Get Adobe Flash player

Coral

The following information on Coral is shared, with permission, directly from NOAA web sites

Staghorn Coral (Acropora cervicornis)

Status | Taxonomy | Species Description | Habitat | Distribution |
Population Trends | Threats | Conservation Efforts | Regulatory Overview |
Key Documents | More Info

 


Staghorn Coral
(Acropora cervicornis)
Did You Know?· Staghorn coral, like many corals, receive most of their energy and oxygen from symbiotic organisms called zooxanthellae.· Like counting rings in the trunk of a tree, the age of corals can be determined by examining coral growth rings.

Status
ESA Threatened – throughout its range

Species Description
Staghorn coral is a branching coral with cylindrical branches ranging from a few centimeters to over 6.5 feet (2 m) in length.

The dominant mode of reproduction for staghorn coral is asexual fragmentation, with new colonies forming when branches break off a colony and reattach to the substrate. Sexual reproduction occurs via broadcast spawning of gametes into the water column once each year in August or September. Individual colonies are both male and female (simultaneous hermaphrodites) and will release millions of “gametes”.

The coral larvae (planula) live in the plankton for several days until finding a suitable area to settle, but very few larvae survive to settle and metamorphose into new colonies. The preponderance of asexual reproduction in this species raises the possibility that genetic diversity is very low in the remnant populations.

This coral exhibits the fastest growth of all known western Atlantic corals, with branches increasing in length by 4-8 inches (10-20 cm) per year. Staghorn coral has been one of the three most important Caribbean corals in terms of its contribution to reef growth and fish habitat.

Species Description
Staghorn coral is a branching coral with cylindrical branches ranging from a few centimeters to over 6.5 feet (2 m) in length.

The dominant mode of reproduction for staghorn coral is asexual fragmentation, with new colonies forming when branches break off a colony and reattach to the substrate. Sexual reproduction occurs via broadcast spawning of gametes into the water column once each year in August or September. Individual colonies are both male and female (simultaneous hermaphrodites) and will release millions of “gametes”.

staghorn images

Staghorn Coral

The coral larvae (planula) live in the plankton for several days until finding a suitable area to settle, but very few larvae survive to settle and metamorphose into new colonies. The preponderance of asexual reproduction in this species raises the possibility that genetic diversity is very low in the remnant populations.

This coral exhibits the fastest growth of all known western Atlantic corals, with branches increasing in length by 4-8 inches (10-20 cm) per year. Staghorn coral has been one of the three most important Caribbean corals in terms of its contribution to reef growth and fish habitat.

staghorn (1)

Staghorn Coral

Habitat
Staghorn coral occur in back reef and fore reef environments from 0-98 feet (0 to 30 m) deep. The upper limit is defined by wave forces, and the lower limit is controlled by suspended sediments and light availability. Fore reef zones at intermediate depths of 16-82 feet (5-25 m) were formerly dominated by extensive single species stands of staghorn coral until the mid 1980s.

NMFS designated critical habitat for elkhorn and staghorn corals in November 2008 in four areas: Florida, Puerto Rico, St. John/St. Thomas, and St. Croix.

Distribution
Staghorn coral is found throughout the Florida Keys, the Bahamas, the Caribbean islands, and Venezuela. This coral occurs in the western Gulf of Mexico, but is absent from U.S. waters in the Gulf of Mexico. The northern limit is on the east coast of Florida, near Boca Raton.

Population Trends
Since 1980, populations have collapsed throughout their range from various threats as detailed below; populations have declined by up to 98% throughout the range, and localized extirpations have occurred.

Threats
The greatest source of region-wide mortality for staghorn coral has been disease outbreaks, mainly of white band disease. Other, more localized losses have been caused by hurricanes, increased predation, bleaching, algae overgrowth, human impacts, and other factors. This species is also particularly susceptible to damage from sedimentation and is sensitive to temperature and salinity variation.

The dominant mode of reproduction for staghorn coral is asexual fragmentation; this life history trait allows rapid population recovery from physical disturbances such as storms. However, this mode of reproduction makes recovery from disease or bleaching episodes (in which entire colonies or even entire stands are killed) very difficult. The large role of asexual reproduction for this species also increases the likelihood that genetic diversity in the remnant populations is very low. Scientists are becoming increasingly concerned for this species based on its demographic paramaters; specifically, how species recruitment and genetic diversity affect recovery potential.

staghorncoral_keysnms
Staghorn Coral
(Acropora cervicornis)staghorn_sm_andybruckner-noaaStaghorn Coral
(Acropora cervicornis)

Conservation Efforts
Florida Keys National Marine Sanctuary (FKNMS), the largest coral reef management entity in the region, has developed a management plan for the Sanctuary’s corals that includes protective activities, such as zoning and channel markings, as well as restoration efforts.

Restoration activities have included efforts to re-attach Acropora fragments generated by ship groundings and hurricane events; these efforts have had mixed success. Similar efforts to re-attach coral fragments have also been made in Puerto Rico and the U.S. Virgin Islands.

Other restoration efforts have included attempts to culture and settle coral larvae with very limited success. New techniques for restoring Acropora, however, are currently being pursued. Such new techniques involve enhancing sexual recruitment, reestablishing ecological roles within reef systems (e.g. herbivorous urchins), and other methods for controlling predators and disease.

