I THE STATE OF CORAL REEFS IN THE WIDER
Interciencia JAN- FEB 1991, VOL. 16 N9 I
Coral reefs are tropical
and subtropical ecosystems that flourish at temperatures between 25 and 29 centigrade in
insular and continental platforms. Living coral cover and species diversity is
highest where waters are clear due to low input of nutrients and fine
Coral reefs are highly
susceptible to disturbance in relation to other nearshore ecosystems, such as
mangrove forests and seagrass beds (Ogden and Gladfelter, 1983). This report
should be viewed in the context of extensive coral bleaching events recently
occurring throughout the
Coral reef degradation
(in terms of observable changes in the relative abundance of major benthic
components resulting from human activities is well known to be underway in
Socioeconomic Importance of Coral Reefs
Although coral reefs are mainly known for their natural beauty and high biotic diversity, this is only a minor portion of what they represent to nations that possess them. Recently it has been suggested that their importance for the maintenance of life on Earth transcends national barriers as explained below. Following is a list of the socioeconomic importance of coral reefs:
Production of Pharmacological Compounds
A large diversity of chemical compounds have resulted possibly as a consequence of complex interactions between species in the coral reef. Some of these substances are highly active biocompoUnds whose applications in medical research are just now being discovered. These include antimicrobial, antileukemic, anticoagulant and cardioactive properties (Fenical, 1980; Rinehart et al., 1981; Saim and Clark, 1982). Coral reef organisms have been used as tools in the elucidation of phyriological mechanisms (e.g., sea hare), (fertilizalion (e.g., sca urchin), regeneration and cell association (c.g,, sponges) arid mechanisms of drug action (e.g,, squids) (Angeles, 1981).
Prevention of Coastal Erosion and Storm Damage
This is particularly important for regions with low lying coastal plains. Coral reefs also contribute to the formation of sandy beaches and sheltered harbors.
The importance of the maintenance of healthy coral reef growth is accentuated in light of the observed sea level rise in the last decades (Etkins and Epstein, 1982; Gornitz ci a!.. 1982). Coastal erosion is likely to be felt more in areas where coral reefs are degenerated since large waves are capable of penetrating more easily in the absence of these natural barriers (Cubit et a!., 1984). Areas with reduced tidal fluctuations are more likely to be affected.
Coral reefs are among
the most productive habitats of the world (Lewis, 1977). Fisheries in the
Tourism on many
Extraction o/ Atmospheric Carbon Dioxide
Coral reefs constitute about 0.17% of the world ocean area and about 15% of the shallow sea floor within the 0-30 m depth range (Smith, 1978). These ecosystems play an important role in the marine carbon budget primarily through the deposition of aragonitic calcium carbonate. Surface tropical waters, which are stratified by a permanent thermocline, are supersaturated with respect to calcium carbonate. The inorganic transfer of atmospheric CO2 across the air-sea interface is, therefore, limited. By extracting CaCO5, coral reef organisms provide a way of bringing more CO2 into the ocean system. Reported rates of CaCO3 deposition by coral reefs demonstrate that these ecosystems are an important buffer in the Earth’s CO2 cycle (Barnes ci a!., 1986).
Human Activities Affecting Coral Reefs
In general, coral reefs within the Wider Caribbean
are threatened by pollution related to industry, domestic wastes and upland
vegetation clearing. Rodriguez (1981), in a review of environmental stress in
coastal waters of the Wider Caribbean, pointed our that there is no widespread
industrial pollution there, apart from contamination by petroleum hydrocarbons.
He added, however, that severe, localized problems do occur and stressed that
these problems threaten the development of economic activities which depend on
a healthy marine environment. The largest industrial concentrations occur
along the coast of
Marine pollution caused by dumping domestic wastes into the ocean (Rodriguez, 1981), and upland vegetation clearing (i.e., be it for industry, urbanization or agriculture) without concern towards appropriate land conservation practices (Johannes, 1975) are two other activities, common to the whole region, that have a negative impact upon coral reefs. These are associated with all major cities in the area.
Other activities that are spatially and temporally
restricted, although not necessarily insignificant, are: mining of coral reefs, military activities,
standing and walking over coral, ship grounding, anchoring, coral collecting,
fishing with explosives and with bleach, dredging and thermal pollution. Of
these, the first seven destroy reef structure directly while the last three
modify the relative abundance of the living components. The effect of most of
these have been documented for the wider
A. Oil Pollution
Many coral reef scientists have expressed their
apprehension concerning the harmful effects of oil spills (e.g., Bak and
Elgershuizen, 1976). Degradation of some
Bak and Elgershuizen (1976) have suggested that
the water soluble fraction of oils in seawater is more harmful to corals than
their direct contact with oil. Riitzler and Sterrer (1970) suggested that
corals escaped observable damage from an oil spill in
Data from laboratory
experiments show that colonies of the scleractinian, Madrocis mirobilis were
more affected by mixtures of various crude oils and Shell dispersant (LTX type)
than by either the crude oils or the dispersant separately (Elgershuizen and de
Kruijf, 1976). These investigators hypothesized that the observed non additive
effects were related to a higher solubility of the toxic oil fraction in sea
water after emulsification by the dispersant. Active ingestion of oil drops by
corals do not occur and it is unlikely that oil is adsorbed to living coral
tissue (Bak and Elgershuizen, 1976). Mucus produced by corals, however, can
trap drops of oil that may be incorporated into the reef food web via the
mucus-eating fish and crustaceans (Elgershuizen a of,, 1975). Zooxanthellae
Shinn (1972) observed that the scieractinian
Monto.strea onnuloris can survive two hours total immersion in Louisiana crude
oil and that Acroporo cervicornts, exposed for two hours to a mixture of
seawater containing one part crude to 6-12 parts seawater, caused immediate
retraction of polyps although recovery was complete after 24 hours. Based on
these observations he remarked that “it would seem safe to conclude then that
crude oil spills do not pose a significant threat to Atlantic coral reefs”.
However, as Johannes (1975) has noted, this statement is premature since Shinn
reported no subsequent observations on these corals. Dodge et ol. (1985) determined
experimentally that corals treated with chemically dispersed oil at concentrations
of 20 ppm showed no depression in calcification. Once again, it is unknown
whether long term impairment of vital functions, such as reproduction or
maintenance, had occurred in individuals of these species. Also, Shinn’s own
experiments illustrate the importance of interspecific response to oil.
Evidence of pathological responses, including impaired development of
reproductive tissues, atrophy of mucous secretory cells and muscle bundles,
has been observed in colonies of the shallow water Caribbean coral Manicina
oreolata during exposure to water accommodated fractions of No. 2 fuel oil
(Peters, et ol., 1981). This atrophy may help explain the decreased capacity of
corals to recover from injuries after subject to oil pollution reported in
Panami by Guzmán and Jackson (1989). Gooding (1971) also documented an
extensive destruction of reef associated biota, other than corals, by an oil
Other effects of oil and
the use of dispersants on coral reefs are the alteration of the physical
properties of the reef surface (which inhibits larval settlement), the
impairment of oxygen exchange across the air-water interface (Blumer, 1971;
Kinsey, 1973) and the interruption of light penetration by surface oil films
(Mergner, 1981). These have not been documented in the
B. Oil Drilling Muds
In addition to the danger of oil spills, potentially detrimental effects of drilling near coral reefs include the actual physical disturbances caused by anchoring, pipeline and drill rig construction, the resuspension of bottom sediment created by such activities shadowing by the rig platform and the discharge of drilling effluent which include sewage, deck drainage, produced formation water, produced sand, materials for treating wells, drill cuttings and drilling muds (Dodge and Szmant, press; Thompson and Bright, 1977). The effects of drilling muds are discussed below.
Drilling muds are introduced in the marine environment during offshore drilling operations. Then are discharged at low levels and occasionally in bulk (up to 2,000 barrels or 14 tons in a few hours) when the muds require renewal or on termination of drilling activities (Thompson cx of., 1980)
Drilling muds are varied in composition and those containing ferrochrome lignosulphonates and other additives such as diesel fuel, appear to be more toxic. Their effect on coral reefs have been recently reviewed by Dodg and Szmant (in press) - Their major conclusion is that more research is needed urgently on this subject.
Exposure to chromiolignosulphate drilling muds leads to the production of mucus as a “stress” response in Porites divaricata, P. furcata P. astreoldes, Montostrea annulari, .Acropora cervicornis and Agoricia ogar cites (Thompson et of., 1980) and may be responsible for decreased growth rate after short term exposure, by M. annularis (Hudson and Robbin, l980~ Dodge (1982) suggested that lower calical relief in corals exposed to usedb drilling muds can result in decrease sediment-shedding capabilities which may remain effective for some time after the period of exposure in M. annularis.
Szmant ci a!. (1981) have further investigated the response of M. annularis to drilling muds. They found that the rates of calcification and respiration of this species decreased by 53% and 25%, respectively, after four weeks of exposure to 100 ppm drilling mud and 84% arid 40% after six weeks of exposuse. Gross photosynthesis was reduced by 36% after five weeks. Nitrate uptake rates decreased by 42% and 48% after four and six weeks while ammonium uptake decreased by 32% and 49% after five and six weeks of exposure. Colonies exposed to 100 ppm were not able to feed on zooplankton and several of the experimental colonies died before completion of the experiment.
C. Siltation From
Siltation of coral reefs results from upland vegetation clearing and is generally considered an important factor controlling coral reefs. It can limit coral reefs by: 1) increasing water turbidity (Jerlov, 1968) and, thus, affecting the photosynthetic output of zooxanthellae, 2) causing energy expenditure in particle rejection (Lasker, 1980), 3) increasing the potential for hacterial infection (Ducklow and Mitchell, 1979; Peters, 1984), 4) abrasion (Wein, 1962; Slorr, 1964), 5) creaeing conditions unsuitable for larval settlement (Maragos, 1972), 6) reducing feeding periods (personal observations) and/or altering heterotrophic and autotrophic feeding efficiencies (Dodge and Szmant, j in press), 7) affecting planktonic food supply (Bak, 1978), and, 8) shifting the relative abundance of fish and promoting the survival of those that graze on the benthos (Galzin, 1981). The removaL of mangrove stands, generally accompanying upland deforestation on developed coastal areas, magnifies the problem of siltation.
These stands act as natural barriers for runoff due to precipitation. In the Puerto Rican southwestern coast it is not uncommon to observe large sediment plumes after heavy rains where the mangroves have been removed and replaced with stilt houses (personal observations). These are located within the maritime zone and many dump raw sewage into the water.
