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St. Martins Marsh Aquatic Preserve

"The St. Martins Marsh Aquatic Preserve is one of the best investments ever made by the state of Florida. Whether it's as a buffer to hurricanes' impacts, a producer of commercial and recreational fisheries, or an ecotourism magnet, the preserve is the investment that keeps on giving generation after generation."
- Gary Maidhof, former Citrus County Development Services Director

  • St. Martins Marsh Aquatic Preserve was established on Oct. 21, 1969. 
  • St. Martins Marsh Aquatic Preserve's freshwater tributaries include two first-magnitude springfed rivers: the Homosassa River to the south and Crystal River to the north.
  • Spring discharge does not fluctuate dramatically from season to season, allowing a constant flow of freshwater into St. Martins Marsh's productive and well-balanced estuary.
  • The area's vast coastal salt marshes, mud flats, oyster bars, mangrove islands and seagrass beds are the southern terminus for migratory waterfowl of the Atlantic and Mississippi flyways. St. Martins Marsh provides stopover and wintering areas for many migratory species. 
  • The Springs Coast is characterized by unique limestone outcroppings and exposed karstic features. Habitats associated with these areas are hardbottom sponge and coral communities and sargassum meadows.

Resource Management 
St. Martins Marsh Aquatic Preserve collects valuable water quality data through a variety of successful partnerships. Project COAST is in its 12th year of data collection in conjunction with University of Florida. Nutrient and other water quality data is taken monthly at 30 fixed stations throughout coastal Citrus County. In addition, bimonthly nutrient and water quality data is taken in conjunction with the Southwest Florida Water Management District (SWFWMD) in King's Bay, headwaters of the Crystal River. Using the latest technology, staff also administer a continuous water quality monitoring program at three fixed stations in partnership with Citrus County and SWFWMD. All of these programs provide resource managers with important water quality information that enables better assessment of the estuary's health.

Other major management activities include seagrass monitoring, diamondback terrapin monitoring, shoreline restoration and prop scar restoration.

Counties: 
Citrus
Location: 
FL
Managed Location Contact: 
Tim Jones
Phone: 
Total Acreage: 
28461.00
Managed-Regulated: 
Managed
Receives State Funding: 
No
State Owned: 
Yes
Public Access: 

St. Martins Marsh Aquatic Preserve is a gem on the Nature Coast of Florida with ample recreational opportunities for people looking to reconnect with nature. Boating, kayaking and canoeing are among the more popular ways to experience St. Martins Marsh. However, you don't need a watercraft to see the aquatic preserve. The trails of Crystal River Preserve State Park allow access to the marsh and water's edge. Fishing and birding are popular from both the land and water. If you want to get into the water, snorkeling and scuba diving are popular. The waters are crystal clear, thanks to the numerous springs just offshore.

Kings Bay, just next to the aquatic preserve, is world famous for the herd of manatees that stay in the area year-round. In the winter, even more manatees crowd the bay, attracted by the relatively warm spring waters.

Another great way to visit the St. Martins Marsh Aquatic Preserve is by volunteering. Volunteer efforts focus around keeping the Nature Coast beautiful. Staff are active participants of the Adopt-A-Shore Program, the Citrus County version of the International Coastal Coastal Cleanup - either hosting a site or helping to coordinate another site. The derelict crab trap removal program is another way to help keep the preserve as pristine as possible. Crab traps often become lost or abandoned because of lost buoys, but the traps continue to catch crabs and other wildlife. During a brief off-season, traps are identified at low tide and removed by staff, local crabbers and other members of the community.

