## 2006 Executive Summary EPA Steering Committee Meeting July 2007

Michael Callahan, Jennifer Wheaton, Carl Beaver, Sandra Brooke,

Dustin Johnson, Jim Kidney, Selena Kupfner, James W. Porter, Meredith Meyers, Shannon Wade, Mic hael Colella, and Matt Bertin

A Report of the Florida Fish and Wildlife Conser vation Commission and the University of Georgia pursuant to the USEPA grant award X7-97468002-3

and NOAA/COP grant award NA04NOS4780025INTRODUCTION The Florida Keys Coral Reef Evaluati on and Monitoring Project (CREMP) was initiated in 1994 to provide data on the st atus of coral reef resources of the Florida Keys National Marine Sanctuary (FKNMS) and document changes in status over time. In 1995, forty site s were identified throughout the FKNMS and permanent sampling stations were inst alled. Data collection began in 1996 and has been conducted annually. Stations were in stalled at three additional sites in the Dry Tortugas in 1999 and incorporated into the annual sampling protocol (Figure 1).

CREMP inventories the number of different stony coral species at each station (species richness). Stony coral percent co ver is obtained from video transects and presented for all stony coral comb ined and for the five most common species. CREMP also monitors other sele cted major benthic functional groups at the taxa level (macroalgae, sponges and octo corals). The incidence of disease and bleaching in stony corals and the abundance of the long-spined sea urchin,

Diadema antillarum , has been recorded at all stations since the inception of the project.

In 2001, surveys of abundance and benthic cover of bioeroding clionid sponges, which aggressively encrust and invade stony coral colonies, were initiated in the FKNMS and the Dry Tortugas. This annual m onitoring was initiated at all CREMP stations in response to concerns that clionids were implicated in coral decline. Between 2002 and 2005, added surveys of stony coral abundance and an expanded stony coral disease survey were conducted at a subset of stations at selected sites. However, these data are not summariz ed herein and will be summarized in a separate report. In 2006, these surveys of stony coral abundance were replaced with a pilot study targeting Montastraea annularis (boulder star coral) due to the continued de cline in percent cover of this important

reef framework builder.

This report presents results for t he FKNMS CREMP stations summarized Sanctuary-wide and by region. The regi ons are defined as Upper Keys, Middle Keys, and Lower Keys (Figure 1). The data for the Dry Tortugas sites are presented separately from t hose for the FKNMS.

1Figure 1. Coral Reef Evaluation and Moni toring Project site locations and region

boundaries.

METHODS

The same methods are employed for all CREMP sites. Each sampling station

within a site is permanently marked with two stainless steel reference stakes. Two steel poles, three plastic chains , and three measuring tapes are used to define a station’s area and sample transects (Figure 2).

2Figure 2. CREMP video transects, station species inventory, and clionid sponge survey station layout.

Station Species Inventory A pair of observers records the presence of every stony coral species in each station (2x22m) (Figure 2) during a 15 -minute search period (Figure 3). The divers initially conduct independent surve ys, then check and verify each other’s data as a quality control assurance. Incidence of condition (disease and bleaching) and presence of long-spined sea urchins ( Diadema antillarum ) are also recorded. Stony coral species ri chness is calculated for each station and averaged Sanctuary-wide.

Figure 3. Divers conducting Station Species Inventory

.

3Video Transects Video is filmed along each of the three 22m transects (F igures 2 and 4) at each

station. Consecutive fram es are extracted from t he video transects and custom software is used to estimate percent benthic cover of stony corals and other

selected taxa.

Figure 4. Diver filming video transects.

Clionid Sponge Survey The sponge survey area is defined by thr ee 1m wide belt trans ects within existing CREMP stations (Figure 2). The location, species, and size of bioeroding sponge species ( Cliona delitrix

, C. lampa and C.caribbaea ) as well as the coral species affected are recorded (Figure 5). The to tal area of clionid sponges measured as square centimeters per square meter of su bstrate is calculated for each station.

4Figure 5. Diver conducting a clionid sponge survey.

