Coral reef

Formation

See also: Fringing reef, Atoll reef, and The Structure and Distribution of Coral Reefs

Most coral reefs were formed after the last glacial period when melting ice caused the sea level to rise and flood the continental shelves. This means that most coral reefs are less than 10,000 years old. As coral reef communities were established on the shelves, they built reefs that grew upwards, keeping pace with the rise in sea level. Reefs that didn’t keep pace could become drowned reefs, covered by so much water that there was insufficient light for further survival.

Coral reefs are also found in the deep sea away from the continental shelves, around oceanic islands and as atolls. The vast majority of these ocean coral islands are volcanic in origin. The few exceptions have tectonic origins where plate movements have lifted the deep ocean floor on the surface.

In 1842 Charles Darwin published his first monograph, The Structure and Distribution of Coral Reefs. There he set out his theory of the formation of atoll reefs, an idea he conceived during the voyage of the Beagle. His theory was that atolls were formed by the uplift and subsidence of the Earth’s crust under the oceans. Darwin theory sets out a sequence of three stages in atoll formation. It starts with a fringing reef forming around an extinct volcanic island as the island and ocean floor subsides. As the subsidence continues, the fringing reef becomes a barrier reef, and ultimately an atoll reef.

Darwin theory starts with a volcanic island which becomes extinct

As the island and ocean floor subside, coral growth builds a fringing reef, often including a shallow lagoon between the land and the main reef

As the subsidence continues the fringing reef becomes a larger barrier reef further from the shore with a bigger and deeper lagoon inside

Ultimately the island sinks below the sea, and the barrier reef becomes an atoll enclosing an open lagoon

A fringing reef can take ten thousand years to form, and an atoll can take up to 30 million years

A small atoll in Maldives.

Darwin predicted that underneath each lagoon would be a bed rock base, the remains of the original volcano. Subsequent drilling has proved this correct. Darwin’s theory followed from his understanding that coral polyps thrive in the clean seas of the tropics where the water is agitated, but can only live within a limited depth of water, starting just below low tide. Where the level of the underlying land stays the same, the corals grow around the coast to form what he called fringing reefs, and can eventually grow out from the shore to become a barrier reef. Where the land is rising, fringing reefs can grow around the coast, but coral raised above sea level dies and becomes white limestone. If the land subsides slowly, the fringing reefs keep pace by growing upwards on a base of dead coral, forming a barrier reef enclosing a lagoon between the reef and the land. A barrier reef can encircle an island, and once the island sinks below sea level a roughly circular atoll of growing coral continues to keep up with the sea level, forming a central lagoon. Barrier reefs and atolls don’t usually form complete circles, but are broken in places by storms. Should the land subside too quickly or sea level rise too fast, the coral dies as it is below its habitable depth.

In general, the two main variables determining the geomorphology, or shape, of coral reefs are the nature of the underlying substrate on which they rest, and the history of the change in sea level relative to that substrate.

As an example of how coral reefs have formed on continental shelves, the current living reef structure of the Great Barrier Reef began growing about 20,000 years ago. The sea level was then 120 metres (390 ft) lower than it is today. As the sea level rose, the water and the corals encroached on what had been the hills of the coastal plain. By 13,000 years ago the sea level was 60 metres (200 ft) lower than at present, and the hills of the coastal plains were, by then, continental islands. As the sea level rise continued most of the continental islands were submerged. The corals could then overgrow the hills, forming the present cays and reefs. The sea level on the Great Barrier Reef has not changed significantly in the last 6,000 years, and the age of the present living reef structure is estimated to be between 6,000 and 8,000 years. Although the Great Barrier Reef formed along a continental shelf, and not around a volcanic island, the same principles apply as outlined by Darwin’s theory above. The Great Barrier Reef development has stopped at the barrier reef stage, since Australia is not about to submerge. It has formed the world’s largest barrier reef, 3001000 metres (330-1100 yards) from shore, and 2,000 kilometres (1,200 mi) long.

Healthy coral reefs grow horizontally from 1 to 3 centimetres (0.39 to 1.2 in) per year, and grow vertically anywhere from 1 to 25 centimetres (0.412 in) per year; however, they are limited to growing above a depth of 150 metres (490 ft) due to their need for sunlight, and cannot grow above sea level.

Types

The three principal reef types are:

Fringing reef a reef that is directly attached to a shore or borders it with an intervening shallow channel or lagoon.

Barrier reef a reef separated from a mainland or island shore by a deep lagoon.

Atoll reef a more or less circular or continuous barrier reef extending all the way around a lagoon without a central island.

Other reef types or variants are:

Patch reef an isolated, comparatively small reef outcrop, usually within a lagoon or embayment, often circular and surrounded by sand or seagrass. Patch reefs are common.

Apron reef a short reef resembling a fringing reef, but more sloped; extending out and downward from a point or peninsular shore.

Bank reef a linear or semi-circular shaped-outline, larger than a patch reef.

Ribbon reef a long, narrow, somewhat winding reef, usually associated with an atoll lagoon.

Table reef an isolated reef, approaching an atoll type, but without a lagoon.

Inhabited cay in the Maldives

Microatolls certain species of corals form communities called microatolls. The vertical growth of microatolls is limited by average tidal height. By analysing the various growth morphologies, microatolls can be used as a low resolution record of patterns of sea level change. Fossilized microatolls can also be dated using radioactive carbon dating. Such methods have been used to reconstruct Holocene sea levels.

Cays small, low-elevation, sandy islands formed on the surface of a coral reef. Material eroded from the reef piles up on parts of the reef or lagoon, forming an area above sea level. Plants can stabilize cays enough for them to be habitable by humans. Cays occur in tropical environments throughout the Pacific, Atlantic and Indian Oceans (including in the Caribbean and on the Great Barrier Reef and Belize Barrier Reef), where they provide habitable and agricultural land for hundreds of thousands of people. Their surrounding reef ecosystems also provide food and building materials for island inhabitants.

When a coral reef cannot keep up with the sinking of a volcanic island, a seamount or guyot is formed. Seamounts and guyots are below the surface of the ocean and may host many species, depending on their location and depth. Seamounts are rounded at the top and guyots are flat. The flat top of the guyot, also called a tablemount, is due to erosion by waves, winds, and atmospheric processes.

Distribution

Locations of coral reefs.

Boundary for 20 C isotherms. Most corals live within this boundary. Note the cooler waters caused by upwelling on the south west coast of Africa and off the coast of Peru.

This map shows areas of upwelling in red. Coral reefs are not found in coastal areas where colder and nutrient rich upwellings occur

Coral reefs are estimated to cover 284,300 square kilometers (109,800 sq mi), which is just under one percent of the surface area occupied by the world oceans. The Indo-Pacific region (including the Red Sea, Indian Ocean, Southeast Asia and the Pacific) account for 91.9% of this total. Southeast Asia accounts for 32.3% of that figure, while the Pacific including Australia accounts for 40.8%. Atlantic and Caribbean coral reefs only account for 7.6%.

Although corals exist both in temperate and tropical waters, shallow-water reefs form only in a zone extending from 30 N to 30 S of the equator. Tropical corals do not grow at depths of over 50 meters (160 ft). The optimum temperature for most coral reefs is 2627 C, and few reefs exist in waters below 18 C. However reefs in the Persian Gulf have adapted to temperatures of 13 C in winter and 38 C in summer.

Deep water coral is more still exceptional since it can exist at greater depths and colder temperatures. Although deep water corals can form reefs, very little is known about them.

Coral reefs are rare along the American west coast, as well as along the African west coast. This is due primarily to upwelling and strong cold coastal currents that reduce water temperatures in these areas (respectively the Peru, Benguela and Canary streams). Corals are seldom found along the coastline of South Asia from the eastern tip of India (Madras) to the border of Bangladesh and Myanmar. They are also rare along the coast around north-eastern South America and Bangladesh due to the freshwater release from the Amazon and Ganges Rivers respectively.

Principal coral reefs and reef areas of the world

The Great Barrier Reef – largest coral reef system in the world, Queensland, Australia.

The Belize Barrier Reef – second largest in the world, stretching from southern Quintana Roo, Mexico along the coast of Belize to the Bay Islands of Honduras.

The New Caledonia Barrier Reef – second longest double barrier reef in the world, with a length of about 1,500 kilometers (930 mi).

The Andros, Bahamas Barrier Reef – third largest in the world, following the east coast of Andros Island, Bahamas, between Andros and Nassau.

The Red Sea Coral Reef – located off the coast of Israel, Egypt, Sudan, Eritrea, Djibouti, Somalia, Jordan, Saudi Arabia, and Yemen.

Pulley Ridge – deepest photosynthetic coral reef, Florida.

Numerous reefs scattered over the Maldives.

Ghe Raja Ampat Islands in Indonesia’s West Papua province offer the highest known marine diversity.

Biology

Anatomy of a coral polyp.

See also: Coral

Live coral should be thought of as small live animals embedded in calcium carbonate. It is a mistake to think of coral as plants or rocks. Coral consists of accumulations of individual animals called polyps, arranged in diverse shapes. Polyps are usually tiny, but they can range in size from a pinhead to a foot across. Reefs grow as polyps along with other organisms deposit calcium carbonate, the basis of coral, as a skeletal structure beneath and around themselves, pushing the coral’s “head” or polyps upwards and outwards. Waves, grazing fish (such as parrotfish), sea urchins, sponges, and other forces and organisms break down coral skeletons into fragments that settle into spaces in the reef structure. Many other organisms living in the reef community contribute skeletal calcium carbonate in the same manner. Coralline algae are important contributors to reef structure in those parts of the reef subjected to the greatest forces by waves (such as the reef front facing the open ocean). These algae deposit limestone in sheets over the reef surface, thereby strengthening it.

Reef-building or hermatypic corals are only found in the photic zone (above 50 m depth), the depth to which sufficient sunlight penetrates the water for photosynthesis to occur. Coral polyps do not photosynthesize, but have a symbiotic relationship with single-celled organisms called zooxanthellae; these cells within the tissues of the coral polyps carry out photosynthesis and produce excess organic nutrients that are then used by the coral polyps. Because of this relationship, coral reefs grow much faster in clear water, which admits more sunlight. Indeed, the relationship is responsible for coral reefs in the sense that without their symbionts, coral growth would be too slow for the corals to form impressive reef structures. Corals get up to 90% of their nutrients from their zooxanthellae symbionts.

