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Choose to view chapter section with a click on the section heading. ►Resource Classification ►Nonrenewable Resources ►Renewable Resources ►Submerged Cultural Resources ►Biological Resources – Marine Mammals ►Biological Resources – Algae, Aquaculture and Medicine Chapter Topic Menu ►Biological Resources – Fish ►The State of the World’s Fisheries – A Bleak Picture ►Commercial Fishing ►Who Owns the Sea? ►Biodiversity and the Future Exit Chapter 17 Pages 17-3 to 17-4 Resource Classification Resource Classification 17 - 2 Menu Previous Next Because there is a broad range of marine resources, it is best to begin by classifying them into different areas. Two common categories are renewable and nonrenewable resources and physical and biological resources. Chapter 17 Pages 17-3 to 17-4 Resource Classification Resource Classification 17 - 3 Menu Previous Next Resource Classification Chapter 17 Pages 17-3 to 17-4 Resource Classification Biological resources are those that involve bioproductivity, such as fisheries and kelp harvesting. Physical resources don’t involve biological processes. These include minerals, energy production, and recreation. Kelp Harvesting in Southern California 17 - 4 Menu Previous Next Resource Classification Chapter 17 Pages 17-3 to 17-4 Resource Classification Renewable resources are those that growing organisms, sunlight, or other processes naturally replace. Nonrenewable resources are those that natural processes don’t replace, or that do so at such a slow rate that they’re not replenished in a human lifespan. 17 - 5 Menu Previous Next Chapter 17 Pages 17-3 to 17-4 Resource Classification Resource Classification Many physical resources, such as oil and natural gas, are nonrenewable. Some, such as wave energy, are renewable because the sun replenishes the energy source daily. People tend to think of biological resources as renewable, and in many cases they are. However, while most marine biological resources are potentially renewable, most are effectively nonrenewable. This happens when a fishery takes a species from the ocean faster than it can reproduce to maintain its population. Whaling and commercial fishing are two of many examples. 17 - 6 Menu Previous Next Chapter 17 Pages 17-5 to 17-14 Nonrenewable Resources Nonrenewable Resources 17 - 7 Menu Previous Next Chapter 17 Pages 17-5 to 17-8 Nonrenewable Resources Energy Petroleum & Natural Gas About one third of the world’s crude oil and about a quarter of the natural gas come from offshore sources. Crude oil is a complex mix of thousands of different compounds. Mostly hydrocarbons, which consist of carbon and hydrogen chains. Hydrocarbons are the source of chemical energy from which refineries distill gasoline, diesel, kerosene, and other fuels. Natural gas, also called methane (CH4), is a gaseous hydrocarbon. 17 - 8 Menu Previous Next Energy Petroleum & Natural Gas Nonrenewable Resources Chapter 17 Pages 17-5 to 17-8 Geologists find petroleum and natural gas in marine and terrestrial sediments. Scientists conclude that petroleum and natural gas form from the remains of primarily marine organisms. Platform Mars in the Gulf of Mexico 17 - 9 Menu Previous Next Energy Nonrenewable Resources Chapter 17 Pages 17-5 to 17-8 Petroleum & Natural Gas After these organisms die, they amass in depressions with little water motion, low oxygen, and few scavenging organisms. Anaerobic bacteria break down the organic matter into simpler organic compounds. As time passes, sediments accumulate on top of these compounds until they’re under high pressure and high temperature. The compounds continue to undergo conversion into hydrocarbons - can take millions of years. This completes the transition of these organisms into crude oil. 17 - 10 Menu Previous Next Energy Nonrenewable Resources Chapter 17 Pages 17-5 to 17-8 Petroleum & Natural Gas Scientists have concluded that this same process results in methane (natural gas–CH4) along with petroleum. In the case of methane the insoluble compounds progress from petroleum to methane when the process continues for longer periods, or at a higher temperature. This explains why geologists have found few oil deposits below 3,000 meters (9,800 feet), and only natural gas deeper than 7,000 meters (23,000 feet). The pressure and temperature are so high that only methane forms. 