Montastraea annularis tracking pilot study

In 2006, a pilot study to track specific colonies of Montastraea annularis (boulder star coral) was initiated. A continued decline in percent cover of this important

reef framework builder has been document ed by CREMP. Designing a method to track changes in the condition of this species is a challenge due to its pattern of growth. Although very ol d colonies can be massive (several meters in height and circumference), these colonies regul arly have portions that have no living tissue. Without adequate photogr aphic documentation it is di fficult to determine if changes in percent cover of M. annularis are due to mortality and re-growth or recruitment. Multiple colonies at multip le stations were photographed in all three Sanctuary regions during 2006. Co mpass bearings and distance from permanent station markers was recorded for each photographed colony to assist in relocation (Figure 6).

5Figure 6. Montastraea annularis tracking pilot study and varied growth forms of the species.

6FKNMS RESULTS Stony Coral Species Richness The maximum number of species recorded in a single year for all CREMP FKNMS stations was 43 species in 1996. This number has not changed significantly through the study period. By region, the Middle Keys species richness has only declined slightly whereas species richness in both the Upper and Lower Keys has undergone greater dec line. However, between 2005 and 2006, the mean number of stony coral spec ies per station declined in all three regions (Figure 7). Statis tical analyses of these data are incomplete and the statistical significance has not been determined.

0 2 4 6 8 10 12 14 16 18 20

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006Mean Number of Species

Lower Keys Middle Keys Upper Keys

Figure 7. Temporal change in mean number of stony coral species per station by region

.

Stony Coral Condition Diseases were recorded as present or abs ent for each species during the Station Species Inventory and the type of dis ease/condition was noted. Data were recorded for three categories; black band, white diseases (i.e. white plague, white band and white pox), and “other” dis eases (including dark spot, yellow band and idiopathic diseases) (Figure 8).

Although the incidence of black band di sease peaked in 1998, it has never been

recorded at more than 10 stations since then. Besides peaks in 1998-1999 and 2001-2002, white disease and the “other ” disease conditions have been generally declining. Although the incidence of “other disease” continued to decline between 2005 and 2006, the incidence of white disease increased to more than 50 of the stations sampled in 2006.

70 10 20 30 40 50 60 70 80 90 100

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006Number of Stations

Black Band Other disease White disease

Figure 8. Number of stations wit h stony coral disease recorded.

Long-Spined Sea Urchin ( Diadema antillarum ) Distribution

D. antillarum has been reported at a maximum of 13 stations for two (2002 and 2005) of the ten years sampled. Howeve r, all CREMP data shows an increase in

D. antillarum distribution mid-way in the projec t. For the first five years of monitoring, D. antillarum were reported at an average of only 5.8 stations. From 2001 to 2005, the average number of stations (11.2) where D. antillarum were observed had nearly doubled. Unfort unately, between 2 005 and 2006 the

observed occurrence of D. antillarum decreased to nearly 2003 levels (Figure 9).

0 2 4 6 8 10 12 14

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006Number of Stations

Figure 9. Stations with D. antillarum recorded.

8Stony Coral Cover Sanctuary-wide Although the same broad geographic cove rage has been maintained for the duration of the project, minor adjustments have been made in the number of sites/stations sampled. Statistical anal yses of the project data in 2001 indicated that sampling a reduced number of stations at sites with low stony coral cover would still produce statistically valid data. During 2006, sampling was omitted for El Radabob (an Upper Keys hardbottom site) which has had less than 0.2% stony coral cover for the duration of the project. Therefore, the total number of

stations from which the data for the summaries was compiled, was reduced. These sampling reductions require adjustment and recalculation of the mean percent cover for all years for valid comparisons. Consequently, the values for the mean stony coral percent cover S anctuary-wide changes slightly from previous reports.

Figure 10 depicts the mean percent cover of stony corals from 1996 through 2006 for the 103 remaining stations. Althoug h the values are slightly different from previous reports, the obvious decline in percent stony coral cover occurred between 1996 and 1999. Percent stony cora l cover remained relatively stable between 1999 and 2003. Stony coral cover declined slightly between 2003 and 2005. Although there is a s ubsequent decline in coral cover from 2005 to 2006, this data has yet to be statistically evaluated.

6.1 6.8 6.7 7.3 7.5 7.5 7.7 7.6 9.8 11.6 12.1

0 2 4 6 8 10 12 14

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006Mean Percent Cover

Figure 10. Sanctuary-wide m ean percent stony coral cover at CREMP stations.

By Region

9The Upper and Lower Keys stations conti nue to show the greatest loss in mean percent stony coral cover since the begi nning of the projec t (Figure 11). Mean percent coral cover in the Middle Keys stations has not changed significantly since 1999. Between 2005 and 2006, a not able decline in mean percent stony
coral cover at CREMP stations Sanctuar y-wide occurs in all three regions.