Archaeological Resources: 

With dozens of archaeological sites documented by the Florida Department of State Division of Historical Resources, the area of St. Martins Marsh Aquatic Preserve is recognized as a major center of aboriginal activity in Florida. Evidence of human presence in the area is dated back to approximately 10,000 years ago with the presence of small bands of nomadic Paleoindians. These peoples were hunter gathers who followed big game animals. At that time, the climate of the area was cooler and drier, and the shoreline extended approximately 60 to 100 miles farther west than it does today. The warming of the climate and receding of the shoreline marked the beginning of the Archaic period of human activity. Archaic people adapted to the changing climate by hunting smaller game, collecting plants, fishing, and shellfish harvesting. With this lifestyle came the onset of more permanent settlements. The best documented evidence of settlement in Citrus County dates back 2,500 years ago to the Deptford Culture settlements, of the Formative stage, along the matured Crystal River System. Groups of the Formative stage are distinguished from Archaic groups by the presence of ceramics. The type of ceramics additionally serves to distinguish Formative groups from each other. Along with late Archaic groups, the Deptford Culture settlements are responsible for the area’s most well-known archaeological sites, shell middens. Shell middens are former dump sites of these cultures, named for their most common remnant, shellfish.

The most well-known site, believed to have been occupied from Deptford through the Late Fort Walton period, lies in Crystal River Archaeological State Park. Known as the Crystal River Indian Mounds, the site was first discovered by C.B. Moore in 1903 and is considered one of the longest continually occupied sites in Florida. The site is a mound complex with four shell and sand platforms, two burial mounds, and an extensive shell midden. Additional mounds from the same time period are found on the small island of Mullet Key. Both the Crystal River Site and Mullet Key are listed on the National Register of Historic Places. The shell middens, among archaeological sites of Citrus County and St. Martins Marsh Aquatic Preserve, presently face issues of erosion brought on by changes in sea level. This poses a threat to the sites, not just in terms of their importance as historical resources, but also their importance as habitat communities they provide St. Martins Marsh Aquatic Preserve.

The end of the Fort Walton period marks the beginning of Spanish contact, or the Leon-Jefferson period. During this time, it is believed that Hernando De Soto marched through present day Citrus County on his quest for gold in La Florida. Upon landing in the Tampa area, De Soto and his troops marched northward, eventually crossing through the present day city of Inverness before crossing the Withlacoochee River and moving farther northwest. This trail is marked via the De Soto Trail of Florida, with parts of the trail occurring along the Withlacoochee State Trail in Inverness. Through contact with Spanish conquistadores, the majority of the native Timucua people were wiped out. This paved way for other groups of Native Americans, later known as the Seminoles, to reoccupy the land. With the further southern progressions of American settlements came conflicts with the Seminoles. These conflicts would result in three separate wars, known as the Seminole Wars (1817-1818, 1835-1842 and 1855-1858). Soon after the First Seminole War, Spain ceded control of Florida to the United States in 1821. In 1830, the Indian Removal Act was passed in an effort to encourage population by American settlers by removing Native American tribes from the land. This would bring about the Second Seminole War, the deadliest of the three, which would include battles in eastern Citrus County. Fort Cooper State Park is a historic site named in honor of Major Mark Anthony Cooper, the commander of the 380 First Georgia Battalion Volunteers. In 1836, Major Cooper built a fort to serve as a stockade to protect the sick and wounded soldiers left behind by General Winfield Scott. The major was ordered to hold his position and await relief troops who were nine days away. During this period, the fort received constant attack from the Seminoles before finally receiving relief 16 days later. Fort Cooper was listed on the National Register of Historic Places in 1972.

Following the Armed Occupation Act of 1845, and the acceptance of Florida as a state in 1845, the establishment of American settlements in the area began to grow. In 1851, David Levy Yulee, the first senator of Florida and first Jewish U.S. senator, would build the Yulee Sugar Mill in present day Homosassa. The site, along with Yulee’s railroad system, would become important tools for the Confederate Army after Florida’s secession from the Union in 1861. The mill would serve as a supplier of sugar for the Confederate Army with the accompanied mansion serving as a stockpile. Yulee’s compound and railroad were destroyed by the Union Army during the Civil War. Following the conclusion of the war, Yulee was imprisoned for a year, accused of aiding the escape of Confederate President Jefferson Davis. After his release from prison, Yulee rebuilt the Florida Railroad; however, the mansion and sugar mill were never repaired. The Yulee Sugar Mill Ruins have since been partially restored and now serve as a landmark of Old Homosassa in Yulee Sugar Mill Ruins Historic State Park and are listed on the National Register of Historic Places.