17 - 11 Menu Previous Next Energy Nonrenewable Resources Chapter 17 Pages 17-5 to 17-8 Petroleum & Natural Gas Oceanographers study sediments with seismic instruments. By studying how sound waves travel and echo within sediment, they can determine variations in density and composition. This method applies well to the search for oil because it is less dense than surrounding sediments. The physical characteristics of the rock surrounding oil and natural gas are important because they determine where the oil or gas collects. 17 - 12 Menu Previous Next Energy Chapter 17 Pages 17-5 to 17-8 Nonrenewable Resources Petroleum & Natural Gas Hydrocarbons form surrounded by source rock. They don’t necessarily stay there, however, and may travel through porous sediments lying over it. When hydrocarbons reach rock that they can’t penetrate, called reserve rock, they collect in the spaces underneath it, allowing the oil or gas to pool. This is called an oil or gas reserve. Sound waves detect the reserves as low-density pockets in the reserve rock. 17 - 13 Menu Previous Next Energy Petroleum & Natural Gas Nonrenewable Resources Chapter 17 Pages 17-5 to 17-8 Drilling For Oil and Gas 17 - 14 Menu Previous Next Energy Chapter 17 Pages 17-5 to 17-8 Nonrenewable Resources Petroleum & Natural Gas Oil companies extract petroleum and natural gas by drilling through sediment and rock into the reserve. Despite the cost and complexity, however, offshore drilling continues to grow to meet the demand for oil and gas. One of the newest deep water platforms is Platform Mars. Today, oil companies are taking more risks and drilling ever deeper wells as their shallower wells run dry. 17 - 15 Menu Previous Next Energy Chapter 17 Pages 17-8 to 17-9 Nonrenewable Resources Methane Hydrates Methane hydrates is another form of nonrenewable marine energy source. They are ice crystals containing methane found on the continental slope. They consist of frozen water molecules that create a cage within sediment. Each of these cages holds a single methane gas molecule. When you bring methane hydrates to the surface, the ice melts, releasing the methane. You can literally light a match and ignite the methane emerging from the sediments. 17 - 16 Menu Previous Next Energy Chapter 17 Pages 17-8 to 17-9 Nonrenewable Resources Methane Hydrates Scientists are still determining exactly how methane hydrates form. Worldwide, more than 11,320 million trillion liters/400 million trillion cubic feet of methane are thought to exist in methane hydrates. That’s enough natural gas to supply the world’s needs for centuries. 17 - 17 Menu Previous Next Energy Chapter 17 Pages 17-8 to 17-9 Nonrenewable Resources Methane Hydrates Despite this tremendous energy resource potential, currently no one uses methane hydrates as fuel. Very expensive to recover them - relatively dangerous to handle. Technologies for handling methane hydrates are being developed - there are challenges. Methane is a greenhouse gas - they could be a problem if changing sea temperatures or the effects of mining caused a sudden release. 17 - 18 Menu Previous Next Chapter 17 Pages 17-8 to 17-9 Nonrenewable Resources Energy Methane Hydrates 17 - 19 Menu Previous Next Chapter 17 Pages 17-10 to 17-13 Nonrenewable Resources Salts and Minerals Ferromanganese Nodules. Ferromanganese nodules commonly form around shark teeth and volcanic fragments. Magnesium Compounds. Magnesium is a strong, lightweight metal essential for aerospace construction and other structural applications. Third most abundant element in seawater. Salts. Evaporites are the salts left behind when seawater evaporates. 17 - 20 Menu Previous Next Phosphorite. Phosphorite deposits are the remains of marine organisms that live in areas with extensive upwelling. Marine Muds and Metals. Hydrothermal vents play a role in supporting chemosynthetic ecosystems and maintaining seawater chemistry. Chapter 17 Pages 17-10 to 17-13 Nonrenewable Resources Salts and Minerals 17 - 21 Menu Previous Next Gravel and Sand Chapter 17 Page 17-13 Nonrenewable Resources At present, gravel and sand are second only to gas and oil in their annual economic value. Mining Sand and Gravel. 