EXAM PRACTICE 1

 Exam practice

Task 1

Reading Coral reefs are among the most biodiverse ecosystems in the ocean, with up to one quarter of all marine species living in or near a reef environment. Sadly, many of these beautiful, fragile structures are dying out. Climate change is a major threat to reefs, but direct human activities have a serious impact, too. Water pollution caused by humans adversely affects coral reefs. Pollutants can affect reefs in two ways. Certain substances that can contaminate ocean water, such as oil and pesticides, are poisonous to coral and other forms of marine life. Other pollutants, such as animal waste and fertilizer, cause an overgrowth of simple plant-like organisms called algae. These algae block sunlight from reaching the coral, causing it to die.   Three exploitive methods of fishing can cause damage and degradation to coral reefs. First, overfishing of some species can lead to a lack of biodiversity that affects the overall health of the reef. Blast fishing - the use of explosives to stun and kill fish so they are easier to catch - often kills coral polyps and destroys sections of the reef. And the use of cyanide, a poison, to stun large, economically-important fish species often kill both coral and smaller species of fish.  Even tourism has been implicated in the destruction of coral reefs. Many reefs are popular sports for diving, and although many tourists are careful, coral is easily damaged when it is touched. Even stirring up sand and small particles from the seafloor can lead to the degradation of reefs. And waste and pollution from tourists’ boats, ocean-front hotels, and even tourists themselves are also a factor.

Lecture The article lists various human activities that pose a threat to coral reefs. I’d like to say that the situation is less serious than the article suggests, but sadly the opposite is true, and human actions really are harming coral reefs around the world.  It has been estimated that pollution may affect up to 30% of all reef systems in the ways that the article explains. A three year study from 2009 to 2012 by scientists based in the USA showed the effects of pollution in more detail. Coral that was exposed to pollution over this period had significantly more disease and stress than coral unaffected by pollutants. Interestingly, when the pollution was removed, the coral recovered in less than one year.  Fishing might sound like a relatively harmless activity compared to causing pollution, but a study carried out by the World Resources Institute in 2002 estimated that roughly two-thirds of reefs in southeast Asia are affected by overfishing and destructive fishing techniques. And a 2013 study by a team of scientists from Australia and Canada shows that overfishing of sharks can affect reefs. When there are fewer sharks, the population of fish that eat algae also declines. The reason is that the shark keeps the population of smaller predator fish low. If there are fewer sharks, these smaller predator fish will feed on the algae eating fish, which means algae levels will rise. And when this happens, reefs diem as the article explains. Tourism may seem like another minor threat to coral, but not according to the National Oceanographic and Atmospheric Administration, the NOAA. that organization has ranked tourism and recreation as either a high priority threat or a medium priority threat to coral reefs at almost two thirds of all reef sites around the world.

Summarize the points made in the lecture you just heard, being sure to specifically explain how they support points made in the reading passage. 

Task 2

In the last 20 years, technology has become both more advanced and more available. In what ways has greater access to advanced technology affected the way people work? Use specific reasons and details to support your answer.