National Park Service

South Florida/Caribbean I&M Network (SFCN)

Coral Reef Monitoring

A diver films a benthic transect for coral research.
A diver films a benthic transect for coral research.

Coral Reef Status & Trends in SFCN Parks

Resource Briefs

Monitoring Reports

Journal Articles & Publications

Protocols

Presentations & Posters

Coral Sampling Videos

Links

For more information contact:

Michael Feeley, Ph D.
Jeff Miller

Importance/Issues

Coral reef communities consist of stony corals, octocorals, sponges, algae, and gorgonians, among others. These reefs support incredible diversity, including endangered sea turtles, conchs and lobsters. Reefs also play a vital role for humans by supporting fisheries, nursery areas, tourism, pharmaceutical bio-prospecting and shoreline protection to name a few. Monitoring coral reefs was identified as a national priority in President Clinton's Executive Order 13089, establishing the Coral Reef Initiative. These coral reefs are negatively impacted by unusually high water temperatures that cause "bleaching," coral disease, vessel scarring, major storms, and in some cases by sedimentation and nutrient enrichment.

Coral reefs within the SFCN represent some of the best examples of Caribbean and Western Atlantic coral reefs within the National Park Service. The enabling legislation that created the parks and/or presidential proclamations for Virgin Islands National Park (VIIS), Buck Island Reef National Monument (BUIS), and Dry Tortugas National Park (DRTO) specifically mention coral reefs within these park units as significant environmental communities.

Monitoring Objectives


Coral Reef Communities

  • Determine whether percent cover of major taxonomic groups (e.g., coral, algae [turf, calcareous, macroalgae], gorgonians, sponge, substrate), coral species diversity, coral community structure, and rugosity are changing through time within selected coral reef sites.
  • Determine how the above mentioned response variables vary in space within park reefs and how these variables, which describe coral reef health, are changing throughout time within different management zones.
  • Track trends and severity in reef-associated covariates such as coral bleaching, coral disease and presence of the herbivorous sea urchin, Diadema antillarum.
  • Maintain and archive a video record of the transects to allow for quantification and future analyses of benthic components not identified in this protocol.

Reef Water Temperature

  • Provide a long-term record of water temperatures at reef depth in-situ at the index and extensive coral monitoring sites established in BISC, BUIS, DRTO, and VIIS.
  • Determine occurrence and duration of warm and cold water events that are above and below thresholds known to cause stress to coral species for the purpose of interpreting trends in coral community metrics.
  • Assess any correlations of warm water events and/or cold water events with coral bleaching events and coral disease outbreaks.

Status and Trends

To see park-specific status and trends, select a park below.

For more information on U.S. Virgin coral bleaching events, see our Coral bleaching page.

Approach

The parks within the South Florida/Caribbean Inventory and Monitoring Network (SFCN) have some of the longest continuous monitoring programs within the Caribbean, and the world, for marine systems, with some annual surveys approaching two decades of data. Annual monitoring began at Yawzi (1988) and Newfound (1989) Reefs at Virgin Islands NP (VIIS) using the linear chain transect method to evaluate composition and changes in benthic community. Development of the Videography and Aquamap protocols that are currently in use by SFCN scientists began under the USGS/NPS prototype program in 1997.

The videography method uses10-meter transects which are filmed annually with a digital video camera in underwater housing. Each transect videotape is broken into frames and 10 dots randomly identified per frame for a total of about 300–350 dots identified to coral species and other benthic community type per transect. Percent cover of living coral by species, macroalgae, turf algae, crustose coralline algae, octocorals, and sponges are calculated. Data on coral disease, bleaching, water temperature, and long-spined sea urchins are also collected. Two different approaches are used for sampling: 1) if an area of interest is relatively small, i.e., less than 50,000 m², 20 transects are randomly placed within the site. If an area of interest is much larger, then multiple 4-transect sites are randomly placed within the larger area. The SFCN has been annually monitoring coral reef sites using videography at: Virgin Islands National Park (VIIS) since 1999, at Buck Island Reef National Monument (BUIS) since 2000, at Dry Tortugas National Park (DRTO) since 2004, at Biscayne National Park (BISC) since 2004, and at Salt River Bay National Historical Park and Ecological Preserve (SARI) since 2012.