Although coral reefs are known to occur under silt laden and/or eutropinc waters (Goenaga, 1988), it is unknown whether these are in the process of disappearing or whether the component biota is or will be capable of adapting to these conditions. The available evidence suggests that at least some of the biotic components which depend more upon sunlight die in deeper, although are able to persist in shallower portions of reefs (Morelock et a!., 1979; Acevedo, 1986; Goenaga, 1988).
D. Sewage Discharge
Sewage discharge into
coastal waters may affect coral reef communities by 1) causing nutrient enrichment
and enhancing the growth of algae at the expense of corals (Marszatek, 1981),
2) depressing oxygen levels Wade a al., 1972), and 3) by introducing toxic
substances such as chlorine (cf. Muchmore and Epel, 1973). Coral morbidity and
mortality under experimental conditions is apparently the result of
competition for space with algae and light and not directly related to effluent
toxicity (Marszalek, 1981). Sewage is known to stress reefs in
The classical example of the effects of
eutrophication on coral reefs is
E. Dredging and Mining
The impact of dredging on coral
reef communities are of three basic types: 1) mechanical damage (resulting in
breakage of coral and octocoral colonies many of which subsequently die), 2)
sediment loading or siltation(i.e., rapid deposition of coarse silt and coastal
waters may affect coral reef com- sand size sediments resulting from sediment
laden water leaking from the dredge pumps) resulting in burial and death of
colonies, and, 3) increased turbidity resulting in loss of color, excessive
mucus secretion or death in scieractinians. Also, waters over dredged areas
have significantly more bacteria than neighboring seawater (Galzin, 1981).
This seems related to the suspension of fine sand particles that are utilized
as a substratum by the bacteria and may result in the elimination of certain
benthic faunal and floral species and the proliferation of tolerant species.
Galzin (1981) also found that sand dredging in Guadaloupe,
One effect of dredging that is usually ignored is the resuspension of toxic materials, such as heavy metals, into the water column. Metals may be detrimental to corals by impairing their physiological processes and possibly by weakening the structure of the aragonite skeleton (Howard and Brown, 1984).
Associated with dredging
operations are mining and smelting processes. Fiftysix large scale mining
operations are reported in the
F. Thermal Pollution
Activities generating thermal pollution, mainly
related to the energy industry, are known to be maintained in the vicinity of
Anchoring on top of coral reefs can represent
considerable disruption to coral reef communities.
However, touristic sightseeing of coral reefs, if
well planned and with adequate supervision, seems to be highly compatible with
the preservation of these ecosystems and can be highly productive in terms of
education and in terms of the employment generated. The economy of many
H. Military Activities
Although military maneuvers near coral reefs are
possibly not widely practiced in the Caribbean, an example from Vieques, off
In 1982, Antonius and Weiner concluded that the “military impact of the Viequen reefs was negligible when compared to natural damage caused by storm — generated wave action”. These conclusions are based on comparisons made between the reefs from Vieques and those in the eastern coast of St. Croix (presumably not subject to military activities) with which they found no differences. A close look at their section on Materials and Methods, however, reveals that, in their work, “the emphasis was on shallow water communities”. It is widely known and has been extensively documented (e.g., Woodley a at, 1981; Graus a al., 1984; among many others) that damage to coral reefs by storms occurs mainly in shallow waters. It is at these depths that corals with the highest growth rates predominate (e.g., Acropora palinata and A. cervicornis). This is one reason why hurricanes have minimal long term effects on coral reefs (Graus a at, 1984). Deeper portions of coral reefs, where slower growing, massive corals predominate, are not affected as heavily by storms. However, military activities do not discriminate between shallow and deeper portions of the reef and bombs drop in shallow and in deep substrates affecting them equally. It seems reasonable, therefore, to question why did Antonius, a consultant for the U.S. Navy, did not investigate the deeper portions of the reefs in Vieques. The same critique applies to the work by Raymond and Dodge (1980).
In another work, Dodge (1981) also concluded that “...a general similarity between (bombing) ran and control stations..." in Vieques, together with “...quantitative coral abundance and diversity data of other namely, data by Antonius and Weint (1982) indicate a lack of anomalous and adverse sedimentation/turbidity cotu tions affecting coral on reefs near range area”. However, several commer must be made. Reef corals, as well other organisms, need energy for processes other than growth, namely reproduction and maintenance. The effet of the presence of the range on these two other processes were not assessed. Coral colony fragmentation, a process knowledged by Antonius and Wein (1982) and Dodge (1982) to occur Vieques, is, in fact, known to. monotastrea annularic, the very same spec utilized by Dodge (1981) in his study.
Aerial photographs eastern Vieques do show extensive cratering resulting from bombing activities on land as well as in the sea. Crater range in diameter from 5 to 13 m and larger effects extend beyond the extent of direct disruption (Rogers et al., 1978). The reefs are littered with artillery and delivered exploded and unexploded ordnance (metal fragments, flare casings, parachutes) which have sustained extensive damage. Damage to reefs in Vieques has been categorized by Rogers et (1978) as follows: 1) damage by direct hits and by shock waves which sheer colonies near the site of impact, 2)damage due to abrasion by steel and rough fragments generated by the blasts, 3)damage by fragments that come to remain on top of living coral tissue, 4) fracturing and weakening of reef structure blasts and direct hits, 5) dislodgement of colonies which can be transported by heavy seas causing greater damage, 6) deposition of coarse sediments on top of living corals, 7) damage by flare parachutes which drape around soft and stony corals, and others.
Large numbers of unexploded ordnance in these reefs limit their future utilization as fishing and/or touristic centers. It is hard to estimate the costs involved in their restoration. We can barely hope that leaching substances from oxidizing and degenerating ordinance do not pollute marine life in these areas.
I Ship Grounding
Ship grounding in coral reefs can abrade, fracture or overturn reef biota and hull breakage can result in the spill of hazardous substances. Also, alteration of the hydrodynamic regime while the ship is grounded over the reef can generate sediment plumes that increase water turbidity and smother corals downcurrent. Direct damage by ship grounding is more localized than that of storms but may alter the reef contour and re1ief to a much greater extent (Smith, 1985).
Curtis (1985) described how portions of Molasses
J. Fishing with Bleach and Explosives
with bleach and With explosives occurs in the
Bleach (sodium hypoch1orite)
is applied to coral heads to drive commercially valuable species into range of
spears and granges,
The manner in
which overfishing may affect coral reefs is uncertain but it is likely that
the community structure is modified. For example, over-fishing of predator
Capacity For Recovery
Denuded coral reef cornmunities can recover by regeneration of partially damaged coLonies or fragments or through recolonization by larval settlement. Factors which can influence coral recolonization include tbe extent of damage and its location, the availability of coral larvae, the requirement for a ‘conditioning” period of the substratum before corals can settle, the availability and diversity of microhabitats for settlements and survival, the role of grazers, and competition with other organisms such as algae and soft corals (Pearson, 1981).
The available evidence suggests that coral communities may recover from major natural disturbance after several decades but are likely to suffer irreversible changes from man-made disturbance (Weiss and Goddard, 1977). Full recovery from man-made disturbances may be prolonged or prevented altogether because of permanent change to the environment or a continuation of chronic, low level disturbances (Pearson, 1981). In 1975 Johannes reviewed the known effects of pollution on coral reef communities. He pointed out that reef corals are central to the integrity of the reef community and when these are selectively killed, migration or death of much of the other reef fauna ensues. Accordingly, the environmental tolerance of the reef communtty as a whole cannot exceed that of its corals.
At this point it is necessary to mention that non-structural coral communities have the same practical importance as coral reefs in terms of coastal protection, nutritional importance, and others. Coral communities differ from coral reefs essentially in the thickness of the biogenic framework. The former form thin veneers over preexisting structures, such as cemented sand dunes, that drowned after sea level rose during the last glacial period. Coral reefs, in contrast, have a thicker framework which, to a larger extent, have been the product of biogenic (i.e., versus physicochemical) activity. Non-structural coral communities give integrity to the underlying structure and prevent its physical or chemical erosion and eventual destruction.
The importance of habitats neighboring coral reefs, such as seagrass beds and mangrove forests, has been stressed by Ogden and Zieman (1977). Seagrass beds are important feeding grounds for nocturnal feeding fishes, such as grunts and snappers, which shelter on reefs by day. When they return to the reef these fishes deposit organic compounds in the form of feces that become available to detritivores and are introduced to the reef food web. Mangroves provide nurseries for juveniles of certain reef fish (chactodontids, scarids, lutjanids) and are also feeding grounds for fish that shelter on reefs; mangroves also introduce fixed nitrogen and organic detritus into the trophic system or reefs as do reef flats and seagrass beds. Consequently, damage to these neighboring communities can potentially have an effect on nearby coral reefs.
Based on this review some recommendations seem logical:
1) Compile a detailed bibliography on the factors that contribute to the degeneration of coral reefs on a world basis.
2) Based on the literature, define parameters known to be related to coral reef degeneration.
3) Monitor polluted and non polluted reef habitats to differentiate between natural and man-induced sources of variation.
4) Establish marine parks in coordination with affected local communities; fishing communities must have an active and principal role in the management of the park.
5) Consider and study the possibility of restoring damaged areas.
6) Update coral reef inventories.
Although in many cases a
causal nexus have not been shown conclusively, the correlation between
unplanned development and coral reef degradation makes it hard to attribute the
latter effect to causes other than the former. Stressed reef communities show
drastic reduction in live coral cover, overgrowth by filamentous algae, erosion
of physical framework and reduction of diversity of associated fish and invertebrates.
Reef degradation has already been shown to result in an increase in wave energy
at beaches, beach erosion and massive sediment movements (Head and Hendry,
1985) not to mention the decline in the catch of edible species. Touristic
development, of primordial importance to many
It is perhaps sad that statements related to the preservation of coral reefs more than a decade ago by Johannes (1975) are as timely as ever and acquire more significance today. Johannes stated that: the allocation of money for coral reef research and management is. - . very small in relation to the importance of these communities to man and... their vulnerability to pollution.
"…environmental crises (related to the destruction of coral reefs) develop faster than they can be completely assessed. In this context it is more important to make interim decisions in time than to make more scientifically satisfying decisions later” (i.e., after the ecosystem is irreversibly damaged).
And also more timely than ever, he adds about scientists that comfortably and cowardly sit over their data, knowledge and/or insights that “those who remain silent when their observations point to environmental decay are the undertaken of the environment; environmental post mortems become their stock and trade.”