Table coral

Close up of polyps arrayed on a coral, waving their tentacles. There can be thousands of polyps on a single coral branch.

Corals can reproduce both sexually and asexually. An individual polyp may use both reproductive modes within its lifetime. Corals reproduce sexually by either internal or external fertilization. The reproductive cells are found on the mesentery membranes that radiate inward from the layer of tissue that lines the stomach cavity. Some mature adult corals are hermaphroditic; others are exclusively male or female. A few even change sex as they grow.

Internally fertilized eggs develop in the polyp for a period ranging from days to weeks. Subsequent development produces a tiny larva, known as a planula. Externally fertilized eggs develop during synchronized spawning. Polyps release eggs and sperm into the water simultaneously. Eggs disperse over a large area. Spawning depends on four factors: time of year, water temperature, and tidal and lunar cycles. Spawning is most successful when there is little variation between high and low tides. The less water movement, the better the chance for fertilization. Ideal timing occurs in the spring. Release of eggs or planula larvae usually occurs at night and is sometimes in phase with the lunar cycle (36 days after a full moon). The period from release to settlement lasts only a few days, but some planulae can survive afloat for several weeks (7, 14). They are vulnerable to heavy predation and adverse environmental conditions. For the lucky few who survive to attach to substrate, the challenge comes from competition for food and space.

There are about one thousand species of coral, which build different shapes such as wrinkled brains, cabbages, table tops, stag antlers, wire strands and pillars.

Brain coral

Staghorn coral

Spiral wire coral

Pillar coral

Darwin’s paradox

Darwin’s paradox

Coral… seems to proliferate when ocean waters are warm, poor, clear and agitated, a fact which Darwin had already noted when he passed through Tahiti in 1842.

This constitutes a fundamental paradox, shown quantitatively by the apparent impossibility of balancing input and output of the nutritive elements which control the coral polyp metabolism.

Recent oceanographic research has brought to light the reality of this paradox by confirming that the oligotrophy of the ocean euphotic zone persists right up to the swell-battered reef crest. When you approach the reef edges and atolls from the quasi-desert of the open sea, the near absence of living matter suddenly becomes a plethora of life, without transition. So why is there something rather than nothing, and more precisely, where do the necessary nutrients for the functioning of this extraordinary coral reef machine come from ? Francis Rougerie

During his voyage on the Beagle, Darwin described tropical coral reefs as oases in the desert of the ocean. He reflected on the paradox that tropical coral reefs, which are among the richest and most diverse ecosystems on earth, flourish when they are surrounded and supported by tropical ocean waters that provide hardly any nutrients. It has been a challenge for scientists to explain this paradox.

Coral reefs cover just under one percent of the surface of the world ocean, yet they support over one-quarter of all marine species. This huge number of species results in complex food webs, with large predator fish eating smaller forage fish that eat yet smaller zooplankton and so on. However, all food webs eventually depend on plants, which are the primary producers. And the primary productivity on a coral reef is very high, resulting in a typical biomass production of 5-10g C m2 day1.

Tropical waters are often described as crystal clear. This is because they are deficient in nutrients and drifting plankton. The sun shines year round in the tropics, warming the surface ocean layer so it is less dense than subsurface layers. The warmer water is separated from the cooler water by a stable thermocline, where the temperature makes a rapid change. This keeps the warm surface waters floating above the cooler deeper waters. There is little exchange between these layers. Organisms that die in aquatic environments generally sink to the bottom where they decompose. This decomposition releases nutrients in the form of nitrogen, phosphorus and potassium. These nutrients, N, P and K, are necessary for plant growth, but in the tropics they are not directly recycled back to the surface.

Plants are the base of the food chain, and need sunlight and nutrients if they are to grow. In the ocean these plants are mainly a type of plankton, microscopic phytoplankton which drift in the water column. They need sunlight for photosynthesis, which powers carbon fixation, so they are found only in the surface waters. But they also need nutrients. Phytoplankton rapidly use any nutrients in the surface waters, and in the tropics these nutrients are not usually replaced because of the thermocline.

Coral polyps

The situation with coral reefs is different. The lagoons that are formed by the upward growth of coral reefs fill in with material eroded from the reef and the island. They become havens for marine life, providing protection from waves and storms.

Most importantly, nutrients are recycled, and not lost like they are in the open ocean. In coral reefs and lagoons, the producers include phytoplankton as well as marine worms, seaweed, and coralline algae, especially small types called turf algae, which pass their nutrients to the corals. The phytoplankton are eaten by fish and crustaceans, who also pass nutrients along the food web. Recycling ensures that fewer nutrients are needed overall to support the community.

Corals harbour numerous symbiotic organisms. In particular, there is a remarkable symbiosis between coral and a microscopic algae, the single cell dinoflagellate known as a zooxanthella. The zooxanthella forms an endosymbiosis with a coral polyp, that is, it lives within the tissues of the polyp. There it absorbs solar energy with special pigments, using photosynthesis to supply the polyp with organic nutrients in the form of glucose, glycerol, and amino acids. Zooxanthellae can provide up to 90% of a coral energy requirements. In return, as an example of mutualism, the coral provides the zooxanthellae, averaging one million for every cubic centimetre of coral, with a relatively safe place to live and a constant supply of the carbon dioxide it needs for photosynthesis.

Corals are nocturnal feeders. Here, in the dark, coral polyps have extended their tentacles to feed on zooplankton

The colour of corals depends on the type zooxanthella they host

Corals also absorb nutrients, including inorganic nitrogen and phosphorus, directly from the water. Many corals extend their tentacles at night to catch zooplankton that brush them when the water is agitated. Zooplankton provides the polyp with nitrogen, and the polyp shares some of the nitrogen with the zooxanthellae, which also require this element. The pigments in different species of zooxanthellae give corals their different colours. Coral which loses its zooxanthellae becomes white and is said to be bleached, a condition which unless corrected can lead to the death of the coral.

A 2001 paper reported that sponges are another key to explaining Darwin paradox. These sponges live in crevices in the coral reefs. They are efficient filter feeders, and in the Red Sea they consume about sixty percent of the phytoplankton that drifts by. The nutrients the sponges absorb from the phytoplankton are then excreted in a form the corals can use.

Researchers in 2002 explained why coral thrives better in agitated waters. They found the roughness of coral surfaces is the key. Normally there is a boundary layer of still water around a submerged object which acts as a barrier. But when waves break on the extremely rough edges of corals the boundary layer is disrupted, allowing the corals access to the few nutrients that are there. The researchers claim that turbulent water promotes rapid reef growth and lots of branching. Although coral ecosysemss are great at recycling, with the wastes of one species becoming the food of another, the researchers also claim that, without the nutritional gains achieved by rough coral surfaces, even the most effective recycling would leave corals wanting in nutrients.

In 2004, another symbiotic organism, a bacteria called Cyanobacteria, was discovered to provide soluble nitrates for the reef via nitrogen fixation.

Coral reefs also often depend on other habitats, such as seagrass meadows and mangrove forests in the surrounding area for the supply of nutrients. Seagrass and mangroves supply dead plants and animals which are rich in nitrogen and also serve to feed fish and animals from the reef by supplying wood and vegetation. Reefs in turn protect mangroves and seagrass from waves and produce sediment for the mangroves and seagrass to root in.

Zones

Coral reef ecosystems contain a number of distinctive zones that represent different kinds of habitats for fishes and invertebrate animals. Usually, three major zones are recognized: the fore reef (outermost and deepest part of the reef), reef crest (shallowest and narrowest zone over which ocean waves break), and the back reef (behind the reef crest and closest to shore, with calm protected waters) which is also frequently referred to as the reef lagoon.

All three zones are physically and ecologically interconnected to some extent, with reef life and oceanic processes creating ample opportunities for exchange of ocean water, sediments, nutrients, and marine life between one another.

Thus, they should properly be viewed as integrated components of the coral reef ecosystem, each playing a role in the support of the abundant and diverse fish assemblages that characterize coral reefs.

Most coral reefs exist in shallow waters less than fifty metres deep. Some are found on tropical continental shelves where cool, nutrient rich upwelling does not occur, such as Great Barrier Reef. Others are found in the deep ocean surrounding islands or as atolls, such as in the Maldives. The reefs surrounding islands form when islands subside into the ocean, and atolls form when an island subsides below the surface of the sea.

Moyle and Cech distinguish six major zones, though most reefs posses only some of the zones.

Water in the reef surface zone is often agitated. This diagram represents a reef on a continental shelf. The water waves at the left travel over the off-reef floor until they encounter the reef slope or fore reef. Then the waves pass over the shallow reef crest. When a wave enters shallow water it shoals, that is, it slows down and the wave height increases.

The reef surface is the shallowest part of the reef. It is subject to the constant surge of waves and the rise and fall of tides. When water waves pass over shallow areas, they shoal, as shown in the diagram at the right. This means that the water in the reef surface zone is often agitated. These are the precise condition under which coral flourish. Shallowness means there is plenty of light for photosynthesis, and agitated water promotes the ability of coral to feed on plankton. However other organisms, such as fish and invertebrates, must be able to withstand the robust conditions to flourish in this zone.

The off-reef floor is the shallow sea floor surrounding a reef. This zone applies to reefs on continental shelves. Reefs around tropical islands and atolls drop abruptly to great depths, and don’t have an off-reef floor. Usually sandy, the off-reef floor often supports seagrass meadows which are important foraging areas for reef fish.

The reef drop-off is, for its first 50 metres, habitat for many reef fish who find shelter on the cliff face and plankton in the water nearby. The drop-off zone applies mainly to the reefs surrounding oceanic islands and atolls.

The reef face is the zone above the reef floor or the reef drop-off. “It is usually the richest habitat for fish and invertebrates. Its complex growths of coral and calcareous algae provide innumerable cracks and crevices for protection, and the abundant invertebrates and epiphytic algae provide an ample source of food.”

The reef flat sandy bottomed flat can be behind the main reef, containing chunks of coral. “The reef flat may be a protective area bordering a lagoon, or it may be a flat, rocky area between the reef and the shore. In the former case, the number of fish species living in the area often is the highest of any reef zone.”

