primary threats to the species. 

The EPA determined the proposed inland nutrient criteria are “not likely to adversely affect” the 

American crocodile. EPA has also deferred setting nutrient criteria for the South Florida 

Region’s inland waters until after 2010. Therefore, because we do not expect crocodiles to be 

present in the area of the State considered in this portion of the rule, we concur that the proposed 

inland nutrient criteria “may affect but are not likely to adversely affect” American crocodiles. 

We will reconsider effects to this species during the development of the South Florida Region 

inland nutrient criteria and the statewide estuarine nutrient criteria (see Appendix B for further 

information). 

 
9 

Gulf Sturgeon 

Effects from increased nutrient inputs in Florida rivers and streams could have adverse impacts 

on Gulf sturgeon populations. The Federal Register listing status for the Gulf sturgeon indicates 

that poor water quality may be a threat to the species (50 CFR 17.49653). The State of Florida’s 

Conservation Plan for Gulf Sturgeon identifies similar threats to the species, stating that “Poor 

water quality, especially low levels of dissolved oxygen, has degraded shortnose sturgeon (and 

probably Gulf sturgeon) nursery grounds in many south-eastern coastal rivers” (Wakefield 

2001). Eutrophication due to increased nutrient loading can lead to diminished water quality and 

lowered dissolved oxygen levels, both of which may impact the species. The conservation plan 

calls for a reduction in nutrient loading in sturgeon habitat where moderate to high levels of 

eutrophication still exist (Wakefield 2001). Because the proposed numeric nutrient criteria 

should aid in the reduction of nutrients in Florida’s rivers and streams where gulf sturgeon 

reside, this reduction should decrease the areas of low dissolved oxygen, and thus result in a 

greater number of waterbodies in compliance with the dissolved oxygen criterion of 5 mg/L, 

which is protective of Gulf sturgeon. Nutrients at the concentrations proposed in the rule should 

not adversely affect the Gulf sturgeon, as any effects are likely beneficial. 

The EPA determined the proposed inland nutrient criteria “may affect, but are not likely to 

adversely affect” the Gulf sturgeon. Based on our analysis, the Service concurs with EPAs 

determination. We will reconsider effects to this species during the development of the 

statewide estuarine nutrient criteria (see Appendix B for further information). 

Okaloosa Darter 

Effects from increased nutrient inputs into Florida rivers and streams could have adverse impacts 

on Okaloosa darter populations. While sedimentation in streams appears to be the greatest threat 

to the species, the recovery plan acknowledges that other water quality issues, including nonpoint discharges of nutrients, impact habitat of the Okaloosa darter. The plan calls for 

monitoring of water quality parameters, including nutrients, and mentions that delisting of the 

species will only occur after water quality has been improved. Another threat to the Okaloosa 

darter is competition with the brown darter, in which water quality may play a role (Service 

1998). Because the proposed numeric nutrient criteria should aid in the reduction of nutrients in 

Florida’s rivers and streams where Okaloosa darters reside, and thus should improve water 

quality, this should not have a detrimental effect on the species and any adverse effects are likely 

insignificant. 

The EPA determined the proposed inland nutrient criteria “may affect, but are not likely to 

adversely affect” the Okaloosa darter. Based on our analysis, the Service concurs with EPAs 

determination (see Appendix C for further information). 

 
10 

Shortnose Sturgeon 

The EPA determined the proposed inland nutrient criteria “may affect, but are not likely to 

adversely affect” the shortnose sturgeon. The shortnose sturgeon determination will be analyzed 

by the National Marine Fisheries Service as it is under their resource jurisdiction. 

Listed Mussels 

(Chipola slabshell mussel, fat threeridge mussel, Gulf moccasinshell mussel, Ocholckonee 

moccasinshell mussel, oval pigtoe mussel, purple bankclimber mussel, shinyrayed pocketbook 

mussel) 

The recovery plan for the seven listed mussel species indicates that the reduction of nutrients into 

streams will be beneficial to the species’ recovery: “Reducing sediment, pesticide, and nutrient 

inputs to streams ... are some of the actions that will aid in the recovery of these species” 

(Service 2003). A study of freshwater mussels (some of the listed FL species were included) in 

the Flint River in southwest GA demonstrated that dissolved oxygen levels were highly 

correlated with mussel mortality in the field. Dissolved oxygen levels below 5 mg/L were 

associated with higher mortality for some species, while other species were more tolerant 

(Johnson et al. 2001). Even with the implementation of the proposed nutrient rule, the minimum 

level of dissolved oxygen of 5 mg/L specified in the State criterion must still be upheld, and this 

criterion is protective of the numerous species analyzed by Johnson et al. (2001), which included 

listed mussel species. Because the proposed numeric nutrient criteria should aid in the reduction 

of nutrients in Florida’s rivers and streams where the listed mussels reside, this should reduce the 

areas of low dissolved oxygen, and thus result in a greater number of waterbodies in compliance 

with the dissolved oxygen criterion of 5 mg/L. Nutrients at the concentrations proposed in the 

rule should not adversely affect the listed mussels, as any effects are likely beneficial. 

The EPA determined the proposed inland nutrient criteria “may affect, but are not likely to 

adversely affect” listed freshwater mussel species of Florida. Based on our analysis, the Service 

concurs with EPAs determination.(see Appendix C for further information). 

Candidate Mussels 

(Choctaw bean, round ebonyshell, southern kidneyshell, fuzzy pigtoe, narrow pigtoe, tapered 

pigtoe, southern sandshell) 

The Service document developed for listing the seven candidate species of mussels in Florida 

cited nutrients as one of the threats to survival of the species. The rivers in Florida where the 

candidate mussels reside (Escambia, Yellow, and Choctawhatchee) have been identified as 

having nutrient loading concerns (Service 2005). A study of freshwater mussels (some of the 

listed FL species were included) in the Flint River in southwest GA demonstrated that dissolved 

oxygen levels were highly correlated with mussel mortality in the field. Dissolved oxygen levels 

below 5 mg/L were associated with higher mortality for some species, while other species were 

more tolerant (Johnson et al. 2001). Even with the implementation of the proposed nutrient rule, 

the minimum level of dissolved oxygen of 5 mg/L specified in the State criterion must still be 
11 

upheld, and this criterion is protective of the numerous species analyzed by Johnson et al. (2001), 

which included listed mussel species. Because the proposed numeric nutrient criteria should aid 

in the reduction of nutrients in Florida’s rivers and streams where the candidate mussels reside, 

this should reduce the areas of low dissolved oxygen, and thus result in a greater number of 

waterbodies in compliance with the dissolved oxygen criterion of 5 mg/L. Nutrients at the 

concentrations proposed in the rule should not adversely affect the candidate mussels, as any 

effects are likely beneficial. The EPA determined the proposed inland nutrient criteria “may 

affect, but are not likely to adversely affect” candidate freshwater mussel species of Florida. 

Based on our analysis, the Service concurs with EPAs determination. (see Appendix C for 

further information). 

Endangered Species Act Section 7 Consultation Summary 

After reviewing the information provided by EPA (EPA’s August 2010 Biological Evaluation), 

the current status of the above listed species and designated critical habitat, the environmental 

baseline as determined by water quality monitoring data provided by the Florida Department of 

Environmental Protection, (FDEP) and the site-specific alternative criteria provision, the Service 

concurs with EPA’s determination of not likely to adversely affect for all listed species in Florida 

and no adverse modification of their designated critical habitat. 

Additional Comments 

Like EPA, the Service appreciates that these assessments are complex and time-consuming and 

therefore, recommend that EPA continues to engage the Service in such consultations early in 

rule-makings and to coordinate the development of future Biological Evaluations at least six 

months in advance of any final rule deadlines. 

The Service recognizes that some water bodies that support listed species may not be enrolled in 

a water sampling program that adequately identifies either their nutrient status or level of nutrient 

impairment. This makes it difficult to assess the potential effects of proposed water quality 

criteria if data are not available. We recommend that EPA and FDEP evaluate the need for 

expanding their water quality sampling network to fill in missing data gaps. Additionally, in 

accordance with the successful implementation of the State’s antidegradation policy, the Service 

recommends that EPA and FDEP verify what nutrient data are available for water bodies that are 

utilized by listed species in Florida (covered under this consultation). This is especially 

important for water bodies used by Everglade snail kites for nesting and foraging. 

The current Florida DEP antidegradation policy protects waters presently containing very low 

nutrient concentrations (less than 0.3 milligrams per liter total nitrogen or less than 0.04 

milligrams per liter total phosphorus) from becoming nutrient enriched. For those low-nutrient 

waters that support threatened and endangered species this means that nitrogen and phosphorus 

concentrations should not be allowed to rise and adverse effects associated with nutrient 

enrichment should not occur. However, the proposed phosphorus criterion (0.05 milligrams per 

liter: colored lakes) is substantially higher than present phosphorus concentrations in some of the 

low-nutrient waters, i.e., East Lake Tohopekaliga and Lake Weohyakapka. Without protections 
12 

afforded by the State’s antidegradation policy, long-term average phosphorus concentrations in 

these lakes could more than double. Therefore, to ensure continued protection of these waters 

from nutrient enrichment and potential adverse effects to threatened and endangered species, we 

recommend that FDEP coordinate with the Service regarding future changes to their 

antidegradation policy and that EPA consult with the Service on the approval of any such 

changes. 

Limited biological response data are available for the systems where these criteria will be 

employed. The biological responses to changes in nutrient concentrations need to be better 

understood. These data gaps should be filled during the implementation of these new criteria so 

that careful adjustments can be made for each specific waterbody as needed. This will allow for 

the specificity that may be required for successful implementation of the numeric nutrient criteria 

approach. 

We appreciate the opportunity to provide comments. Please contact Dr. Jon M. Hemming of this 

office (ext. 238) if you have any questions or comments. 

 Sincerely, 

 /s/ Dr. Donald W. Imm 

 Dr. Donald W. Imm 

 Project Leader 

cc: 

Paul Souza, FWS, Vero Beach, FL 

Dave Hankla, FWS, Jacksonville, FL 

Cindy Dohner, FWS, Atlanta, GA 

Patrick Leonard, FWS, Atlanta, GA 

Dave Flemming, FWS, Atlanta, GA 

Janet Mizzi, FWS, Atlanta, GA 

Rick Sayers, FWS, Washington DC 

George Noguchi, FWS, Washington DC 

Bill Starkel, FWS, Atlanta, GA 

 
13 

Appendix A - Literature Cited from EPA’s Biological Evaluation 

 
14 

Canadian Wildlife Service and U.S. Fish and Wildlife Service. 2007. International recovery plan 

for the whooping crane. Ottawa: Recovery of Nationally Endangered Wildlife (RENEW), 

and U.S. Fish and Wildlife Service, Albuquerque, New Mexico. 162 pp. 