The SFCN also monitors reef-depth water temperatures. Currently, two (replicate) data loggers are deployed at each site, recording temperatures every two hours. The SFCN I&M program maintains the database of a >20 years of temperature records from Virgin Islands National Park.

Coral Reef Monitoring within our network incorporates the expertise of both NPS and USGS scientists who strive to maintain excellence and very high standards in monitoring and sample design, and seek to develop new approaches to data analysis and synthesis.

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Biscayne National Park

Biscayne National Park is a marine park situated over 173,000 acres of submerged and coastal lands in South Florida. SFCN has been monitoring coral reef sites at Biscayne National Park since 2004 and now monitors two coral reef sites annually.

Biscayne National Park map

Amanda's Reef

Amanda's Reef study site Amanda's Reef study site.

Amanda's reef study site was selected by SFCN as being an example of one of the many patch reef communities that make up the near-offshore community of BISC. This reef is an extremely shallow site (3–15 ft) but is larger than Ball Buoy (20,240 m²).

SFCN began monitoring 20 permanent random transects in 2004 with an initial percent stony coral cover of 7.3% (SE=1.6%).

Ball Buoy Reef

Ball Buoy Reef study siteBall Buoy Reef study site.

Ball Buoy reef study site is located at the southern end of BISC, just offshore from the reef crest on the oceanside of the barrier sand islands. Ball Buoy reef was selected by SFCN due to the historical work that has been done at this site. Furthermore, the reef formation and coral reef habitat at this site is very similar to that of sites monitored by the state and located within the upper Florida reef tract. The reef is 14,136 m² and defined by the reef crest to the west, sand to the east, and a narrowing of the forereef habitat to the north and south. The site is shallow near the reef crest and extends to 40 feet on the offshore (east) side.

SFCN monitoring began here in 2004 with an initial percent stony coral cover of 6.6% (SE=1.3%) and has continued annually since then.

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Buck Island Reef National Monument

SFCN has been monitoring coral reef sites at Buck Island Reef National Monument (BUIS) since 2000. BUIS is a marine park situated over 19,000 acres of primarily submerged lands off the northshore of St. Croix, USVI. SFCN now monitors two coral monitoring sites within Buck Island Reef National Monument.

Buck Island Reef National Monument map

South Fore Reef

South Fore Reef study site South Fore Reef study site.

Situated off the southeast shore of the island, the South Fore Reef is a fringing reef of which the area monitored by SFCN is 40,752 m². The site is one of the deepest with transect depths of 11 to 15 meters. The site is bordered by sand on the west, and north; the south and east boundary is defined by the limitations of the mapping equipment as the habitat characterized by this site extends beyond the east and south boundaries.

The site was selected as a representative of a high coral cover, high complexity, Montastraea annularis (complex) dominant habitat typically found extending into the forereef flat on the south side of Buck Island. Monitoring began in 2002 of 20 permanent random transects using the Videography protocol with an initial percent stony coral cover of 17.2% (SE=1.9%)

Western Spur and Groove Reef

Western Spur and Groove Reef study site Western Spur and Groove Reef study site.

Western spur and groove reef study site is a 26,365 m² section of reef located within the larger spur and groove habitat on the north west side of Buck Island Reef National Monument. The habitat is a large open expanse of low relief spur and groove features which extend approximately 5 feet above the sand channels that separate them. The area has relatively low coral cover (compared to the other sites) and is dominated by small head corals and gorgonians. This area is subject to large north swells, primarily in the winter season due to the strong winter surge.

Monitoring at this site began in 2000 with an initial percent stony coral cover of 5.8% (SE=0.5%).

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Dry Tortugas National Park

Dry Tortugas National Park is a marine park situated over approximately 65,000 acres of submerged lands southwest of the Florida Keys. SFCN has been annually monitoring coral reef sites at Dry Tortugas National Park since 2004.