The reef lagoon “many coral reefs completely enclose an area, thereby creating a quiet-water lagoon that usually contains small patched of reef.”

However, the “topography of coral reefs is constantly changing. Each reef is made up of irregular patches of algae, sessile invertebrates, and bare rock an sand. The size, shape and relative abundance of these patches changes from year to year in response to the various factors that favour one type of patch over another. Growing coral, for example, produces constant change in the fine structure of reefs. On a larger scale, tropical storms may knock out large sections of reef and cause boulders on sandy areas to move.” (Connell 1978)

Biodiversity

Tube sponges attracting cardinal fishes, glassfishes and wrasses

Reefs are also home to a large variety of other organisms, including fish, seabirds, sponges, Cnidarians (which includes some types of corals and jellyfish), worms, crustaceans (including shrimp, cleaner shrimp, spiny lobsters and crabs), molluscs (including cephalopods), echinoderms (including starfish, sea urchins and sea cucumbers), sea squirts, sea turtles and sea snakes. Aside from humans, mammals are rare on coral reefs, with visiting cetaceans such as dolphins being the main exception. A few of these varied species feed directly on corals, while others graze on algae on the reef and participate in complex food webs.

Researchers have found evidence of algae dominance in locations of healthy coral reefs. In surveys done around largely uninhabited US Pacific islands, algae inhabit a large percentage of surveyed coral locations. The algae population consists of turf algae, coralline algae, and macroalgae.

Fish

Main article: Coral reef fishes

Coral reefs are home to a variety of tropical or reef fish which can be distinguished. These include:

fish that adjust the coral (such as Labridae and parrotfish) These types of fish feed either on small animals living near the coral, seaweed, or on the coral itself. Fish that feed on small animals include cleaner fish (these fish feed between the jaws of larger predatory fish), bullet fish and Balistidae (these eat sea urchins) while seaweed eating fish include the Pomacentridae (damselfishes). Serranidae cultivate the seaweed by removing creatures feeding on it (as sea urchins), and they remove inedible seaweeds. Fish that eat coral include parrotfish and butterflyfish.

fish that swim nearby the reef. These include predatory fish such as pompanos, groupers, Horse mackerels, certain types of shark, Epinephelus marginatus, barracudas, snappers, …) They also include herbivorous and plankton-eating fish. Fish eating seagrass include Horse mackerel, snapper, Pagellus, Conodon, … Fish eating plankton include Caesio, manta ray, chromis, Holocentridae, pterapogon kauderni, …

Organisms can cover every square inch of a coral reef,

Generally, fish that swim in coral reefs are as colourful as the reef itself. Examples are the beautiful parrotfish, angelfish, damselfish, Pomacanthus paru, Clinidae and butterflyfish. At night, some change to a less vivid color. Besides colorful fish matching their environment, other fish (e.g., predatory and herbivorous fish such as Lampanyctodes hectoris, Holocentridae, Pterapogon kauderni, …) as well as aquatic animals (Comatulida, Crinoidea, Ophiuroidea, …) emerge and become active while others rest.

Other fish groups found on coral reefs include groupers, grunts and wrasses. Over 4,000 species of fish inhabit coral reefs. It has been suggested that the fish species that inhabit coral reefs are able to coexist in such high numbers because any free living space is inhabited by the first planktonic fish larvae that find it in what has been termed “a lottery for living space”.

Seabirds

Coral reef systems provide important habitats for seabird species, some endangered. For example, Midway Atoll supports nearly three million seabirds, including two-thirds (1.5 million) of the global population of Laysan Albatross, and one-third of the global population of black-footed albatross. Each seabird species have specific sites on the atoll where they nest. Altogether, 17 species of seabirds live on Midway. The short-tailed albatross is the rarest, with fewer than 2,200 surviving after excessive feather hunting in the late nineteenth century.

Invertebrates

Invertebrates have their part in the food-chain of the reef. For example, sea urchins, Dotidae and sea slugs eat seaweed. Some species of sea urchins, such as Diadema antillarum, can play a pivotal part in preventing algae overrunning reefs. Hawksbill turtles, Nudibranchia and sea anemones eat sponges.

A number of invertebrates, collectively called cryptofauna, inhabit the coral skeletal substrate itself, either boring into the skeletons (through the process of bioerosion) or living in pre-existing voids and crevices. Those animals boring into the rock include sponges, bivalve molluscs, and sipunculans. Those settling on the reef include many other species, particularly crustaceans and polychaete worms.

Other

Sea snakes feed exclusively on fish and their eggs. Many tropical birds forage on reef fish, such as herons, gannets, pelicans and boobies. Some land based reptiles can be intermittently associated with reefs, such as monitor lizards, the marine crocodile and semi-aquatic snakes like Laticauda colubrina.

Soft coral, cup coral, sponges and ascidians

Crown-tipped coral fungus

Eastern coral snake

Banded coral shrimp

Caribbean reef squid

Giant clam

Green turtle

Shoaling reef fish

Economic value

Coral reefs deliver ecosystem services to tourism, fisheries and coastline protection. The global economic value of coral reefs has been estimated at $30 billion. Coral reefs protect shorelines by absorbing wave energy, and many small islands would not exist without their reef to protect them. According to the WWF, the economic cost over a 25 year period of destroying one kilometre of coral reef is somewhere between $137,000 and $1,200,000. About 6 million tons of fish are taken each year from coral reefs. Well managed coral reefs have an annual yield of 15 tons seafood on average per square kilometre. Southeast Asia’s coral reef fisheries alone yield about $ 2.4 billion annually from seafood.

Issues

Island with fringing reef off Yap, Micronesia. Coral reefs are dying around the world.

Coral reefs are dying around the world. Human activity may represent the greatest threat to coral reefs. In particular, coral mining, pollution (organic and non-organic), overfishing, blast fishing and the digging of canals and access into islands and bays are serious threats to these ecosystems. Coral reefs also face high dangers from pollution, diseases, destructive fishing practices and warming oceans.” In order to find answers for these problems, researchers study the various factors that impact reefs. The list of factors is long, including the ocean’s role as a carbon dioxide sink, atmospheric changes, ultraviolet light, ocean acidification, biological virus, impacts of dust storms carrying agents to far flung reefs, pollutants, algal blooms and others. Reefs are threatened well beyond coastal areas.

Southeast Asian coral reefs are at risk from damaging fishing practices (such as cyanide and blast fishing), overfishing, sedimentation, pollution and bleaching. A variety of activities, including education, regulation, and the establishment of marine protected areas are under way to protect these reefs.

Indonesia, is home to a third of the world’s total corals and a quarter of its fish species, nearly 33,000 square miles (85,000 km2). Indonesia’s coral reefs are located in the heart of the Coral Triangle and have fallen victim to destructive fishing, unregulated tourism, and bleaching due to climatic changes. Data from 414 reef monitoring stations in 2000 found that only 6% are in excellent condition, while 24% are in good condition, and approximately 70% are in poor to fair condition (2003 The Johns Hopkins University).

In 2007, Reef Check, the world largest reef conservation organization, stated that only 5% of Philippines 27,000 square-kilometers of coral reef are in “excellent condition”: Tubbataha Reef, Marine Park in Palawan, Apo Island in Negros Oriental, Apo Reef in Puerto Galera, Mindoro, and Verde Island Passage off Batangas. Philippine coral reefs is second largest in Asia.

General estimates show approximately 10% world’s coral reefs are already dead. It is estimated that about 60% of the world’s reefs are at risk due to destructive, human-related activities. The threat to the health of reefs is particularly strong in Southeast Asia, where 80% of reefs are endangered.

Fishing practices

See also: Overfishing and Environmental effects of fishing

Many valuable fishery species live around coral reefs. Shark and reef fish are fished intensively for fish markets. Seahorses and sea cucumbers are harvested for Chinese pharmacopeia. Lobster are sought for the tourist industry, and shrimp for the export trade.

Overfishing, particularly selective overfishing, can unbalance coral ecosystems by encouraging the excessive growth of coral predators. Predators which eat living coral, such as the crown-of-thorns starfish, are called corallivores. Coral reefs are built from stony coral, which evolved with large amounts of the wax cetyl palmitate in their tissues. Most predators find this wax indigestible. The crown-of-thorns starfish is a large (up to one metre) starfish protected with long, venomous spikes. It has an enzyme system which dissolves the wax in stony corals, and allows the starfish to feed on the living coral. Normally the starfish are kept under control by the giant triton sea snail. However, the giant triton is valued for its shell, and has been severely overfished. As a result, crown-of-thorns starfish populations can periodically explode without check, devastating coral reefs.

The overfished giant triton eats the crown of thorns starfish

The crown of thorns starfish eats coral

Although some aquarium fish species can reproduce in aquaria (such as Pomacentridae), most (95%) are collected from coral reefs. Intense harvesting, especially in South-East Asia (including Indonesia and the Philippines), damages the reefs. This is aggravated by destructive fishing practices, such as cyanide and blast fishing. Most (8090%) aquarium fish from the Philippines are captured with sodium cyanide. This toxic chemical is dissolved in sea water and released into fish shelters. It narcotizes fish, which are then easily captured. However, most fish collected with cyanide die a few months later from liver damage. Moreover, non-marketable species die in the field. A major catalyst of cyanide fishing is poverty within fishing communities. In areas like the Philippines where the cyanide is regularly used, the percentage of the population below the poverty line is 40%. In such developing countries, a fisherman might resort to such practices in order to protect his family from starvation.

Dynamite fishing is another destructive method for gathering fish. Sticks of dynamite, grenades, or home-made explosives are simply thrown in the water. This method of fishing kills the fish within the main blast area, along with many inedible and/or unwanted reef animals. The blast also kills the corals in the area, eliminating the very structure of the reef, destroying the habitat for fish and other animals important for the maintenance of a healthy reef. Other destructive fishing methods, such as muroami and kayakas, kill all fish in certain areas, causing havoc on the ecosystem of the reef.

Hughes, et al., (2003), wrote that “with increased human population and improved storage and transport systems, the scale of human impacts on reefs has grown exponentially. For example, markets for fish and other natural resources have become global, supplying demand for reef resources.”

