State of Sanctuary Resources
This section provides summaries of the condition and trends within four resource areas: water, habitat, living resources and maritime archaeological resources. For each, sanctuary staff and selected outside experts considered a series of questions about each resource area. The set of questions is derived from the National Marine Sanctuary System’s mission, and a system-wide monitoring framework (National Marine Sanctuary Program 2004) developed to ensure the timely flow of data and information to those responsible for managing and protecting resources in the ocean and coastal zone, and to those that use, depend on, and study the ecosystems encompassed by the sanctuaries. The questions are meant to set the limits of judgments so that responses can be confined to certain reporting categories that will later be compared among all sanctuary sites and combined. The Appendix (Rating Scheme for System-Wide Monitoring Questions) clarifies the set of questions and presents statements that were used to judge the status and assign a corresponding color code on a scale from “good” to “poor.” These statements are customized for each question. In addition, the following options are available for all questions: “N/A” – the question does not apply; and “undetermined” – resource status is undetermined. In addition, symbols are used to indicate trends: “ ▲” – conditions appear to be improving; “▬” – conditions do not appear to be changing; “ ▼” – conditions appear to be declining; and “?” – the trend is undetermined.
This section of the report provides answers to the set of questions. Answers are supported by specific examples of data, investigations, monitoring and observations, and the basis for judgment is provided in the text and summarized in the table for each resource area. Where published or additional information exists, the reader is provided with appropriate references and Web links.
Water
1. Are specific or multiple stressors, including changing oceanographic and atmospheric conditions, affecting water quality?
Because selected conditions, such as isolated contaminants, freshwater influxes from terrestrial sources, and increased water temperature, have been shown to affect living resource assemblages and habitats to some extent, this question is rated “good/fair and declining.”
Recent events of coral bleaching (2005 in particular) are the result of higher-than-normal seawater temperature extremes (Precht et al. In press). Further, hourly in situ water measurements taken at the East and West Flower Garden Banks reflected higher-than-average temperatures in 2005, which deviated from the mean temperature more in winter months than in the summer. Preliminary data (Precht et al. In press) indicate that the increased water temperatures are more pronounced at West Flower Garden Bank than at the east bank.
Climate change could certainly affect resources in the sanctuary, particularly as a result of temperature stress or ocean acidification. The recent warm water events (Precht et al. In press) have affected corals to some extent, but there is not yet persistent enough evidence of warming to conclude that climate change effects are yet being exhibited in this sanctuary. This is an area of monitoring that will need to be addressed in the future.
Influxes of fresh water originating from land-based or river sources may contribute to the introduction of pollutants of terrestrial origin including pesticides and fertilizers, and cause lower salinity conditions, all of which can contribute to decreased water quality. Freshwater lenses have been recorded by in situ measurements in the months of June, July, and August at the East and West Flower Garden Banks, but extend through September and October at Stetson Bank. It is noted that this freshwater lens does not appear to extend deeper than around 33 – 50 feet (10 – 15 meters) depth, although in some cases the associated low water quality could inhibit light reaching the substrate (Deslarzes and Lugo-Fernández 2007).
Contaminants also originate from discharges from oil and gas platform operations. The exact contaminants contained in produced water are highly variable and difficult to track accurately. It is known that heavy metals, such as lead, cadmium, mercury and radioactive compounds, are associated with oil and gas activities in some circumstances. Studies have shown that the sediments surrounding the gas production platform known as High Island A389A, located within the sanctuary boundaries, contain comparatively high levels of mercury, lead, cadmium, zinc and other contaminants, probably due to the stipulations that require drilling lubricants and cuttings be shunted to within 10 meters of the seabed to avoid creating a sediment plume that could envelope the shallow reef areas (Kennicutt 1995).
2. What is the eutrophic condition of sanctuary waters and how is it changing?
Nutrient measurements have been made on numerous occasions beginning in the late 1980s as part of the regularly scheduled long-term monitoring program (Gittings and Boland 1991, Gittings et al. 1992b, CSA 1996, Dokken et al. 1999, Dokken et al. 2003, Precht et al. In press). None of the measurements suggest an increasing threat of eutrophication, therefore, the rating for this question is “good and not changing.”