17 - 22 Menu Previous Next Chapter 17 Pages 17-15 to 17-21 Renewable Resources Renewable Resources 17 - 23 Menu Previous Next Energy Chapter 17 Pages 17-15 to 17-16 Renewable Resources Although we customarily think of oil and natural gas when we think of energy from marine resources, the sea offers renewable energy options. Wave energy. Tide energy. Thermal gradient technology. 17 - 24 Menu Previous Next Energy Chapter 17 Pages 17-15 to 17-21 Renewable Resources Of these three renewable energy resources, none are really commercially feasible at present. Tidal power seems the most feasible. Tidal energy has environmental concerns. Thermal gradient technology has been tried experimentally but has largely been abandoned because it has low efficiency. 17 - 25 Menu Previous Next Energy Chapter 17 Pages 17-15 to 17-21 Renewable Resources Harnessing Wave Energy 17 - 26 Menu Previous Next Ocean Thermal Energy Conversion Chapter 17 Pages 17-15 to 17-21 Renewable Resources Energy 17 - 27 Menu Previous Next Chapter 17 Pages 17-17 to 17-18 Renewable Resources Fresh Water It may seem odd to think of fresh water as a marine resource, but it certainly is. Natural fresh water is not always in ample supply. The single most important factor that determines how many people can live in a given area is the availability of fresh water. Extracting fresh water from seawater involves desalinization— the removal of dissolved salts. Distillation is the process of evaporating seawater and capturing the water vapor to leave the salts behind. About a quarter of all desalinization uses reverse osmosis. There are inventors working on low-cost desalinization technologies. 17 - 28 Menu Previous Next Chapter 17 Pages 17-18 to 17-20 Renewable Resources Nonextractive Resources There’s a class of resources that you may not think of as resources, but they most certainly are. Nonextractive resources are those we obtain from the sea without removing anything from the sea. Therefore, they are renewable because there’s nothing that needs renewing. The three most conspicuous uses of the sea are for transport shipping, projection of state power and recreation. These are physical resources in that they involve the physical aspects of the sea. Recreation can also be considered a biological resource in that many recreations involve organisms within the sea. 17 - 29 Menu Previous Next Chapter 17 Pages 17-18 to 17-20 Renewable Resources Nonextractive Resources Sea Transport Shipping: History shows that the ocean is important as a corridor for shipping. Sea transport has been vital for hundreds of years and remains so. At one time, cargo ships needed weeks to load and unload. After World War II, the invention of the cargo container revolutionized sea transport shipping. 17 - 30 Menu Previous Next Nonextractive Resources Chapter 17 Pages 17-18 to 17-20 Renewable Resources Projection of state military power. Recreation. Ecotourism. 17 - 31 Menu Previous Next Chapter 17 Pages 17-22 to 17-23 Submerged Cultural Resources Submerged Cultural Resources 17 - 32 Menu Previous Next Chapter 17 Page 17-22 Submerged Cultural Resources A Definition – Submerged Cultural Resources Submerged cultural resources can be: Shipwrecks. Submerged settlements. Burial and disposal sites. Underwater areas with artifacts left by prehistoric and historic cultures. In addition to the ocean, underwater sinkholes and caves are often rich in archaeology. Shipwrecks give archaeologists with information about how people lived, died and constructed their ships. 17 - 33 Menu Previous Next Chapter 17 Page 17-23 Submerged Cultural Resources Protecting Submerged Cultural Resources Preserving the scientific and historical integrity of submerged cultural resources is important to protect what scientists learn from them. Removing or even just disturbing the contents of sites diminishes the information archaeologists can learn from them. Submerged cultural resources are often protected. Most underwater archaeologists approve of divers visiting sites in a respectful way. Often, national and international laws protect submerged cultural sites to keep them from being looted or defaced. 