1. Other coral sicknesses have been studied recently by Peters (1914) and others.
2. This phenomenon may be related to human activities. Preliminary observations suggest that bleaching is related to higher than normal penetration of solar radiation into the sea (R. Armstrong, C. Goensga and V. Vicente, personal observations). This is consistent with the known fact that the thinning of the ozone layer, particularly in the poles but also in the tropics, results from the usage of chloroftuorocarbons and halons. This subject, however, is outside of the scope of this report.
II Florida’s Coral reefs Beautiful & Alive!
North America's only coral barrier reef lies about six miles offshore and parallels the Florida Keys, a 158-mile long string of islands, surrounded by mangrove forests and seagrass beds, which together form a fragile, interdependent ecosystem.
Mangroves are saltwater-tolerant trees that provide a nesting area for birds. The submerged roots are a nursery and breeding ground for most of the marine life that migrates to the reef. Mangroves trap and produce nutrients for food and habitat, stabilize the shoreline, and filter land-based pollutants.
Seagrasses offer food and habitat for juvenile fish, crustaceans, and shellfish. They filter the water of sediments, release oxygen into the water and stabilize the bottom with their roots.
protect this spectacular marine ecosystem, the
A comprehensive management plan and a water quality protection program are being created for the new sanctuary in cooperation with the public, a citizen's advisory council and several federal, state, and local government agencies for implementation in 1994.
For more information, contact:
Keys National Marine Sanctuary Planning Office
9499 Overseas Highway
For more information on Refuges, contact the Refuge Manager at (305)872-2239.
Fragile & Endangered
Coral, for all its sturdy appearance, is fragile and vulnerable. The millions of annual divers, snorkelers, and fishermen who visit the coral reef ecosystem threaten its very existence!
The careless toss of an anchor can destroy years of coral growth in minutes. Even the lightest touch can damage sensitive coral polyps.
Nutrients from sewage, fertilizers, stormwater run-off, and deteriorating Gulf waters reduce water quality, causing increased occurrence of coral diseases and algal blooms.
Monofilament line and trash wrapped around delicate corals can smother or abrade coral and even break them. Trash can be deadly for birds, fish, and turtles that become entangled or mistake it for food and ingest it.
Boats that stray into shallow waters may Prop dredge, uprooting seagrass beds and damaging nursery and breeding areas. The noisy approach of a boat or jetski can disturb nesting birds in the mangroves, exposing the eggs or nestlings to predators and the intense sun. Disturbance of shallow feeding grounds can lead to the starvation of birds.
What You Can Do to Protect the Coral Reef Ecosystem
Tips for Divers & Snorkelers:
What you do (or don't do) can make a difference to the survival of the Coral Reef Ecosystem:
Before booking a reef trip, check weather conditions; it's best not to go out in rough seas. Poor visibility, strong winds & waves reduce safe interaction at the reef. Remember that even the lightest touch with hands or equipment can damage sensitive coral polyps. Snorkelers should wear float-coats to allow gear adjustments without standing on the coral.
contact with the ocean bottom, divers should only use the weight needed and practice
proper buoyancy control. Lifeless areas may support new growth, if left
undisturbed. Avoid wearing gloves and touching or collecting marine life. Most
tropical fish captured die within a year. Queen conch is a protected species. Please don't feed the fish; it destroys their
natural feeding habits. Remember, it's
illegal to harvest coral in
Snorkeling is an enjoyable way to see the coral reef. Be sure to wear a float coat to avoid standing, stepping on, or touching the fragile living organisms.
Tips for Boaters & Fishermen
Dumping trash at sea is illegal; plastic bags and other debris can injure or kill marine animals. Try to retrieve fishing gear & equipment, especially monofilament line.
Accidental boat groundings damage the reef. Prop damage destroys shallow seagrass beds. Consult tide & navigational charts and steer clear of shallow areas. Remember, "Brown, brown, run aground. Blue, blue, sail on through." Use reef mooring buoys or anchor in sandy areas away from coral and seagrasses so that anchor and chain do not damage the coral or seagrass beds. Use sewage pump-out facilities, biodegradable bilge cleaner, and never discharge bilgewater at the reef.
good seamanship and safe boating. Maintain safe distances from fishermen.
Observe size & catch limits; release all fish you can't eat. Avoid wildlife disturbance: stay 200 feet or
more offshore; keep speed, noise, and wakes to a minimum near mangroves. Camping, campfires, and collecting of any
kind are prohibited on all National Wildlife Refuges. Personal watercraft &
airboats are illegal in all National Parks and Wildlife Refuges in the
Mangroves are home to nesting birds and other animals; maintain a safe distance offshore and bring your trash back to shore.
Healthy seagrass beds are an important part of the coral reef ecosystem; avoid prop dredging by staying in marked channels and away from shallow areas.
RELIEF is a Key West-based non-profit conservation organization
dedicated to "Preserve and Protect the Living Coral Reef of the
Reef mooring buoys have been installed at most
heavily-visited coral reefs in the
John Halas and Harold Hudson of the Key Largo National Marine Sanctuary (now part of the Florida Keys National Marine Sanctuary) designed the original eyebolt and buoy assembly in use at most Keys coral reefs. Buoy technology is developing and Reef Relief has designed the Big Boat Buoy to allow for use of the buoys by large vessels. The Manta Ray design has also been installed at Keys reefs in areas of rubble inappropriate for the single eye or Big Boat moorings. The buoyassembly above the ocean surface is uniform for all reef mooring buoys. The polypropylene pick-up lines are treated for resistance to the damaging rays of the sun and are easily removed for replacement when necessary. The buoy itself floats on the surface and is recognizable from a distance. A reef tract surrounded by buoys provides a warning to boaters that this is an area of shallow water.
" A few basic procedural steps should be taken when using a mooring buoy:
1.Slowly approach the buoy from down wind and/or down current.
2.Smaller boats are encouraged to tie off to one another, thereby allowing larger vessels access to buoys. Remember, the larger the vessel, the more potential damage to the coral (if an anchor is used).
3.All boats should put out extra scope by adding an extra line to create a horizontal pull on the eyebolt. Otherwise, the eyebolt will be pulled out. A good rule to remember is: if the buoy is pulled underwater, you must let out extra scope.
4.Inspect the mooring buoy your boat is tied to -- you are still responsible for your vessel.
5.Sailboats should not leave large sails up as steadying sails when on a buoy; this puts too much strain on the eyebolt.
If you choose not to use a mooring buoy, anchoring is only permitted in the sandy areas, NOT IN THE CORAL!
This is Florida State Law. Presented by The SportFishing WebSite
Reefs In Danger: The State of
Coral reefs are among the world's most fragile and endangered ecosystems. Reefs off of 93 countries have been damaged by human activity, and unless the current trends are reversed, up to 70% of the world's coral reefs may be killed within our lifetime.
Coral reefs are vital environmental and economic resources that give shelter to one quarter of all marine life. Destruction of coral reefs would mean the extinction of thousands of marine species and the elimination of a primary source of income, employment and food for millions of people.
Some of the most serious threats to coral reefs are:
Over-fishing and fishing with cyanide that upset the ecological balance of coral reefs and allow algae or coral predators to overrun the reefs.
Silt from deforestation that smothers coral reefs by blocking sunlight and preventing photosynthesis.
Coral mining and blast fishing that destroy coral reefs with explosives.
Untreated or improperly treated sewage that chokes coral reefs by promoting algae growth.
Runoff of pesticides, fertilizers and other chemicals that poison the reefs.
International Year of the Reef - 1997
Coral reefs around the world are being threatened by factors such as over-fishing, coastal development, runoff from agriculture and logging, high-impact tourism and many other causes. Concern about the state of the world's reefs has inspired scientists and environmental groups to accept the following challenges:
planning and executing major programs of public
education and outreach about coral reefs and coral reef destruction
assessing the conditions of coral reefs worldwide
collaborating with governments, local communities and other reef managers to develop and implement plans for the sustainable use of irreplaceable reef resources
The International Year of the Reef (IYOR) 1997 has begun a major effort of assessment, education and collaboration. Scientists and volunteers from the worldwide diving community are involved in diagnosing the condition of representative reefs throughout the tropical seas. Aquariums, scientists, and conservation organizations are collaborating to produce a variety of courses, video tapes, brochures and other educational materials. Individual coral reef areas are creating or revising management plans for their coastal zones. With the involvement and financial support of governments, foundations and individuals, all these initiatives are being put into place to insure that the world's coral reefs are preserved for the future.
IV Are storms killing coral?
Tue Mar 7 2000 18:01 EST Environmental News Network
Are huge dust storms
from Africa's deserts killing the coral
been watching this for about 40 years," said U.S. Geological Survey
scientist Gene Shinn. "The years with high dust were the same years most
of the coral were damaged."
"No one has gotten into looking at the potential health effects or
what dust does to the environment,"
said Shinn, a self-proclaimed "dust nut" who's hoping to raise awareness and funds for his
cause. Coral reefs throughout the
Shinn believes algal infestation, coral bleaching
and coral killers such as "white
band" and "black band" diseases are connected to the nearly two
billion tons of dust that each year blow from North Africa to the Caribbean. "After we looked around and noticed
coral was dying all over the Caribbean, not just in
The best evidence of Shinn's theory is
Aspergillis, a fungus normally found in soil, that has devastated a particular
species of coral. Since 1983, when Aspergillis first appeared, it has killed
more than 90 percent of the
blamed deforestation runoff on coral demise. Shinn blames dust balls. "We
looked at the dust," said Shinn. "That would explain how it could be all
V BLEACHING DAMAGE SPREADS BEYOND CORALS
From Science News, Vol. 142 11/14/92 p334 from reports from geological Society of America annual meeting
marine organisms known as foraminifera exhibit damage similar to that observed
in bleached corals, reports Pamela
Hallock, an oceanographer at the
Both foraminifera and coral play an important role in the global ecosystem. As these organisms "are very important sources of organic matter and calcium carbonate production...such [bleaching] phenomena could affect the global carbon cycle and the oceanic food chain," Hallock says. Foraminifera and coral filter carbon dioxide out of the atmosphere. If their numbers decline, the atmospheric concentration of this greenhouse gas could potentially increase.
Many foraminifera, like many coral, live in a symbiotic relationship with microorganisms that provide their hosts with not only nourishment, but also color (SN 12/8/90, p 364). A host organism that has lost its symbiotic companion turns white, or bleaches, and its health declines.
first documented study of bleaching foraminifera, Hallock examined four species
of the genus Amphistegina collected from
Hallock found that while most of the population appeared normal throughout the winter months, bleaching began to occur and then increase during the spring of 1992. Bleaching peaked in June and July, with 85 percent of the population showing total or partial loss of color.