Cerco CF. 1995. Response of Chesapeake Bay to nutrient load reductions. Journal of 

 Environmental Engineering. 121(8):549-557. 

Correll DL. 1998. The role of phosphorus in the eutrophication of receiving water: A review. 

Journal of Environmental Quality. 27:261-266. 

Dodds WK, VH Smith, and B Zander. 1997. Developing Nutrient Targets to Control Benthic 

Chlorophyll Levels in Streams: A Case Study of the Clark Fork River. Water Resources. 

31(7):1738-1750. 

FDEP. 2008a. Integrated Water Quality Assessment for Florida: 2008 305(b) Report and 303(d) 

 List Update, p. 67. 

FDEP. 2008b. Total Maximum Daily Load for Nutrients for the Lower St. Johns River. 

 Tallahassee, FL. 

Greening H, A Janicki. 2006. Toward reversal of eutrophic conditions in a subtropical estuary: 

Water quality and seagrass response to nitrogen loading reductions in Tampa Bay, 

Florida, USA. Environmental Management. 38(2): 163-178. 

Harr KE, NJ Szabo, M Cichra, EJ Philips. 2008. Debromoaplysiatoxin in Lyngbya-dominated 

mats on manatees (Trichechus manatus latirostris) in the Florida King’s Bay ecosystem. 

Toxicon. 52:385-388. 

Interland, Sebastian J. and Kilham, Susan S. 2001. Limiting resources and the regulation of 

 diversity in phytoplankton communities. Ecology. 82(5):1270-1282. 

Johnson PM, AE Liner, SW Golladay WK Michener. 2001. Effects of drought on freshwater 

mussels and instream habitat in Coastal Plain tributaries of the Flint River, southwest 

Georgia (July-October, 2000). Final Report given to The Nature Conservancy 

Apalachicola River and Bay Project. 30 pp. 

Livingston RJ. 2007. Phytoplankton bloom effects on a gulf estuary: Water quality changes and 

 biological response. Ecological Applications. 17(5):S110-S128. 

Maier HR, MD Burch, M Bormans. 2001. Flow management strategies to control blooms of the 

cyanobacterium, Anabaena circinalis, in the River Muarry at Morgan, South Australia. 

Regulated Rivers: Research and Management. 17(6):637-650. 

 
15 

NOAA Fisheries. 1998. Recovery Plan for the Shortnose Sturgeon (Acipenser brevirostrum). 

Prepared by the Shortnose Sturgeon Recovery Team for the National Marine Fisheries 

Service, Silver Spring, Maryland. 104 pages. 

NOAA Fisheries. 2003. Biological Opinion on Ambient Water Quality Criteria for Dissolved 

Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal 

Tributaries F/NER/2003/00961. 

Proulx M, FR Pick, A Mazumder, PB Hamilton, RS Lean. 1996. Experimental evidence for 

interactive impacts of human activities on lake algal species richness. Oikos. 76: 191-

195. 

Shen J, T Wang, J Herman, P Mason, GL Arnold. 2008. Hypoxia in a coastal embayment of the 

Chesapeake Bay: A model diagnostic study of oxygen dynamics. Estuaries and Coasts. 

31(4):652-663. 

Stewart TW and RL Lowe. 2008. Benthic algae of Lake Erie (1865-2006): A review of 

assemblage composition, ecology, and causes and consequences of changing abundance. 

Ohio Journal of Science. Vol. 108, no. 5, pp. 82-94. 

US FWS. 1998. Okaloosa Darter (Etheostoma okaloosae) Recovery Plan (Revised). Atlanta, 

 Georgia. 42 pp. 

US FWS. 1999. South Florida Multi-Species Recovery Plan. Atlanta GA. 

US FWS. 2003. Recovery Plan for Endangered Fat Threeridge (Amblemaneislerii), Shinyrayed 

 Pocketbook (Lampsilis subangulata), Gulf Moccasinshell (Medionidus 

penicillatus), Ochlockonee Moccasinshell (Medionidus simpsonianus), and Oval Pigtoe 

(Pleurobema pyriforme); and Threatened Chipola Slabshell (Elliptio chipolaensis), and 

Purple Bankclimber (Elliptoideus sloatianus). Atlanta, Georgia. 142 pp. 

US FWS. 2005. Species assessment and listing priority assignment form for 7 candidate mussel 

 species. http://www.fws.gov/ecos/ajax/docs/candforms_pdf/r4/F030_I01.pdf

US FWS. 2006. Concurrence letter for Service Log No.: 4- 1-06-1-8749. 

http://fish.btstest.com/region4/verobeach/images/pdfLibrary/BCWPA%20concur.pdf

Wakeford, A. 2001. State of Florida conservation plan for gulf sturgeon (Acipenser oxyrinchus 

 desotoi). Florida Marine Research Institute Technical Report TR-8. 100 pp. 

Wetzel RG. 1975. Limnology. p. 520. W. B. Saunders Company, Philadelphia PA. 
16 

Appendix B – South Florida Species and Critical Habitats 

 
17 

September 26, 2010

These comments are provided from Steve Schubert (Fish and Wildlife Biologist; US FWS; South 

Florida Ecological Service Office; Vero Beach Florida) to the Panama City Ecological Services 

Office in accordance with section 7 of the Endangered Species Act of 1973, as amended (87 Stat. 

884; 16 U.S.C. 1531 et seq.). 

Whooping Crane 

EPA determined the proposed numeric inland nutrient criteria “may affect, but are not likely to 

adversely affect” the whooping crane (Grus americana). Due to this species being an 

experimental, nonessential population in Florida, EPA is not required to consult under section 

7(a)2 of the Endangered Species Act for the whooping crane. 

West Indian Manatee 

The endangered West Indian manatee (Trichechus manatus) occurs in inland and coastal waters 

of peninsular Florida including estuaries, bays, rivers, creeks, springs, and canals (Service 2001) 

and may be found in all waters accessible to them. According to the Service’s (South Florida 

Ecological Services Office) geographic information system database, they have been observed 

within major inland freshwater waterways and canals, including Lake Okeechobee, the 

Kissimmee River (i.e., C-38 Canal), and the C-44 and C-43 Canals. As herbivores, manatees 

feed on a wide range of aquatic vegetation. Shallow grass beds, with ready access to deep 

channels, are generally preferred feeding areas in coastal and riverine habitats (Smith 1993). In 

coastal Georgia and northeastern Florida, manatees feed in salt marshes on smooth cordgrass 

(Spartina alterniflora) by timing feeding periods with high tide (Baugh et al. 1989; Zoodsma 

1991). Manatees use springs and freshwater runoff sites for drinking water; secluded canals, 

creeks, embayments, and lagoons for resting, cavorting, mating, calving, and nurturing their 

young; and open waterways and channels as travel corridors. (Gannon, et al. 2007; Marine 

Mammal Commission 1986, 1988). Manatees occupy different habitats during various times of 

the year, with a focus on warm-water sites during winter. Manatees have also adapted to 

changing ecosystems in Florida. Industrial warm-water discharges and deep-dredged areas are 

used as wintering sites, stormwater/freshwater discharges provide manatees with drinking water, 

and the imported exotic plant, Hydrilla sp. (which has replaced native aquatic plant species in 

some areas), has become an important food source at some wintering sites (Smith 1993). 

Previous studies of the manatee in Florida refer to four relatively distinct regional 

“subpopulations”: an Atlantic Coast subpopulation that extends along the entire east coast of 

Florida, into the St. Johns River north of Palatka, and includes the Florida Keys; an Upper St. 

Johns River subpopulation that occurs in the river south of Palatka; a Northwest subpopulation 

that extends from the Florida Panhandle south to the Pasco County line; and a Southwest 

subpopulation that extends from the Pasco County line south to Whitewater Bay in Monroe 

County. Each of these “subpopulations” is composed of individual manatees that tend to return 

to the same warm-water sites each winter and have similar non-winter distribution patterns. 

Exchange of individuals between these subpopulations is considered to be limited during winter 

months, based on data from telemetry (Rathbun et al. 1990; Reid et al. 1991; Weigle et al. 2001; 
18 

Deutsch et al. 1998, and 2003) and photo-identification (Rathbun et al. 1990; Beck 2006; Higgs 

2006). Exchanges between subpopulations occur during warm seasons and there are some 

documented cases of wide-ranging coastal movements and isolated events of intercoastal 

migration (Reid et al. 1991; Deutsch et al. 1998 and 2003). 

Although natural forage for the manatee has diminished in some locations due to human 

activities (including reductions in water quality, outright destruction of forage from coastal and 

riverine construction activities, waterborne recreational and commercial activities, etc.) and 

exotic forage has increased in other areas, the availability of forage is not known to be a limiting 

factor for manatees at this time (Orth et al. 2006). 

Data on manatee mortality in the southeastern United States have been collected since 1974 by 

the Manatee Carcass Salvage Program (O’Shea et al. 1985; Ackerman et al. 1995; Lightsey et al. 

2006). The primary human-related threats include watercraft-related strikes (direct impact 

and/or propeller) which cause injury or death (Rommel et al. 2007; Lightsey et al. 2006), 

entrapment and/or crushing in water control structures (gates, locks, etc.), and entanglement in 

fishing lines, crab pot lines, etc. Natural threats include exposure to cold and in coastal areas, 

red tide. Mortality associated with these natural threats is by cold stress syndrome and 

brevitoxicosis, respectively. 