17 - 34 Menu Previous Next Chapter 17 Pages 17-24 to 17-28 Biological Resources - Marine Mammals Biological Resources - Marine Mammals 17 - 35 Menu Previous Next Whales Chapter 17 Pages 17-24 to 17-26 Biological Resources - Marine Mammals Whaling dates back at least 2,000 years. While the Japanese killed whales for the meat, the Europeans were primarily interested in blubber. 17 - 36 Menu Previous Next Chapter 17 Pages 17-24 to 17-26 Biological Resources - Marine Mammals Whales Until 1868, primitive technology made whaling dangerous and difficult. Harpoons were little more than heavy spears hurled from small longshore boats. The wounded whale would drag the boat (or boats) at high speed in what came to be called a Nantucket sleigh ride, named for the whaling port of Nantucket, Massachusetts. Often the whale towed the longshore boat for hours before it became exhausted enough to be killed. With these crude methods, comparatively few whales could be taken and whale populations remained stable. 17 - 37 Menu Previous Next Whales Chapter 17 Pages 17-24 to 17-26 Biological Resources - Marine Mammals Everything changed in 1868 with the invention of the modern harpoon gun. Instead of hand-thrown spears, the modern whale harpoon launches from a gun and explodes on impact inside the whale. Besides being a more damaging weapon, the modern harpoon can be launched from a steamship. This allowed them to harvest fast whales. Attacking and killing a whale went from taking hours to taking minutes. 17 - 38 Menu Previous Next As with commercial fishing, whalers continued to use new technologies. By the late 1960s, whaling fleets had spotter airplanes looking for pods from the air. They used sonar to track whales trying to escape in the depths. Chapter 17 Pages 17-24 to 17-26 Biological Resources - Marine Mammals Whales 17 - 39 Menu Previous Next Chapter 17 Pages 17-24 to 17-26 Biological Resources - Marine Mammals Whales International whaling has been so successful that whale populations plunged during the 20th century. From an estimated population of 4.4 million in 1900, today the estimated population is around 1 million. Eight of the 11 great whale species became commercially extinct. However, whalers often still took them if they happened across them. 17 - 40 Menu Previous Next Chapter 17 Pages 17-24 to 17-26 Biological Resources - Marine Mammals Whales With whale populations already dwindling by World War II, in 1946 the International Whaling Commission (IWC) formed to set quotas in an effort to stay within maximum sustainable yields. Quotas were too high and populations continued to fall. As international attention focused on the plight of the whales, many nonwhaling nations joined the IWC. Called for indefinite moratorium on whaling; effective in 1986. The results of the moratorium provide a lesson in species recovery. Several major species recovered. 17 - 41 Menu Previous Next Whales Biological Resources - Marine Mammals Chapter 17 Pages 17-24 to 17-26 The lesson appears to be that, given a chance, a species can recover. However, if ending commercial pressure takes too long, a species may not make it and continue into extinction. Despite the moratorium and the continued low population levels, whaling still continues. 17 - 42 Menu Previous Next Chapter 17 Page 17-27 Biological Resources - Marine Mammals Other Cetaceans While large whales tend to be the focus in whaling, far more small cetaceans get killed. IWC doesn’t protect dolphins. Several species face immediate danger. In some countries, dolphin costs less than chicken or beef. Another threat to dolphins and small whales is they are caught in nets set by commercial fishers. Today US tuna fishers and foreign importers must comply with dolphin safe fishing techniques that reduce dolphin kills. It is worth noting that today neither whales nor small cetaceans provide any material that’s not available from some other source. 