3. Do sanctuary waters pose risks to human health?
Because recent outbreaks of ciguatera that have been traced to fish from the Flower Gardens, and because a large proportion of fish tested for mercury exceeded levels for safe consumption, this question is rated “fair/poor and declining.”
Taylor (1973) found concentrations of mercury in barracuda (Sphyraena barracuda) to be as high as 1.82 ppm in muscle tissue and 0.56 ppm in liver. In 2002, samples of five barracuda assessed for mercury levels were above EPA levels for cause for concern (0.3 ppm; Marc Engel, State of Florida). In 2007, 24 of 31 analyzed fish had mercury levels at or above that level (David Evans, NOAA/National Centers for Coastal Ocean Science).
Dr. Tracy Villareal (University of Texas Marine Science Institute) reported the first encounter of the toxic dinoflagellate Gambierdiscus toxicus in algae sampled at the Flower Garden Banks in September 2006. At that time it was unknown whether ciguatoxins were entering the food web of the sanctuary. Villareal et al. (2007) reported that the increased substrate availability provided by the oil and gas industry in the Gulf of Mexico has contributed to the increased levels of ciguatoxins regionally, leading to increased incidents of ciguatera poisoning. In April 2007, the Galveston Daily News reported that two individuals from Galveston, Texas, had suffered from ciguatera poisoning after consuming a grouper caught in the Flower Garden Banks sanctuary. The grouper was later identified as a gag. Analysis by Bob Dickey (U.S. Food and Drug Administration) confirmed that the fish tested positive for ciguatoxin.
In response to this event, the sanctuary collaborated with Villareal, Dickey, Patricia Hay and Quay Dortch (NCCOS), to obtain and analyze fish samples. A vessel was provided by John Stout, a recreational fishing member of the Flower Garden Banks Sanctuary Advisory Committee, and funding was provided by NOAA for the cruise response. On June 5, 2007, 31 fish were collected and provided to the FDA and NCCOS for analysis. In addition to the analysis for ciguatoxin levels, the fish were aged by Dr. Linda Lombardi-Carlson (NMFS/SEFSC, Panama City), and mercury levels were analyzed by Dr. David Evans (NCCOS).
Four of the 31 fish tested positive for elevated levels of ciguatoxin — a marbled grouper (Dermatolepis inermis), scamp grouper (Mycteroperca phenax), barracuda (Sphyraena barracuda) and sand tilefish (Malacanthus plumieri).
On Feb. 5, 2008, the FDA issued an advisory targeting seafood processors purchasing grouper, amberjack, and related predatory reef species captured in the northern Gulf of Mexico (Figure 21). The advisory was issued in response to the FDA's concern over a number of recent outbreaks of ciguatera fish poisoning that had been traced to fish from the vicinity of the sanctuary. The FDA considers ciguatera fish poisoning a likely hazard for hogfish, grouper and snapper species of concern captured within 10 miles of the sanctuary, and amberjack, barracuda and other pelagic species of concern captured within 50 miles of the sanctuary. FDA officials recommended that primary processors avoid purchasing the listed species from the area detailed. To download the full advisory, visit http://www.regulations.gov/ and search for FDA-2008-D-0079-0002
4. What are the levels of human activities that may influence water quality and how are they changing?
Discharges from numerous sources influence water quality at the Flower Garden Banks sanctuary. These include recreational dive charter vessels, recreational and commercial fishing vessels, transiting oil and gas tankers and other ship traffic. Other sources include discharge from oil and gas platforms associated with exploration, development and production facilities. The levels of these activities appear to be stable and significant impacts have not been documented, therefore, this question is rated good/fair and not changing. Oil and gas development activities fluctuate over time due to market conditions and other factors. It is anticipated that within the next 5-10 years many platforms in this region of the Gulf of Mexico will be decommissioned, resulting in short-term increased activity in the vicinity. However, levels of fishing appear to be increasing in and around the sanctuary (though the recent FDA advisory on fish consumption may change this, at least in the short term).
Water Status and Trends
Status: Good Good/Fair Fair Fair/Poor Poor Undet.
Trends:
▲ Conditions appear to be improving. 5. What is the abundance and distribution of major habitat types and how is it changing?