0 2 4 6 8 10 12 14 16 18

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006Mean Percent Cover

Lower Keys Middle Keys Upper Keys

Figure 11. Mean percent stony coral co ver for Upper, Middle and Lower Keys

stations.

By Species Underlying trends in stony coral cove r can be obtained by analyzing the changes in the most common species. The five most common species in the FKNMS have

been Montastraea annularis (species complex), Montastraea cavernosa, Siderastrea siderea, Porites astreoides and Colpophyllia natans since 1999

. All except P. astreoides commonly attain large size and contribute significantly to

the reef framework. Percent cover of M. cavernosa, S. siderea, P. astreoides and
C. natans has been remarkably stable betwe en 1997 and 2006 (Figure 12). However, between 1996 and 1999, drastic declines of Acropora palmata and Millepora complanata , contributed significantly to the overall decline of mean percent coral cover in the Sanctuary. The continued decline of mean percent

cover of M. annularis (boulder star coral) has been a major contributor to the general decline of stony coral co ver since 1999 documented within CREMP sampling stations in FKNMS.

100.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006Mean Percent Cover

Cnat Mann Mcav Past Ssid

Figure 12. Sanctuary-wide mean percent stony coral cover per station for the five most common species; Colpophyllia natans (Cnat) , Montastraea annularis (Mann), Montastraea cavernosa (Mcav), Porites astreoides (Past) and
S iderastrea siderea (Ssid).

Montastraea annularis tracking

Multiple photographs of a total of 105 Montastraea annularis colonies were taken during 2006. Tracking was in itiated at one to three stations at twelve sites representing patch reefs as well as s hallow and deep offshore reef habitats.

Site Name Site Code Region Station Number Number of Colonies

Admiral Patch 9P4 Upper Keys 1,4 12 Alligator Shallow 7S1 Upper Keys 2 2 Grecian Rocks 9S2 Upper Keys 4 9

Porter Patch 9P3 Upper Keys 3 11 Sombero Shallow 5S1 Middle Keys 1 10

Dustan Rocks 7P2 Middle Keys 2 7 W. Turtle Shoal 7P1 Middle Keys 4 9 E. Sambo Deep 5D3 Lower Keys 2,3 11 W. Sambo Shallow 5S4 Lower Keys 1,2 9 W. Sambo Deep 5D4 Lower Keys 1,2 11 Sand Key Deep 2D1 Lower Keys 1,2,4 9

Cliff Green 5P3 Lower Keys 3,4 5

Table 1. Montastraea annularis tracking data for 2006.

11Functional Group Cover Major biotic functional groups defined in this study are stony corals, octocorals, sponges, and macroalgae. As in the Sanctuary-wide figure (10), mean percent stony coral cover declined at the stations sampled from roughly 12 to 6 percent since the inception of the project (incorporati ng the station/site reductions that occurred). Although mean percent octocoral cover calculated from the video increased steadily between 2000 and 2004, a decrease was documented between 2005 and 2006. Whereas the mean percent cover for sponges has steadily remained at about two percent, the mean percent cover for macroalgae has varied widely (Figure 13).

0 2 4 6 8 10 12 14 16 18 20

1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006Mean Percent Cover

Macroalgae Octocoral Sponge Stony coral

Figure 13. Sanctuary-wide m ean percent cover of major biotic functional groups

at CREMP stations.

Clionid Area Three species of clionid sponges ( Cliona delitrix, C. lampa, and C. caribbaea) are monitored by CREMP. Mean area of the three clionid species combined is presented in figure 14 for all CREMP stati ons Sanctuary-wide. In 2001, clionid

area was 7cm 2 /m 2 . Sanctuary-wide clionid area decreased sharply in 2002, increased steadily through 2005, and was virtually unchanged between 2005 and 2006. However, when data are grouped by h abitat a different picture emerges.

Clionid area increased between 2002 and 2 006 at hardbottom habitat stations. At both shallow and deep offshore reef sites, the clionid populations have had

minor fluctuations in mean clionid area through time. Although patch reef sites had consistently higher clionid area than shallow and deep reef sites, the same minor fluctuations in area occurred (Figure 15).