While damaged foraminifera began to regain color as fall approached, the bleaching appears to have had severe effects on reproduction and adult mortality. "There were very few juveniles in the population at a time when you would expect them to be [abundant]," Hallock says.
In the laboratory, bleached foraminifera produce significantly fewer young, and up to 30 percent of these may be deformed or nonviable, the study shows.
Laboratory studies indicate the bleaching can be induced by increasing
the organisms' exposure to ultraviolet light.
Hallock speculates that the bleaching she observed may have resulted
from a minute increase in ultraviolet exposure related to
VI Coral Reefs To Be First Casualty Of CO2 Emissions
Coral reefs will become a casualty of the industrialized world's growing carbon dioxide emissions by the middle of the next century, according to a study published in the April 2 issue of the journal Science.
surface waters will become more acidic as they absorb carbon dioxide in
increasing amounts from the atmosphere, say the study's co-authors, including
"It's an irrevocable thing that we're doing to the planet,"
said Archer, Associate Professor in Geophysical Sciences at
Science article's six co-authors, led by Joan Kleypas of the
In 1700, the concentration of carbon dioxide in the atmosphere was approximately 280 parts per million. Today, it is nearly 370 and rising as much as two parts per million each year.
"It's almost going to double from the pre-industrial value some time in the next century. That's almost unavoidable," Archer said.
Fossil-fuel combustion and deforestation both have contributed to rising
atmospheric carbon dioxide. "There was a long, broad rise of carbon
dioxide throughout the 19th century, which predates the use of coal and other fossil
fuels," Archer said. "They call it 'the pioneer effect,' for when the
This increase in carbon dioxide adds to the greenhouse effect, which traps heat in the atmosphere, possibly leading to global warming. Warming trends during the last 10 years, whether from increased carbon dioxide emissions or natural climatic variation, have already caused bleaching of coral reefs.
Corals normally live in symbiosis with algal plants, but warm temperatures upset the relationship. "For some reason that nobody really quite understands, when corals get stressed they spit out the plants," Archer said. When that happens, corals lose their color, changing from green or brown to white. "This effect of carbon dioxide acidifying the ocean is on top of this already well-known bleaching effect," Archer said.
findings are based on a series of studies showing that acidity interferes with
the growth of coral reefs. One of the studies was conducted in Biosphere 2 near
Coral reefs are mostly made of calcium carbonate. When carbon dioxide dissolves in water it makes carbonic acid, which causes calcium carbonate to deteriorate. Langdon and his colleagues observed a slowdown in coral reef growth when Biosphere 2 contained higher levels of carbon dioxide.
A key element of the Science study was Archer's model of carbon movement from the ocean surface to the deepest sea floor. The model takes into account such factors as fluid dynamics, current velocity, water temperature, salinity and chemistry.
"It's like the models they use to predict weather in the atmosphere, only this is down in the ocean," said Archer, whose work is supported by the David and Lucille Packard Foundation and the Petroleum Research Fund.
Archer's model produced rising carbon dioxide levels that rise over the decades at the ocean surface where coral reefs grow. These areas are warmer than other parts of the ocean and therefore more buoyant and in more continuous contact with the atmosphere, he explained.
Similar models are used to determine how much carbon is going into the ocean today. The burning of fossil fuels and deforestation combined release approximately seven billion metric tons (seven gigatons) of carbon into the atmosphere each year. The amount in the atmosphere is increasing by three gigatons each year. Ocean models predict that the ocean takes up another two gigatons annually. Scientists suspect that the remaining two gigatons might be fertilizing terrestrial plants and soil in the Northern Hemisphere.
"The fate of that two gigatons is still rather mysterious," Archer said. - By Steven N. Koppes
[Contact: Steve Koppes] http://unisci.com/stories/19992/0402994.htm
Death Of Corals In
corals of the Florida Keys could be an early warning of tough times ahead for
the planet's environment,
Increasing global temperatures and worsening pollution, the ecologists say, could place so much stress on ecosystems that organisms of all kinds will face new challenges.
"When we see corals that have persisted for hundreds of years suddenly die from opportunistic infections, we have to wonder what has changed in their environment," says C. Drew Harvell, associate professor of ecology at Cornell.
organized a session, "Diseases of the Ocean: A New Environmental
Challenge," at the annual meeting of the American Association for the
Advancement of Science (AAAS) in Anaheim, Calif. on Jan. 22 to bring together
leading microbiologists, ecologists and pathologists to evaluate the
environmental threats from disease in the ocean. Speaking in the session was
Kiho Kim, a postdoctoral research associate with Harvell at Cornell, who
reported on an unusual disease in
said that monitoring of sea fan corals in the Keys, where up to 40 percent of
sea fans are infected by a fungal disease and many have already died, suggests
that lower water quality and higher ocean temperatures stress corals and
increase their susceptibility to disease. He said the
"We didn't begin our study of sea fans to monitor death and destruction," Harvell said. "Originally, we were interested in the natural disease-resistance properties of corals, such as the anti-bacterial and anti-fungal chemicals they produce, because some of those compounds may be useful in human medicine. That disease resistance normally keeps a coral alive for hundreds of years, despite living in an ocean full of potential pathogens."
said Garrett Smith of the
"Somehow, a soil pathogen that was best known for infecting aged and immune-compromised humans has crossed the land-sea barrier," Harvell said. "Now, one of our jobs is to discover what has compromised the resistance of the corals at some sites. Although a significant number of sea fans have died at a few sites, at many locales they recover from infections, pointing to the success of their natural resistance."
coral disease is reported throughout the Caribbean, the reef ecosystems of the
"Then you have rising water temperatures of the oceans," Harvell added. "Whether you believe that global warming is a function of human activity and whether last year's El Niño was a symptom of global warming, the fact is that sea temperatures globally in 1998 were high. And 1998 was the worst year ever recorded globally for coral bleaching."
Corals bleach (or lose their symbiotic algae) when stressed by high temperatures, Harvell explained, adding: "I think we have to question the relationship between temperature stresses and diseases of the oceans."
Lately in the
"With a very few exceptions, we know so little about the pathogenic organisms that are affecting the coral reefs," Harvell said. "We don't know if new diseases are emerging, if the hosts are becoming more susceptible or both. We need to identify these new diseases and we should do it now while we have the chance. Disease ecology is poorly understood in the ocean because diseases are like lightning strikes -- they hit unexpectedly, burn through a population, and then they are often gone."
and Kim conduct their studies from the Keys Marine Laboratory in Long Key, with
the assistance of Reef Relief in
VII Coral Killer Identified; Is Global Warming An Accomplice?
culprit responsible for killing sea-fan coral from the Florida Keys to
The group reports in the July 9 issue of the journal Nature that a fungus called Aspergillus sydowii has been responsible for the mass destruction of this coral over the last 15 years.
"Aspergillus sydowii is the fungus causing the disease that's
killing them," said John W. Taylor, UC Berkeley professor of plant and
microbial biology. "It's the same fungus throughout the
The sea fan -- a type of animal life, as are all corals -- is an extremely important component of coral reefs, said Ritchie. It hosts many reef organisms and provides a refuge for reef fish.
interesting about the attacking fungus Aspergillus sydowii, said
One explanation for this is that the fungus mutated in recent years to become more virulent. But more likely, the researchers said, the problem lies with the coral itself. They suspect that weakening of the sea-fan immune system or some other damage to the organism, possibly from changes in the environment, could be making the coral more vulnerable to infection. Thus, the marine creatures may no longer be able to fight off the fungus.
The fungus was identified by genetic studies of DNA taken from infected corals. The studies, done at UC Berkeley from samples provided by researchers at the other two institutions, placed the pathogen solidly among other known samples of A. sydowii, a well-known fungus described in the scientific literature in 1913 but undoubtedly in existence much earlier.
"It's a temptation when you see a new disease to think that you
have a new organism," said Taylor, a fungi expert. "But that's not
necessarily true." In this case, explained
The proof is that healthy sea-fan colonies exposed to A. sydowii from diseased tissue also come down with sickness, the researchers found. Alarmingly, the incidence of the coral reef disease "is increasing at a pretty intense rate," said Ritchie. "The reasons for this are highly debated and range from global warming to human factors like pollution and land run-off."
Generally, she said, "disease occurs most frequently in organisms that are stressed. If the sea fans are not healthy, that is an indication of trouble, and the reefs are certainly not healthy."
Aspergillus fungi have been found not only in Caribbean waters, but in
many other places including soil from
relative of penicillium, the fungus is well adapted to conditions of high salt
or other solutes, such as sugar. "If you open up a jelly jar in the
refrigerator and there's mold on it," said
Sea fans are made up of polyps -- small finger-like cylinders of tissue -- attached in a fan-like pattern to a central internal skeleton. Overlaid by the polyps, the inert skeleton supports all branches of a colony. The polyps produce blue-green spores for reproduction.
"Sea-fan colonies can get up to a meter and a half (about five feet) or even larger, (but) these are really old colonies," said Ritchie. "The colonies that we used for the inoculation experiments in our Nature article were small -- around 20 centimeters (about eight inches)."
species of sea fan, Gorgonia ventalin and Gorgonia flabellum, are found
disease has been reported in the Virgin Islands, Puerto Rico, the
"You can clearly see places where the coral has died," said
the coral, the researchers said not to look for any solutions soon. Even if
there were a safe, effective cure to rescue the sea fans, which at the moment
there doesn't appear to be, "I don't think it would be economically
possible to treat sea fans in their natural environment," said
"We need to understand what is making the infection possible. If we're lucky, it may be some kind of pollution or something else we could prevent. But if it's something like rising ocean temperature, good luck." - Kathleen Scalise
Coral reefs are specialized
habitats that provide shelter, food and breeding sites for numerous plants and
animals. They form a breakwater for the adjacent coast, providing natural
storm protection. They are very important to southeast
Coral reef development occurs only in areas with specific environmental characteristics: a solid structure for the base; warm and predictable water temperatures; oceanic salinities; clear, transparent waters low in phosphate and nitrogen nutrients, and moderate wave action to disperse wastes and bring oxygen and plankton to the reef.
YOUR HELP IS NEEDED
The tropical setting in
Every year careless boaters run aground,
destroying coral colonies that are hundreds of years old. Seen from the surface,
reefs have a unique golden-brown color. If you see brown, you may be about to
run aground. Be cautious when anchoring your boat. Do not deploy the anchor
directly in coral. Usually there are sandy areas close by; anchor in the sand.