The abundance and distribution of major habitat types in the sanctuary is considered to be “good and not changing.” With over 50% living coral coverage the Flower Garden Banks is considered to be one of the healthiest reef systems in the Caribbean (Lang et al. 2001). Monitoring data collected since the 1970s indicate no significant changes in the nature of habitats on the coral reefs, with short-term exceptions being those caused by the die-off of many Diadema antillarum sea urchins in 1983-84, and mechanical damage caused by certain human activities such as anchoring (Gittings 1998). The sea urchin die-off resulted in high leafy algae cover that persisted for about a year, but no measured loss in coral cover. Several anchoring incidents have resulted in damage at the Flower Garden Banks, most leaving toppled, fractured and abraded corals (Gittings et al. 1997). Anchor damage in deep habitats on the banks has not been measured directly, though evidence of disturbance can be seen on side-scan and multi-beam images of the seafloor. Isolated damage has also been caused by tow cable drags, one of which affected individual coral colonies along a path of about 300 meters. Though scars persisted for many years, most corals affected by these incidents survived and healed.
Habitat impacts were caused by Hurricane Rita in 2005, which passed within 34 miles (55 km) of the sanctuary. Considerable sand movement and toppling of numerous large coral colonies were evident (Robbart et al. In press). Fields of Madracis mirabilis suffered extensive damage as a result of the hurricane. Mechanical damage continued to be visible in July 2007. These natural changes have been seen in previous hurricanes (e.g., Hurricane Allen in 1980) and reef organisms appear to recover from these impacts if they are not too severe.
6. What is the condition of biologically structured habitats and how is it changing?
Long-term monitoring suggests that coral-dominated habitats are in “good/fair” condition, as numerous human activities have affected portions of the otherwise thriving coral reef. Coral cover and growth rates have been nearly the same for decades (Figure 22) (Gittings and Boland 1991, Gittings et al. 1992c, CSA 1996, Dokken et al. 1999, Dokken et al. 2003, Precht et al. In press). Nevertheless, some habitat disturbance and loss has resulted from fishing gear (nets, longlines and monofilament line) entanglement, seismic cable entanglement, anchoring, and cable dragging. Also, discarded industry equipment such as pipes has been encountered during ROV surveys.
Impacts have been documented on the coral reefs, caused by a major coral bleaching event in 2005 that resulted in the loss of approximately 1% (Robbart et al. In press) of the fire coral (Millepora alcicornis). Bleaching has been documented in the past (Hagman and Gittings 1992), but mortality was minimal. It is uncertain whether recent bleaching events are evidence of increasing severity in general or simply isolated severe events. It appears that fire coral at Stetson Bank suffered mortality during the 2005 season due to increased water temperature. Data analysis is currently underway to verify these observations.
Also at Stetson Bank, observations of fragmented rock outcrops suggest that fishing gear or anchoring — possibly both — have caused their destruction. The claystone outcrops on Stetson Bank are very fragile compared to those on coral reefs, which are a form of limestone. At Stetson Bank, corals and sponges grow in abundance on these outcrops, but when fishing gear or anchors snag on the features, both the living organisms and the rocks themselves can be destroyed. The rock itself, in breaking loose, becomes more susceptible to movement and therefore less suitable for invertebrate recruitment and survival. 7. What are the contaminant concentrations in sanctuary habitats and how are they changing? Limited investigations have not shown any contaminants within the coral reef zone. Therefore, the rating for this question is “good.” Because there are limited investigations to date, a trend is “undetermined.” Numerous contaminants have been documented in sediments (discharged drill cuttings and lubricants) below the gas production platform, (HIA389A) at depths of 400 feet (120 meters) within the sanctuary, but they are very localized and do not appear to have the potential to affect resources on East Flower Garden Bank itself (Kennicutt 1995).