Dry Tortugas National Park map

Bird Key and Bird Key North Monitoring Sites

Bird Key and Bird Key North monitoring sites Bird Key and Bird Key North monitoring sites.

Bird Key Reef is a 2000m long spur and groove reef track that runs north-south beginning offshore of Garden Key.  This is one of the largest and well developed reef tracts within DRTO and the location of two abutting sites for SFCN monitoring.

Bird Key sample site was chosen primarily due to the historical work that has been conducted at the site beginning with the TRACTS work in the 1980s up to Florida Marine Resource Institute (FMRI) work in the 1990s. The SFCN site encompasses the locations of all this work and expands the area to 19,765 m². The area is a well-developed spur and groove reef with the deep buttresses in approximately 60 feet, and the shallow (west) end terminating in a gorgonian hardbottom and sand community at approximately 20 foot depth.

Twenty permanent 10-meter transects were established and sampled in 2004 with an initial percent stony coral cover of 13.2% (SE=1.6%).

From 2005–2011, an additional 20 transects were monitored at a Bird Key North Site. However SFCN has chosen to reduce the frequency of sampling at this site in order to increase the sampling throughout the park using 4-transect sites inside and outside the Research Natural Area and to increase focus in two high coral cover reefs in the west of the park (Loggerhead Forest) and to the northeast of the park (Santa's Village).

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Virgin Islands National Park

Virgin Islands National Park is situated on over 7,000 acres of submerged and terrestrial lands in and around the island of St. John in the US Virgin Islands. NPS has been monitoring coral reef sites annually at Virgin Islands National Park since 1988. US Geological Survey coral reef ecologist Dr. Caroline Rogers used the linear chain transect method and haphazardly selected, permanent transects at two reef sites with relatively high coral cover, diversity and complexity: Yawzi Reef (monitoring established 1988) and Newfound Reef (monitoring established in 1989). In 1997, with the initiation of the I&M prototype program, video monitoring was developed and combined with the linear chain transects at these same sites. A methods comparison was conducted annually from 1988 through 2002 (Rogers and Miller 2006). Additionally, a new approach to sampling was developed with the random sample selection protocol. Sampling was expanded from 100 meters of haphazardly selected transects to 200 meters (20 x 10 meter) of randomly selected transects within a defined study site (reef). SFCN now monitors 100 transects at five coral monitoring sites in and around Virgin Islands National Park.

Virgin Islands National Park Map

Mennebeck Reef

Mennebeck Reef study site Mennebeck Reef study site.

Mennebeck Reef study site is 12,495 m² in size and is located within a completely undeveloped watershed within the VIIS boundary. There are no roads or trails to this site and it is not marked or known as a destination for divers or snorkelers, therefore it receives very little visitation. The site is defined by a depth contour of 4m (north), fragmentation of the reef structure with increased sand channels (both in frequency and size) to the east and west, and the forereef slope to the sand base at 18m (south).

The SFCN has been monitoring at this site using the videography protocol since 2000 with an initial percent stony coral cover of 22.9% (SE=3.3%).

 

Haulover Reef

Haulover Reef study site Haulover Reef study site.

This reef is located on the north-east end of St. John, within Virgin Islands National Park. The site is on the north side of Haulover Bay, a bay which is bisected by the boundary of the park. Currently, development is progressing on the southern shore of the bay.

The study site is a 13,568 m² fore reef site located on the outer edge fore reef along the north side of the bay. The site is defined by a 10 m depth gradient to the west, rocky outcroppings on the north and south, and the forereef slope on the east.

SFCN began monitoring here using the Videography Protocol in 2003 with an initial percent stony coral cover of 22.1% (SE=2.7%).

Newfound Reef

Newfound Reef study site Newfound Reef study site.

Newfound Reef is a 13,768 m² study site located on the East end of St. John, outside the boundary of Virgin Islands National Park. The site is within a watershed that is privately owned, but undeveloped at this time. The forereef site is defined by a depth gradient of 15 m to the west, a line from a rocky outcropping to the north, the sand channel that enters into Newfound Bay backreef to the south, and the edge of the forereef slope to the east. Shoreward of the study site is a backreef lagoon, which is a popular anchorage site for day-charter boats bringing visitors to this reef.