A significant habitat threat to the Florida manatee is the potential loss of warm water at natural, 

warm-water springs (Laist and Reynolds 2005a, b). Natural springs are threatened by potential 

reductions in flow, worsening water quality, and by factors which affect manatee access and use 

of the springs (Florida Springs Task Force 2001). Total nitrate-nitrogen concentrations in some 

springs have increased significantly from historic levels and are problematic (Florida Department 

of Environmental Protection [FDEP] 2005). Increased nutrient inputs may affect manatees by 

contributing to harmful algal blooms, such as Lyngbya sp. These species bloom when excess 

nutrients are available and out-compete native submerged aquatic vegetation, such as those that 

are consumed by manatees. Additionally, the toxins produced by Lyngbya sp. are associated 

with ulcerative dermatitis in manatees (Harr et al. 2008). Reduction of nutrient inputs through 

implementation of numeric nutrient criteria could aid in decreasing the frequency or magnitude 

of Lyngbya sp. blooms, which in turn could increase habitat for the manatee’s food source. The 

Service expects that nitrogen is the limiting nutrient that controls aquatic plant growth in springs 

located within EPAs Peninsula Region. In the three primary spring systems in Citrus County 

that manatees are best known for using (Crystal Spring, Homosassa Springs, and 

Chassahowitzka Spring) the total nitrate-nitrite concentrations range from 0.35 mg/l (equal to 

EPAs proposed standard) up to 2.60 mg/l (Southwest Florida Water Management District 

[SWFWMD] 2010). For nine water samples taken during 2005 (most recent data available) at 

Homosassa Springs, the total nitrate-nitrite ranged from 0.41 mg/l to 0.55 mg/l (SWFWMD 

2010). Our analysis indicates that EPAs proposed standard for total nitrate-nitrite in springs 

(0.35 mg/l) would seem to be either protective or restorative (i.e., implementation of the 

proposed standard would reduce nitrogen concentrations and decrease the frequency of Lyngbya 

sp. blooms) of nitrogen conditions for manatees in those springs. 
19 

Additionally, the Service expects that phosphorus is the limiting nutrient in inland lakes and 

streams within EPAs Peninsula Region. Therefore, we did not consider the proposed nitrogen 

standard to be a factor in our effects analysis for manatees in lakes and streams (as we did for 

springs). The existing phosphorus conditions in these inland waterways are higher than the 

proposed phosphorus standard. For example, the proposed phosphorus standard for Lake 

Okeechobee is 50 ug/l (0.050 mg/l) (roughly equivalent to 50 parts per billion [ppb]) of total 

phosphorus, but the lake has averaged over 100 ppb (0.100 mg/l) of total phosphorus annually 

since 1996 (RECOVER 2010). Consequently, the C-44 Canal (St. Lucie River) and C-43 Canal 

(Caloosahatchee River) receive high-phosphorus surface flows out of Lake Okeechobee. 

Therefore, the attainment of 50 ppb total phosphorus in the lake would also decrease the 

phosphorus concentrations in the C-44 and C-43 Canals and be protective or restorative of the 

existing phosphorus conditions for manatees in those waterbodies. 

The EPA determined the proposed inland nutrient criteria “may affect, but are not likely to 

adversely affect” the West Indian manatee. Based on the above information, the Service concurs 

with EPAs determination. We will reconsider effects to this species during the development of 

the South Florida Region inland nutrient criteria and the statewide estuarine nutrient criteria. 

West Indian Manatee Critical Habitat 

Critical habitat was originally designated for the Florida manatee in 1976 in areas of Citrus, 

Hillsborough, Manatee, Sarasota, Charlotte, De Soto, Lee, Collier, Monroe, Dade, Palm Beach, 

Martin, West Palm Beach, Volusia, Brevard, Nassau and Duval counties (50 CFR Part 17.95(a); 

Figure 1 and Figure 2). That critical habitat designation was made before critical habitat 

regulations and guidance were developed. Therefore, it does not identify those essential features 

needed for the species conservation. Instead, it describes specific waterways that were known to 

be important concentration areas for manatees at that time. Service biologists also recognize that 

the geographic areas originally described as manatee critical habitat need to be updated, based on 

recent scientific studies of manatee distribution, habitat use, and habitat needs. Manatee critical 

habitat occurs mostly within the coastal areas to be covered under EPAs 2012 estuarine nutrient 

criteria. However, there is one critical habitat area – the St. John’s River – for which the inland 

nutrient criteria for EPAs Peninsula Region applies. According to the Service’s (South Florida 

Ecological Services Office) geographic information system database, manatees do not seem to 

occupy much of the freshwater portion of the St. Johns’ River watershed with the exception of 

Blue Spring (Volusia County; manatee synoptic data 1991- 2007). The long-term (15 years) 

median total nitrogen concentration for Blue Spring is 0.62 mg/l (N=82; St. John’s River Water 

Management District [SJRWMD] 2010a). According to the SJRWMD (2010b), “pollution in the 

St. John’s River has, at times, triggered algal blooms and subsequent fish kills. The blooms are 

caused by nutrient-rich discharges. As a result, portions of the St. Johns River fail to meet state 

and federal water quality criteria.” The implementation of the proposed phosphorus standard 

was designed to eliminate algal blooms, and therefore, should be either protective or restorative 

of phosphorus conditions of manatee critical habitat in the freshwater portion of the St. John’s 

River. 

 
20 

EPA did not make an effect determination for manatee critical habitat for the proposed numeric 

nutrient criteria in inland waters. There is no critical habitat for the West Indian manatee in lakes 

in Florida; therefore, none will be affected. Based on the available information, the Service 

believes that the proposed nutrient rule “may affect, but is not likely to adversely affect” West 

Indian manatee critical habitat in Florida inland streams or springs. Should EPA choose to, this 

letter can be used as concurrence of that conclusion. We will reconsider effects to this species’ 

critical habitat during the development of the South Florida Region inland nutrient criteria next 

year and the estuarine nutrient criteria (set for 2012). 

American Crocodile

Crocodiles occur along both coasts of southern Mexico and Central America, south to Ecuador 

on the Pacific coast, and Venezuela on the Atlantic coast of South America. They can also be 

found on the islands of Cuba, Jamaica, and Hispaniola. The threatened American crocodile 

(Crocodylus acutus) reaches the northern end of its range in extreme South Florida (Figure 3). 

The American crocodile is found primarily in mangrove swamps and along low-energy 

mangrove-lined bays, creeks, and inland swamps. Natural nesting habitat includes sites with 

sandy shorelines or raised marl creek banks adjacent to deep water. During the non-nesting 

season, they are found primarily in the fresh and brackish-water inland swamps, creeks, and 

bays, retreating further into the back country in fall and winter. Although crocodiles occur in 

estuarine areas, they prefer lower salinities except for nesting activities. 

The original rule proposing this species’ listing identified intensive human development and 

subsequent loss of habitat as a primary threat to crocodiles. Since listing, much of the nesting 

habitat has remained intact and been afforded some form of protection. Construction and 

development within coastal areas continues to grow, and still poses a threat to remaining 

crocodile habitat that is not protected. 

The EPA determined the proposed inland nutrient criteria are “not likely to adversely affect” the 

American crocodile. EPA has also deferred setting nutrient criteria for the South Florida 

Region’s inland waters until after 2010. Therefore, because we do not expect crocodiles to be 

present in the area of the State considered in this portion of the rule we concur that the proposed 

inland nutrient criteria “may affect but are not likely to adversely affect” American crocodiles. 

We will reconsider effects to this species during the development of the South Florida Region 

inland nutrient criteria and the statewide estuarine nutrient criteria. 

American Crocodile Critical Habitat 

According to 41 FR 41914, September 24, 1976, this species’ critical habitat extends along the 

coast from Biscayne Bay on the Atlantic side of Florida to Cape Sable in Everglades National 

Park, and includes Florida Bay and portions of the Upper Florida Keys (Figure 3). The inland 

and estuarine nutrient criteria have not been set for this area and will be proposed as part of the 

2011 South Florida Region’s standards and the 2012 statewide estuarine standards. EPA did not 

make an effect determination for American crocodile critical habitat for their numeric nutrient 
21 

criteria in inland waters. Because there is no American crocodile critical habitat within EPAs 

Peninsula Region of the proposed nutrient rule, none will be affected. We will reconsider effects 

to this species’ critical habitat during the development of the South Florida Region inland 

nutrient criteria and the statewide estuarine nutrient criteria. 

Everglade Snail Kite 

The endangered Everglade snail kite (Rostrhamus sociabilis plumbeus) is one of three subspecies 

of snail kite, a wide-ranging New World raptor found primarily in lowland freshwater marshes in 

tropical and subtropical America from Florida, Cuba, and Mexico south to Argentina and Peru. 

The Everglade subspecies occurs in Florida and Cuba, though only the Florida population is 

listed. The Florida population was first listed under the Endangered Species Preservation Act in 

1967, and protection was continued under the Endangered Species Conservation Act of 1969. 

The Everglade snail kite, and all other species listed under the Endangered Species Conservation 

Act were the first species protected under the Endangered Species Act of 1973, as amended, and 

all of these species were given the ‘endangered’ status. 

Everglade snail kites are dietary specialists, with the Florida apple snail (Pomacea paludosa) 

being the kite’s principal prey in Florida (Sykes 1987a; Kitchens et al. 2002). Under normal 

conditions, Everglade snail kites are nearly completely dependent on apple snails as prey. The 

close tie between the Everglade snail kite and the Florida apple snail requires consideration of 

both species when developing management strategies and addressing potential impacts. 

Everglade snail kites and apple snails are both wetland-dependent species that rely on wetland 

habitats for all aspects of their life history. The primary wetland habitat types upon which kites 

rely consist of freshwater marshes and the shallow vegetated littoral zones along the edges of 

lakes (natural and man-made) where apple snails occur in relatively high abundance and can be 

found and captured by kites. The current distribution of the snail kite in Florida is limited to 

central and southern portions of the State. Six large freshwater systems are located within the 

current range of the snail kite: Upper St. Johns marshes, Kissimmee Chain of Lakes, Lake 

Okeechobee, Loxahatchee Slough, the Everglades, and the Big Cypress basin (Beissinger and 

Takekawa 1983; Sykes 1984; Rodgers et al. 1988; Bennetts and Kitchens 1997; Rumbold and 

Mihalik 1994; Sykes et al. 1995). In the Kissimmee Chain of Lakes, snail kites may occur 

within most of the lakes and adjacent wetlands, with the majority of kite nesting occurring within 

Lake Kissimmee, Lake Tohopekaliga, and East Lake Tohopekaliga. Lake Okeechobee and 

surrounding wetlands historically supported significant snail kite nesting and foraging habitats. 

Most of the recent nesting in Lake Okeechobee has occurred within the expansive marsh in the 

southwestern portion of the lake and the area southwest of the inflow of the Kissimmee River 

(Martin et al. 2006). 

In addition to the primary wetlands where most kite nesting has been documented, there are 

numerous records of kite occurrence and/or nesting within isolated wetlands throughout the 

region. The Savannas State Preserve, in St. Lucie County, the Hancock impoundment in Hendry 

County, and Lehigh Acres in Lee County are among the smaller more isolated wetlands used by 

snail kites (Sykes et al. 1995). Takekawa and Beissinger (1989) identified numerous wetlands 
22 

that they considered drought refugia which may provide kite foraging habitat when conditions in 

the larger more traditionally occupied wetlands are unsuitable. Although the above list generally 

describes the current range of the species, radio tracking of snail kites has revealed that the 

network of habitats used by the species includes many smaller, widely dispersed wetlands within 

this overall range (Bennetts and Kitchens 1997). Snail kites may use nearly any wetland within 

southern Florida under some conditions and during some portions of their life history. 

Studies of apple snail abundance and occurrence within traditional snail kite nesting areas also 

support conclusions that foraging conditions may be poor. Darby et al. (2005) reported that 

apple snail abundance has recently declined substantially within Water Conservation Area 3A. 

In 2005, Darby (2005a, 2005b) reported that apple snail abundance was relatively low in areas of 

traditional snail kite use within Lakes Kissimmee, Tohopekaliga, and Okeechobee. 