In 1998, the United States Coral Reef Task Force was established by Presidential Executive Order 13089 to coordinate and strengthen efforts for protecting coral reef ecosystems. The Task Force is co-chaired by the Departments of Commerce and Interior, and includes leaders of 12 federal agencies, seven U.S. states and territories, and three freely associated states. In 2002, the Task Force adopted a resolution calling for the development of Local Action Strategies, which are locally-driven plans for collaborative and cooperative action among federal, state, territory, and non-governmental partners to reduce key threats on valuable coral reef resources. Three Local Action Strategies have been developed within the range of staghorn coral for Florida, Puerto Rico, and the U.S. Virgin Islands. These strategies are now underway and will be implemented over a three-year period (FY2005-2007).

Regulatory Overview
On March 4, 2004, the Center for Biological Diversity petitioned NOAA’s National Marine Fisheries Service (NMFS) to list elkhorn (Acropora palmata), staghorn (A. cervicornis), and fused-staghorn (A. prolifera) coral under the Endangered Species Act (ESA). On June 23, 2004, NMFS found that listing these species may be warranted [pdf] and initiated a formal review of their biological status. NMFS convened the Atlantic Acropora Biological Review Team (BRT) to summarize the best available scientific and commercial data available for these species in the status review report.

The BRT completed the status review [pdf] [4.9 MB] on March 3, 2005. On March 18, 2005, NMFS determined that elkhorn and staghorn corals warrant listing [pdf] as “threatened” species under the ESA. However, NMFS also concluded that listing fused-staghorn coral is not warranted, as it is a hybrid and does not constitute a species as defined under the ESA. On May 9, 2005, NMFS proposed adding elkhorn and staghorn coral to the Endangered Species list [pdf].

 

Elkhorn Coral (Acropora palmata)

Status | Taxonomy | Species Description | Habitat | Distribution |
Population Trends | Threats | Conservation Efforts | Regulatory Overview |
Key Documents | More Info

 staghorn. 2jpgElkhorn Coral
(Acropora palmata)
Did You Know?· Elkhorn coral, like many corals, receive most of their energy and oxygen from symbiotic organisms called zooxanthellae.· Like counting rings in the trunk of a tree, the age of corals can be determined by examining coral growth rings.

Status
ESA Threatened – throughout its range

Species Description
Elkhorn coral is a large, branching coral with thick and sturdy antler-like branches.

The dominant mode of reproduction for elkhorn coral is asexual, with new colonies forming when branches break off of a colony and reattach to the substrate. Sexual reproduction occurs via broadcast spawning of gametes into the water column once each year in August or September. Individual colonies are both male and female (simultaneous hermaphrodites) and will typically release millions of “gametes”.

The coral larvae (planula) live in the plankton for several days until finding a suitable area to settle, but very few larvae survive to settle and metamorphose into new colonies. The preponderance of asexual reproduction in this species raises the possibility that genetic diversity may be very low in the remnant populations.

Colonies are fast growing: branches increase in length by 2-4 inches (5-10 cm) per year, with colonies reaching their maximum size in approximately 10-12 years. Over the last 10,000 years, elkhorn coral has been one of the three most important Caribbean corals contributing to reef growth and development and providing essential fish habitat.

elkhorn images 3

Elkhorn Coral

Habitat

Elkhorn coral was formerly the dominant species in shallow water (3 ft-16 ft (1-5 m) deep) throughout the Caribbean and on the Florida Reef Tract, forming extensive, densely aggregated thickets (stands) in areas of heavy surf. Coral colonies prefer exposed reef crest and fore reef environments in depths of less than 20 feet (6 m), although isolated corals may occur to 65 feet (20 m).

NMFS designated critical habitat for elkhorn and staghorn corals in November 2008 in four areas: Florida, Puerto Rico, St. John/St. Thomas, and St. Croix.

Elkhorn Coral

Elkhorn Coral

Population Trends
In areas where loss has been quantified, estimates are in the range of 90-95% reduction in abundance since 1980. Additional drastic reductions (e.g., 75-90%) were recently observed in some areas such as the Florida Keys in 1998 due to bleaching and hurricane damage.

Threats
Since 1980, populations have collapsed throughout their range from disease outbreaks with losses compounded locally by hurricanes, increased predation, bleaching, elevated temperatures, and other factors. This species is also particularly susceptible to damage from sedimentation.

In 1998, the United States Coral Reef Task Force was established by Presidential Executive Order 13089 to coordinate and strengthen efforts for protecting coral reef ecosystems. The Task Force is   co-chaired by the Departments of Commerce and Interior, and includes leaders of 12 federal agencies, seven U.S. states and territories, and three freely associated states. In 2002, the Task Force adopted a resolution calling for the development of Local Action Strategies, which are locally-driven plans for collaborative and cooperative action among federal, state, territory, and non-governmental partners to reduce key threats on valuable coral reef resources. Three Local Action Strategies have been developed within the range of elkhorn coral for Florida, Puerto Rico, and the U.S. Virgin Islands. These strategies are underway and will be implemented over a three-year period (FY2005-2007).

Leave a Reply

Your email address will not be published. Required fields are marked *

Register to Vote / Subscribe

Please provide your Confidential email to vote and receive updates

Donate Your Time and Money