Why are some coastal environments under threat? Coastal areas have become increasingly under threat in recent years. Climate change is having a huge effect on coastal areas, making them much more likely to flood. Pollution is also having a negative effect on the coastline, as is development of economic and industrial activities, particularly coastal tourism.
What are coral reefs? Coral reefs are marine ecosystems. They are being damaged by human activity. Over half of the world's coral reefs have been damaged by human activity and they could become extinct within 40 years if they are not protected and managed sustainably. Coral reefs in the Indo-Pacific are disappearing twice as fast as tropical rainforests. Coral reefs form in warm, shallow, clean seas. The sea temperatures must be above 21 degrees for coral to form, and because they need sunlight to grow, the coral must not be more than 30-40 metres from the sea surface.
Coral reefs form in warm, shallow, clean seas. The sea temperatures must be above 21 degrees for coral to form, and because they need sunlight to grow, the coral must not be more than 30-40 metres from the sea surface. They are made of animals called stony corals. Corals are made up of tiny organisms called polyps. The polyp sits inside a calyx, or cup, made of limestone (calcium carbonate). As the polyps live, reproduce, and die, they leave their skeletons behind. A coral reef is built up by layers of these skeletons covered by living polyps, which are further cemented together by organisms like coralline algae, and physical processes like waves washing sand into spaces in the reef. Researchers may look at the amount of living coral on a reef to determine how healthy it is. There are 3 types of coral reefs: Fringing reefs, which grow close to the coast in shallow waters Barrier reefs, which are large, continuous and are separated from land by a lagoon (the Great Barrier Reef is the largest example of a barrier reef) Atolls, which are ring-shaped and located near the sea surface on top of underwater islands or inactive volcanoes
The red dots on the map show the location of the world's coral reefs. The majority are between 30 degrees north and south of the equator.
Why are coral reefs important? - They provide a home and food (nutrients) for many different species of fish. Without coral reefs, these fish are left homeless with nowhere to live and nowhere to have their babies. They increase the world's biodiversity. - Reef fish and molluscs feed between 30 and 40 million people every year. - Reef fish make beautiful pets and the money made by catching and selling these animals provides many people with an income so that they can feed their families. - Coral are very important in controlling how much carbon dioxide is in the ocean water. The coral polyp turns carbon dioxide in the water into a limestone shell. Without coral, the amount of carbon dioxide in the water would rise dramatically and that would affect all living things on Earth. - Coral reefs protect coasts from strong currents and waves by slowing down the water before it gets to the shore. They provide a barrier between the ocean and the shore.
Destruction of the coral reefs 10% of the world's coral reefs have already been completely destroyed. In the Philippines, where coral reef destruction is the worst, over 70% have been destroyed and only 5% can be said to be in good condition. So what has happened to destroy the reefs? It s us! Humans damage the reef - indirectly and directly: Indirectly, we have destroyed their environment. Coral reefs can live only within a certain temperature range. Global warming caused by the greenhouse effect has increased the temperature of the oceans so high that the coral get sick and die. Even a rise of one degree in the average water temperature can hurt the coral. The most obvious sign that coral is sick is coral bleaching. That is when either the algae inside die, or the algae leave the coral The direct way in which humans destroy coral reefs is by physically killing them. All over the world divers catch the fish that live in and around coral reefs. Often they blow up a coral reef with explosives and then catch all the stunned fish swimming around. This completely destroys the reefs. The creatures that do survive are left homeless. Corals may also be blasted to get stone to build houses. Tourism is also having an effect. Illegal collection of coral for souvenirs is becoming a major threat. Huge numbers of hotels, restaurants and bars have been built for the tourists and all of the waste water finds its way into the sea. In heavy rain, the drainage and sewage systems cannot work effectively and filthy water pours into the sea. Oil from cruise ships carrying tourists may also leak into the sea, adding to pollution levels and blocking sunlight from reaching the reefs.
Managing the coral reef - The Great Barrier Reef Marine Park Authority The Great Barrier Reef is the largest coral reef in the world. It is made of over 2900 individual reefs and 900 islands stretching for over 3000 kilometres. It is in the Coral Sea, which lies off the coast of Queensland in North-East Australia. The Great Barrier Reef is so large that it can be seen from outer space. It was selected as a UNSECO World Heritage Site in 1981. The Great Barrier Reef Marine Park is a multiple-use area. It covers 344,000 square kilometres. Zoning helps to manage and protect the Marine Park so that all users can enjoy it, now and in the future. Zoning therefore helps to make sure that the Park is managed in a sustainable way. Zoning Plans say what activities can happen where, both to protect the marine environment and to separate potentially conflicting activities. The current Zoning Plan was introduced in 2004. Watch the video to find out more about the background to the zoning plan.