125.7 5.7

5.2 4.4 4.4 7.1

0 1 2 3 4 5 6 7 8 9 10

2001 2002 2003 2004 2005 2006Mean Clionid Area (cm2/m2)

Figure 14. Sanctuary-wide temporal c hanges in area of clionid sponges at

CREMP stations.

0 5 10 15 20 25

2001 2002 2003 2004 2005 2006Mean Clionid Area (cm2/m2)

Hardbottom Deep Shallow Patch

Figure 15. Temporal changes in area of clionid sponges by habitat at CREMP

stations.

13DRY TORTUGAS RESULTS Stony Coral Species Richness A maximum of 33 species has been recor ded for the Dry Tortugas in a single year in 1999, compared to a maximum of 43 species in the FKNMS in 1996. This is partly due to the limited number of stat ions sampled in the Dry Tortugas and the range of habitat types sampled in t he Florida Keys. Ho wever, mean stony coral species richness by station is oft en higher in the Dry Tortugas than in the Florida Keys.

Although the mean number of species recorded between 1999 and 2003 was relatively similar, the mean number of species for 2004 through 2006 has declined (Figure 16). Statis tical analyses of these data are incomplete.

17.0 17.5 17.7 19.8 20.0 21.8

20.0 21.5

0 5 10 15 20 25

1999 2000 2001 2002 2003 2004 2005 2006Mean Number of Species

Figure 16. Temporal changes in the m ean number of stony coral species by station at the Dry Tortugas.

Stony Coral Condition Between 1999 and 2004, at least one dis ease condition recorded during CREMP sampling was present in 80-100% of t he 12 stations sampled (Figure 17). Although black band disease was recorded in 2000, it has not been present in any station since then. “Other” disease c onditions were recorded consistently in 9-10 stations through 2003, but presence in stations declined consistently from 2003 to 2005 and leveled off between 2005 and 2006. Although white disease

was recorded in all 12 stations in 2000 and 2003, the presence of this condition has varied significantly throughout the durat ion of sampling in the Dry Tortugas. Although no white disease conditions were observed at any stations in 2005,

incidence was recorded in 7 stations in 2006.

140 2 4 6 8 10 12

1999 2000 2001 2002 2003 2004 2005 2006Number of Stations

Black band White disease Other disease

Figure 17. Number of stations with incidence of thr ee disease conditions at the Dry Tortugas

.

Long-Spined Sea Urchin ( D. antillarum ) Occurrence Among the Dry Tortugas CREMP st ations, observations of D. antillarum declined between 1999 and 2000, rebounded slightly for the next three years and again declined between 2003 and 2005 (F igure 18). Although, it wa s reported from only

1/3 of the stations in 1999 and none of the stations in 2000, in 2006 the number

of stations with D. antillarum increased to the same num ber of stations as in

1999.

0 2 4 6 8 10 12

1999 2000 2001 2002 2003 2004 2005 2006Number of Stations

Figure 18. Number of stations with l ong-spined urchins ( Diadema antillarum) at the Dry Tortugas.

15Stony Coral Cover Mean percent stony coral cover for the tw elve Dry Tortugas stations was nearly 19% in 1999 with a slight decrease to about 17% through 2001. Since 2001, the mean percent stony coral cover decreased fairly steadily to 11% in 2005 then dropped to less than 9% in 2006 (Figure 19). Statistical analyses of these data is incomplete.

8.8 11.4 11.7 13.4 14.1 17.4 17.4 18.9

0 5 10 15 20 25

1999 2000 2001 2002 2003 2004 2005 2006Mean Percent Cover

Figure 19. Temporal changes in mean percent stony coral cover by station at the Dry Tortugas.

By Habitat The highest mean percent coral cover at the Dry Tortugas has been recorded at the two deep reef habitat sites (Figure 20). The patch reef site has consistently had less than half the mean percent coral co ver as the deep reef sites since the inception of sampling. Except for a s light increase at the deep reef sites from 2000 to 2001 mean percent coral cover at the Dry Tortugas has declined steadily at all sites over the past eight years.

.

160 5 10 15 20 25

1999 2000 2001 2002 2003 2004 2005 2006Mean Percent Cover

Deep Patch

Figure 20. Temporal changes in mean st ony coral cover by habitat at Dry Tortugas stations.

