St. Andrews Aquatic Preserve

Coral Reefs

There are currently several species of coral and related species on the rocks and the surrounding sand of the jetties in St. Andrews Aquatic Preserve. The appearance of these corals was first noted in 2010 by Panama City Marine Institute and has continued to spread.

The largest concentration is on the pass side of the western jetty wall at a depth of 10 to 25 feet. There are also growing colonies of the Gulf side as well. Each area has at least two distinct species, one being the tube coral (Cladocora arbuscula ) and the diffuse ivory bush coral (Oculina diffusa). There are also reports of robust ivory tree coral (Oculina robusta) in the area, but identification has not yet been verified. The concentration of corals can be dense in some spots, specifically on the pass side where there is a greater flow of water. Further information about the distribution, abundance and condition of coral reef in St. Andrews Aquatic Preserve is still needed.

Octocoral Beds

The dominant animal species of octocoral beds are soft corals such as gorgonians, sea fans, sea feathers, sea fingers, sea pansies, sea plumes, sea rods and sea whips. This community is confined to the subtidal zone since the sessile organisms are highly susceptible to desiccation. Other sessile animals typically occurring in association with these soft corals are sea anemones. 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.

The distribution, abundance and condition of octocoral beds in St. Andrews Aquatic Preserve is unknown at this time. Management considerations should include locating all true octocoral beds and providing protection for them from external degradation. Primary threats to octocoral beds include siltation from beach renourishment or beach restoration projects; anchor damage by nautical craft; trawling by commercial anglers; collection for tourist-oriented trade; and water pollution, particularly oil spills.

Seagrass Beds

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This community occurs in subtidal (rarely intertidal) zones, in clear, coastal waters where wave energy is moderate. Seagrasses are not true grasses but are more closely related to terrestrial lilies and gingers than grasses. The three most common species of seagrasses in Florida are turtle grass (Thalassia testudinum), manatee grass (Syringodium filiforme) and shoal grass (Halodule wrightii), which are all found in St. Andrews Aquatic Preserve. 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) also can 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, sea turtles and many fish. The dense seagrasses also serve as shelter or nursery grounds for many invertebrates and fish.

St. Andrews Aquatic Preserve contains approximately 944 acres of seagrass beds, making up about 4% of the natural communities present in the aquatic preserve.

The St. Andrew Bay Resource Management Association conducted seagrass monitoring in the aquatic preserve (as well as other areas of St. Andrews Bay) from 2000-2010. A statewide FWC Fish and Wildlife Research Institute report stated that from 1992-2003, seagrass cover had increased throughout the bay. However, tropical storms in 2004 and 2005 along with increasing watershed development may have impacted seagrasses since the last mapping effort .

Salt Marshes

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Salt marshes are expanses of grasses, rushes and sedges along coastlines of low wave energy and river mouths. The area just inside the border of St. Andrews Aquatic Preserve contains 15 acres of salt marsh, making up less than 1% of the natural communities present in the aquatic preserve, but more extensive marshes are immediately adjacent. Most of the salt marsh occurs on the bay side of Shell Island over much of the length of the island, and it is in good condition.

Black needlerush (Juncus roemerianus) and sawgrass (Cladium mariscoides) dominate this community. The salt marsh community on Shell Island declined following the hurricane activities of 2004 and 2005 due to an influx of saltwater and overwash throughout the island. Many of these areas are now beach dune or coastal grassland habitat due to sand migration and the subsequent increase in beach elevation that no longer succumbs to tidal inundation.

Algal Beds

Algal beds are areas with large populations of non-drift 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, animal populations will be similar to populations associated with octocoral beds and sponge beds. Those associated with soft bottom substrate may have similar benthic and pelagic species in addition to infauna species. Recent research has shown that algal beds provide critical habitat for juvenile spiny lobsters, a species of great commercial importance.

The distribution, abundance and condition of algal beds in St. Andrews Aquatic Preserve is unknown at this time.

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.

Sponge Beds

The dominant animal species of sponge beds are sponges such as branching candle sponge (Aplysina cauliformis), Florida loggerhead sponge (Spheciospongia vesparium) and sheepswool sponge (Hippospongia 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.

The distribution, abundance and condition of sponge beds in St. Andrews Aquatic Preserve is unknown at this time. Management considerations include locating all true sponge beds within the aquatic preserve and providing protection for them from external degradation. Primary threats to sponge beds include siltation from beach renourishment or beach restoration projects; anchor damage by nautical craft; trawling by commercial anglers; collection for tourist-oriented trade; and water pollution, particularly oil spills.

Consolidated Substrate

Consolidated substrates are solidified rock or shell conglomerates and include coquina, limerock or relic reef materials that lack dense populations of sessile plant and animal species. 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 distribution and abundance of consolidated substrate in St. Andrews Aquatic Preserve is unknown at this time.

Unconsolidated Substrate

Unconsolidated substrates 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, mollusks, isopods, amphipods, burrowing shrimp and an assortment of crabs).

The condition of this community within the adjacent St. Andrews State Park is considered to be excellent. Generally fine sugar-white sand is the major constituent on the gulf side of the park. Many renourishment activities have been used to abate erosion of the state park’s mainland beach.

Tidal flats are present on the bay side of Shell Island. This natural community extends itself from the low tide line along the bay shoreline landward. This community grades into seagrass beds and salt marsh habitat in some locations. Some areas of the bay shore are eroding and others are accreting. In the eroding areas, exposed roots can be found along the bay shore at low tide, indicating the amount of erosion. Other eroding areas on Shell Island are converting into salt marsh habitat due to lower elevations and the resulting salt water intrusion. Wider beach areas along the bay shore and exposed tidal flats are utilized by foraging shorebirds.

In particular, areas with open access from the beach dune habitat or marine unconsolidated habitat are important foraging areas for shorebird broods (i.e., with flightless young) at low tides.

Composite Substrate

Composite substrates consist of a combination of natural communities such as “beds” of algae and seagrasses or areas with small patches of consolidated and unconsolidated bottom with or without sessile floral and faunal populations.

Composite substrates may be dominated by any combination of marine and estuarine sessile flora or fauna, or mineral substrate type. Typical combinations of plants, animals and substrates representing composite substrates include soft and stony corals with sponges on a hard bottom such as a limerock outcrop; algae and seagrasses scattered over a sand bottom; and patch reefs throughout a coralgal bottom. Any of the remaining marine and estuarine natural communities can grade into composite substrate communities.

The distribution, abundance and condition of composite substrate in St. Andrews Aquatic Preserve is currently unknown. Combinations of consolidated and unconsolidated substrate components, like those likely found in St. Andrews Aquatic Preserve, offer the greatest opportunity for diversity and should be high priority areas for protection. Management requirements are negligible providing the composite community is adequately protected.

Protection efforts will vary slightly based on components of the composite substrate community. Generally, degradation of physical and chemical water quality parameters should be prevented, as well as mechanical disturbance from anchoring, dredging, trawling and similar activities.