Pollution

Main article: Marine pollution

This image of an algae bloom off the southern coast of England, though not in a coral region, shows what a bloom can look like from a satellite remote sensing system

Runoff caused by farming and construction of roads, buildings, ports, channels, and harbours, can carry soil laden with carbon, nitrogen, phosphorus, and minerals. This nutrient-rich water can cause fleshy algae and phytoplankton to thrive in coastal areas, known as algal blooms, which have the potential to create hypoxic conditions by using all available oxygen. Some algae are toxic, and both plants reduce the levels of sunlight and oxygen, killing marine organisms such as fish and coral. The addition of too many nutrients such as phosphates and nitrates, a process known as eutrophication, is very damaging to reefs. High nitrate levels are toxic to corals, while phosphates slow down the growth of coral skeleton.

Reefs in close proximity to human populations can be faced with local stresses, including poor water quality from land-based sources of pollution. Copper, a common industrial pollutant has been shown to interfere with the life history and development of coral polyps. Poor water quality has also been shown to encourage the spread of infectious diseases among corals.

Barbados dust graph

In addition to soil runoff, additional soil and sand is blown in from other regions. Dust from the Sahara moving around the southern periphery of the subtropical ridge moves into the Caribbean and Florida during the warm season as the ridge builds and moves northward through the subtropical Atlantic. Dust can also be attributed to a global transport from the Gobi and Taklamakan deserts across Korea, Japan, and the Northern Pacific to the Hawaiian Islands. Since 1970, dust outbreaks have worsened due to periods of drought in Africa. There is a large variability in dust transport to the Caribbean and Florida from year to year; however, the flux is greater during positive phases of the North Atlantic Oscillation. The USGS links dust events to a decline in the health of coral reefs across the Caribbean and Florida, primarily since the 1970s. Studies have shown that corals can incorporate dust into their skeletons as identified from dust from the 1883 eruption of Krakatoa in Indonesia in the annular bands of the reef-building coral Montastraea annularis from the Florida reef tract.

Climate change

See also: Coral bleaching

Unbleached and bleached coral

Any rise in the sea level due to climate change would effectively ask coral to grow faster to keep up. Also, water temperature changes can be very disturbing to the coral. This was seen during the 1998 and 2004 El Nio weather phenomena, in which sea surface temperatures rose well above normal, bleaching or killing many coral reefs. High seas surface temperature (SSTs) coupled with high irradiance (light intensity), triggers the loss of zooxanthellae, a symbiotic algae, and its dinoflagellate pigmentation in corals causing coral bleaching. Zooxanthellae provides up to 90% of the energy to the coral host. Reefs can often recover from bleaching if they are healthy to begin with and water temperatures cool. However, recovery may not be possible if CO2 levels rise to 500 ppm because there may not be enough carbonate ions present. Refer to Hoegh-Guldberg 1999 for more information.

Warming may also be the basis of a new emerging problem: increasing coral diseases. Warming, thought to be the main cause of coral bleaching, weakens corals. In their weakened state, coral is much more prone to diseases including black band disease, white band disease and skeletal eroding band. If global temperatures increase by 2 C, coral may not be able to adapt quickly enough physiologically or genetically. It has been estimated that, in order to counter the threat of ocean acidification through global warming, a reduction of up to 40% of current emissions is needed, and up to 95% by 2050. This requires emission reductions larger than the reductions currently proposed for these dates by the EU.

Ocean acidification

Main article: Ocean acidification

Bamboo coral is an early harbinger of ocean acification

Another problem related to climate change is ocean acidification. Ocean acidification results from increases in the atmospheric carbon dioxide, which increases the amount of carbon dioxide dissolved in the oceans. The dissolved carbon dioxide gas reacts with the water to form carbonic acid, and thus acidifies the ocean. This decreasing ocean surface pH is another long-term concern for the survival of coral reefs.

Ocean surface pH is estimated to have decreased from about 8.25 to 8.14 since the beginning of the industrial era, and it is estimated that it will drop by a further 0.30.4 units by 2100 as the ocean absorbs more anthropogenic carbon dioxide. Normally, the conditions for calcium carbonate production are stable in surface waters since the carbonate ion is at supersaturating concentrations. However, as ocean pH falls, so does the concentration of this ion, and when carbonate becomes under-saturated, structures made of calcium carbonate are vulnerable to dissolution. Research has already found that corals experience reduced calcification or enhanced dissolution when exposed to elevated CO2.

Bamboo coral is a deep sea coral which produces growth rings similar to a tree. The growth rings picture how growth rates change as deep sea condition change over time, and can also record changes due to ocean acidification. This coral is especially long-lived. Coral specimens as old as 4,000 years old have given scientists “4,000 years worth of information about what has been going on in the deep ocean interior”.

Other issues

Eroded coral

Within the last 20 years, once prolific seagrassbeds and mangrove forests, which absorb massive amounts of nutrients and sediment, have been destroyed. Both the loss of wetlands, mangrove habitats and seagrassbeds affect the water quality of inshore reefs.

Coral mining is another threat. Both small scale harvesting by villagers and industrial scale mining by companies are serious threats. Mining is usually done to produce construction material which is valued as much as 50% cheaper than other rocks, such as from quarries. The rocks are ground and mixed with other materials, like cement to make concrete. Ancient coral used for construction is known as coral rag. Building directly on the reef also takes its toll, altering water circulation and the tides which bring the nutrients to the reef. The pressing reason for building on reefs is simply lack of space.

Boats and ships require access points into bays and islands to load and unload cargo and people. For this, parts of reefs are often chopped away to clear a path. Although this may seems a minor destruction of the reef, negative consequences can include altered water circulation and altered tidal patterns which result in a turnaround in the reef’s supply of nutrients; sometimes destroying a great part of the reef. Fishing vessels and other large boats occasionally run aground on a reef. Two types of damage can result. Collision damage occurs when a coral reef is crushed and split by a vessel’s hull into multiple fragments. Scarring occurs when boat propellers tear off the live coral and expose the skeleton. The physical damage can be noticed as striations in the reefs. Mooring also causes damage which can be reduced by using mooring buoys.

Threatened species

The global standard for recording threatened marine species is the IUCN Red List of Threatened Species. This list is the foundation for marine conservation priorities worldwide. A species is listed in the threatened category if it is considered to be critically endangered, endangered, or vulnerable. Other categories are near threatened and data deficient. By 2008, the IUCN had assessed all known reef-building corals species as follows

Group

Species

Threatened

Near threatened

Data deficient

Reef-building corals

845

27%

20%

17%

The coral triangle (Indo-Malay-Philippine archipelago) region has the highest number of reef-building coral species in threatened category as well as the highest coral species diversity. The loss of coral reef ecosystems will have devastating effects on many marine species, as well as on people that depend on reef resources for their livelihoods.

Protected areas

Main article: Coral reef protection

Coral reefs and fish in Papua New Guinea

Marine Protected Areas (MPAs) have become increasingly prominent for reef management. MPAs in Southeast Asia and elsewhere around the world attempt to promote responsible fishery management and habitat protection. Much like national parks and wild life refuges, MPAs prohibit potentially damaging extraction activities. The objectives of MPAs are both social and biological, including reef restoration, aesthetics, increased and protected biodiversity, and economic benefits. Conflicts surrounding MPAs involve lack of participation, clashing views and perceptions of effectiveness, and funding.

Biosphere reserves are other protected areas that may protect reefs. Also, Marine parks, as well as world heritage sites can protect reefs. World heritage designation can also play a vital role. For example the Chagos archipelago, Sian Ka’an, the Great Barrier Reef, Henderson Island, the Galapagos islands, Belize’s Barrier reef and Palau have been designated as protected by nomination as a world heritage site.

In Australia, the Great Barrier Reef is protected by the Great Barrier Reef Marine Park Authority, and is the subject of much legislation, including a Biodiversity Action Plan.

Inhabitants of Ahus Island, Manus Province, Papua New Guinea, have followed a generations-old practice of restricting fishing in six areas of their reef lagoon. Their cultural traditions allow line fishing but not net and spear fishing. The result is that both the biomass and individual fish sizes are significantly larger in these areas than in places where fishing is unrestricted.

Restoration technologies

Main article: Coral reef restoration

Low voltage electrical currents applied through seawater crystallize dissolved minerals onto steel structures. The resultant white carbonate (aragonite) is the same mineral that makes up natural coral reefs. Corals rapidly colonize and grow at accelerated rates on these coated structures. The electrical currents also accelerate formation and growth of both chemical limestone rock and the skeletons of corals and other shell-bearing organisms. The vicinity of the anode and cathode provides a high pH environment which inhibits the growth of filamentous and fleshy algae, which compete with coral for space. The increased growth rates cease when the mineral accretion process stops.

During mineral accretion, the settled corals display an increased growth rate, and size, and density, but after the process is complete, growth rate and density return to levels that are comparable to naturally growing corallites, and are about the same size or slightly smaller.

In large restoration projects, depending on the type of coral, placement of propagated hermatype coral unto substrate is often done with metal pins, superglue or milliput. Needle and thread can also attach A-hermatype coral to substrate. Concrete has also been used to restore large sections of broken coral reef. Finally, special structures as reef balls can be placed to provide corals a base to grow on.