By Species The five most common species in the Dry Tortugas have been Montastraea

annularis (species complex), Montastraea cavernosa, Colpophyllia natans, Acropora cervicornis and Siderastrea siderea throughout the duration of the project

. Among the five most comm on in the Florida Keys, Porites astreoides, is replaced by A. cervicornis in the Dry Tortugas.

Losses in overall mean stony coral cove r at the Dry Tortugas stations between 2001 and 2002 were likely driven by the abr upt decline of the boulder star coral

M. annularis . A decline in mean percent cover of this important framework building coral has been documented from 2001 to 2006 (Figure 21). The boulder type corals, C. natans (a brain coral) and S. siderea, (a star coral), together represent about 3 percent of the mean percent cover at CREMP stations in 1999 through 2001, but only represented about 1 percent each in 2006. Mean percent cover of the other boulder forming coral, Montastraea cavernosa, has also steadily, albeit slowly, declined through 2006. The staghorn coral ( A. cervicornis ) represented about 2 percent of the mean percent cover at sampling stations in 1999, but was virtually absent from these stations in 2006 (Figure 21).

170 1 2 3 4 5 6 7 8 9 10

1999 2000 2001 2002 2003 2004 2005 2006Mean Percent Cover

Acer Cnat Mann Mcav Ssid

Figure 21. Mean percent stony coral cove r of the five most common species; Acropora cervicornis (Acer), Colpophyllia natans (Cnat) , Montastraea annularis (Mann), Montastraea cavernosa (Mcav) and S iderastrea siderea (Ssid) by station at the Dry Tortugas.

Functional Group Cover Mean percent cover for octocorals fluctuated at slightly mo re than 12% between 1999 and 2003, but has declined steadily over the past three years. The decline in mean percent sponge cover has been very slow. Since 1999 the mean percent cover has declined from nearly 4% to roughly 1%. Mean percent cover of macroalgae peaked in 2003, declined to its lowest point in 2005, but increased

between 2005 and 2006

.

180 2 4 6 8 10 12 14 16 18 20

1999 2000 2001 2002 2003 2004 2005 2006Mean Percent Cover

Macroalgae Octocoral Sponge Stony coral

Figure 22. Mean percent cover of major biot ic functional groups by station at the Dry Tortugas.

Clionid Area

Mean clionid area decreased between 2001 a nd 2003, but has steadily increased to the highest cover recorded in 2006 (Figure 23).

13.6 9.9 9.4 5.9 7.3 12.3

0 5 10 15 20 25

2001 2002 2003 2004 2005 2006Mean Clionid Area (cm2/m2)

Figure 23. Temporal change in area of c lionid sponges by station at the Dry Tortugas.

19DISCUSSION

FKNMS The Station Species Inventory data indicate that the stony coral species richness
for all CREMP stations combined Sanc tuary-wide has declined from a maximum of 43 species recorded in 1996. The mean number of stony coral species recorded per station has continued to dec rease over time. Data on stony coral condition, also collected during the St ation Species Inventory shows that incidence of white disease per stat ion has declined between 2002 and 2005; however, it rebounded to more than 50% of the CREMP stations in 2006. This

increase in occurrence of white disease was accompanied by a decrease in the

number of stations with “o ther” disease in 2006.

Long spined urchins are herbivores t hat help keep corals free of algal overgrowth. The ecological importance of the long-spined sea urchins is well documented. Urchin populations suffer ed a Caribbean-wide mortality event in 1983-84 and their recovery has been slow. CREMP inventory of the long-spined sea urchin, D. antillarum , has shown a fluctuation in di stribution of this important

herbivore. Between 1996 and 20 00, these urchins were never observed in more than 7 CREMP stations. Since 2001, urchin observations have been recorded at a range of 8 to 13 stations.

Analysis of the percent cover data from the video transects shows that the mean stony coral cover at CREMP sites withi n the FKNMS declined sharply between

1996 and 1999. From 1999 th rough 2003, mean percent stony coral cover was
maintained at over 7% for all CREMP sites combined. By 2006, the combined sites had a mean percent stony coral cove r barely over 6%. The hurricanes and tropical storms that affe cted Florida recently have undoubtedly had some impact on the coral habitats. In 2005 hurricanes Dennis, Katrina, Rita and Wilma each passed over some part of the Fl orida reef tract (Figure 24).

20Figure 24. Image of south Florida showing the tracks of four major hurricanes that impacted Flori da between 2005 and 2006.