In 1903, Crystal River formed a municipal government, and by 1923 became a city. The formation of the city coincided with the real estate boom of the 1920s and its steep decline leading into the Great Depression. It was during the Depression that newly elected president Franklin D. Roosevelt implemented the Works Progress Administration (later known as Works Projects Administration). The Works Progress Administration was a major component of the New Deal and provided millions of jobs through public works projects. Several projects were performed in Citrus County with the most notable ones being the Lecanto Canning Plant, Crystal River Airport, and the Old Crystal River City Hall. The Crystal River Airport is the only structure of the three that is still in active, originally purposed use. The Crystal River City Hall remained in use until 1970 and is currently listed on the National Register of Historic Places. The building currently houses the Coastal Heritage Museum.

Wildlife Habitat Description: 

St. Martins Marsh Aquatic Preserve is within transitional zones between temperate and tropical, and between upland and aquatic. Consequently, it has a tremendous diversity of communities.

Hydric Hammock

Hydric hammock is an evergreen and/or palm closed-canopy forest where palms and ferns are commonly found in moist soils and occur in low, flat, wet sites. Limestone is often found near the surface of the soil. High soil moisture is maintained throughout the year due to rainfall accumulation and periodic flooding from rivers, springs, and seepage on poorly drained soils.  Areas of hammock immediately bordering salt marsh or other coastal areas are called coastal hydric hammock. Species composition is limited by salinity, but the predominant species are cabbage palm, live oak and red cedar.

Species diversity and composition is primarily determined by flooding patterns. Environments that are saturated and frequently flooded typically contain hydrophytic trees such as swamp tupelo. The frequency of floods and depths at which they occur have a prominent effect on oak canopy composition; saturated soils support mostly swamp laurel oak, whereas environments that experience less flooding are more abundant with live oak. The St. Martins Marsh Aquatic Preserve hydric hammocks occur within and adjacent to Crystal River Preserve State Park. According to the park biologist, this natural community is in good condition.

Shell Mounds

Shell mounds are small hills elevated entirely by mollusk shells that were discarded by Native Americans several centuries ago. These mounds support a diverse hardwood, closed-canopy forest with the rich calcareous soil composed of shell fragments. If hammock vegetation is not available, a sparse shrubby community has been known to develop. Shell mounds tend to host tropical plant species which is in constant flux. It is natural for species to be eliminated by freezes and re-colonized via bird dispersal. The St. Martins Marsh Aquatic Preserve shell mounds occur within and adjacent to Crystal River Preserve State Park. According to the park biologist, this natural community is in good to fair condition. Erosion, by boat wake and tidal surge, is the primary cause for concern relating to shell mounds in the area.

Salt Marsh

Salt marsh occurs in coastal zones that are greatly affected by tides and seawater. These herbaceous communities are protected by large waves by the broad, gently sloping topography of the shore, by a barrier island, or by location along a bay or estuary. The width of the intertidal zone depends on the slope of the shore and the tidal range. It is not uncommon for salt marsh to have distinct zones of vegetation, with each zone dominated by a single plant species. Salt marsh cordgrass (Spartina alterniflora) dominates the areas that are most frequently flooded, the seaward edge and borders of tidal creeks. Needle rush (Juncus roemerianus) dominates higher, less frequently flooded areas..