Organizations

Organizations which currently undertake coral reef/atoll restoration projects using simple methods of plant propagation:

Coral Cay

Counterpart

U.S. Coral Reef Task Force (CRTF)

National Coral Reef Institute (NCRI)

US Department of Commerce National Oceanic and Atmospheric Administration (NOAA): Coral Reef Conservation Program

National Center for Coral Reef Research (NCORE)

Reef Ball

Southeast Florida Coral Reef Initiative (SEFCRI)

Foundation of the peoples of the South Pacific

WorldFishCenter: promotes sustainable mariculture techniques to grow reef organisms as tridacnidae

Coral Restoration Foundation (CRF) : Adopt a Coral

Organizations which promote interest, provide knowledge bases about coral reef survival, and promote activities to protect and restore coral reefs:

Australian Coral Reef Society

Biosphere Foundation

Chagos Conservation Trust

Conservation Society of Pohnpei

Coral Reef Care

Coral Reef Alliance (CORAL)

Coral Reef Targeted Research and Capacity Building for Management

Coral Triangle Initiative

Cousteau Society

Crusoe Reef Society

CEDAM International

Earthwatch

Environmental Defense Fund

Environmental Solutions International

Friends of Saba Marine Park

Global Coral Reef Alliance (GCRA)

Global Coral Reef Monitoring Network

Great Barrier Reef Marine Park Authority

ICRAN Mesoamerican Reef Alliance

International Marinelife Alliance

International Society for Reef Studies

Intercoast Network

Kosrae Conservation and Safety Organization

Marine Conservation Group

Marine Conservation Society

Mesoamerican Reef Tourism Initiative (MARTI)

NSF Moorea Coral Reef Long-term Ecological Research site

Nature Conservancy

Ocean Voice International

PADI

Planetary Coral Reef Foundation

Practical Action

Project Reefkeeper

ReefBase

Reef Check

Reef Relief

Reefwatch

Seacology

SECORE

Singapore Underwater Federation

Society for Andaman and Nicobar Ecology

Tubbataha Foundation

Wildlife Conservation International

WWF

Reefs in the past

Ancient coral reefs

Throughout Earth history, from a few thousand years after hard skeletons were developed by marine organisms, there were almost always reefs. The times of maximum development were in the Middle Cambrian (513-501 Ma), Devonian (416-359 Ma) and Carboniferous (359-299 Ma), due to Order Rugosa extinct corals, and Late Cretaceous (100-65 Ma) and all Neogene (23 Ma – present), due to Order Scleractinia corals.

Not all reefs in the past were formed by corals: in the Early Cambrian (542-513 Ma) resulted from calcareous algae and archaeocyathids (small animals with conical shape, probably related to sponges) and in the Late Cretaceous (100 – 65 Ma), when there also existed reefs formed by a group of bivalves called rudists; one of the valves formed the main conical structure and the other, much smaller valve acted as a cap.

See also

Ecology portal

Marine biology

List of environmental issues

Notes

^ Mulhall M (2007) Saving rainforests of the sea: An analysis of international efforts to conserve coral reefs Duke Environmental Law and Policy Forum 19:321351.

^ “Corals reveal impact of land use”. ARC Centre of Excellence for Coral Reef Studies. http://www.coralcoe.org.au/news_stories/landimpacts.html. Retrieved 12 July 2007. 

^ Coral reef The Encyclopedia of Earth, Updated February 27, 2009.

^ Darwin, Charles (1842), The Structure and Distribution of Coral Reefs. Being the first part of the geology of the voyage of the Beagle, under the command of Capt. Fitzroy, R.N. during the years 1832 to 1836, London: Smith Elder and Co, http://darwin-online.org.uk/content/frameset?viewtype=text&itemID=F271&pageseq=1 

^ a b Gordon Chancellor (2008), Introduction to Coral reefs, Darwin Online, http://darwin-online.org.uk/EditorialIntroductions/Chancellor_CoralReefs.html, retrieved 2009-01-20 

^ Animation of coral atoll formation NOAA Ocean Education Service. Retrieved 9 January 2010.

^ a b c Anderson, G (2003) Coral Reef Formation Marine Science.

^ Great Barrier Reef Marine Park Authority (2006). “A “big picture” view of the Great Barrier Reef” (PDF). Reef Facts for Tour Guides. http://www.gbrmpa.gov.au/__data/assets/pdf_file/0017/12437/Reef-Facts-01.pdf. Retrieved 18 June 2007. 

^ a b Tobin, Barry (1998, revised 2003). “How the Great Barrier Reef was formed”. Australian Institute of Marine Science. http://www.aims.gov.au/pages/research/project-net/reefs/apnet-reefs00.html. Retrieved 22 November 2006. 

^ CRC Reef Research Centre Ltd. “What is the Great Barrier Reef?”. http://www.reef.crc.org.au/discover/coralreefs/coralgbr.html. Retrieved 28 May 2006. 

^ Four Types of Coral Reef Microdocs, Stanford Education. Retrieved 10 January 2010.

^ MSN Encarta (2006). “Great Barrier Reef”. Great Barrier Reef. http://encarta.msn.com/encyclopedia_761575831/Great_Barrier_Reef.html. Retrieved 11 December 2006. 

^ Smithers, S.G. and Woodroffe, C.D. (August 2000). “Microatolls as sea-level indicators on a mid-ocean atoll.”. Marine Geology 168 (14): 6178. doi:10.1016/S0025-3227(00)00043-8. http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V6M-40WDSPX-4&_user=10&_coverDate=08/15/2000&_rdoc=1&_fmt=summary&_orig=browse&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=844934e86d603e4aa8f0c42faa6b42ef. 

^ a b c d Spalding, Mark, Corinna Ravilious, and Edmund Green. 2001. World Atlas of Coral Reefs. Berkeley, CA: University of California Press and UNEP/WCMC.

^ Achituv, Y. and Dubinsky, Z. 1990. Evolution and Zoogeography of Coral Reefs Ecosystems of the World. Vol. 25:1-8.

^ a b The Greenpeace Book of Coral Reefs

^ a b Nybakken, James. 1997. Marine Biology: An Ecological Approach. 4th ed. Menlo Park, CA: Addison Wesley.

^ Ultra Marine: In far eastern Indonesia, the Raja Ampat islands embrace a phenomenal coral wilderness, by David Doubilet, National Geographic, September 2007

^ Sherman, C.D.H. “The Importance of Fine-scale Environmental Heterogeneity in Determining Levels of Genotypic Diversity and Local Adaption.” University of Wollongong Ph.D. Thesis. 2006. Accessed 2009-06-07.

^ Stacy, J., Marion, G., McCulloch, M. and Hoegh-Guldberg, O. “Long-term changes to Mackay Whitsunday water quality and connectivity between terrestrial, mangrove and coral reef ecosystems: Clues from coral proxies and remote sensing records – Synthesis of research from an ARC Linkage Grant (2004-2007).” University of Queensland – Centre for Marine Studies. May 2007. Accessed 2009-06-07.

^ Nothdurft, L.D. “Microstructure and early diagensis of recent reef building scleractinian corals, Heron Reef, Great Barrier Reef: Implications for palaeoclimate analysis.” Queensland University of Technology Ph.D. Thesis. 2007. Accessed 2009-06-07.

^ Wilson, R.A. “The Biological Notion of Individual.” Stanford Encyclopedia of Philosophy. August 9, 2007. Accessed 2009-06-07.

^ Paul Marshall and Heidi Schuttenberg.; Marshall, Paul; Schuttenberg, Heidi. (2006). A Reef Manager Guide to Coral Bleaching. Townsville, Australia: Great Barrier Reef Marine Park Authority,. ISBN 1 876945 40 0. http://www.gbrmpa.gov.au/corp_site/info_services/publications/misc_pub/a_reef_managers_guide_to_coral_bleaching. 

^ Rougerier, F The functioning of coral reefs and atolls: from paradox to paradigm ORSTOM, Papeete.

^ Sorokin, Y. I. Coral Reef Ecology. Germany. Sringer-Herlag, Berlin Heidelberg. 1993.

^ a b c Castro, Peter and Michael Huber. 2000. Marine Biology. 3rd ed. Boston: McGraw-Hill.

^ http://oceanservice.noaa.gov/education/kits/corals/coral02_zooxanthellae.html

^ A Reef Manager Guide to Coral Bleaching. Townsville, Australia: Great Barrier Reef Marine Park Authority,. 2006. ISBN 1 876945 40 0. http://www.gbrmpa.gov.au/corp_site/info_services/publications/misc_pub/a_reef_managers_guide_to_coral_bleaching. 

^ Rich Coral Reefs in Nutrient-Poor Water: Paradox Explained? National Geographic News, November 7, 2001.

^ Corals play rough over Darwin’s paradox New Scientist, 21 September 2002.

^ Wilson E (2004) “Coral Symbiotic Bacteria Fluoresce, Fix Nitrogen” Chemical and engineering news, 82(33): 7.

^ Greenpeace Book of Coral Reefs

^ a b c d Moyle and Cech, 2003, p. 556.

^ Vroom, Peter S.; Page, Kimberly N.; Kenyon, Jean C.; Brainard, Russell E. (2006), “Algae-Dominated Reefs”, American Scientist 94 (5): 430437 .

^ Coexistence of coral reef fishes lottery for living space PF Sale 1978 – Environmental Biology of Fishes, 1978

^ http://the.honoluluadvertiser.com/article/2005/Jan/17/ln/ln23p.html

^ “U.S. Fish & Wildlife Service – Birds of Midway Atoll”. http://www.fws.gov/midway/midwaywildlifebirds.html. Retrieved August 19, 2009. 

^ Osborne, Patrick L. (2000). Tropical Ecosystem and Ecological Concepts. Cambridge: Cambridge University Press. pp. 464. ISBN 0 521 64523 9. 

^ Testimony of Dr. Lara J. Hansen before the Senate Committee on Commerce, Science and Transportation, May 10, 2007.

^ a b The Importance of Coral to People WWF. Retrieved 12 January 2009.

^ a b Coral reefs around the world Guardian.co.uk, 2 September 2009.

^ Space Daily etal. (2009). “Coral reefs tough it out against seaweed.”science”". 

^ Abs-Cbn Interactive, “RP coral reefs, second largest in Asia, in bad shape”

^ a b Kleypas, J.A., R.A. Feely, V.J. Fabry, C. Langdon, C.L. Sabine, and L.L. Robbins, 2006, Impacts of Ocean Acidification on Coral Reefs and Other Marine Calcifiers: A guide for Future Research, NSF, NOAA, & USGS, 88 pp.

^ Save Our Seas, 1997 Summer Newsletter, Dr. Cindy Hunter and Dr. Alan Friedlander

^ Tun, K., L.M. Chou, A. Cabanban, V.S. Tuan, Philreefs, T. Yeemin, Suharsono, K.Sour, and D. Lane, 2004, p:235-276 in C. Wilkinson (ed.), Status of Coral Reefs of the world: 2004.

^ Benson AA and Muscatine L (1974) Wax in Coral Mucus: Energy Transfer From Corals to Reef Fishes Limnology and Oceanography, 19 (5) 810-814. Download

^ Predators and Prey PBS.org. Retrieved 11 December 2009.