By species, the greatest loss has been obs erved in mean percent cover of the boulder star coral ( Montastraea annularis species complex), which forms very large colonies (>2m diameter) throughout the Florida Keys. The complete or partial mortality of a single boulder star coral colony represents a large decrease in coral cover and ultimately habitat structure. The pilot study initiated in 2006 will provide baseline tracking for colonies at selected sites from which to develop a standard monitoring protocol.

Functional group cover shows the prev alence of other important habitat components such as octocorals, sponges, and macroalgae. Changes in the percent cover of major functional gr oups provides valuable community information, but can also raise a “red flag” for further investigation into the factors driving the changes in coral habitat.

Clionid sponges are common bi oeroders of stony corals world-wide, but despite their global distribution very little is know n about their biology or ecology. Clionid populations may be influenced by differences in water quality or sponge recruitment dynamics. Inference from CREMP clionid sponge data indicates these sponges have not significantly cont ributed to the decline in coral cover within CREMP stations in the Sanctuary since the beginning of the clionid survey

in 2001.

21DRY TORTUGAS

Since the inception of monitoring in the Dry Tortugas in 1999, a combination of disease, hurricanes and potentially some unknown stressors have caused a decline in both coral cover and species richness at CREMP stations. The mean stony coral cover loss appears to have been primarily driven by cover losses in

M. annularis species complex. However, high levels of mortality from white diseases of the boulder brain coral ( C. natans ) (Figure 25) and the staghorn coral ( A. cervicornis ) have also contributed to the over all decline. A mortality event, documented in 2003, contributed to the fu rther overall decline of acroporids at the Dry Tortugas (Figure 26). Surveys of acroporids, recently listed under ESA, conducted by FWRI for the Department of Interior/National Park Service are documenting distribution of t hese species at sites within Dry Tortugas National Park. The 2003 acroporid mortality coin cides with the peak in white disease recorded at CREMP monitoring sites in 2003.

Figure 25. Brain coral colony ( Colpophyilla natans ) at Bird Key Reef, Dry Tortugas.

22Figure 26. Acroporid mortality at Dry Tortugas in 2003.

PROPOSED RESEARCH TO BE INCORPORATED IN 2007

In addition to the photographic tracking of multiple M. annularis colonies among different habitat types, baseline health sampling (Figure 27) will be conducted on colonies adjacent to the CREMP sampling stations. Site selection for this baseline health sampling is based on t he decline in percent cover documented

for M. annularis since monitoring was initiat ed in 1996. Sampling will not be conducted in any of the CREMP sites within Sanctuary protection zones.

23Figure 27. Illustration of proposed Montastraea annularis health sampling. A

B

C

D 1 2 3 1 = Samples for histopathology (1 x 1 x 1cm plug) – A,B, C, D along

transect** 2 = Samples for bacteriology – (syringe, 1ml) A, B along transect 3 = Samples for microalgae – (scrape with spatula) A, B, C, D along transect 4 = Sample for TEM 3 x 3 x 3mm plug (maximum size)

Health

Black

Necrotic

Necroticmicroalgal overgrowth Montastraea annularis health sampling protocol (representative samples from different diseases :

Beginning in 2007, data will be collected on three additional sponge species (C hondrilla nucula, Xestospongia muta, and Spheciospongia vesparium ). These three sponges are well studied and can be identified with little difficulty in the

field. Chondrilla nucula is a common overgrowing sp onge found in many of the Florida Key’s reef habitat types. Xestospongia muta is commonly found on coral reefs typically at depths gr eater than 10 m. This s ponge contributes greatly to overall sponge biomass and is important in determining reef health, exhibiting bleaching similar to coral. Spheciospongia vesparium is also a common reef sponge that is a major contributor to ov erall sponge biomass on the reef.

Throughout the Florida Keys National Ma rine Sanctuary, there are numerous unmapped and uncharacterized patch r eefs located in and around Hawk Channel. It has been suggested that these patch reefs contribute significantly to the overall stony coral cover of the FKNMS. In an effort to better represent this habitat type, permanent stati ons will be installed at se lected patch reefs in the Upper, Middle, and Lower Keys. Satellite imagery in ad dition to local knowledge will be used to select potentia l monitoring sites (Figure 28).

24Figure 28. IKONOS imagery (courtesy of NOAA) used to help select potential patch reefs for CREMP monitoring. High lighted circles represent areas of high

interest.

25