Many popular reefs off
Anglers should avoid shallow coral reefs when trolling. Hooks can scar and injure the coral, leaving it vulnerable to infection by microscopic organisms that can kill the animals. When fishing for lobster, avoid placing traps on reefs. Heavy traps break corals and damage the bottom when the traps are pulled.
When diving or snorkeling, look, but do not touch!
Do not grasp, stand or sit on living coral. You may damage the coral and hurt
yourself in the process. All coral is protected. It is against the law to
collect, harvest or sell
Environmental Protection Florida Marine Research Institute
IX Crown-of-Thorns Starfish [Acanthaster planci ]
National Geographic March 1970 p527
Once they head down the windward side of the island, we’ll lose them,” the marine scientist shouted over the outboard’s roar. “It’s too rough out there for small boats.”
Sounds like a sheriff leading his posse after a
gang of outlaws, I thought, as we knifed along the northern coast of
Rare nocturnal predators only a decade ago, these spiny multipedes have undergone a mysterious population explosion and now, by day as well as by night, menace coral reefs in widely scattered areas of the Pacific.
Casualty List Spans Half an Ocean
The prickly starfish, known commonly as the crown-of-thorns and scientifically as Acanthaster planci, eats the tiny coral polyps that create such reefs. In a single day it can graze an area twice the size of its 6- to l2~inch central disk.
Acanthaster has killed more than 90
percent of the coral along 24 miles of
At last our scientist
skipper, Dr. Richard H. Chesher of the
We strapped on scuba gear and started down. Each of us carried a special hypodermic syringe with which to inject a fatal dose of formaldehyde solution into our prey.
I soon spotted the sea stars sixty feet below me. Their dark multi-armed bodies stood out clearly against the pale sea floor. I could see scores of them traveling in a herd about ten yards wide and perhaps a hundred yards long. Their orderly formation reminded me of a parade moving to the cadence of a band. But I was sure that these starfish marched only to the beat of their own private drum.
I dropped down for a close look at one and was again reminded of the aptness of the name “crown-of-thorns.” Dozens of sharp spines jut out from each of the animal’s arms as well as from the central disk. Besides simple pricking power, these thorns can poison: injuries from them sometimes cause swelling. pain, and even nausea.
I drew my knife and flipped a two-footwde creature onto its back. Its underside was covered with tiny yellow tube feet which enabled it to move in any direction.
Those tube feet, I soon discovered, function like suction cups. I lifted the star with my knife and tried to balance it on my underwater camera. It immediately wrapped its arms around the camera, enveloping everything but the strap. I used that to tow my living pincushion to the boat, where I had to use my knife again to break the grip of its arms and tube feet on the camera.
Spears Are the Answer on Small Atolls
“Man, I’ve never seen so many in one place before,” Mick gasped as he tried to catch his breath. “They were all over the place, moving as if they were playing follow-the-leader. It looked like a scene from a science-fiction movie—an invasion from inner space.”
can control the invasion here in
Driving home from the dock, Dr. Chesher told me that people living on low-lying Pacific islands face real danger as a result of the starfish’s depredations.
“When live coral is killed, reefs may break down,” he said. “Then storm waves might eventually eat away shorelines. But before this could happen, islanders might be forced to leave or starve. They get almost all their protein from the sea. Once the reefs die, food fish go too.”
The possibility that
such a disaster might strike the
But the team also studied the animal’s
behavior, particularly it’s eating habits. Dr. Ralph W. Brauer, of the
Wrightsville Marine BioMedical Laboratory in
I accompanied Dr. Brauer
and his two colleagues, David Barnes and Mike Jordan, on a collecting
expedition to an infested reef along
“Be careful when you handle these critters.” Dr. Brauer warned us. “I don’t want you to damage the animals or yourselves. Watch out for their spines!”
We headed for the bottom. Here the seafloor was covered with coral heads of all shapes and sizes, Only a few Acanthaster were feeding on top of the heads. Most of them were well hidden under the coral, to which they held firmly with their arms and tube feet. To remove the starfish, I used my knife with the care of a surgeon, heeding Dr. Brauers warnings as I worked.
Spines Can Cause Painful Wounds
The four of us shuttled back and forth between the raft and the coral heads on the bottom. On each trip up we brought one starfish to the surface, put it in a bucket on the raft, and headed back down for another.
On Mikes last trip to the surface, he handed a starfish to David, who was in the raft. A spine brushed David’s finger. Light as the touch was, it gashed his skin. David yelped. “Force the cut to bleed” Dr. Brauer told him, “get the stuff out of the wound. If you do it right away, you’ll have less pain later.”
When we released our starfish in glass walled tanks at the university, Dr. Brauer ran sea water over some living coral, filled a hypodermic syringe with the polyp flavored water, and squirted it under a starfish creeping up the glass wall.
Mistaking the coral taste for live coral, the starfish opened its mouth (located in the center of its underside) and everted its stomach. The fleshy digestive sac covered an area larger than a man’s palm.
Next Dr. Brauer placed a hungry starfish on a piece of living coral. Out came the
stomach. It spread over the coral polyps and its digestive juices began to dissolve them inside their limey shelters. After an hour, the polyps were reduced to semifluid shreds. Where colonies of colorful little animals had lived, there remained only a bleached white skeleton.
‘In a single night,” Dr. Brauer told me, ‘an adult starfish can clear off a coral head that might have taken fifty years to grow’.
Giant Tritons Prey on Stars
While such studies of
the sea star’s habits may lead eventually to a means of controlling the present
plague, some scientists are seeking more immediate solutions. Australian biologists,
concerned about the threat to the
“1 have calculated that
shell collectors took at least 100,000 tritons from the Great Barrier Reef
between 1949 and 1959,” says Dr. Robert Endean of the
Having once watched a giant triton devour an Acanthaster, I can vouch for its voraciousness. The triton first located the star with its two tentacles. The threatened starfish tried to creep away, but its pursuer chased it across a coral head and caught it. The mollusk first seized the starfish, holding it between shell and foot, then began to tear it to shreds and eat it. Several hours later, it ejected the spines.
isolated or somehow contained within a given coral area, the crown-of-thorns
soon curbs its own population explosion—at the cost of a totally dead reef. “.‘Acanthaster
become so numerous they eat themselves out of house and home,” explained Richard
Randall, an expert on the corals of the
While I browsed
through the dozens of coral-laden racks in his house on
Man May Have Set Off the Plague
Can a reef recover from a starfish attack? Mr. Randall is trying to find out.
Coral regeneration is difficult because the porous skeleton of a ruined reef is soon covered with algae which prevent new growth. Within two or three days the white skeleton becomes a dismal gray, coated with fuzz or festooned with long green strands.
No single theory
offered to date has adequately explained the starfish plague and its wide
distribution. Some scientists speculate that the population explosion has no
unusual cause but is only a natural periodic phenomenon. Other theories seem
valid for certain areas but not for others. Many Australian scientists are
convinced that over-collection of giant tritons created the plague on the
his office at the
Dr. Chesher explained that under normal conditions only a tiny percentage of the millions of eggs spawned by the female Acanthaster ever reach adulthood Many of the floating starfish larvae are devoured by living coral polyps. But when an area of reef is killed by man, the vulnerable larvae can settle upon it and mature in safety.
Because there is usually living coral immediately adjacent to the dead reef, the young adults have a ready food source once they begin to eat polyps. As the adult starfish destroy even more of the reef, they enlarge the sanctuary for their young. The result of the reaction is a population explosion,
for my hypothesis,” Dr. Chesher pointed out. “comes from the fact that
infestations in Guam,
residues washed into the oceans from the land.
Whatever the cause may prove to be, all the theories advanced so far—except that of natural periodic population growth—pointed to the activities of man. Whether by dredging or shell collecting, or pollution, this latest disturbance of the balance of nature seems be a further example of man’s disruption of his world.
Resource Guide by Mike Mullins Hillsborough CC 1989
THE PHYSICAL SETTING
200 emerald green islands make up the
To the west of this island arc are the
nutrient rich, shallow waters of
the Keys lie in the temperate zone about 70 miles north of the Tropic of
Cancer, they have a tropical climate due to the warming effect of the
TENTERATURE AND RAINFALL -
J F m A m J J A S 0 N D
TEMP. 71 72 73 75 77 79 80 81 79 75 73 71
PPT. 1.5 1.5 2.2 ,2.7 6.0 9.5 8.7 7.2 9.2 6.0 1.5 1.0
The dry season runs from October to April and the wet season begins in May and extends through September. Although this climatic pattern is fairly consistent throughout the Keys, occasional extreme weather conditions exist. During the summer, afternoon thundershowers are a significant factor in the weather.
rising column of air is created each summer day as the land heats up faster
than the surrounding water. This rising
air creates a localized low-pressure area over the islands. The area of low pressure is filled by air
rushing in across the water from both sides of the islands. This air is filled with water vapor, which
evaporates from the ocean surface more rapidly in the moving air. As this moisture rich air arrives over the
islands. it too rises. This cycle
creates a sea breeze. As the water vapor
rises. it begins to cool and condenses to form a cloud. This cumulus cloud grows until it reaches
cold air where the top flattens off forming a typical
Another significant weather factor during the summer is the hurricane. Tropical storms and hurricanes are a normal part of the summer in the Keys. Even when they do not hit the islands directly, they can make a major contribution to the summer rainfall. During historic times, several of these storms have had a major impact on the Keys.
A hurricane in 1622 sank the fabled Nuestra Senora de Atocha near the Marques islands off the western end of the Keys. In 1733 another hurricane scattered a Spanish treasure fleet along the reefs of the middle keys. Many of these reefs were later marked by lighthouses so that ships could detect their location during storms.
The most devastating storm to hit the keys in this century was the Labor Day hurricane of 1935. It battered the Middle Keys with 200 mile an hour winds. This storm left over 500 people dead in its wake including a large contingent of CCC workers who were killed when a rescue train was destroyed by high winds and waves. A monument was erected on Islamorada as a memorial to those who died in the storm. A second great storm, hurricane Donna in 1960, caused millions of dollars worth of property damage but thanks to advance warning, there was little loss of life.
In the winter, cold fronts
occasionally move down through the Keys from the mainland. When this cold arctic air slides in under the
warm, moisture rich tropical air, it can bring cold temperatures and set off
heavy rainstorms. A series of such
fronts dropped 23.3 Inches of rain on
Geologically, the Keys are a chain of small Iimerock islands witch average 3 to 4 feet above sea level in elevation. The maximum natural elevation of 18 feet is found on Lignum Vitae Key.