^ “CRC Reef Research Centre Technical Report No. 32 Crown-of-thorns starfish(Acanthaster planci) in the central Great Barrier Reef region. Results of fine-scale surveys conducted in 1999-2000.”. http://www.reef.crc.org.au/publications/techreport/techrept32.htm. Retrieved 7 June 2007. 

^ CRC Reef Research Centre. “Crown-of-thorns starfish on the Great Barrier Reef”. http://www.reef.crc.org.au/publications/brochures/COTS_web_Nov2003.pdf. Retrieved 28 August 2006.  (PDF)

^ “David LECCHINI, Sandrine POLTI, Yohei NAKAMURA, Pascal MOSCONI, Makoto TSUCHIYA, Georges REMOISSENET, Serge PLANES (2006) “New perspectives on aquarium fish trade” Fisheries Science 72 (1), 4047″. Blackwell Synergy. http://www.blackwell-synergy.com/doi/full/10.1111/j.1444-2906.2006.01114.x. Retrieved 16 January 2007. 

^ “CIA The World Factbook Philippines”. CIA. https://www.cia.gov/library/publications/the-world-factbook/geos/rp.html. Retrieved 2 November 2006. 

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^ Hughes etal. (2003). “Climate Change, Human Impacts, and the Resilience of Coral Reefs. Science. Vol 301 15 August 2003″. http://www.sciencemag.org/cgi/content/abstract/301/5635/929. Retrieved 3 June 2008. 

^ a b http://celebrating200years.noaa.gov/visions/coral/side.html

^ Eutrofication and corals

^ Emma Young (2003). “Copper decimates coral reef spawning”. http://www.newscientist.com/article.ns?id=dn4391. Retrieved 26 August 2006. 

^ Rachel Nowak (11 January 2004). “Sewage nutrients fuel coral disease”. New Scientist. http://www.newscientist.com/article.ns?id=dn4539. Retrieved 10 August 2006. 

^ Duce, R.A., Unni, C.K., Ray, B.J., Prospero, J.M., Merrill, J.T. 1980. Long-range atmospheric transport of soil dust from Asia to the tropical North Pacific: Temporal variability. Science 209:15221524.

^ Usinfo.state.gov. Study Says African Dust Affects Climate in U.S., Caribbean. Retrieved on 10 June 2007.

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^ Merman, E.A. 2001. Atmospheric inputs to the tropical oceannlocking the record in annually banded corals. Master thesis. University of South Florida, St. Petersburg.

^ Leahy, Stephen(2007). “Environment: Between a Reef and a Hard Place.” NoticiasFinancieras.

^ P.W.Glynn “Coral Reef Bleaching: Ecological Perspectives” Earth and Environmental Science. Vol 12:1 March 1993.

^ Ocean acidification emission levels decrease

^ “The Ocean and the Carbon Cycle”. NASA Oceanography (science@nasa). 21 June 2005. http://science.hq.nasa.gov/oceans/system/carbon.html. Retrieved 4 March 2007. 

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^ Gattuso, J.-P., Frankignoulle, M., Bourge, I., Romaine, S. and Buddemeier, R. W. (1998). Effect of calcium carbonate saturation of seawater on coral calcification. Glob. Planet. Change 18, 37-46.

^ “National Oceanic and Atmospheric Administration – New Deep-Sea Coral Discovered on NOAA-Supported Mission”. www.noaanews.noaa.gov. http://www.noaanews.noaa.gov/stories2009/20090305_coral.html. Retrieved 11 May …
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A Map of the World $3.95 From the author of the widely acclaimed @lt;b@gt;The Book of Ruth@lt;/b@gt; comes a harrowing, heartbreaking drama about a rural American family and a disastrous event that forever changes their lives.@lt;br@gt;@lt;br@gt;The Goodwins, Howard, Alice, and their little girls, Emma and Claire, live on a dairy farm in Wisconsin. Although suspiciously regarded by their neighbors as "that hippie couple" because of their well-educated, urban background, Howard and Alice believe they have found a source of emotional strength in the farm, he tending the barn while Alice works as a nurse in the local elementary school.@lt;br@gt;@lt;br@gt;But their peaceful life is shattered one day when a neighbor’s two-year-old daughter drowns in the Goodwins’ pond while under Alice’s care. Tormented by the accident, Alice descends even further into darkness when she is accused of sexually abusing of a student at the elementary school. Soon, Alice is arrested, incarcerated, and as good as convicted in the eyes of a suspicious community. As a child, Alice designed her own map of the world to find her bearings. Now, as an adult, she must find her way again, through a maze of lies, doubt and ill will. @lt;br@gt;@lt;br@gt;A vivid human drama of guilt and betrayal, @lt;b@gt;A Map of the World@lt;/b@gt; chronicles the intricate geographies of the human heart and all its mysterious, uncharted terrain. The result is a piercing drama about family bonds and a disappearing rural American life.

Classic World Wall Map $60 Perfect for home, business or education, this Classic World Wall Map is a Political map of the world, presented in a warm, traditional color palette. Special features include blue colored oceans and a white border. This map of the world uses the Van Der Grinten projection.Detail included on this Wall Map of the World Time Zone Clocks Major Physical Features Major Water Features Major Mountain Peaks International Boundaries International Capitals Major Cities Shaded Relief Major Island ChainsInsets Antarctica

World and U.S. Map $5.31 11" x 17" size, designed with education in mind. x0D; Easy to read, with the U.S. map on one side and the world map on the other side. x0D; 4-page laminated guide includes: – map of United States – map of the world – major river lengths – major bodies of water lengths – highest & lowest points of the world – % of world’s population – 2004 – most populous nations – most densely populated regions

World with Flags Travel Map $10.95 Explore the World with this World Political Map. The world is a big place, and Michelin has been mapping it for a long time. Loaded with political information, this World Political Map includes Continents Countries Major Cities Lines of Latitude Longitude National Flags Oceans Rivers Seas Time Zones Insets of North and South Poles

Children’s World Wall Map $19.95 This colorful informative world map is made especially for children. Heavily illustrated with fun pictures and descriptive text, this map can keep children entertained for hours. The illustrations depict where mountain ranges, deserts, seas, etc. are located and what types of animals can be found in each region of the world. Not only is this map fun, but it is educational as well. It makes the perfect addition to any classroom, children’s bedroom, or playroom. Adults will also enjoy the fun nature of this one-of-a-kind map of the world.

Political World Wall Map $124.95 Introducing the Political Map of the World by Compart Maps. Loaded with place names, this World map is highly detailed with up-to-date accuracy. Beautifully illustrated with subtle hues, the detail is legible with international boundaries clearly defined. Perfect for any home or office, this map can be used for general reference, to track current events, or a piece of art.This Political World Wall Map featuresCities State Borders PhysicalTerrain International Borders LatitudeLongitude lines Points of Interest Capitals Ocean Relief

World Map 1960 $14.95 The National Geographic 1960 World map was published in the midst of sweeping changes in Africa, as many countries gained their independence. This map shows all the changes that had been made as of September, 1960, when the map went to press. Bright boundaries highlight international borders, and the map features extrordinary detail on land and in the oceans. A perfect map for anyone interested in the changes from colonialism to independent rule in Africa.The 1960 World map features Classic National Geographic cartography and detail, with vivid country borders Thousands of place names, including country capitals Insets for the North Polar and South Polar Regions An inset map showing the United Nations countries and the Communist World Inset for international time zones Principal airports, canals, depth curves and soundings in fathoms, elevations, prevailing winds, warm and cold ocean currentsCoverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica

World Risk Travel Map $3.5 Whether you are the Indiana Jones type or the political scientist, the World Risk Map is the perfect addition to your map case. Extensive effort has been put into the researching of this map, to the extent that Pinkerton’s Global Intelligence endorses it. Topics ranging from health risks, common threats to travelers, and security tips, to passport and visa information are presented both in graphic and text form. Besides the map, there is useful contact information for every country in the world, plus phone numbers and websites to get any up-to-the-minute information that is available.

World Political Wall Map $29.95 Breathtaking and functional, this world political map is one of the best available. The gorgeous color scheme and softly shaded outlines give this map a classic elegance while striking shaded relief gives it a 3D feel that jumps off the page. Subtly framed with a natural color border, this map is certain to look great on any wall. This map is up to date and packed with content. Over three thousand labeled places including countries, capitals, cities, roads, political regions, and natural features are clearly displayed without clutter. This world map is ideal for any classroom, office, or homeFeatures included on this World Wall MapCities InterstatesHighways PhysicalTerrain International Borders LatitudeLongitude lines Legend Elevation Info Capitals

World Map 1970 $49.95 A great map is as much a reflection of its time in history as it is beautifully crafted. This world map accomplishes both. Stunning colors, detailed geographical information, and timely insets make this a classic map for any history buff. A perfect companion to the World maps published in 1943 and 1951.The 1970 World map features Classic National Geographic cartography and detail, with vivid country borders Thousands of place names, including country capitals Insets for the Northern and Southern Hemispheres An inset map showing the United Nations countries Insets for vegetation and land use, population density, and world time zones Airports, canals, depth curves and soundings in fathoms, elevations, prevailing winds, ocean currents, channel depths for principal ports, and manned space flight tracking stations Map notes embellish this classic to make it a perfect reference for its time.Coverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica

Roxy Tahiti II Sandals $9.95 You’re the kind of girl who would take off an epic trip around the world – a la Elizabeth Gilbert in her best-selling memoir – Eat. Pray. Love. That is – if it were up to you. If there weren’t obligations like work – your car payment – etc. Darn responsibility and its grounding effects. Embrace your carefree spirit every day in the Tahiti II flip flops from Roxy. When you can’t get away on that spontaneous vacation – throw these on and at least try to take a walk on the beach if you’re lucky enough to live near one. Tahiti II features a soft EVA and PVC upper with a sweet molded Roxy heart logo. The dual density EVA insole offers up plenty o’ comfort – perfect for strolling the streets in your hometown – or in downtown Venice. (Italy – that is).

World Vegetation Wall Map $75 Perfect for business or education, this colorful map shows the types of vegetation (forest, scrubland, desert, tundra, grassland, scrubland, rain forest, savanna) found across the world. Pictures of each vegetation region depict typical types of plant life found in those areas.Detail included on this map of the World Vegetation International Boundaries Vegetation Zones

World Map Office Desk $135 The World Map Office Desk features a unique world map print to give your office or dorm room a unique look! This desk features a tempered glass atop a sturdy steel frame. Works great as a drafting table as well.

