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Read the text again and answer the following questions
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What is the role of oceans on our planet?
How does the population influence on the oceanic environment?
What do coastal wetlands include?
What are coastlines effected by?
What is the role of coral reefs in life?
Where are the coral reef suffering especially greatly?
What are the reasons of damaging coral reefs?
What is coastal erosion caused by?
What does coastal erosion lead to?
Talk about the ways of protecting oceans and oceanic resources.
Collapsing fisheries
Coastal, inland and ocean fisheries - the largest harvest of a wild food source on the planet - remain in serious trouble. Commercial fleets, totalling 4 million vessels (2.1 million with motors) landed 81.9 million tons of fish, shellfish and marine plants in 2006, according to the UN Food and Agriculture Organization (FAO). This is a decrease of two million tons compared to 2005 and the third lowest annual take since 1994. Most stocks remain fully exploited or over-exploited. As of 2006, FAO reports that 52 percent of the world's commercial fish stocks are fully exploited, 19 per cent are over-exploited, with 8 per cent "significantly depleted" and one per cent slowly recovering. Only 20 per cent of stocks are considered under-exploited or moderately exploited (meaning there is some room for increasing catches).
Of the world's 15 major fishing regions, productivity has fallen over the past few years in all but four. Landings of the most valuable species of fish, including cod, tuna, and haddock, have dropped by one-quarter since 1970. In the four hardest hit regions - the northwest, the west-central and the southeast Atlantic, and the east-central Pacific - catches have plummeted by more than 30 per cent since 1989.
The alarming state of capture fisheries prompted FAO to warn: "the maximum wild capture fishery potential from the world's oceans has probably been reached and reinforces the calls for more cautious and effective fisheries management to rebuild depleted stocks and prevent the decline of those being exploited at or close to their maximum potential."
In the Black Sea over the 30-year period the number of commercially valuable fish species plunged from 26 to 5. Catches of commercial fish fell from 1 million metric tons in 1992 to around 100,000 metric tons in 2002. In many areas the sea no longer has any exploitable marine life. The Black Sea is well on its way to becoming a "dead" sea in terms of biological diversity due to pollution spilled over the past four decades (see "Coastal Pollution," below). All waters below 150-200 metres are without oxygen, and only 10 per cent of the total volume of near-surface water has enough oxygen to sustain life higher than micro-organisms.
In Southeast Asia nearly all waters within 15 kilometres of land are considered over-fished, according to Ed Gomez, Director of the Marine Science Institute of the University of the Philippines in Metro Manila. Trawlers, the strip miners of the sea, often precipitate the collapse of fish stocks from years of over-harvesting. But it is small-scale fishers and their families who often pay the price and are forced to use illegal and destructive fishing gear, such as poisons, dynamite and fine mesh nets to put food on the table.
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Disappearance of the world's marine catch of fish and shellfish has ominous implications for the food supply of the world's 2.6 billion people who rely on seafood to supply 20 per cent of their daily animal protein intake. In Southeast Asia and the South Pacific, the sea provides up to 100 per cent of all animal protein in daily diets.
In the late 1990s, the world's fishing fleets were discarding around 20 million metric tons of fish and shellfish every year as by-catch from their operations. Most of the waste was due to trawlers which harvest enormous quantities of marine life in their relentless search for squid, shrimp or bottom dwelling fish (such as halibut, sole or flounder). This loss of potential protein (and income) amounted to one-quarter of the world's annual take from the seas. Newer estimates by FAO put the amount of discarded fish at between 7 and 8 million tons in 2004. The big decrease is due to the expansion of target species, thereby reducing the by-catch.
Can aquaculture substitute for the declining ocean fish catch? Production of farmed fish and shellfish has increased dramatically over the past 15 years. In 2006, FAO reported that 51.7 million tons of fish, shellfish and seaweeds were farmed (both marine and freshwater), representing more than a doubling of farmed organisms since 1994, when 21 million tons were farmed.
China continues to account for the largest share of farmed marine and freshwater species, with 70 of the total volume and over 50 per cent of the total value. Aquaculture and mariculture are now worth $78.8 billion a year (in 2006). Worldwide, the sector has grown by an average rate of nearly 9 per cent a year since 1970. In 2006, the top three producers were: China (with 34.4 million tons), India (with 3.1 million tons) and Vietnam (with 1.6 million tons).