The keys are divided into two
distinct types of islands, which differ in shapes, orientation, and the
composition of their surface rocks. The
surface rocks of the upper Keys are composed of a collection of fossilized
coral reefs known as the Key Largo Formation.
This large fossilized reef system first outcrops at the surface at
Soldier Key in
The Key Largo Limestone Formation is the older of the two formations. It is a collection of fossilized coral reefs which vary in thickness from 35 to 180 feet. The ancient reef tract originated about 100,000 to 125,000 years ago during the geological epoch known as the Pleistocene. During this period sea level fluctuated several hundred feet as water was taken lip into glaciers and then released again as the glaciers melted.
The ancient reef system was
wider than the present reef system. In places it extended up to five miles
eastward to the edge of the continental shell Sea level at the time of its
formation was approximately 20 feet higher than it is at present. No islands existed to block the exchange of
water between the Gulf of Mexico and the
Over time, the slow growing corals
built a wide, nearly solid reef system about 150 miles long. Before the system could became a completely
solid reef, glacier formation began and sea level began to fall. The former
reefs were exposed to the air and became a string of islands. As sea level
continued to fall the ancient reef tract became a solid landmass which blocked
the flow of water between. the
At the end of the Pleistocene some 6,000
to 10,000 years ago. the last glaciers began to melt and sea level began to
rise. Most of the present day
About 3.500 ago sea level rose to
the point where
Whereas the Key Largo Limestone was created by the actions of sea animals, the Miami Oolite had chemical origins. Ooids are small egg shaped spheres of calcium carbonate. They are formed under ideal conditions in warm water seas.
Ooid formation begins when the
temperature of seawater reaches a level where calcium carbonate or lime can no
longer stay in solution. This chemical
begins to take on solid form in the water.
It begins to collect around tiny grains of sediment, microscopic plants
and animals or bacteria. The calcium
carbonate continues to collect in concentric layers until it reaches a mass
which causes the tiny egg-like particle to sink to the bottom. This process of ooid formation occurred over
a large portion of south
At a time when sea level was higher,
extensive areas of oolite ooze were deposited in the prehistoric
Both the Miami Oolite and the Key Largo Limestone have been greatly affected by their exposure above sea level. Some of the original limestone structure has been melted by the presence of tannic acids from the decay of plant leaves. The paste-like material has acted as cement to attach together the individual particles and to fill in the spaces between individual coral heads. At the same time, this acidic water has eroded portions of the limerock. This process has created pits, holes and even large solution cavities in the rock. These larger solution cavities form fresh water catch basins which serve as watering holes for terrestrial wildlife.
Because of the orientation of the
ancient reel the islands where the Key Largo Formations outcrops are long and
thin. Their general orientation is
northeast to southwest. The southern
oolitic islands are much different in shape and orientation. They are generally wider than the northern
islands and their orientation is northwest to southeast. The transition between these two types of
islands is best noted on Big Pine Key where the big island is Miami Oolite in
origin and the small string of islands which make up the
The unique climate and geology of the
The higher portions of the
Surrounding most of the islands
throughout the Keys are fringing mangrove forests. In some places, the mangroves are absent,
replaced by a rocky intertidal community.
In the shallow portions of
In the shallow water just beyond the edges of the mangrove community is found another community consisting of calcareous green algae growing on soft carbonate sand and mud. As the water gets slightly deeper, the type of algae changes to a soft green variety mixed with several species of sea grasses. With increased water depth, sponge and soft coral communities appear.
Scattered in a line between the islands and the outer fringing reef communities are mounds of large corals known as patch reef communities.
Of all the communities found in the Keys. It is the outer reefs which attract so many people to the islands. And, of all the organisms, it is this human species which will ultimately determine the ecology of this tropical paradise.
islands of the
Hammock is the name used to describe
the rich, green, jungle-like growth which originally covered all of the high
ground in the upper keys. This community is typically compose of less than a
dozen species of tropical hardwood trees and several species of palm. Almost all of these plants are of
As is the case with manv tropical
forests. the vegetation of the hammock community is divided into a series of
layers. The upper or canopy layer is
dominated by giant mahogany, tamarind, poison wood. Jamaican dogwood, mastic and gumbo limbo trees. The trees of the second layer include pigeon
plum, black ironwood, and satinleaf. The
third layer is dominated by cat claw and
Growing in and on the trees are a variety of epiphytes including orchids, bromeliads, resurrection fem and Spanish moss. Growing up from the ground into the trees are Virginia creeper, wild grape. nicker bean and cat briar vines. A unique parasite of the hammock is the strangler fig.
Among the abundant animal life of these
tropical hammocks are several types of swallowtail butterflies. blue land
crabs. several species of lizards, the Keys raccoon, and several endangered
species, the keys tree snails, the
The West Indian mahogany, Swietenia mahagoni grows to between 50
and 60 feet in height. This tree grows well in thin soils, limerock and brackish water conditions found
in the Keys. The West Indian Mahogany has a thick crown of
compound leaves with four to six leaflets.
The large seed pods contain winged seeds which are similar in appearance to maples trees. The wood of this mahogany tree is heavv, close-grained, hard,
strong and durable. It has a deep, dark
red-brown color which darkens with age.
This beautiful wood is highly
desirable for building and the mahogany tree has been cut since the coming of
the Spanish. As a result the
The gumbo limbo, Bursera simaruba, is one of the largest growing trees of the hammock. It can attain a girth of 10 ft. and a height of over 60 feet. The bark of the gumbo limbo is a rich reddish green. On mature trees it peels off in thin paper-like red sheets.
The lignum vitae. Guaiacum sancturyl now on the endangered species list. was once common enough in the keys hammocks to support a small commercial timber industry. Its extremely hard, dense wood was used for the bearings of prop driven steam ships.
The poison wood. Metopium toxiferuril is one of the most common trees in the hammock. it is also one of the trees to avoid. The sap and the black gum-like resin exuded when the bark is bruised are poisonous. Contact with human skin causes a rash similar to that produced by poison ivy. The poison wood is a pioneer plant and usually colonizes an area after a fire.
The strangler fig, Ficus aurea. which can grow from a seed planted in the ground, often begins life as an epiphyte growing in the boot of a cabbage palm. In time, it sends out a root which winds its way down the trunk of its host until it reaches the ground. As the roots grow downward, a thick crown of glossy green leaves is produced. Down from the spreading branches come a. large number of drop roots which support the increasingly dense foliage. As it continues. to grow the fig slowly, but completely, kills its host. '
The trees of the hammock typically have shallow root systems due to the thin layer of black soil spread over the solid rock below. Only a few of the roots penetrate through cracks in the rock to tap the freshwater lens below. The hammock vegetation protects the soil from erosion and moderates the temperature in the hammock through evaporation of water through openings in their large leaves.
The leaves which fall from these trees are decomposed by leafmold. This contributes humus to the sterile sandy soil. When the hammock vegetation is cleared, the soil nutrients are quickly lost and the land is largely unproductive.
Pine Rockland Forests
on the large,
The islands have an abundance of solution holes extending down from the surface into the water table. These breaks in the rocks provide homes and habitats for a number of freshwater plant and animal species. They also serve as water holes for animals such as the key deer and the rare white key raccoon.
In addition to the pines. a number of
other plants arc abundant in the pine rocklands. These include saw palmetto, key thatch
The pine rocklands are the home of the
diminutive key deer. These animals are
small subspecies of the
The pine rocklands environment is an
inviting one for building homes. As a
result, much of this habitat has been utilized for this purpose. This has created a problem for the deer herd. The development on the
THE MANGROVE FORESTS
term "Mangrove" is applied to a diverse group of tropical salt
tolerant trees which are abundant in the
Types of Mangrove Trees
are three species of mangroves found in
The red mangrove is the most noticeable of the three. It grows in the deepest water and its arching prop roots support the tree above the water as if it were walking on stilts. Wart-like lenticels on these prop roots provide openings where oxygen can be taken in and pumped through the system to the underground roots growing in the anaerobic mud. Since red mangroves grow close together, their roots form an impenetrable tangled network which slows down the movement of water underneath the trees. This causes a deposition of sediment and traps an enormous collection of debris. This build up of sediment and debris under the right conditions can create a thick layer of organic peat.
The leathery evergreen leaves of the red mangrove form a dense canopy which are highly efficient in converting sunlight to organic molecules. Sprinkled in among the leaves are yellow and white flowers. The red mangroves have an unusual reproductive adaptation enabling the seedling to survive in the watery environment. The seed germinates from the fruit while it is still attached to the parent tree. Many fruits with finger-like seedlings, often twelve or more inches in length, can be seen hanging in clusters. When mature, the seedlings break free from the fruit and fail into the water. Some may stick in the soft mud around the base of the parent tree and begin to grow. Many more float around with the tide. After floating in the water for a short period of time, the pointed end absorbs water and begins to sink. When the seedling becomes grounded in the mud, roots are quickly produced from the pointed end and the seedling begins to put out leaves.
In the keys, the black or honey mangrove usually forms a zone behind that of the red mangrove. This tree takes its name from its dark scaly bark. Black mangroves usually grow in soils that are exposed to the air at low tide but covered by high tide. Where they seldom experience frost, as in the Keys, black mangroves can develop into large trees over 50 feet tall. Their 2 to 4 inch long leaves are dark green above with silvery, hairy undersides. In these leaves there are special glands that excrete salt extracted from the water taken in by the roots. The salt often forms a white crust-like coating on their upper surface. Black mangroves have small white flowers which produce abundant nectar used by bees. They have no prop roots but their root system produces many slender upright aerating roots known as pneumatophores. They cover the muddy soil around the base of the tree and supply the root system with oxygen.
Black mangrove seeds are the size and shape of very large lima beans. They germinate as soon as they fall into the water. The seedlings are smaller than the red mangrove seedlings so they are washed farther up into the forest by tides. Here they become entangled in mats of detritus trapped by the mangrove roots and begin to grow.
White mangroves grow in sandy soils at the upper edge of the intertidal zone. Their round pale green leaves are notched at the tip and have a pair of salt excreting glands on either side of their petioles. The white mangroves have small peg roots which help anchor them in the sandy soil.
The small green seeds of the white mangroves begin to develop after they fall into the water. Over time they turn brown and wrinkled. Due to their small size, the white mangrove seeds are carried high in the swamp by the tide. When the seeds are finally deposited in the strand line, they germinate. The seedlings quickly put down roots and produce a pair of notched tip leaves.