17 - 43 Menu Previous Next Chapter 17 Pages 17-27 to 17-28 Biological Resources - Marine Mammals Seals and Sea Lions Historically, seals and sea lions have been biological resources exploited for their fur and for food. At the turn of the 19th century, fur seal populations were so decimated that Russia, Japan, Great Britain and the US entered into the Fur Seal Treaty of 1911, which remained in effect for 30 years. It was the first international treaty involving several countries that dealt with wildlife conservation and was a role model for future treaties. Within five years, the population rebounded and protection was extended in 1966. 17 - 44 Menu Previous Next Chapter 17 Pages 17-27 to 17-28 Biological Resources - Marine Mammals Seals and Sea Lions Although the marine mammal fur trade no longer exists in the US due to the Marine Mammal Protection Act and consumer pressure, worldwide up to half a million of these marine mammals die for their fur annually. The most famous fur hunt is the harp seal hunt, which takes place on the Canadian coast on the Labrador Sea. 17 - 45 Menu Previous Next Chapter 17 Pages 17-29 to 17-32 Biological Resources - Algae, Aquaculture, and Medicine Biological Resources-Algae, Aquaculture, and Medicine 17 - 46 Menu Previous Next Animals aren’t the only biological resources people take from the sea. Marine algae is another resource used as food. Seaweeds and algae make up 10% of the Japanese diet; much of this is red algae nori. Nori is the most-consumed alga in the world and is often served with sushi. Chapter 17 Page 17-29 Biological Resources - Algae, Aquaculture, and Medicine Algae 17 - 47 Menu Previous Next Chapter 17 Page 17-29 Biological Resources - Algae, Aquaculture, and Medicine Algae You may be surprised to learn how much algae you consume. Algin is useful in food processing and other applications. Used in salad dressing, ice cream, beer and wine. You also find algin in paint and abrasives. With widespread applications in food and chemical processes, industry uses nearly $250 million worth of algin annually. 17 - 48 Menu Previous Next Chapter 17 Pages 17-29 to 17-31 Biological Resources - Algae, Aquaculture, and Medicine Farming the Sea Commercial fishing is comparable to terrestrial hunting and gathering. It entails living off what happens to grow naturally. More recently, aquaculture has come onto the scene. Aquaculture is comparable to terrestrial farming and ranching. It uses farming techniques to grow and harvest aquatic organisms. Mariculture is aquaculture specific to the marine environment. 17 - 49 Menu Previous Next Biological Resources - Algae, Aquaculture, and Medicine Chapter 17 Pages 17-29 to 17-31 Farming the Sea The growth trend in aquaculture is steeply upward. According to the Food and Agriculture Organization, the total contribution of aquaculture to global supplies of fish, crustaceans, mollusks and other aquatic animals grew from 4% in 1970 to 27% in 2000 and 32% in 2004. In 2004, aquaculture produced more than 60 million tons of fish, seafood, and other biological resources. The estimated value was about $70 million. China alone accounts for about 70% of the total quantity of aquaculture production. 17 - 50 Menu Previous Next Today, about 30% of the world’s seafood comes from aquaculture. Aquaculture may sound like the solution to overfishing, but it’s not without its problems. Chapter 17 Pages 17-29 to 17-31 Biological Resources - Algae, Aquaculture, and Medicine Farming the Sea Sea Farming Aquaculture Pens Salmon Aquaculture 17 - 51 Menu Previous Next Biological Resources - Algae, Aquaculture, and Medicine Chapter 17 Pages 17-29 to 17-31 Farming the Sea 17 - 52 Menu Previous Next Biological Resources - Algae, Aquaculture, and Medicine Chapter 17 Pages 17-29 to 17-31 Farming the Sea Aquaculture problems include: Fish meal made from wild-caught fish is used in aquaculture. Only about 10% of the biomass from one level makes it to the next. Disease due to close quarter living. Concentrated waste from raised animals. Consumes resources that could be used by wild animals. Genetic problems. 17 - 53 Menu Previous Next Chapter 17 Pages 17-31 to 17-32 Biological Resources - Algae, Aquaculture, and Medicine New Medicines from the Ocean About half of the drugs available to modern medicine come from nature. They’re either natural substances or synthesized from natural substances, including those found in the sea. Marine scientists estimate that we’ve barely scratched the surface when it comes to identifying organisms with potential pharmacological importance. 