ST. JOHNS COUNTY MANATEE PROTECTION PLAN INVENTORY OF EXISTING CONDITIONS A. Habitat Manatees are large, air-breathing aquatic mammals that are found in marine, estuarine and freshwater systems throughout Florida, and which appear to move freely between these differing salinities without problems. They can be found in clear waters or in areas where underwater visibility is exceedingly low. They use these water bodies for food, shelter, migratory pathways, and/or warm water refugia. Water depths of at least one to two meters (3-7 feet) appear to be preferred, and flats and shallows are generally avoided unless these areas are adjacent to deeper water (FPL, 1987). This section contains a description of the aquatic areas within St. Johns County that are accessible to manatees. 1. Locations Manatee habitat in St. Johns County can be separated into five distinct areas: • Nearshore Atlantic Ocean; • The Atlantic Intracoastal Waterway (AICW) north of St. Augustine Inlet, including the Tolomato River and its tributaries, creeks and man-made canals; • The AICW between St. Augustine and Matanzas Inlets, including the Matanzas River and its tributaries, creeks, and man-made canals; • The AICW South of Matanzas Inlet, including the Matanzas River, its tributaries, creeks, and man-made canals; and • The St. Johns River, including its tributaries, creeks, and man-made canals. General areas of manatee habitat in St. Johns County are shown on Figure 4. Areas of high marsh (that would typically be too high in elevation for manatees to access except during periods of unusually high tides) and areas upstream of various structures (e.g., bridges, culverts, stormwater control structures…) are identified as ‘potential habitat’ but development of this MPP has not involved a detailed field effort or reconnaissance of culvert sizes to determine accessibility by manatees. Nearshore Waters of the Atlantic Ocean As described in Section I.C.1, St. Johns County is located on the southeast coast of Florida between Duval County to the north and Flagler County to the south (Figure 2). It has approximately 42 miles of frontage on the Atlantic Ocean, with the St. Augustine Inlet and the Matanzas Inlet providing two surface-water connections between the ocean and inland waterways. Although manatees are most frequently observed in the inshore waters (e.g., Tolomato and Matanzas Rivers and their tributaries, and the St. Johns River and other inland waters), there has been credible documentation of the occasional presence of manatees along the coast in the shallow, nearshore waters of the Atlantic Ocean. Much of the nearshore Atlantic Ocean in St. Johns County, however, consists of barren sandy substrate that provides little, if any, food for manatees. Nearshore hardbottom is present intermittently along the County’s southern Atlantic coastline, and in other areas, manatees have been known to graze on the marine algae that grows on hardbottom. The extent to which GNV/2005/051093A/DGB/ATM/STJMPP/9-30-05 18 St. Johns County Manatee Habitat Ponte Vedra Beach P o n t e V e d r R a o B s o c u o l e e 4 v B a o r u d l e v a r d 036 Miles JACKSONVILLE d Cre oa Du rbin e R k y le Fruit al V Cove lm Pa ingha DUVAL CO. unn m G C Cr ee ST. JOHNS CO. u k a n a L a k e R o be r t s R o Switzerland a d MN210 G ree NORTH 13 nbria r Roa d A1A NORTH Hallowes 671 Cove 210 k MN e e r C 95 §¨¦ S South Ponte t ay u kw Vedra Beach o r t r a P T f . ol G 'l nt GREEN I COVE MN16A SPRINGS J o A T L A N T I C O C E A N h S ix m il e n 16 C r e s e k ST. AUGUSTINE Vilano 208 208 Beach MN MN 16 Picolata R i k 13 e e MN r Silano 13A C v Cove MN i o e c 312 o T 214 r MN MN214 St. Augustine Beach k e C re k e Cr e rie lt u o M h g u o l l u 207 C c M MN13A SOUTH 671 Mo c c asin Elkton C re ek §¨¦95 MN305 SOUTH De e p A1A 13 MN Crescent C r e Beach e k WEST 206 HASTINGS PUTNAM CO. ST. JOHNS CO. er ic ll e P Cr e e k PALATKA MN204 ST. JOHNS CO. Legend FLAGLER CO. j10181 Primary Manatee Habitat DISCLAIMER: This map is for reference use only. Data provided are derived from multiple sources with varying levels of accuracy. The St. Johns County Secondary Manatee Habitat GIS Division disclaims all responsiblilty for the accuracy of completeness of the data shown hereon. Figure 4 ST. JOHNS COUNTY MANATEE PROTECTION PLAN manatees feed on these resources along St. Johns County beaches is not known, but is expected to be minimal if at all. A large freshwater spring introduces land-based waters into the Atlantic Ocean at a location approximately 2.5 miles offshore of St. Johns County in the vicinity of Crescent Beach (Appendix A). Estimates of discharge rates are 10-300 ft3/sec, a