Above the normal high tide line grows a relative of the white mangrove the buttonwood or grey mangrove. These trees get their name from their spherical berry-like fruits. Like the white mangrove, the buttonwood has salt glands on its leaf petioles. The buttonwood tree has a twisted trunk covered with a loose bark. The bark is a favored grow site for epiphytes.
On some of the lower keys, buttonwoods are found growing in depressions on the interior of the islands surrounded by hardwood hammock plants. Early residents of the Keys used the wood of these trees to make charcoal.
Types of Mangrove Forests
of different conditions of tide, substrate, freshwater runoff, nutrients and
exposure, a variety of types of mangrove forests exist throughout the
world. Two scientists,
Overwash mangrove islands are
abundant along the Florida Keys and in
Because of their isolation, mangrove overwash islands are an ideal habitat for the nests and roosts of coastal birds
Overwash mangrove islands:
1. Are overwashed by daily Tides
2. Have a high rate of organic export
3. Are dominated by red mangroves
mangrove forests grow along the shorelines of the
Fringing mangrove wetlands may intermix with basin mangroves behind them or may end abruptly at the top of a land berm. If the shoreline is steep, white, black and/or buttonwood trees-may grow behind the red mangrove and be considered part of the fringing mangrove system. On a gently sloping beach, the width of red mangroves may vary considerably.
Like the overwash islands, fringing mangrove forests harbor extensive communities of plants and animals on their roots. They also act as refuges for fish and other wildlife during periods of rough weather and heavy seas. These fringing forests protect the shoreline from storm damage and export a great amount of organic detritus into the Coastal lagoons.
Small areas of basin mangrove forests
occur in the Florida Keys, primarly on the
Dwarf mangrove forests are the first mangrove
areas encountered on the trip dowm U.S. 1 from
Ecological Value of Mangrove Forests
Every part of the mangrove forest, from the roots to the top most branches, which may reach as high as 60 feet, provide shelter or food for a multitude of creatures. These organisms range from tiny sand flies to large tarpon offshore.
One of the birds that finds its home in the tree tops of the mangroves is the brown pelican. The pelicans share their "rookeries" with egrets, herons, wood storks, ospreys, and cormorants.
A host of other creatures make use of the mangroves to forage. Racoons favor the coon oysters that live on the prop root of the red mangrove. Spiders weave many webs to catch unsuspecting insects; snakes slither up the tree trunks after birds' eggs and nestlings; and cormorants dine chiefly on the fish in the nearby waters. Fiddler crabs and their larger relatives the land crabs move out during the low tide to perform a large service. They aerate the soil as they probe the sediment for food, thereby increasing the supply of oxygen to the trees that attract the creatures.
However. when the tide comes in covering the roots and pneumatophores of the mangrove forest, it becomes part of a marine nursery. The mangrove forest provides a place where young fish. as well as other organisms such as blue crabs, are protected from predators and competing species which are unable to enter the lower salinity water. The young of herbivores and detritivores occur in hordes. Oysters, barnacles, and sponges along with the ribbed mussels are found in great Quantities in the mangrove root zone.
It is well documented that the mangrove forest plays an important role In the ecology of the Keys. The food chains and webs which begin in this rich habitat extend all the way out to the reel. They also serve as a nursery and spawning ground for many of the organisms which live in other key communities as adults. Lastly they provide protection for the delicate terrestrial communities from all but the most severe storms.
THE CORAL REEFS
Coral reefs are marine communities built of calcium carbonate secreted by a primitive types of animals called coral polyps In addition to the polyps. certain red and green algae, polychaetes, mollusks and bryozoans all play a role in the construction of coral reefs.
Coral reefs have been prominent features in the warm, shallow waters of the world ocean for over two billion years. They flourish in clear near-shore waters where the average annual temperature is at least 23.0 C. and seldom falls below 18.0 C. This puts them in a band that lies between the Tropic of Cancer and the Tropic of Capricorn. The warm water reduces the solubility of calcium carbonate and increases the ability of the corals to produce their skeletons. In addition to temperature, light, salinity, immersion, sedimentation, and substrate are the major factors influencing reef development.
Coral polyps are similar to small sea anemones. They have a circle of tentacles surrounding single body opening which serves as both a mouth and an anus. Their sac shaped bodies are composed of two cell layers and are internally divided into segments.
Polyps are nocturnal predators which feed on microscopic animals called zooplankton. They trap their prey with specialized cells located on their tentacles. These expode when an animal brushes against them releasing threads which stab, entangle or stick to the prey. The tentacles are also covered by cilia. In some species, a thick mucus curtain is secreted from the tentacles. Planktonic organisms become trapped in the mucus and the cilia transfer them from the tentacles to the mouth. In most species, the cilia sweep back and forth keeping the polyp free of silt and sediment.
The organisms which form the basic structure of today's coral reefs are known as hermatypic, or reef-building coral. These reef-building corals are colonial animals that differ from other members of their phylum (Cnidaria) primarily by the fact that each individual coral animal, or polyp, secretes a calcareous skeletal cup around its soft body. These delicate polyps can withdraw inside their rigid outer casing for protection. This hard casing is one reason why corals are often thought of as rock rather than the animals they are. In fact, the living polyps occupy only the upper few millimeters the massive limestone structures that their species have secreted and subsequently grown out of over the past millennia.
Algae known at zooxanthellae are as important to reef development as are the coral polyps. These tiny dinoflagellates in the genus Symbiodinium,live in the tissues of the hermatypic corals. They have a mutualisuc relationship with the coral polyps. The coral offers protection and nutrients to the zooxanthellae. The zooxanthehae remove metabolic waste and provide nutrients and oxygen to the coral. Zooxantheflae also aid in the calcification of the coral skeleton. It is only with the assistance of the zooxanthellae that the corals are able to form massive reefs. Environmental factors such as increased turbidity, reduced light, and fresh water effect the health of the zooxanthellae and thus the health of the corals.
In the waters of continental United
States individual coral colonies are found are found as far north as North
Carolina in the Atlantic and Cedar Key in the Gulf. They are also found off the
There are three types of coral reef
communities commonly found in the
A typical outer bank reef community is composed of three sections. The fore reef is composed of large heads of star (Montastrea), boulder and pillar coral. These thrive in the turbulence created by the waves. Behind the large colonies are found the branching elkhom coral and frequently a branching form of fire coral. In the shallowest portion of the outer reefs a ridge of the coralline red algae forms the reef crest which breaks up the action of the waves and protects the back side of the reef. On back reef the more delicate staghorn coral grows.
During storms, the reef crest takes a tremendous pounding. A great deal of coral may be broken off during this process and, occasionally, new channels may be carved through the reef. This creates a pattern called spur and groove. The impact from hurricanes and the constant pounding of the waves produce large quantities of sand from the coral skeletons.
Rising from the quiet lagoons behind the outer reefs is a different type of coral reef corrimunit3r called a patch reel Ms type of reef community is primarily composed of species of large brain corals overgrown in places by staghorn coral. The patch reefs also support numerous species of soft corals called gargonians.
In addition to corals, reefs are home to a large number of colorful and fascinating species. Blue tangs. Acanthurus coeruleus, and princess parrotfish, Scarus taeniopterus wander over the reef clipping or scraping algae from the reef surface. Herbivorous damselflsh defend their reef-top territories while trumpetfish, Aulostomus maculates, search for prey among the coral heads and waving gorgonians. Yellow goatflsh, Mulloidichthys martinicus , probe the sandy bottoms in search of food and spotted drum, Equetus punctatus, lurk under overhanging ledges.
Many symbiotic relationships exist between various species of reef fish. Pilot fish, Naucrates, form commensal associations with large sharks. Shrimpfish, Aeloiscus maintain a relationship with the sea urchin. Centrechinus, and the man-of-war fish, Nomeus, swims among the dangling tentacles of the Portuguese man-of-war, Physalia.
As alreadv mentioned, hurricanes and
tropical storms can devastate coral reefs.
Changes in water conditions can also take their toll. Mass bleaching (loss of zooxanthellac or
pigments) appears to be increasing in coral reef areas in both the Pacific and
4 - THE GRASS FLAT COMMUNITIES
grass flat communities occur both in
The Sea Grasses
There are several types of flowering
marine plants are found in the sea grass community of the
In the Keys, the sea grass community grows from near the low tide line to about 50 meters of water. This luxurious growth is possible due to the protective action of the reefs which reduce the wave energy.
Like many, land grasses, sea grasses have an underground stem known as rhizome. These grow horizontally, occasionally sending up a cluster of leaves and sending down a bundle of roots. The leaves of the grasses slow down the flow of water and cause a deposition of sediment.
The marine grass flat is a diverse community of plants and animals. The grass blades provide food for some organisms, refuge for many and a substrate for others. Like wise the sediment around and under the grasses provides a habitat which is exploited by a number of organisms.
wide blades of the turtle grass and the smaller blades of manatee, shoal and
star grasses provide a habitat for a variety of plants and animals. In the
The epiphytic animals found on sea grass leaves include both attached and mobile forms. The attached forms such as forams, hydroids, anemones, sponges, and bryozoans. These animals feed on both plankton and particulate detritus.
The mobile fauna are primarily crustaceans such as shrimp, amphipods, and isopods. These feed on the sea grass leaves as well as the other epiphytic Plants and animals.
Like the epiphytic organisms, the epifauna have both sessile and mobile forms.The sessile or attached animals include soft corals, hard corals, anemones, sponges and tunicates. Patches of finger corals. Porites porities, are frequently common in areas of the grass flats. Most of these sessile organisms feed on plankton and detritus.
The mobile epifauna are dominated by echinoderms. Sea stars. brittle stars, sea urchins, sea biscuits. sand dollars and sea cucumbers are all abundant. One echinoderm, the long-spined black urchin, Diadema antillarum, is a nocturnal feeder on sea grasses, but spends its days tucked into the nooks and crannies of coral reefs. This grazing pattern creates a zone of bare sand around the edges of the reefs. This "halo" Is especially evident around patch reefs which are usually surrounded by grass beds.
Another unusual group of echinoderms which are common in the sea grass beds are the sea cucumbers. Unlike most echinoderms which are radially symmetrical, the sea cucumbers are built bilaterally. The small ones resemble worms and the larger ones, which can stretch up to 3 ft. in length, resemble the vegetables for which they are named. Sea cucumbers feed on benthic detritus using five tentacles which protrude from their mouths.