Salt marshes are one of the most biologically productive natural communities in the world due to the tidal fluctuations that cycle nutrients and allow marine and estuarine fauna to access the marsh. Salt marshes are also extremely important because of their storm buffering capacity and their pollutant filtering actions. The dense roots and stems hold the soils together, reducing the impact of storm wave surge. The plants, animals, and soils filter, absorb, and neutralize many pollutants before they can reach adjacent marine and estuarine communities. The St. Martins Marsh Aquatic Preserve salt marshes occur within and adjacent to Crystal River Preserve State Park. According to the park biologist, this natural community is in good condition.

Variation: Salt Flat

Salt flats are slightly elevated areas within the salt marsh. It floods only from storm tides or extreme high tides. Due to the isolation from freshwater, these communities are very saline and are dominated by species that can only tolerate increased salinities, such as saltwort (Batis maritima), annual glasswort (Salicornia bigelovii), and saltgrass (Distichlis spicata). Some salt flats are too elevated and become too saline and are unable to sustain much plant life. Vegetation is limited to a very sparse and stunted cover of succulents and/or shoregrasses with much bare ground.

Mangrove Swamp

Mangrove swamp is a dense forest that can be found along flat marine and estuarine shorelines with low wave energy. These communities occur in flat coastal areas along saline or brackish portions of rivers, along the edges of low-energy estuaries, and along the seaward fringes of salt marshes and rockland hammocks. Soils are generally anaerobic and are saturated with brackish water at all times, becoming inundated during high tides. Mangrove swamp occurs on a wide variety of soils, ranging from sands and mud to solid limestone rock. Mangrove swamps predominately consist of red mangrove (Rhizophora mangle), black mangrove (Avicennia germinans), white mangrove (Laguncularia racemosa), and buttonwood (Conocarpus erectus). These species can be found together in mixed stands or separated in monospecific zones that reflect varying degrees of tidal influence, levels of salinity, and types of substrate. In the lowest, deep water zone, red mangrove tends to dominate, black mangrove is most likely to be found in the intermediate zone, followed by white mangrove and buttonwood in the highest, least tidally-influenced zone.

Mangroves can range considerably within the mangrove swamp. Mangroves can typically be found in dense stands but it is not uncommon to find them in sparse patches, especially in upper tidal zones where salt marsh species dominate. The range of the mangroves varies from 80 foot tall trees to dwarf shrubs that thrive on limestone rock. Usually, the mangroves average about 10 to 20 feet tall. Mangrove swamps often exist with no understory, although shrubs ,vines, and herbaceous species may occur in openings and along swamp edges. Mangrove swamp communities are important because they provide homes for Florida’s commercially and recreationally significant fish and shellfish. These natural communities are also the breeding grounds for substantial populations of wading birds, shorebirds, and other animals. The continuous shedding of mangrove leaves and other plant components produce as much as 80 percent of the total organic material available in the aquatic food web. Additionally, mangrove swamps help protect other inland communities by absorbing the brunt of tropical storms and hurricanes. This natural community is currently in good/stable condition in St. Martins Marsh Aquatic Preserve.

Consolidated Substrate

Marine and estuarine consolidated substrates are mineral-based natural communities generally characterized as expansive, relatively open areas of subtidal, intertidal and supratidal zones which lack dense populations of sessile plant and animal species. Consolidated substrates are solidified rock or shell conglomerates and include coquina, limerock or relic reef materials. These communities may be sparsely inhabited by sessile, planktonic, epifaunal, and pelagic plants and animals but house few infaunal organisms (i.e., animals living within the substrate).

The three kinds of consolidated substrate communities occurring in Florida are of limited distribution. Coquina, which is a limestone composed of broken shells, corals and other organic debris, occurs primarily along the east coast, in marine areas in the vicinity of St. Johns and Flagler counties. Relic reefs, the skeletal remains of formerly living reefs, are more limited in distribution than limerock outcrops but more common than coquina substrate. Limerock substrates occur as outcrops of bedded sedimentary deposits consisting primarily of calcium carbonate, and is the most widespread consolidated substrate. It can be found in a patchy distribution under both marine and estuarine conditions from north Florida to the lower-most keys in Monroe County, including in St. Martins Marsh Aquatic Preserve.