Snail kites use two visual foraging methods: course-hunting, while flying 5 to 33 feet (ft) above 

the water surface, or still-hunting from a perch (Sykes 1987a; Sykes et al. 1995). Snails are 

captured with the feet at or below the surface, to a maximum reach of about 6 inches below the 

surface. Snail kites do not plunge into the water to capture snails and never use the bill to 

capture prey. 

While kites are capable of foraging successfully under a variety of habitat conditions, the 

preferred foraging habitat is typically a combination of relatively short-stature, sparse graminoid 

marsh vegetation less than 6.5 ft (2 meters) in height. The apple snail requires emergent aquatic 

plants to provide substrate that allows them to reach the water surface to breathe and lay eggs. 

However, for kites to feed, the emergents must be sparse enough that they are capable of locating 

and capturing snails (Kitchens et al. 2002). Marshes and lake littoral zones composed of 

interdigitated areas of open water 0.6 to 4.3 ft deep which is relatively clear and calm and 

patches of herbaceous emergent wetland plants or sparse continuous growth of herbaceous 

wetland plants generally provide the appropriate balance of emergent vegetation and open water 

(Sykes et al. 1995; Kitchens et al. 2002). Periphyton growth on the submerged substrate 

provides food source for apple snails, and submergent aquatic plants such as bladderworts 

(Utricularia spp.) and eelgrass (Vallisneria spp) may contribute to favorable conditions for 

apple snails while not preventing kites from detecting snails (Sykes et al. 1995). If these lakes 

become more eutrophic, the littoral zones may become more overgrown with emergent plants 

and water lilies and algae blooms may result. Foraging habitat conditions that differ 

substantially from those described above will result in either reduced apple snail density or 

reduced ability of snail kites to locate and capture snails. Vegetation cover that is either too 

dense or too sparse can result in reduction in the quality of the area as foraging habitat. 

The Everglade snail kite breeding season in Florida varies from year to year (from December 

through July) with the peak in nest initiation occurring from February to April (Sykes 1987b). 

Adult kites generally attempt to breed every year with the exception of drought years when some 

kites may not attempt to nest (Sykes et al. 1995). Nesting almost always occurs over water, 

which deters predation (Sykes 1987c). Extensive stands of contiguous woody vegetation are 

generally unsuitable for nesting and suitable nest sites consist of single trees or shrubs or small 

clumps of trees and shrubs within or adjacent to an extensive area of suitable foraging habitat. 
23 

Nesting also can occur in herbaceous vegetation, such as sawgrass (Cladium jamaicense), cattail 

(Typha sp.), bulrush (Scirpus sp.), and reed (Phragmites australis) (Sykes et al. 1995). 

Snail kites are considered nomadic, and this behavior pattern is probably a response to changing 

hydrologic conditions (Sykes 1979). During breeding season, kites remain close to their nest 

sites until they fledge young or fail. Following fledging, adults may remain around the nest for 

several weeks, but once young are fully independent adults may depart the area. Outside of the 

breeding season, snail kites regularly travel long distances within and among wetland systems in 

southern Florida (Bennetts and Kitchens 1997). While most movements may be in response to 

droughts or other unfavorable conditions, kites may also move away from wetlands when 

conditions appear favorable. Movements within large wetlands and movements among adjacent 

wetland units occurred frequently, while movements among spatially isolated wetlands occurred 

less frequently (Martin et al. 2006). Fledgling kites also move frequently, but are more likely to 

move to immediately adjacent wetland units than adults, and this may indicate a degree of 

familiarity with the availability of wetlands across the landscape that adult kites acquire through 

experience. 

Historic records of snail kite nesting include areas as far north as Crescent Lake and Lake 

Panasoffke in north-central Florida and as far west as the Wakulla River (Howell 1932; Sykes 

1984). Several authors (Nicholson 1926; Howell 1932; Bent 1937) indicated that the snail kite 

was numerous in central and southern Florida marshes during the early 1900s, with groups of up 

to 100 birds. Reports of snail kite population declines in the 1940s and 1950s suggested that as 

few as 6 to 100 individuals remained (Sykes 1979). Refined population estimates were 

generated for the Everglade snail kite using a mark-recapture method beginning in 1997 (Dreitz 

et al. 2002). The population size estimate generated from mark-recapture estimates for 1997-

2000 (2,700 to 3,500 birds) was about 2 to 3 times higher than count-based estimates made in 

1993 and 1995 (Bennetts and Kitchens 1997; Dreitz et al. 2002). From 1997 through 1999, the 

snail kite population was estimated to be about 3,000 birds (Dreitz et al. 2002). From 1999 

through 2002, the population estimates declined each year until they reached a low level of about 

1,400 birds in 2002 and 2003, then increased slightly to about 1,700 birds in 2004 and 2005 

(Martin et al. 2006). The 2006 snail kite population size estimate was about 1,600 birds. In 

2007, the estimate was 1,204 birds; in 2008 it was 685 birds; and in 2009, the estimate was 662 

snail kites (Cattau et al. 2009). 

The state-wide snail kite population declined from 1999 to 2003, and may have been exacerbated 

by a regional drought that affected southern Florida during 2000 to 2001. During this period, 

nest success was generally low (Martin et al. 2006), and demographic parameters estimated from 

mark-recapture methods also indicated that juvenile survival rates were low, and even adult 

survival declined during 2001 (Martin et al. 2006). However, following the end of the drought 

conditions in 2002 and a return to normal or wetter-than-normal hydrologic conditions from 

2002 to 2006 that generally provide favorable snail kite nesting conditions, population estimates 

remained low, and nest success and juvenile survival rates also remained low (Martin et al. 

2006). 

 
24 

South Florida experienced another intense and widespread drought in 2007 covering the entire 

range of the Everglade snail kite. The majority (approximately 80%) of observed nesting 

occurred in the Kissimmee Chain of Lakes, especially Lake Tohopekaliga, with few nests 

observed in the WCAs, Lake Okeechobee, St. Johns Marsh, or Grassy Waters (Table 1). This 

apparent shift of the breeding population to the northern lakes suggests a level of adaptability 

and resilience in the population in response to the severe stress of the drought. Data from 2007 

monitoring efforts indicated an overall lower number of active nests but higher nest success than 

in previous years, with over 95 percent of successful nests occurring in the Kissimmee Chain of 

Lakes. Two successful nests occurred in Lake Istokpoga, while no successful nesting occurred 

in the WCAs, Lake Okeechobee, or other monitored areas. In addition to potential effects of the 

drought on snail kites, it will also be interesting to observe how quickly apple snails can return 

after the drought to an abundance that will support successful kite nesting in Lake Okeechobee 

and the other major wetland complexes essential to the species. 

There are a variety of threats that have been identified which affect kite nesting, foraging, and 

survival. These threats include loss of wetland habitats, degradation of wetland habitat, changes 

in hydrologic conditions, and impacts to prey base. 

The principal threat to the snail kite is the loss or degradation of wetlands in central and southern 

Florida. Nearly half of the Everglades has been drained for agriculture and urban development 

(Davis and Ogden 1994). The Corps’ Central and South Florida Project encompasses 18,000 

square-miles from Orlando to Florida Bay and includes about 994 miles each of canals and 

levees, 150 water control structures, and 16 major pump stations. This system has disrupted the 

volume, timing, direction, and velocity of freshwater flow. 

Degradation of water quality, particularly runoff of phosphorus from agricultural and urban 

sources, is another concern for the snail kite. The Everglades was historically an oligotrophic 

system, but major portions have become eutrophic, primarily due to anthropogenic sources of 

phosphorus and nitrogen (cultural eutrophication). Most of this increase has been attributed to 

non-point source runoff from agricultural lands north of Lake Okeechobee, in the Kissimmee 

River, Taylor Slough, and Nubbin Slough drainages (Federico et al. 1981). Cultural 

eutrophication also is a concern in the Kissimmee Chain of Lakes. Nutrient enrichment leads to 

growth of dense stands of herbaceous emergent vegetation, floating vegetation (primarily water 

hyacinth [Eichhornia crassipes] and water lettuce [Pistia stratiotes]) and woody vegetation, 

which inhibits the ability of snail kites to forage along the shorelines of lake areas. Regulation of 

water stages in lakes and the WCAs is particularly important to maintain the balance of 

vegetative communities required to sustain snail kites. 

There are no direct scientific investigations that we are aware of that directly relate effects of 

differing nutrient concentrations to snail kites, snail kite habitat, apple snails, or apple snail 

habitat. However, there is a weight of evidence that indicates that most of these lakes receive 

nutrient inputs higher than normal and at levels which requires various governmental agencies to 

perform habitat management. These attempts to control, reduce and eliminate the spread of 

invasive and exotic species have also had negative effects on snail kites. Rodgers et al. (2001) 
25 

described a program to reduce impacts of aquatic plant management on snail kites. They found 

that the actions of several agencies in controlling aquatic plants have caused nest collapse, 

particularly in herbaceous vegetation such as cattail and bulrush. They state that these impacts in 

Lake Okeechobee and the Kissimmee Chain of Lakes were reduced through cooperation and 

improved communication between agencies. In addition to the potential collapse of nests, the 

Service is concerned about any excessive application of herbicides because this would reduce 

available habitat for apple snails. The Service has expanded on these coordination efforts to 

notify aquatic plant management groups during the kite nesting season on the location of active 

snail kite nests (Service 2006) to assist them in avoiding or minimizing effects. 

In 1996, Lake Kissimmee was drawn down because the shallow-water littoral habitat had slowly 

degraded over the years. Muck removal, burning, and discing occurred during an extreme draw 

down to restore productive aquatic habitat. In 2002, Lakes Tohopekaliga, Kissimmee, 

Hatchineha, Cypress, and Tiger were also drawn down to improve habitat conditions in the 

lake’s littoral zones (i.e., remove excess vegetation and organic muck sediments to allow for reestablishment of beneficial aquatic plants through aggressive post-drawdown herbicide 

application). For all these draw downs, the combination of excessive nutrients and non-natural 

water regulation schedules (promoting water supply, flood protection, and navigation) was the 

cause of the problem. These lake draw downs usually last long enough to disrupt the kite 

foraging and/or nesting. In the case of Lake Kissimmee, the apple snail population took years to 

recover. 

Darby et al. (1998) concluded that the apple snail population in Lake Kissimmee declined by 80 

percent as a result of the 1996 drawdown. Five years later, Darby (2001) found that the apple 

snails had not yet recovered to pre-drawdown levels on Lake Kissimmee. Their results concern 

the Service because suboptimal levels of a prey species may have adverse effects on snail kites. 