The Preservation Zone - the Pink Zone - is a 'no go' area. A person cannot enter a Pink Zone unless they have written permission and extractive activities (eg. removing coral or fishing) are strictly prohibited. Research may occur in a Pink Zone, if it cannot be done elsewhere, but only if the research is relevant to, and a priority for, management. A permit is required to conduct research in this zone. The Pink Zone makes up less than 1% of the Great Barrier Reef Marine Park. Pink Zones provide high-level protection for special and unique places, habitats, plants and animals within the Marine Park and provides an undisturbed baseline for comparison with other zones. The Marine National Park Zone - the Green Zone - is a 'no-take' area and extractive activities like fishing or collecting are not allowed without written permission from Marine Park authorities. Anyone can enter a Green Zone and participate in activities such as boating, swimming, snorkelling and sailing. Fishing gear, such as rods with attached hooks, must be stowed inboard the boat or in rod holders. All fishing apparatus must be out of the water. Anchoring is also allowed in a Green Zone, however in high use and sensitive areas use of a mooring may be necessary or there may be a no anchoring area defined by buoys. The Green Zone makes up about 33% of the Great Barrier Reef Marine Park.
Green Zones protect the biodiversity within the Great Barrier Reef Marine Park by protecting important breeding and nursery areas such as seagrass beds, mangrove communities, deepwater shoals and reefs. The size of fish within no-take areas will increase and these bigger fish will produce more offspring. Adult fish and their offspring are not confined to the no-take areas and can move into adjacent areas, creating a spillover effect that helps replenish fish stocks in areas where fishing is allowed. The Scientific Research Zone - the Orange Zone - makes up less than 1% of the Park. It facilitates research, in areas primarily around scientific research facilities that are relatively undisturbed by extractive activities. The Orange Zone helps to manage research activities and separates research from conflicting, high impact activities. This helps to ensure research and data gathered within the Great Barrier Reef Marine Park is less influenced by human activity. The Buffer Zone - the Olive-Green Zone - makes up about 3% of the Park. It provides for the protection and conservation of areas of the Marine Parks in their natural state, while allowing the public to appreciate and enjoy the relatively undisturbed nature of the area. Trolling for pelagic fish species is allowed in the Buffer Zone. However, all other forms of extractive activities such as bottom fishing and spearfishing are prohibited in this zone. Pelagic species include species of trevally, scad, queenfish, rainbow runner, dolphinfish, black kingfish or cobia, barracuda, sailfish, marlin, swordfish, mackerel, tuna, bonito, wahoo, small toothed jobfish and green jobfish.
The Conservation Park Zone - the Yellow Zone - allows for increased protection and conservation of areas of the Marine Park, while providing opportunities forreasonable use and enjoyment including limited extractive use. Most extractive activities are allowed in a Yellow Zone with additional restrictions for most fishing activities. Fishing activities allowed in a Conservation Park (Yellow) Zone include: - limited line fishing (one hand-held rod or one hand-held line per person, with no more than one hook attached to that line) - trolling (no more than three lines per person and up to six hooks combined total per person) - limited spearfishing (snorkel only) - bait netting - limited crabbing (four crab pots, dillies or inverted dillies) - limited collecting (includes oysters and bait, excludes take of coral (live or dead and anemones) The Habitat Protection Zone - the Dark Blue Zone - provides for the conservation of areas of the Great Barrier Reef Marine Park by protecting and managing sensitive habitats and ensuring they are generally free from potentially damaging activities. Trawling is not permitted in the Habitat Protection Zone. The Zone continues to provide for reasonable use of areas and makes up about 28% of the Great Barrier Reef Marine Park.
The General Use Zone - the Light-Blue Zone - is to provide opportunities for reasonable use of the Great Barrier Reef Marine Park, while still allowing for theconservation of these areas. The General Use Zone in the Great Barrier Reef Marine Park is very similar to the Queensland (State) General Use Zone. The Queensland Government manages commercial fishing in the Marine Park. The main management strategies are: - limits on the number of fishing licences - seasonal closures - restrictions on the size of fishing boats - restrictions on the length, mesh sizes and number of nets used - limits on the number of hooks used - limits on the numbers of traps such as crab pots used - limits on the total allowable catch restrictions on the size of fish