8. What are the levels of human activities that may influence habitat quality and how are they changing? Because some potentially harmful activities exist in the sanctuary this question is rated “good/fair and not changing.” One recreational dive charter operator is currently operating, running trips with two vessels to the sanctuary, each with a carrying capacity of 20 – 34 customers. Approximately 2,500 divers visit the sanctuary each year, making a total of at least 10,000 dives in the sanctuary. The level of diving activity has not changed substantially in recent years. The level of private, charter and commercial fishing are not well documented, but appears to be increasing. Discarded fishing gear and injured or dead fish, moray eels and sharks have been documented. A spear gun was recently found at East Flower Garden Bank, and spear tips have been recovered from all three banks, indicating that prohibited activities are taking place. Longline fishing is illegal within the sanctuary, as is bottom trawling, yet longline gear is often encountered during ROV operations in deeper waters, as are discarded trawl nets. Active longline fishing within the sanctuary boundaries has been witnessed by dive charter operators. Artificial reef program activities should be monitored for potential impacts to sanctuary resources, as well as other important biological reefs and banks in the region. With the expectation that a large number of oil and gas platforms in the northwestern Gulf of Mexico will be retired in the next 10 years, there will be pressure for an increasing level of “reefing” of oil and gas structures in the area. Impacts could include the addition of non-native species, which could harbor exotic diseases and parasites. The development of fish aquaculture using artificial structures such as platforms is being actively investigated and, if implemented, may affect the sanctuary area in the near future. Habitat Status and Trends Status: Good Good/Fair Fair Fair/Poor Poor Undet. Trends:
▲ Conditions appear to be improving. 9. What is the status of biodiversity and how is it changing?
Data collected as part of the long-term monitoring program at the Flower Garden Banks indicate that in most respects, the coral reef community is stable, including living coral cover, species dominance and diversity, and growth rates (Gittings and Boland 1991, Gittings et al. 1992b, CSA 1996, Dokken et al. 1999, Dokken et al. 2003, Precht et al. In press). For this reason, the status of biodiversity in the sanctuary is considered to be “good and not changing.” As mentioned above, some loss of fire coral cover occurred after the 2005 bleaching event. The research team and partners from academic institutions, consulting firms, and non-profit organizations (e.g., Reef Environmental Education Foundation) continue to add to the species known within the sanctuary as more observations are made. The Mardi Gras wrasse, a new species of wrasse described in 2007, appears to be thriving at Stetson Bank.
10. What is the status of environmentally sustainable fishing and how is it changing?
No directed studies have occurred to address this question, though they are clearly needed in both shallow and deep areas of the sanctuary to assess rates of removal and impacts to the food web. Anecdotal reports from experienced observers, including numerous researchers and recreational divers, suggest a decline in the number of large fish (principally groupers and jacks). Also, lower numbers of large pelagic sharks, primarily the scalloped hammerhead, have been observed during the winter months in recent years. For these reasons, the status of environmentally sustainable fishing is considered to be “fair,” though the trend is “undetermined.”
11. What is the status of non-indigenous species and how is it changing?
Some non-indigenous species exist in the sanctuary, but they are sparse enough to preclude substantial or persistent degradation to the ecosystem. Therefore, this question is rated “good/fair”. Three colonies of an Indo-Pacific species of orange cup coral (Tubastraea coccinea) have been found in the sanctuary. This species may be becoming better established in the region. Prior to this finding, the coral had been reported in the Gulf of Mexico, but primarily on artificial structures such as oil and gas platforms. Tubastraea is thriving on HIA389A, but has only recently been documented at East Flower Garden Bank (1 mile from the platform). No colonies have been reported at West Flower Garden Bank. On neighboring Geyer Bank, nearly 50 colonies of Tubastraea were removed by sanctuary research divers in 2004. Over 100 colonies were observed at Geyer Bank during surveys in 2007. Tubastraea appears to be an aggressive colonizer, and sanctuary leadership has decided to remove it from the reef when it is encountered.
A Pacific species of nudibranch (Thecacera pacifica) was recently documented at Stetson Bank. It was photographed during reproduction, so it is likely that this species is becoming established. It is unknown how this species will impact the Stetson Bank ecosystem. 12. What is the status of key species and how is it changing?