Foraging efficiency may be lowered as snail kites spend more time hunting for a lower density of 

prey species. Consequently, snail kite metabolic reserves may be compromised which may 

negatively affect reproduction and juvenile survival. Darby and Percival (2000) have performed 

several studies to observe apple snail response to drawdowns. Telemetry indicates that during 

drawdowns, apple snails do not tend to move towards deep-water refuge habitat. Instead, apple 

snails aestivate to minimize dehydration, metabolic loss, and predation. 

Emergent plant control also occurs in Lakes Istokpoga, Tohopekaliga, and Kissimmee. In Lake 

Istokpoga, pickerelweed (Pontederia cordata) and cattail are mechanically removed or sprayed 

with herbicide. In the other two lakes, only herbicide is used. The plants are controlled because 

they are too dense in the littoral zone. As emergent plants in general become denser, kites 

cannot see the snails, and therefore, cannot forage there. As pickerelweed becomes even denser 

and forms mats, as in Lake Istokpoga, it becomes unavailable to even apple snails. All the major 

lakes in the Kissimmee Chain of Lakes that supported snail kite nesting or, at least, foraging this 

year with the exception of East Lake Tohopekaliga and Lake Weohyakapka, received herbicide 

spraying for Hydrilla sp. control. Past spraying for Hydrilla sp. in East Lake Tohopekaliga has 

been sparse, further supporting evidence that excess nutrients exacerbate Hydrilla sp. growth and 

cause agencies to enact management strategies that may adversely affect kites. As another 

example, there were 10 snail kite nests along the western side of Lake Istokpoga in 2008. Later 
26 

that year, the Florida Fish and Wildlife Conservation Commission (FWC) removed dense 

emergent vegetation and performed Hydrilla sp. treatments. Snail kite nest initiation has been 

greatly reduced in that lake since then. The implementation of the proposed nutrient criteria 

should reduce the future need for as intensive management activities and therefore, lessen the 

potential for adverse effects on snail kites. For the same reason, the Service is concerned that 

allowing waterbodies such as East Lake Tohopekaliga and Lake Weohyakapka to become more 

polluted with phosphorus will require new or more intensive management activities there and 

could adversely affect the snail kite. 

Our analysis of effects for this species was based on the assumption that excess nutrients in kite 

lakes could have adverse effects on the species through habitat modification for either the kite 

directly or the kite’s primary prey, the apple snail. Increased phosphorus concentrations may 

affect snail kite habitat (cause overgrown littoral zones and/or algal blooms that inhibit the kite’s 

ability to forage on apple snails), and have indirect effects on kites through potential changes to 

apple snail abundance or other the floral and faunal communities (species diversity and 

abundance). Effects of water chemistry changes on apple snails are not well understood. While 

there is little or no literature investigating direct toxicity or other effects of phosphorus on apple 

snails, some studies suggest that snails may be affected by changes in dissolved oxygen, 

hardness, alkalinity and temperature. 

The Kissimmee Chain of Lakes (particularly Lake Tohopekaliga, East Lake Tohopekaliga, and 

Lake Kissimmee) have been critical to the continued reproduction and maintenance of the 

endangered Everglade snail kite over the last few years especially during drought years when the 

Greater Everglades system is dry. Due to its critically endangered status (less than 700 birds), it 

is important that we fully assess the effects of this proposed rule, particularly on the Kissimmee 

Chain of Lakes. Today these lakes are used by a high percentage of snail kites on a yearly basis. 

Although it is recognized that other factors such as lake level, drought, hurricanes, water 

management, and other habitat management may also affect snail kites, a proper evaluation of 

the proposed nutrient criteria and associated impacts on the species is still warranted. Total 

phosphorus and other water quality data were provided by staff from EPA, DEP, South Florida 

Water Management District (SFWMD), or SJRWMD, or were recovered from SFWMDs 

DBHydro water quality database 

(http://www.sfwmd.gov/portal/page/portal/xweb%20environmental%20monitoring/dbhydro%20

application), or SWFWMDs Water Management Information System database 

(http://www8.swfwmd.state.fl.us/WMIS/ResourceData/ExtDefault.aspx). 

Table 2 displays the total phosphorus data that were available to the Service for the major lakes 

that we presume or know are used by snail kites that are also potentially affected by the proposed 

nutrient criteria in the Peninsula Region. Successful snail kite nesting during 2010 in the 

Kissimmee Chain of Lakes occurred only in Lake Tohopekaliga, East Lake Tohopekaliga, Lake 

Kissimmee, Lake Hatchineha, and Lake Jackson (Table 1). However, we anticipate that kites 

will forage in any of these lakes listed in Table 2 or other nearby water bodies. Data in Table 2 

were limited for some lakes (i.e., some data were over 15 years old, and as such may not 

represent current phosphorus conditions in those waterbodies). For the lakes with robust 

phosphorus data, it appears that implementation of the proposed inland phosphorus standard (50 
27 

ppb) would either maintain or improve the existing phosphorus status (i.e., the long-term mean 

total phosphorus concentration) for 10 of these 12 lakes (including the three lakes in Table 2 that 

are not part of the Kissimmee Chain of Lakes). For two lakes (East Lake Tohopekaliga and Lake 

Weohyakapka) it appears that the proposed rule would allow a doubling of the mean phosphorus 

in these lakes (East Lake Tohopekaliga = 21 ppb; Lake Weohyakapka = 23 ppb). The Service 

believes that allowing the average phosphorus concentration to increase to EPAs proposed 

standard in these two lakes could be considered an adverse effect on the species. However, the 

State of Florida has in place an antidegradation policy that would maintain the low-phosphorus 

condition that these, and possibly other nearby lakes, currently exhibit. 

According to Florida State law (62-302.300 Findings, Intent and Antidegradation Policy for 

Surface Water Quality; Part 13), the Department finds that excessive nutrients (total nitrogen and 

total phosphorus) constitute one of the most severe water quality problems facing the State. It 

shall be the Department's policy to limit the introduction of man-induced nutrients into waters of 

the State. Particular consideration shall be given to the protection from further nutrient 

enrichment of waters which are presently high in nutrient concentrations or sensitive to further 

nutrient concentrations and sensitive to further nutrient loadings. Also, particular consideration 

shall be given to the protection from nutrient enrichment of those presently containing very low 

nutrient concentrations: less than 0.3 milligrams per liter total nitrogen or less than 0.04 

milligrams per liter total phosphorus” (http://www.dep.state.fl.us/legal/Rules/shared/62-302/62-

302.pdf) 

Antidegradation reviews (public interest reviews) in Florida are conducted by FDEP as part of 

any new permitting request for point source discharges under EPAs National Pollutant Discharge 

Elimination System Program (Marks 2010). As part of this review process, basin loadings would 

be partitioned amongst both point and non-point sources for the water quality parameter being 

considered, and FDEP must consider the effects to any federally listed threatened or endangered 

species (Marks 2010). This involves notification and coordination with the Service before any 

relaxation of water quality standards could occur. The phrase “...particular consideration shall 

be given...” in the above quote means, in part, that DEP will coordinate with the Service on 

federally listed species whenever there is a public interest review (Marks 2010). 

In the case of East Lake Tohopekaliga (where snail kites nest and forage) and Lake 

Weohyakapka (where we expect kites to occasionally forage), the antidegradation policy would 

require the FDEP to consult with the Service to determine if the permitting of additional 

phosphorus loading into those water bodies would adversely affect kites. 

EPA has determined that the proposed nutrient criteria will “not likely adversely affect” the 

Everglade snail kite. As a result of the antidegradation policy already in place to protect lownutrient waters (i.e., lower than 40 ppb), and the existing phosphorus condition of other 

waterbodies utilized by kites (greater than 50 ppb), the Service concurs with EPA, that the 

proposed rule “may affect, but is not likely to adversely affect” the Everglade snail kite. The 

Service will reassess potential effects to this species during development of EPAs South Florida 

Region’s inland nutrient standards. 
28 

Everglade Snail Kite Critical Habitat 

Critical habitat for the Everglade snail kite was designated in 1977 (Service 1977). The 

designation identified nine units of critical habitat that included three small reservoirs, the littoral 

zone of Lake Okeechobee, and areas of Everglades’ marshes within the Water Conservation 

Areas and Everglades National Park. Of these, only the critical habitat within Lake Okeechobee 

and the three reservoirs occurs within EPAs Peninsula Region for the proposed rule. 

The three critical habitat waterbodies occur in St. Lucie and Indian River Counties. They are St. 

John’s Reservoir, Cloud Lake Reservoir (also known as Minute Maid Reservoir) and Strazulla 

Reservoir (Figure 4). A determination has been made by FDEP that considers the Strazulla 

Reservoir to be a wetland and therefore, not covered by the proposed nutrient rule. A 

determination has not yet been made for the other two reservoirs. There is some debate as to 

whether or not an artificial impoundment that is used primarily for citrus irrigation and flood 

control – which may dry out during drought conditions – is considered to be a “lake” under the 

proposed rule. Regardless, we have assumed the proposed rule to be in effect for these two 

reservoirs and have considered the nutrient status of both reservoirs in our effects determination. 

The 1,700-ac St. John’s Reservoir is managed for irrigation for local citrus grove interests. The 

reservoir is only a few feet deep and receives input from rainfall and irrigation water drained 

from the adjacent citrus groves. The water elevation fluctuates greatly based on rainfall and 

pumping rates and the reservoir periodically dries in droughts (Miller 2010). It is also 

overgrown with water hyacinth (Pistia stratiotes). As a result of poor habitat, snail kites have 

not used this site for nesting in at least, the last 10 years (Miller 2010). However, we would 

expect, given its proximity to snail kite nesting and foraging areas in the St John’s Marsh north 

of this reservoir, that snail kites could occasionally forage in the reservoir depending on 

conditions. 

The average total phosphorus concentration in the outflow of the St John’s Reservoir was 265 

ppb over the last seven years (2004 to 2010; N= 27). Phosphorus data in the canal immediately 

downstream of the St John’s Reservoir (at the State Route 60 Bridge) where additional inflows 

from citrus groves mix, indicated a long term average of 177 ppb total phosphorus (2000-2010; 

N=119). 

The critical habitat known as Cloud Lake Reservoir (640 acres) is similar to the St. John’s 

Reservoir except that snail kites have been observed foraging in this reservoir in August and 

September 2006, and we therefore, expect that snail kites could forage in this reservoir in most 

years. This 5-feet deep reservoir was part of the larger Cloud Grove site which historically was 

part of the St. John’s Marsh and flowed north into the St. John’s River. The area was converted 

to citrus in the 1950’s and 1960’s (Glatting Jackson Kercher Anglin Lopez Rhinehart, Inc. 2006) 

and now, due to construction of additional drainage feature, this area drains south into the C-25 

Canal and the Indian River Lagoon at Fort Peirce, Florida. Excess stormwater from the groves is 

routed into the reservoir where it is stored for irrigation. Water levels in the reservoir vary 

 
29 

depending on the season and the irrigation or drainage needs of the grove. The SFWMD has 

acknowledged in their permitting process that the reservoir is “operated at the property owner’s 

discretion” (Glatting Jackson Kercher Anglin Lopez Rhinehart, Inc. 2006). 