17 - 54 Menu Previous Next Chapter 17 Pages 17-31 to 17-32 Biological Resources - Algae, Aquaculture, and Medicine New Medicines from the Ocean The search for organisms with pharmacological or other chemical benefits is called bioprospecting. Is important in the development of new drugs because it is in nature that chemists often find new ways to fight disease. The potential exists for a wide range of drugs that combat viruses, inflammation, cancer, heart disease, AIDS/HIV, and others. Even insecticides and a new class of steroids have been found in sea organisms. 17 - 55 Menu Previous Next Chapter 17 Pages 17-31 to 17-32 Biological Resources - Algae, Aquaculture, and Medicine New Medicines from the Ocean So as not to destroy natural reefs while bioprospecting, marine scientists are examining the possibility of harvesting marine organisms for possible drugs from artificial reefs – like shipwrecks and oil platforms. Biosprospecting can only continue with a healthy sea. We could accidentally cause the extinction of the organism that holds the cure to the disease that you or someone you love has. This is a personal reason everyone has to preserve a healthy ocean. 17 - 56 Menu Previous Next Chapter 17 Pages 17-33 to 17-39 Biological Resources - Fish Biological Resources - Fish 17 - 57 Menu Previous Next Chapter 17 Pages 17-33 to 17-34 Biological Resources - Fish Fisheries for Food and Industry Compared to terrestrial foods, seafood in its many forms seems a minor contribution to the human diet. Worldwide, seafood accounts for only about 4% of what people eat. On the other hand, it accounts for about 18% of the protein we eat - 15% consumed directly as seafood and about 3% indirectly through fish meal and other seafood byproducts fed to livestock. 17 - 58 Menu Previous Next Chapter 17 Pages 17-33 to 17-34 Biological Resources - Fish Fisheries for Food and Industry The amount of seafood consumed varies by nation and culture. About 89% of world’s wild-caught fish comes from the ocean, with the rest coming from freshwater sources. For some small island developing states, seafood provides more than 50% of people’s annual protein intake. 17 - 59 Menu Previous Next Commercial fishing targets both pelagic and groundfish. Pelagic fish live in the open water column. Groundfish are benthic, living on or near the sea bottom. Yet of all the species in the sea, only about 500 make up the vast majority of the catch. Chapter 17 Pages 17-33 to 17-34 Biological Resources - Fish Fisheries for Food and Industry 17 - 60 Menu Previous Next Chapter 17 Pages 17-33 to 17-34 Biological Resources - Fish Fisheries for Food and Industry Commercially important fish are found primarily in two places: the waters of the continental shelves and a few offshore regions with abundant upwelling. The reason is that most of the ocean has relatively low bioproductivity. The continental shelves and the upwelling regions have high productivity because of the ample supply of nutrients and sunlight. 17 - 61 Menu Previous Next Chapter 17 Pages 17-33 to 17-34 Biological Resources - Fish Fisheries for Food and Industry 17 - 62 Menu Previous Next Chapter 17 Pages 17-33 to 17-34 Biological Resources - Fish Fisheries for Food and Industry In 2005, the total world fisheries catch and aquaculture combined production was an estimated 142 million metric tons. This was made up of inland (freshwater) capture and aquaculture production as well as marine capture and aquaculture. The total amount of wild fish captured from the ocean in 2005 was 84 million metric tons. Of the total fisheries production, 108 million metric tons was used for direct human production and 34 million metric tons was used for non-food purposes. Non-food: 1) fish protein concentrate, 2) fish oil used in food products, cosmetics and paint. 17 - 63 Menu Previous Next Fisheries for Food and Industry Chapter 17 Pages 17-33 to 17-34 Biological Resources - Fish Catching fish for purposes other than direct human consumption is called reduction fishing. In 1950, reduction fisheries accounted for only about 10% of commercial fishing. Today, about one-quarter of the world commercial fish catch is used for reduction. 