Because substantial changes have been observed, both in the long term and in recent years, for certain key species in the Flower Gardens sanctuary, the status overall is rated at “good/fair.” But because rates of change and recovery have not been adequately assessed, the trend is rated as “undetermined.” Monitoring results indicate that coral populations are stable, although there is some concern about the potential effects of the apparent emergence of diseases that affect them (Gittings and Boland 1991, Gittings et al. 1992b, CSA 1996, Dokken et al. 1999, Dokken et al. 2003, Precht et al. In press). Based on frequent but non-quantified observations by sanctuary staff and others, abundance of hammerhead sharks, groupers and jacks appears to be lower than a decade or so ago. Sea turtle, manta ray and whale shark populations appear to be stable, though their numbers fluctuate annually. Whale shark encounters remain unpredictable, so changes in their abundance are difficult to assess. Long-spined sea urchins (Diadema antillarum), which many consider an important keystone species on Caribbean reefs, experienced almost complete mortality at the Flower Garden Banks in 1983-84, and remain in low abundance. Interestingly, Diadema are more abundant at Stetson Bank, and populations at West Flower Garden Bank are increasing slowly. There is a lack of information on species in deep habitats, particularly groupers, jacks and snappers that inhabit those areas.
13. What is the condition or health of key species and how is it changing?
Coral growth rates, levels of fecundity (based on observations during mass spawning events), and other indices of coral vitality appear to be comparable to those observed since the banks were first studied (Gittings and Boland 1991, Gittings et al. 1992c, CSA 1996, Dokken et al. 1999, Dokken et al. 2003, Precht et al. In press). Coral spawning at the Flower Garden Banks sanctuary continues to be one of the most prolific and predictable events in the Caribbean, and the few recruitment studies (Baggett 1985, Snell 1998, Hagman 2001) conducted suggest good conditions and levels of recruitment of coral larvae. However, recent ephemeral outbreaks of coral disease, which has resulted in tissue loss on affected colonies, and the 2005 coral bleaching event suggest that the health of key species may be less than optimal. The bleaching event was severe, and there was measurable loss of fire coral (Millepora alcicornis). For this reason, the condition of key species in the sanctuary is considered to be “good/fair and declining.”
In winter 2005, the first significant documented coral disease outbreak at the Flower Garden Banks occurred, affecting multiple coral species and numerous colonies. Repeat occurrences of this plague-like event happened in the winters of 2006, 2007 and 2008. These events have been unusual, as typical coral disease events elsewhere are more severe during the warmer water temperatures. The Flower Garden Banks coral disease events have, to date, been active during the winter months, and declined significantly as the water temperatures increased. No overall decrease in coral cover has been documented as a result of these disease events through the long-term monitoring program; however, tissue loss on individual affected coral colonies has been documented, and gives cause for concern over the long term (Precht et al. In press). Sea turtles appear to be in good health, based on body size and mass, as do the manta rays, grouper and sharks found in the sanctuary. Some whale sharks, however, show signs of vessel strikes (scars and gouges on their bodies and fins). 14. What are the levels of human activities that may influence living resource quality and how are they changing?
The most common and persistent human activities occurring at the Flower Garden Banks are diving and fishing, but other activities, such as anchoring by large vessels and dragging of tow cables, occasionally occur. All these activities can cause measurable impacts to habitats and living resources, but evidence to date suggests effects are localized, not widespread. Thus, this question is rated “fair”.
The levels of recreational diving activities appear stable, though at present, the sanctuary does not have a system in place to fully monitor diving activity. A new dive operator has indicated their intention to begin a charter at the Flower Garden Banks, so levels may increase. It is important to estimate the carrying capacity of the reef and implement a system to evaluate the numbers of visitors to the reef. Also, it may become necessary to rotate buoys used by recreational divers if localized impacts are shown to result from heavy use of moorings. No formal reporting process is in place to evaluate recreational and commercial fishing use at the sanctuary, therefore, the trend rating for this question is “undetermined.” Observations by long-time users and sanctuary staff indicate elevated visitation by recreational fisherman at all three banks in the sanctuary. Levels of commercial fishing are not well known, but investigations following the recent outbreak of ciguatera originating in fish from the banks suggest that a considerable number of commercial fish, including some that are quite rare throughout their range (i.e., marbled grouper), are taken from deep habitats at the Flower Garden Banks. Living Resources and Trends Status: Good Good/Fair Fair Fair/Poor Poor Undet. Trends:
▲ Conditions appear to be improving. Although no significant maritime archaeological artifacts have been identified in the Flower Garden Banks sanctuary, regulations prohibit the removal, damage, or disturbance of any historical or cultural resource within the boundaries of the sanctuary. Several fluked anchors have been observed during ROV surveys. These anchors could be 100 years old based on the design of the flukes..