Consolidated substrates are important in that they form the foundation for the development of other marine and estuarine natural communities when conditions become appropriate. Consolidated substrate communities are easily destroyed through siltation or placement of fill, and deliberate removal by actions such as blasting or non-deliberate destruction by forces such as vehicular traffic. The limerock substrate type is the prevalent consolidated substrate of the aquatic preserve, and is currently in good/stable condition.

Unconsolidated Substrate

Marine and estuarine unconsolidated substrates are mineral-based natural communities generally characterized as expansive, relatively open areas of subtidal, intertidal, and supratidal zones which lack dense populations of sessile plant and animal species. Unconsolidated substrates are unsolidified material and include coralgal, marl, mud, mud/sand, sand or shell. This community may support a large population of infaunal organisms as well as a variety of transient planktonic and pelagic organisms (e.g., tube worms, sand dollars (Clypeasteroida), mollusks, isopods, amphipods, burrowing shrimp (Thalassinidea), and an assortment of crabs).

In general, marine and estuarine unconsolidated substrate communities are the most widespread communities in the world. However, unconsolidated substrates vary greatly throughout Florida, based on surrounding parent material. Unconsolidated sediments can originate from organic sources, such as decaying plant tissues (e.g., mud) or from calcium carbonate depositions of plants or animals (e.g., coralgal, marl and shell substrates). Marl and coralgal substrates are primarily restricted to the southern portion of the state. The remaining four kinds of unconsolidated substrate, mud, mud/sand, sand, and shell, are found throughout the coastal areas of Florida. While these areas may seem relatively barren, the densities of infaunal organisms in subtidal zones can reach the tens of thousands per meter square, making these areas important feeding grounds for many bottom feeding fish, such as red drum or redfish (Sciaenops ocellatus), spot (Leiostomus xanthurus), and sheepshead (Archosargus probatocephalus). The intertidal and supratidal zones are extremely important feeding grounds for many shorebirds and invertebrates.

Unconsolidated substrates are important in that they form the foundation for the development of other marine and estuarine natural communities when conditions become appropriate. Unconsolidated substrate communities are associated with and often grade into beach dunes, salt marshes, mangrove swamps, seagrass beds, coral reefs, mollusk reefs, worm reefs, octocoral beds, sponge beds, and algal beds.

Octocoral Beds

Octocoral beds are characterized by their large populations of sessile invertebrates including soft corals such as gorgonians, sea fans, sea feathers and sea plumes (Pseudopterogorgia spp.), sea fingers (Briareum asbetinum), sea pansies (Renilla spp.), sea rods (Plexaura spp.) and sea whips (Leptogorgia spp.). This community is confined to the subtidal zone, and organisms are likely to dry out if not completely saturated. Sea anemones also typically occur in these communities.

An assortment of non-sessile benthic and pelagic invertebrates and vertebrates (e.g., sponges, mollusks, tube worms, burrowing shrimp, crabs, isopods, amphipods, sand dollars, and fishes) are associated with octocoral beds. Species include flamingo tongue snail (Cyphoma gibbosa) and the giant basket starfish (Astrophyton muricatum). Sessile and drift algae can also be found scattered throughout octocoral beds.

Octocoral beds require hard bottom (consolidated) substrate (i.e., coquina, limerock, relic reefs) on which to anchor. Hard bottom substrate occurs sparsely throughout Florida in marine and estuarine areas; however, soft corals prefer the warmer waters of the southern portion of the state, severely limiting the distribution. This natural community in the aquatic preserve is currently in good/stable condition.

