Human Impact

By Avery and Tatum

Coral Reefs

Did you know that approximately 500 million people worldwide depend upon reefs? In fact, 30 million are virtually totally dependent upon reefs. Coral ecosystems are a source of food for millions; protect coastlines from storms and erosion; provide habitat, spawning and nursery grounds for economically important fish species; provide jobs and income to local economies from fishing, recreation, and tourism; are a source of new medicines, and are hotspots of marine biodiversity. These values contribute approximately $29.8 billion to world economies each year. Continued decline of reefs will have alarming consequences for people worldwide.
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Tubbataha Reef

Coral Reefs and the Environment

Coral reefs are often called the rain forests of the sea, both due to the vast amount of species they harbor, and to the high productivity they yield. Aside from the hundreds of species of coral, reefs support extraordinary biodiversity and are home to a multitude of different types of fish, invertebrates and sea mammals. Covering less than one percent of the ocean floor, reefs support an estimated twenty-five percent of all marine life, with over 4,000 species of fish alone. Reefs provide spawning, nursery, refuge and feeding areas for a large variety of organisms, including sponges, cnidarians, worms, crustaceans (including shrimp, spiny lobsters and crabs), mollusks (including cephalopods), echinoderms (including starfish, sea urchins and sea cucumbers), sea squirts, sea turtles and sea snakes. Reef structures play an important role as natural breakwaters, which minimize wave impacts from storms such as cyclones, hurricanes or typhoons. Also, their beauty makes coral reefs a powerful attraction for tourism, and well managed tourism provides a sustainable means of earning foreign currency and employment for people around the world, even in remote areas of developing countries. Several attempts have been made to estimate the value of coral reefs in terms of dollars. Benefits from coral reefs can be categorized into 2 types: "direct use values" (fisheries and tourism industry), and "indirect use values" (benefit derived from coastline protection). According to a United Nations estimate, the total economic value of coral reefs range from US$ 100,000 to 600,000 per square kilometre per year

Effects of Damage Done to Coral Reefs

  • Roughly one-quarter of coral reefs worldwide are already considered damaged beyond repair, with another two-thirds under serious threat. Major threats to coral reefs and their habitats include:
  • Destructive fishing practices: These include cyanide fishing, blast or dynamite fishing, bottom trawling, and muro-ami (banging on the reef with sticks). Bottom-trawling is one of the greatest threats to cold-water coral reefs.
  • Overfishing: This affects the ecological balance of coral reef communities, warping the food chain and causing effects far beyond the directly overfished population.
  • Careless tourism: Careless boating, diving, snorkeling, and fishing happens around the world, with people touching reefs, stirring up sediment, collecting coral, and dropping anchors on reefs. Some tourist resorts and infrastructure have been built directly on top of reefs, and some resorts empty their sewage or other wastes directly into water surrounding coral reefs.
  • Pollution: Urban and industrial waste, sewage, agrochemicals, and oil pollution are poisoning reefs. These toxins are dumped directly into the ocean or carried by river systems from sources upstream. Some pollutants, such as sewage and runoff from farming, increase the level of nitrogen in seawater, causing an overgrowth of algae, which 'smothers' reefs by cutting off their sunlight.
  • Sedimentation: Erosion caused by construction (both along coasts and inland), mining, logging, and farming is leading to increased sediment in rivers. This ends up in the ocean, where it can 'smother' corals by depriving them of the light needed to survive. The destruction of mangrove forests, which normally trap large amounts of sediment, is exacerbating the problem.
  • Coral mining: Live coral is removed from reefs for use as bricks, road-fill, or cement for new buildings. Corals are also sold as souvenirs to tourists and to exporters who don't know or don't care about the longer term damage done, and harvested for the live rock trade.
  • Climate change: Corals cannot survive if the water temperature is too high. Global warming has already led to increased levels of coral bleaching, and this is predicted to increase in frequency and severity in the coming decades. Such bleaching events may be the final nail in the coffin for already stressed coral reefs and reef ecosystems.

Damaged Coral Reefs


Did you know that around 80% of marine litter originates on land? Pollution has a severe impact on our environment and our economy. Sea birds, whales, turtles, and other life in the ocean are eating the pollution and dying from choking or it getting stuck in their body.

Most of the pollution in the ocean is plastic pollution. 90% of all trash floating i the ocean is plastic, with 46,000 pieces of plastic per square mile. Unlike other types of trash, plastic does not biodegrade, instead it breaks down into smaller and smaller pieces in the sunlight, but they never really dissappear. These plastic pieces are eaten by marine life, wash up on beaches, or break down into plastic dust and attract more debris.

Other pollution like Toxic and Toxic pollution can travel through the atmosphere and can be deposited far from its origional source.