Maritime Archaeological Resources and Trends Status: Good Good/Fair Fair Fair/Poor Poor Undet. Trends:
▲ Conditions appear to be improving.
- Conditions do not appear to be changing.
▼ Conditions appear to be declining.
? Undeterminted trend.
N/A Question not applicable.
#
Status
Rating
Basis For Judgement
Description of Findings
1.
Stressors
Isolated contaminants; freshwater influxes from terrestrial sources; increased water temperature.
Selected conditions may preclude full development of living resource assemblages and habitats, but are not likely to cause substantial or persistent declines.
2.
Eutrophic Condition
No evidence based on ongoing monitoring since the late 1980s.
Conditions do not appear to have the potential to negatively affect living resources or habitat quality.
3.
Human Health
Recent outbreaks of ciguatera traced to fish from the Flower Gardens; large proportion of fish tested for mercury exceeded levels for safe consumption.
Selected conditions have caused or are likely to cause severe impacts, but cases to date have not suggested a pervasive problem.
4.
Human Activities
Vessel discharges, oil and gas platform and pipeline discharges.
Some potentially harmful activities exist, but they do not appear to have had a negative effect on water quality.
Habitat
- Conditions do not appear to be changing.
▼ Conditions appear to be declining.
? Undeterminted trend.
N/A Question not applicable.
#
Status
Rating
Basis For Judgement
Description of Findings
5.
Abundance/ Distribution
Major habitat types appear to be stable, although additional monitoring in deeper communities is warranted.
Habitats are in pristine or near-pristine condition and are unlikely to preclude full community development.
6.
Structure
Damage by anchoring; lost or discarded fishing gear and cables, mostly in deep habitats; destabilization by fishing gear and/or anchors at Stetson Bank.
Selected habitat loss or alteration has taken place, precluding full development of living resources, but it is unlikely to cause substantial or persistent degradation in living resources or water quality.
7.
Contaminants
Limited investigations suggest low levels of contaminants.
Contaminants do not appear to have the potential to negatively affect living resources or water quality.
8.
Human Activities
Limited number of dive charters, some fishing gear impacts, some illegal fishing.
Some potentially harmful activities exist, but they do not appear to have had a negative effect on habitat quality.
Living Resources
- Conditions do not appear to be changing.
▼ Conditions appear to be declining.
? Undeterminted trend.
N/A Question not applicable.
#
Status
Rating
Basis For Judgement
Description of Findings
9.
Biodiversity
Long-term monitoring of coral reef communities and other information collected since the 1970s
Biodiversity appears to reflect pristine or near-pristine conditions and promotes ecosystem integrity (full community development and function).
10.
Extracted Species
Unpublished observations suggest a decline in certain species of fish, e.g. grouper and jacks.
Extraction may inhibit full community development and function and may cause measurable but not severe degradation of ecosystem integrity.
11.
Non-indigenous Species
Recent invasive species have been discovered, but abundances are low and there is no evidence that they have become established in natural areas.
Non-indigenous species exist, precluding full community development and function, but are unlikely to cause substantial or persistent degradation of ecosystem integrity.
12.
Key Species
Coral, mantas and sea turtles appear to be stable. Hammerhead, grouper, snapper, and jacks may be declining. Diadema sea urchin populations remain depressed since the 1983-84 die-off.
Selected key or keystone species are at reduced levels, perhaps precluding full community development and function, but substantial or persistent declines are not expected.
13.
Health of Key Species
Observations of coral disease for four straight years, though no apparent population impact to date; loss of some Millepora alcicornis due to bleaching.
The condition of selected key resources is not optimal, perhaps precluding full ecological function, but substantial or persistent declines are not expected.
14.
Human Activities
Stable levels of recreational diving, apparent increase and effectiveness of private and commercial fishing; no monitoring of use levels is in place.
Selected activities have resulted in measurable living resource impacts, but evidence suggests effects are localized, not widespread.
Maritime Archaeological Resources
- Conditions do not appear to be changing.
▼ Conditions appear to be declining.
? Undeterminted trend.
N/A Question not applicable.
#
Status
Rating
Basis For Judgement
Description of Findings
15.
Integrity
No documented underwater archaeological sites
N/A
16.
Threat to Environment
No documented underwater archaeological sites
N/A
17.
Human Activities
No documented underwater archaeological sites
N/A