World 1943 Framed Map $279.95 Beautifully framed with high quality wood, choose from two colors to make this Framed Wall Map of The World 1943, the perfect custom map for home, office, or classroom. National Geographic published this classic world map in December 1943, in the midst of WWII. Compared to many of the other world maps by the National Geographic Society, this one had a decidedly dark cast, possibly a reflection of the tone of discouragement felt by many as the War continued on. A perfect companion to the World maps of 1951 and 1970.The 1943 World map features International boundaries as of Sept. 1, 1939 Insets for the Northern and Southern Hemispheres An inset showing the world alliances during WWI An inset showing the alliances in WWII as of the publication of this map Classic colorization depicting mountain ranges and areas of high elevation Ocean currents and time zonesCoverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica

World Wall Map $29.95 Clean, concise, colorful- this a great map! The Map Link World Map is produced by the worlds number one map distributor. The colors are clear and the political information is to-the-point. Cities: few Country Borders: yes U.S. State Border: yes Roads: no Physical/Terrain Shading: yes Timezones: no Ocean Relief: no Projection: Mercator

World 1943 Mounted Map $219.95 Mounted on wood material with beveled edges, similar to a plaque, choose from four colors to make this Mounted Wall Map of The World, 1935 the perfect custom map for home, office, or classroom. National Geographic published this classic world map in December 1943, in the midst of WWII. Compared to many of the other world maps by the National Geographic Society, this one had a decidedly dark cast, possibly a reflection of the tone of discouragement felt by many as the War continued on. A perfect companion to the World maps of 1951 and 1970.The 1943 World map features International boundaries as of Sept. 1, 1939 Insets for the Northern and Southern Hemispheres An inset showing the world alliances during WWI An inset showing the alliances in WWII as of the publication of this map Classic colorization depicting mountain ranges and areas of high elevation Ocean currents and time zonesCoverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica.This Mounted Map is a fine art plaque that consists of your selected map printed on art print paper with a heat activated adhesive that adheres the map to a piece of MDF wood. A UV Blocking Laminate is added on top for protection (but not for dry erase).Click here to download sample images

World Magnetic Puzzle Map $12.95 Play and Learn with this retro-vintage style World Magnetic Map Puzzle. Place the magnetic country onto its corresponding color and shape on the map, or for a bigger challenge, put the World together on your refrigerator or other metal surface. The World Magnetic Puzzle Map features Interactive magnetic playboard 70 Magnetic Pieces containing Geographic Place Names and fun Graphics Retro and vintage style with bright colorsContains small parts Not recommended for children under five years of age.

Mens Hinano Tahiti Tahiti Summer $20 Tahiti Summer

World Map 1981 $49.95 This beautiful World Map combines strong colors, detailed geographical information, and informative insets to give you the World as only National Geographic can present it. First published in December 1981, this map became an instant classic with its cartograhic excellence and fine attention to detail.The 1981 World map features Classic National Geographic cartography and detail, with vivid country borders Thousands of place names, including country capitals Insets for the Arctic and Antarctic regions An inset map showing Language Groups of the world An inset map showing Religions of the world and their primary locations Insets for population density and time zonesCoverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica

Contemporary World Wall Map $29.95 Why settle for a mundane or boring map, when you can get a map that combines usefulness with style This contemporary wall map of the World is up-to-date, fully featured, and loaded with detail – more than 3000 places are shown. But unlike other maps, this map displays world geography with striking aesthetics sure to grab attention. The vibrant colors and intense 3-D mountains look bold and majestic in contrast with the dark oceans and seas while the eye-catching border provides the finishing touch on this dramatic map. With its functionality and unprecedented style, this contemporary world map is guaranteed to stand out and look great on any wall – whether in the classroom, office, or homeCities PhysicalTerrain International Borders LatitudeLongitude lines Legend Elevation Info Capitals

World Map Magnetic Puzzle $13.99 Learn about the geography of the world from this World Map Magnetic Puzzle! Magnetic pieces stick to playboard. Measures 17W x 11 H inches. Ages 3 and Up.

World Coffee Map $12.95 Some drink it, many start their day with it, and other can’t live without it…now you can see where it all comes from, it’s The World Coffee Map! A handsomely illustrative world map adorns one side of this new and interesting product. Complete with coffee producing information graphics based on country, continent, and consumption. The reverse side is full to the brim with historical information, photographs, and statistics. But it doesn’t stop there, information on growing, preparing, and brewing is also included. This is the map for the coffee lover in your life!

Tahiti Dances $4.99 For everything you do, there’s a song that hits the spot. MOG brings them all to you: a world of music on demand, unlimited mobile downloads and ways to discover music free from the limitations of Pandora. The music you love, with you everywhere you go.

Tahiti Coco $4.99 For everything you do, there’s a song that hits the spot. MOG brings them all to you: a world of music on demand, unlimited mobile downloads and ways to discover music free from the limitations of Pandora. The music you love, with you everywhere you go.

Iaora Tahiti $4.99 For everything you do, there’s a song that hits the spot. MOG brings them all to you: a world of music on demand, unlimited mobile downloads and ways to discover music free from the limitations of Pandora. The music you love, with you everywhere you go.

National Geographic Islands of the Pacific Wall Map $24.95 Never before offered, stunning, large-format print from the award-winning National Geographic World Atlas. These finely-detailed, informative maps are perfect for home, office, or school. Includes the Solomon Islands, Fiji Islands, Guam, Okinawa, Tahiti and Moorea, Samoa, Palau, and many more.

World Climate Wall Map $75 Perfect for business or education, this colorful map of the worlds climate zones shows temperature and precipitation extremes as well as major ocean currents. Pictures of each climate zone depict typical types of vegetation found in those areas.Detail included on this map of the World Climate International Boundaries Climate Zones Ocean Currents

World 1935 Mounted Map $219.95 Mounted on wood material with beveled edges, similar to a plaque, choose from four colors to make this Mounted Wall Map of The World, 1935 the perfect custom map for home, office, or classroom. A National Geographic classic, this world map is as much a work of art as it is an incomparable reference for its time. In this map, the worlds eastern and western hemispheres are show separately to give the viewer a true sense of area across the continents. The 1935 World map features The Eastern and Western Hemispheres, beautifully created with the Azimuthal Equal-Area Projection Thousands of place names, including major cities and capitals Railway lines, Airplane routes, Canals, and Glaciers Elevations and depressions, and ocean depths An Earth chart filled with information about the Earths mass, areas of continents, mountain heights, ocean depths, and much more Separate insets for the Northern and Southern Hemispheres Insets showing the time zones for the Eastern and Western HemispheresCoverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica.This Mounted Map is a fine art plaque that consists of your selected map printed on art print paper with a heat activated adhesive that adheres the map to a piece of MDF wood. A UV Blocking Laminate is added on top for protection (but not for dry erase).Click here to download sample images

Jumbo Gold World Map Medallion & Chain $79 Jumbo Gold World Map Medallion & Chain

World Map 1932 $49.95 Vintage National Geographic colors and spectacular detail accentuate this beautiful world map, first published in National Geographic Magazine in December of 1932, accompanying an article entitled, The Story of the Map. The 1932 World map features International Provincial Borders Countries, Provinces, States, Capitals and Cities Insets for North and South Polar regions Inset showing World Vegetation with Ocean Currents Inset showing World Population Density and Wind Currents Van der Grinten ProjectionCoverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica

Political World Map 1975 $29.95 The World as only National Geographic can show it. This beautiful map emphasizes international boundaries, and is peppered with thousands of place names across the globe. First published in November of 1975, this world map continued the long tradition of fine cartography for which National Geographic is known.The 1975 Political World map features Country borders, thousands of place names, capitals Mountain ranges with beautiful relief shading Insets for the Arctic and Antarctic Polar Regions Insets for Language Groups, Religions of the World Insets for Population Density and International Time ZonesCoverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica

Classic pink World Map Kids’ Shirts $12.89 World Map,Kids’ Shirts, classic pink.

Brown World Map Women’s T-Shirts $21.89 World Map,Women’s T-Shirts, brown.

Veritime Metal Wall Clock With World Map Dial $999999 Veritime Metal Wall Clock With World Map Dial

Map of World Tray – Set of 3 by Tozai Home $96.99 Map of World Tray – Set of 3 by Tozai Home

Michelin Map World Satellite Photo Map $22.59 The satellite photo map of the world, displaying the globe’s bright colors–a unique view of the earth which evokes a desire to explore the world. Laminated for durable use.

World Map 1988 $49.95 This World Map, first published on the National Geographic centennial in December 1988, accompanied an article called, Earth 88 Will We Mend Our Earth The world map combines the classic National Geographic cartographic style with several inset maps to provide a comprehensive look at our planet. New insets for this map included stunningly realistic physical maps for the Eastern and Western Hemispheres, and updated Religions of the World, and Population maps.The 1988 World map features Classic National Geographic cartography and detail, with vivid country borders Thousands of place names, including country capitals Insets for the Arctic and Antarctic regions Dramatic physical earth insets for the Eastern and Western Hemispheres Insets for Population, and Religions of the World Relief shading to visualize mountain rangesCoverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica

World Map 1951 $49.95 The first World Map published by National Geographic following WWII, this classic is a perfect companion to the World Map published in December 1943. The brightness of this map communicates the optimism following WWII, with an inset showing the United Nations, along with a list of the nations who had joined as of December 1951. The 1951 World map features International boundaries reflecting the changes following WWII Insets for Antarctica and the Arctic An inset showing the United Nations countries, along with a list of the countries. The inset also shows the Communist World, and Atlantic Pact countries Major cities and capitals Rail routes, major roads Ocean currents are shown on the mapCoverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica

World Physical Wall Map $49.95 Introducing Compart Maps newest Physical World Wall Map. Loaded with place names, this Iran map is highly detailed with up-to-date accuracy. Beautifully illustrated with subtle hues, the detail is legible with international borders clearly defined. In classic Atlas style, portions of neighboring countries are also present. Perfect for any home, office or classroom, this map can be used for general reference, to track current events, or a piece of art.Cities State Borders PhysicalTerrain International Borders LatitudeLongitude lines Points of Interest Capitals Insets Ocean Relief