We do not have phosphorus data for Cloud Lake Reservoir, but we do have water quality data 

from a nearby location that is downstream of the reservoir. In the C-25 Canal upstream of the S99 Structure, the long term average phosphorus concentration from 1990 to 1996 (most recent 

data available; N=46) was 170 ppb (SFWMD 2010). It is reasonable to assume that given the 

operation of the reservoir to service local citrus groves (where phosphorus is applied as 

fertilizer), and the limited water quality data that we do have, that the concentration of 

phosphorus in the Cloud Lake Reservoir is greater than the proposed standard of 50 ppb. 

As indicated previously, the nutrient status of Lake Okeechobee is hypereutrophic (greater than 

100 ppb). Therefore, implementation of the proposed nutrient standard should improve the 

critical habitat conditions for the snail kite in Lake Okeechobee. 

EPA did not make an effect determination for snail kite critical habitat. However, based on the 

available information, the Service determines that the proposed rule “may affect, but is not likely 

to adversely affect snail kite critical habitat.” Should EPA choose, this letter can be used as 

concurrence of that determination. The Service will re-assess the effects to this species’ critical 

habitat when EPA develops their South Florida Region nutrient rule. 

 
30 

Literature Cited 

Baugh, T.M., J.A. Valade, and B.J. Zoodsma. 1989. Manatee use of Spartina alterniflora in 

Cumberland Sound. Marine Mammal Science 5(1):88-90. 

Beck, C.A. 2006. USGS FISC Sirenia Project. Unpublished data. 

Bent, A.C. 1937. Life histories of North American birds of prey. U.S. National Museum 

Bulletin 167. 

Darby, P. C. 2001. The affect of habitat restoration activities on applesnail abundance in central 

Florida lakes. Progress Report prepared for Florida Game and Fresh Water Fish 

Commission. Tallahassee, Florida. 

Darby, P. C. 2005a. Apple snail abundance in snail kite foraging sites on Lake Okeechobee in 

2005. Unpublished report to the Florida Fish and Wildlife Conservation Commission. 

Tallahassee, Florida. 

Darby, P. C. 2005b. Apple snail habitat relationships on central Florida lakes. Unpublished 

report to the Florida Fish and Wildlife Conservation Commission. Tallahassee, Florida. 

Darby, P. C. and F. H. Percival. 2000. Apple snail populations: persistence in hydrologically 

fluctuating environments. Abstract in proceedings from the Greater Everglades 

Ecosystem Restoration (G.E.E.R.) Science Conference. Naples, Florida. December 11-

15, 2000. 

Darby, P.C., P. Valentine-Darby, and H.F. Percival. 1998. Assessing the impact of the 

Lake Kissimmee restoration on apple snails. Final Report submitted to the Florida Game 

and Fresh Water Fish Commission; Tallahassee, Florida.

Davis, S. and J. Ogden. 1994. Introduction. Pages 3-8 in S. Davis and J. Ogden, eds. 

Everglades: the ecosystem and its restoration. St. Lucie Press; Delray Beach, Florida. 

Deutsch, C.J., R.K. Bonde, and J.P. Reid. 1998. Radio-tracking manatees from land and space: 

Tag design, implementation, and lessons learned from long-term study. Marine 

Technology Society Journal 32(1):18-29. 

Deutsch, C.J., J.P. Reid, R.K. Bonde, D.E. Easton, H.I. Kochman, and T.J. O’Shea. 2003. 

Seasonal movements, migratory behavior and site fidelity of West Indian manatees along 

the Atlantic Coast of the United States. Wildlife Monographs 151:1-77. 

 
31 

Dreitz, V.J., J.D. Nichols, J.E. Hines, R.E. Bennetts, W.M. Kitchens, and D.E. DeAngelis. 2002. 

The use of resighting data to estimate the rate of population growth of the snail kite in 

Florida. Journal of Applied statistics 29(4):609-623. 

Federico, A.C., K.G. Dickson, C.R. Kratzer, and F.E. Davis. 1981. Lake Okeechobee water 

quality studies and eutrophication assessment. Technical publication 81-2, South Florida 

Water Management District; West Palm Beach, Florida. 

Florida Department of Environmental Protection. 2005. Homosassa Springs Wildlife State 

Park. Unit management plan. Division of Recreation and Parks. June 3. 

Florida Springs Task Force. 2001. Florida’s springs: strategies for protection and restoration. 

Prepared for David B. Struhs, Secretary, Florida Department of Environmental Protection 

and the Citizens of the State of Florida. 59 pp. 

Gannon, J.G., K.M. Scolardi, J.E. Reynolds III, J.K. Koelsch, T.J. Kessenich. 2007. Habitat 

selection by manatees in Sarasota Bay, Florida. Marine Mammal Science 23(1): 133-143. 

Glatting Jackson Kercher Anglin Lopez Rhinehart, Inc. 2006. Development of Regional 

Impact. Application for Development Approval. Prepared for Florida Conservancy and 

Development Group, LLC. October. 

Harr KE, NJ Szabo, M Cichra, EJ Philips. 2008. Debromoaplysiatoxin in Lyngbya-dominated 

mats on manatees (Trichechus manatus latirostris) in the Florida King’s Bay ecosystem. 

Toxicon. 52:385-388. 

Higgs, K. 2006. FWC Fish and Wildlife Research Institute. Unpublished data. 

Howell, A.H. 1932. Florida bird life. Coward-McCann; New York, New York. 

Kitchens, W.M., R.E. Bennetts, and D.L. DeAngelis. 2002. Linkages between the snail kite 

population and wetland dynamics in a highly fragmented south Florida hydroscape. 

Pages 183-201 in J.W Porter and K.G. Porter, eds. The Everglades, Florida Bay, 

and Coral Reefs of the Florida Keys: An Ecosystem Sourcebook. CRC Press; 

Boca Raton, Florida. 

Laist, D.W. and J.E. Reynolds, III. 2005a. Influence of power plants and other warm-water 

refuges on Florida manatees. Marine Mammal Science 21(4): 739-764. 

Laist, D.W. and J.E. Reynolds, III. 2005b. Florida manatees, warm-water refuges, and an 

uncertain future. Coastal Management 33: 279-295. 

 
32 

Lightsey, J.D., Rommel, S.A., A.M. Costidis, and T.D. Pitchford. 2006. Methods used during 

gross necropsy to determine watercraft-related mortality in the Florida manatee 

(Trichechus manatus latirostris). J. of Zoo and Wildlife Medicine 37(3):262-275. 

Marine Mammal Commission. 1988. Preliminary assessment of habitat protection needs for 

West Indian manatees on the east coast of Florida and Georgia. Document No. PB89-

162002, National Technical Information Service. Silver Spring, Maryland. 120 pp. 

Marine Mammal Commission. 1986. Habitat protection needs for the subpopulation of West 

Indian manatees in the Crystal River area of northwest Florida. Document No. PB86-

200250, National Technical Information Service. Silver Spring, Maryland. 46 pp. 

Marks, E. 2010. Personal Communication. Environmental Administrator – Restoration 

Planning and Permitting. Phone call to the U.S. Fish and Wildlife Service on September 

23, 2010. Florida Department of Environmental Protection. Tallahassee, Florida. 

Martin, J., J.D. Nichols, W.M. Kitchens, and J.E. Hines. 2006. Multiscale patterns of movement 

in fragmented landscapes and consequences on demography of the snail kite in Florida. 

Journal of Animal Ecology 75: 527-539. 

Miller, S.J. 2010. Personal Communication. Environmental Scientist VI. Phone call to the U.S. 

Fish and Wildlife Service on September 24, 2010. St. John’s River Water Management 

District. Palatka, Florida. 

Nicholson, D.J. 1926. Nesting habitats of the Everglade kite in Florida. Auk 43:62-67. 

Orth, R.J., T.J.B. Carruthers, W.C. Dennison, C.M. Duarte, J.W. Fourqurean, K.L.Heck, Jr., A.R. 

Hughes, G.A. Kendrick, W.J. Kenworthy, S. Olyarnik, F.T. Short, M.Waycott, and S.L. 

Williams. 2006. A global crisis for seagrass ecosystems. BioScience 56 (12): 987-996. 

O’Shea, T.J., C.A. Beck, R.K. Bonde, H.I. Kochman, and D.K. Odell. 1985. An analysis of 

manatee mortality patterns in Florida 1976-1981. J. of Wildlife Management 49(1):1-11. 

Rathbun, G.B., J. P. Reid, and G. Carowan. 1990. Distribution and movement patterns of 

manatees (Trichechus manatus) in Northwestern peninsular Florida. Florida Marine 

Research Institute Publication No 48. 33 pp. 

Reid, J.P., G.B. Rathbun, and J.R. Wilcox. 1991. Distribution patterns of individually 

identifiable West Indian manatees (Trichechus manatus) in Florida. Marine Mammal 

Science 7(2):180-190. 

 
33 

Restoration Coordiniation and Verifcation. 2010. Comprehensive Everglades Restoration Plan 

2009 Draft System Status Report. Figure 3-10; pg 3-12. February. Available at: 

http://www.evergladesplan.org/pm/recover/assess_team_ssr_2009.aspx 

Rodgers, J.A., Jr., S.T. Schwikert, and A.S. Wenner. 1988. Status of the snail kite in Florida: 

1981-1985. American Birds 42:30-35. 

Rodgers, J.A., Jr., H.T. Smith, and D.D. Thayer. 2001. Integrating Nonindigenous Aquatic 

Plant Control with Protection of Snail Kite Nests in Florida. Environmental Management 

28(1):31-37. 

Rommel, S.A., A.M. Costidis, T.D. Pitchford, J.D. Lightsey, R.H. Snyder, and E.M. Haubold. 

2007. Forensic methods for characterizing watercraft from watercraft-induced wounds 

on the Florida manatee (Trichechus manatus latirostris). Marine Mammal Science 

23(1):110-132. 

Rumbold, D.G. and M.B. Mihalik. 1994. Snail kite use of a drought-related habitat and 

communal roost in West Palm Beach, Florida: 1987-1991. Florida Field Naturalist 

22:29-38. 

Smith, K.N. 1993. Manatee habitat and human-related threats to seagrass in Florida: a review. 

Florida Department of Environmental Protection, Bureau of Protected Species 

Management. Report. Tallahassee, Florida. 38 pp. 