This site has a rich history of monitoring, beginning in 1990 when Dr. Caroline Rogers, then with the NPS, established one 100-meter transect (subdivided into ten 10-meter transects) within the middle of the forereef, along a 26m depth gradient through exceptionally diverse and complex coral cover. Monitoring was conducted annually at this site using the linear chain transect method from 1990 through 2002 (Rogers and Miller 2006).

Beginning in 1997, and as part of the USGS prototype protocol development program, 20 10-meter transects were established in a random sample design with the Aquamap protocol. The transects were sampled with digital video and analyzed with the Videography protocol. During the protocol development, the historical "chain" transects were also sampled annually with the same Videography protocol, allowing for a methods comparison (Rogers and Miller 2001). Sampling of the 20 random transects has been conducted annually since 1999 through the I&M program, now under the auspices of SFCN, with an initial percent stony coral cover in 1999 of 18.0% (SE=1.4%).

Tektite Reef

Tektite Reef study site Tektite Reef study site.

Located on the south side of St. John, in a bay to the north and west of Cabritte Horn Point, the study site is 18,711 m² in size. Its boundary was determined on the north, east, and south by the determination of where the linear reef gave way to a more patch reef habitat. The site is bounded by deep sand to the west. The depth at this site varies from 15–63 feet.

The most extensive and complete set of historical marine science research within VIIS was conducted at Tektite Reef. From 1969–1970, this site was the location of the long-term submerged laboratory programs, Tektite I and Tektite II. For more information about this program, see Collete: Results of the Tektite Program: Ecology of coral-reef fishes.

Monitoring by the SFCN began in 2005 with an initial percent stony coral cover of 24.7% (SE=2.5%).

Yawzi Reef

Yawzi Reef study site Yawzi Reef study site.

Yawzi Reef is located near Tektite Reef on the south side of St. John at Yawzi point. Yawzi point is a promontory between Great Lameshur Bay and Little Lameshur Bay. The site is the smallest site monitored by SFCN at 7,125 m². It is defined by a perimeter sand plateau on all sides except the north, where the reef boundary is defined by a change in habitat from scattered corals to a boulder and gorgonian dominated community.

Monitoring at this site began in 1988 when Dr. Caroline Rogers set up five 20 meter chain transects within areas of high diversity, complexity, and coral cover. These transects were permanently marked with brass survey stakes and were monitored from 1988 through 2002 (Roger and Miller 2006).

As with Newfound Reef, this site was used during the development of the video monitoring protocol and as such, dual sampling of the chain transects by using the chain method and the video method were conducted during several samplings in 1998 (Roger and Miller 2001).

SFCN monitoring began with the establishment of 20 ten-meter transects in 1999 and annual sampling conducted using the videography protocol with an initial percent stony coral cover in 1999 of 7.1% (SE=1.3%).

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Salt River Bay National Historical Park and Ecological Preserve

In 2012 SFCN established a monitoring site in Salt River Bay National Historical Park and Ecological Preserve in areas along the western and eastern walls of Salt River Canyon and in the spur and groove formation to the immediate northwest of the canyon. These areas were chosen because of relatively high coral cover, reef complexity, historical significance and were constrained to 33 m depth. Twenty randomly chosen transects were established and initial percent stony coral cover in 2012 using the videography protocol was 10.6% (SE=1.1%).

Salt River Bay National Historical Park and Ecological Preserve Map

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Coral Reef Community Biology

Coral Head with visible coral polyp Coral Head with visible coral polyp.

Corals are animals that contain microscopic algae called zooxanthellae in their tissue. These algae give the corals their greenish-brown, orange, purple, or other color. More importantly, the algae use sunlight (through photosynthesis) to provide food for the coral. If corals didn't have these plants helping them grow, coral reefs wouldn't exist the way we see them today. Corals can't get enough energy from the food they eat; they have to have an extra energy source, and it comes from the algae within their tissue.

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Last Updated: March 28, 2017 Contact Webmaster