World Map at Lake Klejtrup $73.28 High Quality Content by WIKIPEDIA articles The World Map at Lake Klejtrup (Danish: Verdenskortet ved Klejtrup So) is a miniature world map built of stones and grass in Klejtrup So near the village of Klejtrup, Viborg Municipality, Denmark. In 1943, Soren Poulsen, the creator of the World Map, was working on the drainage of the surrounding meadows. He found a stone shaped like Jutland, which inspired him to create a small world of his own. During the winter months, with the use of primitive tools, big stones were placed carefully on the ice and when spring arrived they could easily be tilted into place, and slowly the World Map took shape. Author: Surhone, Lambert M./ Tennoe, Mariam T./ Henssonow, Susan F. Binding Type: Paperback Number of Pages: 76 Publication Date: 2010/11/20 Language: English Dimensions: 9.02 x 5.98 x 0.18 inches

Tahiti National Football Team $62.13 High Quality Content by WIKIPEDIA articles The Tahiti national football team is the national team of French Polynesia and is controlled by the Federation Tahitienne de Football. They finished second in the OFC Nations Cup in its first three installments, 1973, 1980, and 1996. In 2009 the under 20 team qualified for the FIFA U20 World Cup in Egypt. The Federation Tahitienne de Football is the governing body of football in French Polynesia. Author: Surhone, Lambert M./ Tennoe, Mariam T./ Henssonow, Susan F. Binding Type: Paperback Number of Pages: 72 Publication Date: 2010/12/31 Language: English Dimensions: 6.00 x 9.02 x 0.17 inches

World of Baseball Travel Map $9.95 Hot off the press and endorsed by the Hall of Fame, comes The World of Baseball Map! This is THE definitive map of the cultural geography of the national pastime. On one side is a color-coded map of the United States detailing the existence of every professional baseball team from today’s Major leagues to the Women’s league, Negro leagues, and minor leagues. The reverse side contains more than 100 graphics: inset maps, images, and photographs painting a wonderful portrait of the history of the game. Also included are foreign leagues, text, statistics, and team movement. Start the season and the new century with the greatest historical Baseball Map ever made!

The Map $4.99 For everything you do, there’s a song that hits the spot. MOG brings them all to you: a world of music on demand, unlimited mobile downloads and ways to discover music free from the limitations of Pandora. The music you love, with you everywhere you go.

World Map 1941 $49.95 The Classic National Geographic World map of 1941. One of the last maps published prior to the bombing of Pearl Harbor, this extaordinary map shows the Eastern and Western Hemispheres, and features classic colorization to show the country borders and relief shading. A perfect complement to any world map collection.The 1941 World map features The Eastern and Western Hemispheres, beautifully created with the Azimuthal Equal-Area Projection Classic colorization to depict country borders in force in 1941 Thousands of place names, including country capitals Insets for the Land and Water Hemispheres, showing elevation and ocean depths Insets showing population density for the Eastern and Western Hemispheres Coverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica

Montessori World Wall Map $39 This Montessori World Map is based on the continent color palette of the widely used Montessori geography materials Globe of the Continents and Puzzle Map of the World. Nearly 100 years ago, an Italian physician inspired the birth of a worldwide educational movement. Today Dr. Maria Montessoris visionary ideas flourish as the cornerstone of a thriving educational practice. There are thousands of Montessori schools in the U.S. including hundreds of programs in public and charter schools. The Montessori inspired World Map was designed to complement the geography curricula of the American Montessori Society (AMS) and Association Montessori Internationale (AMI).The Montessori World Map includes Country Borders Continent Labels Colored Continents Ocean Labels Scale BarThe Paper version is printed on high quality semi-gloss paper, perfect for framing. The Laminated version uses 3mm laminate on both sides for durability, is easy to clean and markable.

World Political Folded Map $13.95 Excellent for general reference.This map of the World includes up-to-date information and features International and National Boundaries Capital Cities Distances between selected points Index of Country Flags Index in Multiple Languages

Scratch World Map $28.95 The Scratch World Map is the perfect gift for any world traveler. This high quality map features a gold top foil layer that you scratch away, as you would a scratch card, to reveal a whole new world below. The vibrant color and geographical detail will help your track your travels, while bringing worldly style to any room.Size – 32 1/4″ x 23″

Multi Panel Map World $6.98 Designed for Fabric Traditions, this panel features a world map with countyr names. The color palette includes blue, red, green, yellow and orange. The panel measures 35” x 60”. Use for quilting and craft projects.

Whales Of The World Map $29.95 The Whales of the World poster was printed in December 1976 as a supplement to the Great Whales map. Featuring an overview article about whales, information about each species, and beautiful paintings by Larry Foster, this work is a must-have for anyone enamored of these magnificent giants of the sea.The 1976 Whales of the World map features Illustrations and information on each species An brief article about whalesCoverage Area World

World Elevation Digital Map $12.95 This Hypsometric Map uses color shading to show the measurement of the elevation of land above sea level.

Antique Style World Map $124.95 Introducing Comparts Decorative Antique Style World Wall Map. Loaded with place names, this Antique World map is highly detailed with up-to-date accuracy. Beautifully illustrated with subtle parchment hues and iconic sea monsters graphics, the detail is highly legible with international borders clearly defined. Perfect for any home library, bedroom, office or classroom this map can be used for general reference, to track current events, or a piece of art. It is an interior designers dream wall covering.Cities State Borders PhysicalTerrain International Borders LatitudeLongitude lines Points of Interest Capitals Insets Ocean Relief

World Map 1943 $49.95 National Geographic published this classic world map in December 1943, in the midst of WWII. Compared to many of the other world maps by the National Geographic Society, this one had a decidedly dark cast, possibly a reflection of the tone of discouragement felt by many as the War continued on. A perfect companion to the World maps of 1951 and 1970.The 1943 World map features International boundaries as of Sept. 1, 1939 Insets for the Northern and Southern Hemispheres An inset showing the world alliances during WWI An inset showing the alliances in WWII as of the publication of this map Classic colorization depicting mountain ranges and areas of high elevation Ocean currents and time zonesCoverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica

World Map 1965 $49.95 This stunning world map, first published in February of 1965, accompanied an article, entitled Four-Ocean Navy in the Nuclear Age. In addtion to its beautiful colors and distinct National Geographic cartographic style, this world map includes detailed ocean depth and ocean currents information. Detailed geographical information and timely insets make this a classic map for any history buff. A perfect companion to the World maps published in 1943 and 1951.The 1965 World map features Classic National Geographic cartography and detail, with vivid country borders Thousands of place names, including country capitals International time zones, largest countries, major cities, vegetation and land use Insets showing the North Polar Region and South Polar Region An inset map showing the United Nations countries Insets for vegetation and land use, population density, and world time zones Airports, canals, depth curves and soundings in fathoms, elevations, prevailing winds, ocean currents, channel depths for principal portsCoverage Area The World, North America, South America, Africa, Asia, Australia, Europe, Oceania, Antarctica

Children’s World Map $49.95 A colorful map of the World. It shows more geographical features including state borders, state capital, major cities, mountain ranges, lakes and major rivers. More than 300 illustrations on the map show animals throughout the world and indicates the areas where they live, historical items and cultural items. Cities PhysicalTerrain International Borders Legend Index Capitals Ocean Relief

Illustrated Map of the World for Kids $49.95 A colorful Political map of the World. It shows more geographical features including state borders, state capital, major cities, mountain ranges, lakes and major rivers. More than 300 illustrations on the map show animals throughout the world and indicates the areas where they live, historical items and cultural items. Cities PhysicalTerrain International Borders Index Capitals Ocean Relief

World Wall Map with Flags $12.95 Maps International maps are highly detailed using crisp clear text, a vibrant color palette and attractive terrain shading. Perfect for home, office or classroom, this wall map of the World with Flags is informative and eye-catching. This World with Flags Wall Map features National Boundaries National Capitals Cities Country Flags Latitude and Longitude Lines Physical Features and Terrain Shading Ocean Bathymetry Detailed Scale 130,000,000 and 140,000,000

World Megamap Wall Map $27.95 Maps International maps are highly detailed using crisp clear text, a vibrant color palette and attractive terrain shading. Perfect for home, office or classroom, this wall map of the World is informative and eye-catching. This World Wall Map features National Boundaries National Capitals Cities Latitude and Longitude Lines Physical Features and Terrain Shading Ocean Bathymetry Detailed Scale 120,000,000

Captain Cook: The Seaman’s Seaman $18.39 New – The most important explorer of his day, Captain James Cook’s coat of arms carries the motto: “He left nothing unattempted”. During three major voyages, first in HMS “Endeavour” and subsequently in HMS “Resolution”, Cook added many new places to the world map, including the islands of Hawaii. He charted the coast of New Zealand, and the east coast of Australia, conducted important astronomical observations, witnessing the transit of Venus from Tahiti, and began the search for a north-west p

Captain Cook: The Seaman’s Seaman $5.31 New – The most important explorer of his day, Captain James Cook’s coat of arms carries the motto: “He left nothing unattempted”. During three major voyages, first in HMS “Endeavour” and subsequently in HMS “Resolution”, Cook added many new places to the world map, including the islands of Hawaii. He charted the coast of New Zealand, and the east coast of Australia, conducted important astronomical observations, witnessing the transit of Venus from Tahiti, and began the search for a north-west p

James Cook $8.95 In the 1700s, Captain James Cook was hired to seek an undiscovered continent known as Terra Australis Incognita. Cook proved that it did not exist, dramatically changing Europeans’ understanding of their world. Young readers will be fascinated by Cook’s encounters with the native peoples of Tahiti and Hawaii. A recipe from the period is also included.- Cook’s youth as an apprentice and early training in the British Royal Navy- a map of Cook’s routes- the discovery of Tahiti, Hawaii, Australia, and New Zealand- customs of the Kaua’i, Maori, and Tahitians- Cook’s ships–the Adventure and the Resolution- the responsibilities of the crew and how they coped with illnesses such as scurvy- colorful maps and images showing the areas explored- sections on the age of exploration- the political climates of various countries that made explorers venture out into the unknown- real recipes for foods the explorers ate on their travels- how explorers lived while on the high seas, on the trail, or in the encampment