Southwest Florida Water Management District. 2010. Water Management Information System 

database. Accessed September 22, 2010. 

http://www8.swfwmd.state.fl.us/WMIS/ResourceData/ExtDefault.aspx 

South Florida Water Management District. 2010. DBHydro environmental database. Accessed 

from September 13 through September 24, 2010. 

http://www.sfwmd.gov/portal/page/portal/xweb%20environmental%20monitoring/dbhyd

ro%20application 

St. John’s River Water Management District. 2010a. Water quality data for Blue Spring. 

http://www.sjrwmd.com/watershedfacts/factPages/BLSPR.html#waterquality. Accessed 

on September 24, 2010. 

St. John’s River Water Management District. 2010b. The St. Johns River. Website information. 

http://www.sjrwmd.com/stjohnsriver/index.html. Accessed on September 25, 2010. 

Sykes, P.W., Jr. 1979. Status of the Everglade kite in Florida 1968-1978. Wilson 

Bulletin 91:495-511. 

 
34 

Sykes, P.W., Jr. 1984. The range of the snail kite and its history in Florida. Bulletin, Florida 

State Museum, Biological Sciences 29:211-264. 

Sykes, P.W., Jr. 1987a. The feeding habits of the snail kite in Florida, USA. Colonial 

Waterbirds 10(1):84-92. 

Sykes, P.W., Jr. 1987b. Some aspects of the breeding biology of the snail kite in Florida. 

Journal Field Ornithology 58:171-189. 

Sykes, P.W., Jr. 1987c. Snail kite nesting ecology in Florida. Florida Field Naturalist 15:57-84. 

Sykes, P.W., Jr., J.A. Rodgers, Jr., and R.E. Bennetts. 1995. Snail kite (Rostrhamus sociabilis). 

In A. Poole and F. Gill, eds. The birds of North America, Number 171, The Academy of 

Natural Sciences, Philadelphia, and the American Ornithologists Union; Washington, 

D.C. 

Takekawa, J.E. and S.R. Beissinger. 1989. Cyclic drought, dispersal, and the conservation of 

the snail kite in Florida: lessons in critical habitat. Conservation Biology 3:302-311. 

U.S. Fish and Wildlife Service. 2007. West Indian Manatee (Trichechus manatus). Five-year 

Review: Summary and Evaluation. Atlanta, Georgia. 

Weigle, B.L., I.E. Wright, M. Ross, and R.O. Flamm. 2001. Movements of radio-tagged 

manatees in Tampa Bay and along Florida’s west coast, 1991-1996. Florida Marine 

Research Institute Technical Report TR-7. St. Petersburg, Florida 156 pp. 

Zoodsma, B.J. 1991. Distribution and behavioral ecology of manatees in southeastern Georgia. 

MS Thesis. University of Florida. Gainesville, Florida. 202 pp. 
Table 1. Number of successful snail kite nests by water body, 1996 through 2010 (note: 2010 

data are incomplete). 

Regions 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

East Lake Tohopekaliga - - - - - 0 2 0 0 0 1 1 4 1 2

Lake Tohopekaliga 4 5 0 1 2 4 12 4 0 12 5 42 28 15 11

Lake Hatchineha 000000000000 0 1 3

Lake Jackson 000000000000 0 1 1

Lake Kissimmee 0 1 1 12 0 9 3 7 4 1 0 2 1 2 1

Lake Istokpoga - - - - - - - - -402 6 1 1

Lake Okeechobee 15 0 4 0 0 0 0 1 3 3 7 0 0 0 2

St. Johns Marsh 751210033220 0 0 1

West Palm/ Grassy Waters 0 0 0 0 0 0 0 1 0 1 0 0 0 0 3

WCA 1 -05 - - -0 -0000 0 0 0

WCA 2A 000000000000 0 0 0

WCA 2B 1 5 53 0 0 0 4 3 11 0 0 0 0 0 0

WCA 3A 35 140 84 14 33 0 24 28 19 0 11 0 0 0 0

WCA 3B 0 0 2 3 15 0 3 0 3 0 3 0 0 0 4

Everglades National Park 4 0 0 0 6 0 0 0 0 0 13 0 0 3 0

Others 6043 - - - - - -00 0 0 3

Total 72 156 154 35 57 13 48 47 43 23 42 47 39 24 32

35 
36 

Table 2. Total phosphorus concentrations for various lakes within the Kissimmee Chain of 

Lakes, and Lake Arbuckle, Lake Istokpoga, and Lake Okeechobee, Florida. 

Minimum 

(ppb)

Mean 

(ppb)

Maximum 

(ppb) N Data Years

Lake Hart 21 25 31 4 1993-1994

East Lake 

Tohopekaliga 13 21 32 119 2000-2009

Lake Tohopekaliga 19 52 131 318 2000-2009

Lake Myrtle 27 60 101 54 2006-2010

Lake Lizzie 16 17 19 2 1993-1994

Alligator Lake 10 15 32 6 1993-1994

Lake Gentry 12 12 12 1 1994

Lake Cypress 35 75 127 96 2000-2009

Lake Hatchineha 31 60 160 208 2000-2009

Lake Weohyakapka 9 23 62 222 2000-2009

Lake Tiger 31 83 262 28 2000-2009

Lake Marian 49 132 346 48 2000-2009

Lake Jackson 67 86 100 5 2004-2006

Lake Kissimmee 29 59 159 214 2000-2009

Lake Arbuckle 37 73 231 100 2000-2009

Lake Istokpoga 43 82 208 320 2000-2009

Lake Okeechobee 15 135 552 2984 2000-2009
Figure 1. West Indian manatee critical habitat in the northern half of Florida overlain on the 

various regions for EPAs statewide nutrient rule. 

37 
Figure 2. West Indian manatee critical habitat in the southern half of Florida overlain on the 

various regions for EPAs statewide nutrient rule. 

38 
Figure 3. American crocodile range and critical habitat in Florida overlain on the various regions 

for EPAs statewide nutrient rule. 

39 
Figure 4. Everglade snail kite nesting and critical habitat in Florida overlain on the various 

regions for EPAs statewide nutrient rule. 

40 
Figure 5. Phosphorus concentrations in the Kissimmee Chain of Lakes. The five lakes in which 

snail kites nested in 2010 are designated with a dot. 

41 
42 

Appendix C – Florida Panhandle Species and Critical Habitats 
43 

Florida Panhandle

Florida panhandle waters that provide habitat for federally protected species or are designated as 

Critical Habitat for such species were evaluated by the Panama City Field Office of the Fish and 

Wildlife Service (Service). Two Florida “Regions” were included, panhandle west and 

panhandle east as per EPA’s State segregation for ecoregional specificity. For each individual 

watershed segment with listed species, the proposed nutrient criteria were compared to existing 

available total nitrogen, total phosphorus, and chlorophyll data provided by the Florida 

Department of Environmental Protection (STORET, 2000-2010). In no cases were the 

differences between the existing data and the proposed criteria expected to increase or decrease 

system loading to the point where it would be expected to negatively affect listed species or their 

habitats. However, limited biological response data are available and these data gaps need to be 

filled during the implementation of these new criteria so that careful adjustments can be made for 

each specific waterbody as needed. See conservation recommendations. 

Gulf Sturgeon 

The Gulf sturgeon (Acipenser oxyrinchus (=oxyrhynchus) desotoi), also known as the Gulf of 

Mexico sturgeon, is an anadromous fish (breeding in freshwater after migrating up rivers from 

marine and estuarine environments), inhabiting coastal rivers from Louisiana to Florida during 

the warmer months and over wintering in estuaries, bays, and the Gulf of Mexico. It is a nearly 

cylindrical primitive fish embedded with bony plates or scutes. The head ends in a hard, 

extended snout; the mouth is inferior and protrusible and is preceded by four conspicuous 

barbels. The caudal fin (tail) is heterocercal (upper lobe is longer than the lower lobe). Adults 

range from 1.2 to 2.4 m (4 to 8 ft) in length, with adult females larger than males. The Gulf 

sturgeon is distinguished from the geographically disjunct Atlantic coast subspecies (A. o. 

oxyrinchus) by its longer head, pectoral fins, and spleen (Vladykov 1955; Wooley 1985). King 

et al. (2001) have documented substantial divergence between A. o. oxyrinchus and A. o. desotoi 

using microsatellite DNA testing. 

The Service and NOAA Fisheries jointly designated Gulf sturgeon critical habitat on April 18, 

2003 (68 FR 13370, March 19, 2003). Gulf sturgeon critical habitat includes areas within the 

major river systems that support the seven currently reproducing subpopulations and associated 

estuarine and marine habitats (Figure 6). Gulf sturgeon use rivers for spawning, larval and 

juvenile feeding, adult resting and staging, and moving between the areas that support these life 

history components. Gulf sturgeon use the lower riverine, estuarine, and marine environment 

during winter months primarily for feeding and, more rarely, for inter-river movements. 
Figure 6. Critical habitat for Gulf sturgeon in the Florida panhandle. 

Critical habitat determinations focus on those physical and biological features (primary 

constituent elements [PCEs]) that are essential to the conservation of the species (50 CFR 

424.12). Federal agencies must insure that their activities are not likely to result in the 

destruction or adverse modification of designated critical habitats. Therefore, proposed actions 

that may affect designated critical habitat require an analysis of potential impacts to the PCEs. 

For the purposes of this assessment (fresh waters), Gulf sturgeon critical habitat must possess an 

abundance of food items, such as detritus, aquatic insects, worms, and/or mollusks, within 

riverine habitats for larval and juvenile life stages. Riverine spawning sites with substrates 

suitable for egg deposition and development, such as limestone outcrops and cut limestone 

banks, bedrock, large gravel or cobble beds, marl, soapstone, or hard clay must also remain clear 

and available. Overall, water quality must be maintained to support normal behavior, growth, 

and viability of all life stages. Likewise, sediment quality, including texture and other chemical 

characteristics, must provide for normal behavior, growth, and viability of all life stages. 

44 

Nutrient data for the riverine portions of Gulf sturgeon critical habitat were reviewed relative to 

the chlorophyll biotic endpoint data and qualitative trophic status information. In no cases were 

the differences between the existing nutrient data and the proposed criteria expected to increase 

or decrease system loading to the point where it would be expected to negatively affect Gulf 
45 

sturgeon or their habitat. However, limited biological response data are available for such 

determinations. More data is required to fully assess the relationship between nutrient 

concentrations and primary constituent elements of Gulf sturgeon critical habitat. Through the 

acquisition of these data during the implementation of these new criteria, careful adjustments can 

be made for each specific waterbody as needed. 

Okaloosa Darter 

The Okaloosa darter, Etheostoma okaloosae, is a small percid fish (maximum size 49 millimeters 

Standard Length) with a well-developed humeral spot, a series of five to eight rows of small 

spots along the sides of the body, and a first anal spine longer than the second. General body 

coloration varies from red-brown to green-yellow dorsally, and lighter ventrally, although 

breeding males have a bright orange submarginal stripe on the first dorsal fin (Burkhead et al. 