Experts worry that aquaculture production, if left unregulated, will end up destroying coastal wetlands and mangrove swamps, necessary as breeding and nursery grounds for wild fish stocks and also the source of fry for aquaculture operations. Furthermore, since much of the production from fish farms is exported, up to three-quarters, this source of protein contributes little to the diets of local people.
Vocabulary
fishery – рыболовный промысел
inland fishery - рыболовство во внутренних водоемах
vessel – судно, корабль
fish stocks – рыбные ресурсы, рыбные запасы
species of fish – виды рыб
rebuild depleted stocks – восстановить истощенные запасы
over-exploited – чрезмерно использованный
capture fisheries – рыболовный промысел, рыболовство
squid – кальмар, приманка для ловли рыбы
shrimp - креветка
bottom dwelling fish – придонная рыба
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halibut – палтус, камбаловые
sole – морской язык
flounder – речная камбала
protein intake – потребление белка
food supply – кормовая база, пищевые ресурсы
Read the text and answer the following questions:
1. Talk about the state of fisheries.
2. What is the state of fisheries in the Black sea?
3. What are the main reasons of collapse of fisheries?
4. What are the consequences of collapsing fisheries?
5. Can aquaculture substitute for the declining ocean fish catch?
6. What countries are the top fish producers?
Coastal pollution
Rapidly expanding populations and the growth of cities along coastlines has contributed to a rising tide of pollution in nearly all of the world's seas. Between 80 per cent and 90 per cent of all commercial fish are caught within 320 kilometres of land, and many within 50 kilometres. Thus pollution, mostly from land-based sources, is a contributing factor in falling catches.
Coastal urban areas dump increasing loads of toxic wastes into the sea. In fact, waters around many coastal cities have turned into virtual cesspools, so thick with pollution that virtually no marine life can survive. Let us consider the following:
· Despite over two decades of cleanup efforts, the Mediterranean Sea is on the receiving end of between 30 and 50 million metric tons of untreated or partially treated sewage every year;
· The Lagoon of Iddo in Lagos, Nigeria, gets 60 million litres of raw sewage a year, along with vast quantities of industrial waste;
· Calcutta and Bombay, India, respectively, dump 400 million metric tons and 365 million metric tons of raw sewage and other municipal wastes into coastal waters every year;
· Karachi, Pakistan's largest city, empties 175 million metric tons of untreated sewage and industrial filth into the Arabian Sea every year;
· Chinese cities and towns along the Yellow Sea discharge 50-60 million metric tons of untreated or partially treated municipal wastes every day into coastal waters;
· The Bays of Valparaiso and Concepcion, Chile receive a combined total of 244 million metric tons of untreated effluents a year, mostly from copper mines, pulp and paper mills, fish processing plants and oil refineries;
· In 2007, researchers identified over 200 'dead zones' around the world's coastlines, an increase of 51 such zones since 2003, when scientists reported 149 such biological dead zones in the world's seas. Dead zones are areas where the dissolved oxygen levels are so low that no marine life can be sustained (other than micro-organisms). Moreover, these biologically dead areas are expanding due mainly to high nutrient pollution levels brought in by rivers and streams and washed off coastal land. Since the 1960s, the number of dead zones has doubled every decade. The dead zone in the Gulf of Mexico, now the world's second largest, covers 21,000 square kilometres, an area the size of New Jersey. The world's largest dead zone is in the Baltic Sea, covering some 70,000 square kilometers of seabed.
Ocean currents transport pollutants into the remotest corners of the world's seas. No place in the world ocean is immune from the depredations of humanity. Toxic chemicals, such as PCBs and DDT, for instance, have turned up in the fatty tissues and blubber of seals in the Arctic and penguins in the Antarctic, thousands of kilometers from population centers. Beluga whales found in the mouth of Canada's St. Lawrence River have such high levels of PCBs in their blubber that under Canadian law they qualify as "toxic waste dumps".
Vocabulary
tide – морской прилив и отлив
tide of pollution – поток загрязнения
urban area – городская территория
dump – груда хлама, свалка
cesspool – сточный колодец, сточная яма
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wastes – отходы
depredations of humanity – хищническое уничтожение человечеством
blubber – китовый жир
seals – тюлени
fatty tissues – жировая ткань, жировая клетчатка
untreated – необработанный, неочищенный
effluents – жидкие промышленные отходы
pulp and paper mills- целлюлозно-бумажный комбинат
fish processing plant – рыбообрабатывающий завод
oil refineries – нефтеперерабатывающий завод
Read the text and answer the following questions:
What is dead zone?
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