volume that, if present at a more appropriate location, could be sizable enough to attract manatees. The distance from shore, though, coupled with the water depth at the point of discharge being approximately 60’ and comparatively little manatee presence in the nearshore area makes it unlikely that manatees are attracted to this site. Additionally, none of the manatee survey data have documented that manatees travel to the spring site. The Atlantic Intracoastal Waterway AICW north of St. Augustine Inlet, including the Tolomato River and its tributaries, creeks and manmade canals The Tolomato River is a natural, tidally influenced waterbody that extends northward from St. Augustine Inlet. It varies somewhat in width but is generally less than one mile wide. The Atlantic Intracoastal Waterway is a navigation channel within the Tolomato River, and approximately 12 miles north of the inlet, near Pine Island, the natural Tolomato is replaced by the dredged AICW channel that extends approximately 12 miles further northward to the St. Johns/Duval County line and further. This water body (although it is named differently in different areas) parallels the coast for the entire length of St. Johns County (Figure 2). Vast areas of low-elevation marshes border the Tolomato and AICW making the shorelines largely inaccessible to people except by watercraft. Numerous creeks (e.g., Robinson Creek, Indian Creek, Stokes Creek, Deep Creek, Capo Creek, Pablo Creek) also flow into the Tolomato. Jointly, Guana Lake and Guana River comprise a long, narrow aquatic ecosystem located on the west side of the barrier island bordered by State Rd A1A and the Atlantic Ocean to the east and the Tolomato River to the west. Although Guana Lake is largely inaccessible to manatees due to the presence of a dam and water control structure located in its southern portion, on rare occasions manatees have accessed portions of Guana Lake north of the water control structure and dam. On two occasions (once in May 1991 and once in October 1993) a manatee capture took place at this location and the rescued manatee was released on the downstream side of the water control structure. Due to the comparatively high quality condition of the varied habitats, various portions of Guana River have been acquired and are managed for public purposes. Guana River Wildlife Management Area consists of approximately 9,800 acres of state-owned land, and recently, the area known as Guana River State Park was absorbed into the new Guana-Tolomato-Matanzas National Estuarine Research Reserve (GTMNERR). Although manatees are well known for their diet of seagrass, particularly manatee grass (Syringodium filiforme), St. Johns County is too far north for the typical existence of most seagrasses. Manatees are known to also feed at high tide in salt marshes on smooth cordgrass (Spartina alterniflora) (FWS 2000). Due to the extensive cordgrass marshes along the Tolomato River and AICW, including various embayments and connected tributaries, these areas are considered habitat for manatees. The lack of preferred food material, however, prevents this area from being higher in value for manatees. GNV/2005/051093A/DGB/ATM/STJMPP/9-30-05 20 ST. JOHNS COUNTY MANATEE PROTECTION PLAN The Atlantic Intracoastal Waterway between St. Augustine and Matanzas Inlets and the Matanzas River, including its tributaries, creeks, and man-made canals The Matanzas River is a natural, tidally influenced waterbody that extends southward from the St. Augustine Inlet along the eastern portion of St. Johns County. It varies somewhat in width and reaches a maximum width of approximately 1.5 miles just north of State Road 206 in the area of Crescent Beach. South of S.R. 206, there are extensive tidal marshes on the western side of the river. The AICW navigation channel is within the Matanzas River. The stretch of the Matanzas River between the St. Augustine and Matanzas Inlets is approximately 15 miles in length. As with the Tolomato River to the north, there are numerous creeks (e.g., San Sebastian River, Moultrie Creek, East Creek, San Julian Creek,) that also flow into the Matanzas. The shoreline vegetation, including cordgrass, that is present along most of these creeks, may be browsed upon by manatees, and therefore the entire Matanzas River and AICW, including various embayments and tributaries where water depths are adequate, are prime habitat for manatees. The Atlantic Intracoastal Waterway south of Matanzas Inlet , including the Matanzas River, and its tributaries, creeks, and man-made canals The Matanzas River and AICW extend approximately three miles south from the Matanzas Inlet to the St.