Sponge Beds

Marine and estuarine sponge beds are soft faunal-based natural communities characterized as dense populations of sponges. The dominant animal species are sponges such as branching candle sponge (Verongia longissima), Florida loggerhead sponge (Spheciospongia vesparium), and sheepswool sponge (Hippiospongia lachne). Although concentrations of living sponges can occur in marine and estuarine intertidal zones, sponge beds are confined primarily to subtidal zones. Other sessile animals typically occurring in association with these sponges are stony corals, sea anemones, mollusks, tube worms, isopods, amphipods, burrowing shrimp, crabs, sand dollars and fishes. Sessile and drift algae can also be found scattered throughout sponge beds.

Sponge beds require hard bottom (consolidated) substrate (i.e., coquina, limerock, relic reefs) on which to anchor. Hard bottom substrate occurs sparsely throughout Florida in marine and estuarine areas; however, sponges prefer the warmer waters of the southern portion of the state, significantly limiting the distribution severely. This natural community in St. Martins Marsh Aquatic Preserve is currently in good/stable condition.

Algal Beds

Marine and estuarine algal beds are floral-based natural communities with large populations of nondrift macro or micro algae. This community may occur in subtidal, intertidal and supratidal zones on soft and hard bottom substrates. Vascular plants (e.g., seagrasses) may occur in algal beds associated with soft bottoms. Sessile animals associated with algal beds will vary based on bottom type. For algal beds associated with hard bottom substrate (lithophytic), faunal populations will be similar to populations associated with octocoral beds and sponge beds. Those associated with soft bottom substrate (psammophytic) may have similar benthic and pelagic species in addition to infauna species. Algal beds provide critical habitat for juvenile spiny lobsters (Panulirus argus), a species of great commercial importance.

Lithophytic algal beds are thought to be less widespread within Florida than psammophytic algal beds. The precise distribution of both kinds is not known; however, the distribution is thought to be less than for marine and estuarine seagrass beds.

Marine and estuarine algal beds may grade into seagrass beds, salt marsh, mangrove swamp, or many of the other marine or estuarine natural communities. Supratidal algal beds such as periphyton beds (e.g., blue-green algal mats) may grade into various coastal palustrine and terrestrial natural communities.

Distribution information for algal beds is lacking. The location of major beds must be determined before this natural community can be managed adequately. Existing state dredge and fill laws provide specific protection for marine and estuarine seagrass beds but not for algal beds. The correction of this deficiency could prove to be the most effective management tool available.

The primary threat to marine and estuarine algal beds are dredging and filling activities that physically remove or bury the beds. Other damage occurs from increased turbidity in the water column, which reduces available light; pollution, particularly from oil spills; and damage from boats. This natural community in St. Martins Marsh Aquatic Preserve is currently in good/stable condition.

Seagrass Beds

Marine and estuarine seagrass beds are floral-based natural communities typically characterized as expansive stands of vascular plants. This community occurs in subtidal (rarely intertidal) zones, in clear, coastal waters where wave energy is moderate. Seagrasses are not true grasses, but more closely related to lilies. The three most common species of seagrasses in Florida are turtle grass (Thalassia testudinum), manatee grass (Syringodium filiforme) and shoal grass (Halodule wrightii). Nearly pure stands of any one of these species can occur, but mixed stands are also common. Species of Halophila may be intermingled with the other seagrasses, but species of this genus are considerably less common than turtle grass, manatee grass and shoal grass. Widgeon grass (Ruppia maritima) can also be found occurring with the previously listed seagrasses although they occur primarily under high salinities while widgeon grass occurs in areas of lower salinity. Attached to the seagrass leaf blades are numerous species of epiphytic algae and invertebrates. Together, seagrasses and their epiphytes serve as important food sources for manatees, marine turtles and many fish, including spotted sea trout, spot, sheepshead and red drum. The dense seagrasses also serve as shelter or nursery grounds for many invertebrates and fish, including marine snails, clams, bay scallops (Argopecten irradians), polychaete worms, pink shrimp, blue crab, sea stars, sea urchins, tarpon, seahorses, Florida pompano, permit, striped mullet, great barracuda and long-horned cowfish.