1992). The brown darter, Etheostoma edwini, is similar in size, but the blotched patterns on the 

sides are not organized into rows and breeding males have bright red spots on the body and fins. 

The Service listed the Okaloosa darter as endangered on June 4, 1973 (38 FR 14678). No critical 

habitat has been designated for this species. 

The Okaloosa darter was initially listed because of its extremely limited range and potential 

problems resulting from erosion, water impoundment, and competition with introduced brown 

darters (Figure 7). The areas inhabited by the Okaloosa darter are typically the margins of 

flowing streams where detritus, root mats, and vegetation are present. Densities average about 

one darter in every 0.45 meters of stream length (Jordan and Jelks 2005). Okaloosa darters have 

rarely been collected in areas where there is no current or open, sandy areas in the middle of 

stream channels. Brown darters also occupy similar stream margins; however, they are capable 

of living in areas of little to no flow (Burkhead et al. 1994). Okaloosa darters feed primarily on 

fly, mayfly, and caddis fly larvae (Ogilvie 1980). The breeding season extends from late March 

through October, although it usually peaks in April. Spawning pairs have been videographed 

attaching one or two eggs to vegetation, and they also have been observed attaching eggs to 

woody debris and root mats (Burkhead et al. 1994; Collette and Yerger 1962). Ogilvie (1980) 

found a mean of 76 ova and 29 mature ova in 201 female Okaloosa darters. These numbers may 

under-represent annual fecundity as the prolonged spawning season is an indication of fractional 

spawning (i.e., eggs develop and mature throughout the spawning season). Estimates of 

longevity range from two to three years (Burkhead et al. 1992; Mettee and Crittenden 1979; 

Ogilvie 1980). 
Figure 7. Okaloosa darter habitat in the Florida panhandle. 

The food sources in darter streams could be influenced by shifts in nutrient concentrations that 

could either provide for too much or too little productivity leading to a change in the diversity 

and abundance of available invertebrate prey species. Sufficient changes in nutrient 

concentrations could lead to altered stream flows via an increase in vegetation or algal cover, 

conversely it is less like likely nutrients would be insufficient to provide for natural growth 

within these groundwater fed systems. In reviewing the available habitat, the low nutrient status 

of Okaloosa darter streams may be key to ensuring sufficient flow and food resources for the 

Okaloosa dater. In these small groundwater fed watersheds, low nutrients are expected to be 

prevalent. A nutrient monitoring program that include both benthic macroinvertebrate and 

phytoplankton response endpoints would be essential for these streams for use in the 

development of the Site-Specific Alternative Criteria to ensure that the natural nutrient balance 

for these unique systems be maintained. 

 

46 
47 

Listed and Candidate Freshwater Mussels Species 

Freshwater mussels are bivalve mollusks (clams) of the family Unionidae. Unionid mussels 

generally live embedded in the bottom of rivers, streams, and other bodies of water. They siphon 

water into their shells and across four gills that are specialized for respiration and food 

collection. Known food items include detritus (disintegrated organic debris), diatoms, 

phytoplankton, zooplankton, and other microorganisms (Coker et al. 1921; Churchill and Lewis 

1924; Fuller 1974). Adults are filter feeders and generally orient themselves on or near the 

substrate surface to take food and oxygen from the water above them (Kraemer 1979). Juveniles 

typically burrow completely beneath the substrate surface and are pedal (foot) feeders (bringing 

food particles that adhere to the foot while it is extended outside the shell, inside the shell for 

ingestion) until the structures for filter feeding are more fully developed (Gatenby et al. 1997; 

Yeager et al. 1994). 

On November 15, 2007, the Service designated critical habitat in the eastern panhandle for seven 

federally listed freshwater mussel species (Figure 8), however candidate species do occur in the 

rivers systems in the western panhandle as well (Escambia and Choctawhatchee River systems). 

Each of the designated critical habitat units for these seven listed mussels contains one or more 

of the primary constituent elements (PCEs) that the Service describes as essential to the 

conservation of the species, and which may require special management considerations or 

protection. The PCEs pertinent to this assessment involve ensuring adequate water quality to 

meet or exceed the current aquatic life criteria established under the Clean Water Act (33 U.S.C. 

1251-1387). Essentially, water quality must be maintained to support normal behavior, growth, 

and viability of all freshwater mussel life stages, as well as their fish that support larval life 

stages of the mussels. 
Figure 8. Critical habitat for listed freshwater mussels species in the Florida panhandle. 

Nutrient data for the riverine portions of freshwater mussel critical habitat were reviewed relative 

to the chlorophyll biotic endpoint data and qualitative trophic status information. In no cases 

were the differences between the existing nutrient data and the proposed criteria expected to 

increase or decrease system loading to the point where it would be expected to negatively affect 

freshwater mussel species or the suitability of their designated critical habitat. However, limited 

biological response data are available for such determinations. More data is required to fully 

assess the relationship between nutrient concentrations and primary constituent elements of 

freshwater mussel critical habitat. Through the acquisition of these data during the 

implementation of these new criteria careful adjustments can be made for each specific 

waterbody as needed. 

 

48 
49 

Literature Cited 

Burkhead, N.M., J.D. Williams, and R.W. Yerger. 1992. Okaloosa darter, Etheostoma 

okaloosae, p. 23-30 In C. R. Gilbert [ed.] Rare and endangered biota of Florida. 

Volume III. Fishes. University Presses of Florida, Gainesville. 

Burkhead, N.M., H.L. Jelks, F. Jordan, D.C. Weaver, and J.D. Williams. 1994. The 

comparative ecology of Okaloosa (Etheostoma okaloosae) and brown darters (E. edwini) 

in Boggy and Rocky Bayou stream systems, Choctawhatchee Bay, Florida. Final Report 

to Eglin Air Force Base. 90 p. 

Churchill, E.P., Jr., and S.I. Lewis. 1924. Food and feeding in freshwater mussels. Bulletin of 

the Bureau of Fisheries 39:439-471. 

Collette, B.B., and R.W. Yerger. 1962. The American percid fishes of the subgenus Villora. 

 Tulane Studies in Zoology 9:213-230. 

Coker, R.E., A.F. Shira, H.W. Clark, and A.D. Howard. 1921. Natural history and propagation 

of freshwater mussels. Bulletin of the U.S. Bureau of Fisheries 37:77-181. 

Fuller, S.L.H. 1974. Clams and mussels (Mollusca: Bivalvia). Pages 215-273 in: C.W. Hart 

and S.L.H. Fuller, editors, Pollution ecology of freshwater invertebrates. Academic 

Press, New York. 

Gatenby, C.M., B.C. Parker, and R.J. Neves. 1997. Growth and survival of juvenile rainbow 

mussels, Villosa iris (Lea, 1829) (Bivalvia: Unionidae), reared on algal diets and 

sediment. American Malacological Bulletin 14(1):57-66. 

Jordan, F., and H.L. Jelks. 2005. Population monitoring of the endangered Okaloosa darter. 

 Annual report to Eglin Air Force Base. 38 p. 

King, T. L., B. A. Lubinski, and A. P. Spidle. 2001. Microsatellite DNA variation in Atlantic 

sturgeon (Acipsenser oxyrhynchus oxyrinchus) and cross-species amplification in the 

Acipenseridae. Conservation Genetics 2:103-119. 

Kraemer, L.R. 1979. Corbicula (Bivalvia: Sphaeriacea) vs. indigenous mussels (Bivalvia: 

Unionacea) in U.S. rivers: a hard case for interspecific competition? American Zoologist 

19:1085-1096. 

Mettee, M.F. and E. Crittenden. 1979. A study on the distribution of Etheostoma okaloosae 

(Fowler) and Etheostoma edwini (Hubbs and Cannon) in Swift and Rocky Creeks, 

Okaloosa and Walton Counties, Florida, during 1975-78. U.S. Fish and Wildlife Service 

Report 14-14-004-78-002. 101 p. 

 
50 

Ogilvie, V.E. 1980. Unpublished Florida Game and Freshwater Fish Commission Endangered 

 Wildlife Project E-1. Annual Progress Report. Tallahassee, Florida. 19 p. 

Vladykov, V.D. 1955. A comparison of Atlantic sea sturgeon with a new subspecies from the 

Gulf of Mexico (Acipenser oxyrhynchus desotoi). Journal Fish Research Board Canada 

12(5):754-761. 

Wooley, C.M . 1985. Evaluation of morphometric characters used in taxonomic separation of 

Gulf of Mexico sturgeon, Acipenser oxyrhynchus desotoi, pp. 97-103 In North American 

Sturgeon, Vol. 6., Developments in Environmental Biology of Fishes, edited by D.W.F. 

Binkowsi and S. I. Doroshov, Junk Publishing, The Netherlands. 

Yeager, M.M., D.S. Cherry, and R.J. Neves. 1994. Feeding and burrowing behaviors of juvenile 

rainbow mussels, Villosa iris (Bivalvia: Unionidae). Journal of the North American 

Benthological Society 13(2):217-222. 
51 

Appendix D – North Florida- Wood Stork 

 
52 

Wood Stork 

The wood stork is a large, long-legged wading bird. The species uses a variety of freshwater and 

estuarine wetlands for nesting, feeding, and roosting. Throughout its range in the southeastern 

United States, the wood stork are dependent upon wetlands for breeding and foraging. Wood 

storks feed almost entirely on fish between 2 and 25 cm (1 and 10 in) in length (Kahl 1964, 

pp.107-108; Ogden et al. 1976, pp. 325-327). They also occasionally consume crustaceans, 

amphibians, reptiles, mammals, birds, and arthropods. Fish populations reach high numbers 

during the wet season, but become concentrated in increasingly restricted habitats as drying 

occurs. Consumers such as the wood stork are able to exploit high concentrations of fish in 

drying ponds and sloughs. 

As described in the multi-species recovery plan for the wood stork, the major threat to this 

species is loss of habitat from the disruption of natural water flow in swamp areas of south 

Florida (Service 1997). No information regarding direct or indirect effects of nutrients on this 

species could be identified, and thus the frequency of potential effects to wood stork are expected 

to be negligible compared to the primary threats to the species. Wood stork are not expected to 

be directly affected by nutrient concentrations. 

Literature Cited 

Kahl, M.P., Jr. 1964. Food ecology of the Wood Stork (Mycteria americana). Ecological 

Monographs 34:97-117. 

Ogden, J.C., J.A. Kushlan, and J.T. Tilmant. 1976. Prey selectivity by the wood stork. Condor 

78(3): 324-330. 

U.S. Fish and Wildlife Service. 1997. Revised recovery plan for the U.S. breeding population of 

the wood stork. U.S. Fish and Wildlife Service. Atlanta, Georgia. 41 pp. 

S:\STAFF\Jon\letters\ EPA_numeric_nutrient_florida_101010final