The most common sea cucumber in the Key's sea grass community is the donkey dung, Holothuria mexicana. Each one eats huge volumes of sand each day and digest out the organic detritus. In its wake it leaves a collection of elongated whit fecal pellets about the size and shape of a human thumb.
The mollusks are also well represented in the in the epifaunal habitat. The large edible queen conch, Strombus gigas, from which the Key's natives take their nicknames, feeds on both epiphytes and benthic detritus. Th king helmet conch, Cassis tuberose, are active predators. They primarily feed on echinoderms with the sea egg urchin, Tilpneustes ventricosus, being their favorite prey.
The crustaceans are a common component of the sea grass epibenthic community. A variety of shrimp including grass, broken back, and commercial shrimp feed on epiphytes, infauna, and detritus. The spider crab is a seldom seen resident of the marine grass flat community.
The first people to live in the Keys were the Pre Columbian Indians. Anthropologist are not sure who these early groups Were but there evidence pointing to the Tequesta in the Upper Keys and the fierce Vescayno and Matecumbes Indians in the Lower Keys. There is very little evidence of permanent villages in the Keys but these frequent visitors left behind middens filled with the bones of fish, shellfish, turtles and manatees.
The natural resources harvested by the Indians were occasionally supplemented by supplies salvaged from the ships of the early Spanish explorers who fell victim to the treacherous coral reefs. ay the 1570's, when the Spanish began to explore the Keys, these early visitors had all but disappeared.
These early Indians who the Spanish
first encountered the Keys were replaced by the Calusa which ruled much of the
The last Indians who visited the Keys were the Seminoles. They raided Indian Key on August 7, 1840 in retaliation for bounty hunting of members of their tribe by a resident, Jacob Houseman.
The Spanish explorer, Juan once de Leon discovered the Keys during his 1513 expedition. With a dramatic flair he named them Los Martires,.the martyrs, because they appeared to have a twisted and tortured shape. The Spanish interest in the islands was limited. They logged out both hardwood and pine trees but did not establish any permanent settlements. There wasn't any gold, there was very little fresh water and there were hordes of mosquitoes. Their principal interest was in mapping the reefs which took a great toll on the Spanish treasure fleets.
For several centuries the keys were used
by a variety of pirates and wreckers who sometimes attacked Spanish shipping
but who more frequently plundered ships that wrecked on the reefs. Many of these were "conchs", They
were descendents of Englishmen who settled Eleuthera and the
The Teal pirates, such as Blackbeard and his lueitenant Black Caesar, continued to prey on shipping. The situation remained bad enough however, that in 1822 the United States Navy sent its West Indian Squadron of eight small shallow draught schooners under the command of Commodore David Porter. This small determined group soon made the Keys an unsafe place to be a pirate. One of these brave ships, the USS Alligator, went aground off Matecumbe Key on a reef which now bears its name. The ship was blown up by its own crew to prevent it falling into pirate hands.
Many former pirates turned to the
practice of wrecking. The salvaged cargo
was taken to
The Spanish name for Indian Key was
The island was home to Dr. Henry
Perrine, a physician who was also a botanist. He
imported many plants to the island, many from
By 1840, the town of
On August 7, of 1846, the Indians took advantage of the fleet being away and attacked the island. They burned most of the buildings and killed sixteen of the residents including Dr. Perrine who tried to plead with them to stop the attack. Many of the people including Dr. Perrine's family and Houseman survived by hiding in the water filled cisterns underneath their burning houses.
In, 1832 when Indian Key was just
beginning as a town it was visited by a budding birder and artist John James
Audubon. He continued on to Key Vaca,
Where as the wreckers of the Keys found the reefs an aid to profit the owners of the wrecked ships did not. They demanded that the federal government provide navigation aids to make the passage along the Keys safer. A string of light ships were anchored along the reefs, but there were they were insufficient. Their lights were weak and they were frequently either blown off the reef or wrecked themselves during storms. From 1850 to 1880 a string of seven steel light houses were built on the most dangerous reefs. These' employed a unique construction. A series of steel piles were screwed into the bed rock of the reefs. The lighthouse was then attached to these structures. The spider leg support allowed storm waves to pass through the lighthouse with out doing much damage.
At the close of the War Between the States
in 1865, the key played a part in history.
They were the pipeline through which Judith P. Benjamin, the Confederate
Secretary of State was smuggled to safety in the
The Keys Have been the home of many entrepheurs. Plantations which grew pineapples, tomatoes and coconuts briefly flourished throughout the Kevs. Most of the failed due to poor soil, mosquitoes, hurricanes or a combination there of.
In the 1880's Vincent Ybor
established a cigar industry in
Around the turn of the century sponging became important in the Keys. The rich sponge beds provided a high yield cash crop. They were harvested from boats with three pronged hooks and glass bottom buckets. Financial problems created by World War I and finally the sponge blight finished the industry in the 20's and it moved to Tarpon Springs.
In 1904, Henry Flagler, president of
the Florida East Coast Railroad realized the economic advantage of having a
railhead close to the Panama Canal and only 90 miles from Cuba. He gave to go ahead to extend his railroad
south from the farming community of
In March of 1926, bond sales were
approved by the voters to begin construction of an overseas highway linking
1.How old is the recent Caribbean Coral Reef System?
2. That “Coral reefs are highly susceptible to disturbance in relation to other nearshore ecosystems” Is this fact or opinion? Where could you check this statement?
3What is an endodermal symbiont?
4. List 5 socioeconomic importance’s of coral reefs and give an example of each.
5. How are reefs a buffer for the CO2 cycle?
6. What 3 human activities threaten
7. What part of oil is the most harmful to corals?
8. How does upland clearing effect coral reef?
9. How does sewage discharge effect coral reefs?
10. The statement on page 16-G. Anchoring “Standing and walking over coral and coral collecting can also ruin large portions of the reefs..”is this fact or opinion and explain.
11. What type of damage was observed from military activities on the reef?
12. Where is this place?
13. How can overfishing---fish, not coral, effect
14. Can these coral reefs recover...explain.
15. Summarize the 6 recommendations the author makes.
16. The discovery of what about coral has made the destruction of reefs an international interest?
1. What is the most diverse marine ecosystem in the world?
Where do you find
Where, when and why was the
4. What human effect can harm corals?
5. What is meant by prop-dredge?
6. What is the saying for boaters around reefs?
7. What is the uses and benefits of a mooring buoy?
8. How much of the reefs may be killed in our lifetime?
9. List the serious threats to the reef.
10. What is IYOR...when was it and what was done?
3 Are Storms Killing Coral?
1. How much dust is
blowing from North Africa to the
2. List how this dust can harm the corals?
3. What organisms may benefit from this dust?
4. What is found in the dust?
5. How is the dust tracked?
11. What animals play a large role in taking CO2 out of the atmosphere?
12. What species was studied?
13. When did bleaching peak?
14. What were effects of bleached foraminifera?
15. What did Hallock speculate caused the bleaching?
5a 1st Casulaty of CO2 Emissions Name.................................................pd....
16. How much has the CO2 levels risen since 1700?
17. What has lead to this increase?
18. What happens when corals are stressed?
19. What is this result known as?
20. Where did they discover how acidity interfered with the growth of coral reefs?
21. What is this acidity effect on corals?
22. What happens to the 2 gigatons of CO2 a year?
23. Why are corals suddenly getting diseases?
24. What causes sea fan disease?
25. Why is the sea fan important?
26. Give 2 reasons the seafan is now getting this disease?
27. What 2 species of seafans are found in the keys?
28. What attiude does the author take if the cause is found to be from pollution? Rising sea temperature?
Read the statements carefully. If it is stated in the article, put TRUE...if not, put False. Refer to these statements for part 2 as well.
..........1. Coral-killing starfish are destroying living reefs that shelter coastlines from continual pounding of the sea.
...........2. Acanthaster planci may be used to control a population explosion that threatens coral reefs.
...........3. Scientists are following the spread of the crown-of-thorn starfish.
............4. A major tactic in dealing with the crown-of-thorns starfish involves hunting and killing the animals by man.
............5. Dead reefs pose few problems to the islands they surround.
...........6. Shell collectors took at least 100,000
tritons from the
............7. Blasting for channels and channel dredging kills the coral animals.
..........8. Animal populations in nature tend to fluctuate.
..........9. Pollution may have an effect on corAl reef growth.
Science deals with causes and effects. Effects are visable things brought about by a cause. They are the results. The cause produces the effect. Most of the true statements above are either cause or effect statements. Select the cause and effect statements and put the number below the proper heading.
Causes listed above should be testable using scientific method (causes could be formulated as an hypothesis). Read the statements below releating to the details and authors interpretations drawn from the selection and write the number of the causes (from the 1st part) the statement is designed to test.
..........16. Austrailian biologists are raising tritons
for future release as adults along the
..........17. Marine Biologists in Guam and
..........18. Scientists in
1. What causes the keys to have a tropical climate?
2. How does a tropical wet-dry climate differ from a tropical wet climate?
3. When is the dry season in the keys?
4. How do the afternoon summer thundershowers form?
5. Describe the most devastating hurricane that ever hit the keys?
6. What is the highest natural elevation in the Keys? What is the average?
7. What are the two distinct types of islands found in the Keys and describe the differences between them?
8. Describe the different types of trees throughout the Keys.
9. What is the existence of slash pines growing an indicator of?
10. What problems do mangrove trees have to cope with?
11. What are the three species of mangroves in the Keys?
12. Distinguish between these species.
13. What is a pneumatophore.
14. What is an overwash mangrove island?
15. List 3 functions of the fringing mangrove forests.
16. What organisms play a role in the construction of the reef?
17. What environmental factors are bad for the zooxanthellae?
Why do the reefs off
19. Name the three types of reef communities commonly found in the Keys.
20. What types of coral are located on the fore reef?
Which is more delicate, staghorne or
22. What is a gargonian and where are they usually found?
23. Name 3 fish found living in a symbiotic relationship with another organism?
24. What may be bringing about mass bleaching?
25. What is the most dominant species of sea grass?
26. What causes the zone of bare sand around edges of reefs?
27. How do fish use the grass flat community?
28. What happened on Aug. 7, 1840?
29. What was the principle interest the Spanish had in the Keys?
30. What strange practice became a major industry in the Keys?
How did Jacob Houseman avoid the salvage rules and fees of
32. How were the lighthouses constructed over the reefs?
33. What mistake had the engineers building the railroad made when the 1st hurricane destroyed part of it in 1909?
34. What replaced the railroad in 1935 after the hurricane?
35. Who built the railroad?