Seagrass beds occur most frequently on unconsolidated substrates of marl, muck or sand, although they may also occur on other unconsolidated substrates. The dense blanket of leaf blades reduces the wave-energy on the bottom and promotes settling of suspended particulates. The settled particles become stabilized by the dense roots and rhizomes of the seagrasses. Thus, seagrass beds are generally areas of soil accumulation. Other factors affecting the establishment and growth of seagrass beds include water temperature, salinity, wave-energy, tidal activity and available light. Generally, seagrasses are found in waters with temperatures ranging from between 68°- 86 °F (20° and 30 °C). Seagrasses occur most frequently in areas with moderate current velocities, as opposed to either low or high velocities. Although seagrass beds are most commonly submerged in shallow subtidal zones, they may be exposed for brief periods of time during extreme low tides.

One of the more important factors influencing seagrass communities is the amount of solar radiation reaching the leaf blades. In general, the water must be fairly clear because turbidity blocks essential light necessary for photosynthesis. The rapid growth rate of seagrass under optimum conditions rivals that of most intensive agricultural practices, without energy input from man.

Seagrass beds are often associated with and grade into unconsolidated substrate, coral reefs, mangrove swamps and salt marshes, but may also be associated with any other marine and estuarine natural community.

Seagrass beds are extremely vulnerable to human impacts. Many have been destroyed through dredging and filling activities or have been damaged by sewage outfalls and industrial wastes. In these instances, the seagrasses are either physically destroyed or succumb as a result of decreased solar radiation resulting from increased water turbidity. Seagrass beds are also highly vulnerable to oil spills. Low concentrations of oil are known to greatly reduce the ability of seagrasses to photosynthesize. Extreme high temperatures also have adverse impacts on seagrass beds. The area surrounding power plant outfalls, where water temperatures may exceed 95 °F (35 °C), has been found to be lethal to seagrasses. Seagrass beds are susceptible to long-term scarring cuts from boat propellers, anchors and trawls. Such gouges may require many years to become revegetated. When protected from disturbances, seagrasses have the ability to regenerate and recolonize areas. Additionally, some successful replantings of seagrass beds have been conducted. However, the best management is to preserve and protect seagrass beds in their natural state. The seagrass beds in St. Martins Marsh Aquatic Preserve as a whole are currently in good/stable condition.

Aquatic Caves

A cave system is classified as cavities below the surface of the ground in karst areas. All caves develop under aquatic conditions; therefore, terrestrial caves can be considered dry aquatic caves. Aquatic caves vary from shallow pools that are highly susceptible to disturbance, to more stable systems that are completely submerged. The dependence of troglobites on detrital inputs and other nutrients imported from the surface generally limits the distribution of well-developed aquatic cave communities to karst areas with surface connections.

Flowing waters within a cave generally have a lower pH, is often unsaturated due to carbonates, and is relatively richer in fauna. Cave water characteristics may vary seasonally because of fluvial inputs from interconnected surface streams, or because of detrital pulses and other surface inputs during periods of substantial aquifer recharge. In general, aquatic caves are very stable environments with relatively constant physical and chemical characteristics.

Aquatic caves occur in the form of the numerous spring vents in the bays of the aquatic preserve.

Florida Natural Areas inventory natural communities in St. Martins Marsh Aquatic Preserve
Natural Community Acreage
Hydric Hammock 1,518
Shell Mound unknown
Mangrove Swamp 1,607
Salt Marsh 4,677
Consolidated Substrate unknown
Unconsolidated Substrate unknown
Mollusk Reef 49
Octocoral Bed unknown
Sponge Bed unknown
Algal Bed unknown
Seagrass Bed 17,705
Aquatic Caves unknown
Habitat-Wildlife Type: 
Aquatic Preserves
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Last Modified:
November 20, 2017 - 3:57pm

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