17 - 64 Menu Previous Next Chapter 17 Pages 17-35 to 17-37 Biological Resources - Fish Trends in the Worldwide Commercial Fish Catch About a billion people rely on fish as their primary protein source. Worldwide commercial fishing and fishing related activities employ about 15 million people directly. This number does not include people who catch fish in small quantities for their own consumption. Commercial fishing is a physically demanding and dangerous occupation. 17 - 65 Menu Previous Next Chapter 17 Pages 17-35 to 17-37 Biological Resources - Fish Trends in the Worldwide Commercial Fish Catch In addition to those directly involved in commercial fishing, another 200 million people have jobs related to commercial fish processing or distribution. By the end of 2004, the world’s fishing fleet was made up of 4 million vessels. The most modern fleets catch fish using scout planes, satellite-based sensors, current profilers, sonar, and other technologies. Huge factory ships follow many of these fleets, taking and processing the catch so it’s filleted and frozen before reaching shore. 17 - 66 Menu Previous Next Chapter 17 Pages 17-35 to 17-37 Biological Resources - Fish Trends in the Worldwide Commercial Fish Catch In 1967 a Commission on Marine Science Engineering and Resources was appointed to investigate current and future US coastal and ocean resources. Released its report in 1969 entitled “Our Nations and the Sea: A Plan for National Action.” Report said it would be realistic – even conservative – to expect to be able to harvest between 400 and 500 million metric tons of fish annually. This suggests that at the time, we still considered the ocean’s resources almost limitless. 17 - 67 Menu Previous Next Biological Resources - Fish Chapter 17 Pages 17-35 to 17-37 Trends in the Worldwide Commercial Fish Catch By 1989, the annual catch reached 86 million metric tons and has held about level at between 70 to 85 million metric tons ever since. In 2005, the FAO estimated that about half the commercially targeted fish stocks were fully exploited, and about a quarter were overexploited, depleted or recovering from depletion. Its 2006 report confirmed earlier observations that the maximum capacity of wild capture fisheries from the ocean has been reached. Instead of reaching the 500 million metric ton catch level estimated in 1967, commercial fishing from the ocean was already nearing the probable maximum output. 17 - 68 Menu Previous Next Biological Resources - Fish Chapter 17 Pages 17-35 to 17-37 Trends in the Worldwide Commercial Fish Catch 17 - 69 Menu Previous Next Biological Resources - Fish Chapter 17 Pages 17-35 to 17-37 Trends in the Worldwide Commercial Fish Catch Many researchers and scientists have their doubts about the accuracies of reported catch numbers. As fish stocks decline, overfishing causes shifts in the fish that are caught. Average size of the fish caught declines. Leads to the collapse of the target fish populations - targets fish previously considered unappealing for human consumption. This is called fishing down the food web. Bycatch – the catching of non-target species of fish, birds and turtles – has resulted in millions of tons of fish being dumped or discarded at sea. Bycatch is not included in the fishing statistics. 17 - 70 Menu Previous Next Biological Resources - Fish Chapter 17 Pages 17-35 to 17-37 Trends in the Worldwide Commercial Fish Catch 17 - 71 Menu Previous Next Chapter 17 Pages 17-39 to 17-44 The State of the World’s Fisheries - A Bleak Picture The State of the World’s Fisheries – A Bleak Picture 17 - 72 Menu Previous Next Chapter 17 Pages 17-39 to 17-40 The State of the World’s Fisheries - A Bleak Picture Maximum Sustainable Yield, Overfishing and Ecosystem-Based Management Until the 20th century, people believed that the sea was an infinite resource. Today, however, a limitless sea is a myth. Technology and rising demand make it possible to exhaust biological resources. We can catch fish and other organisms more quickly than they can reproduce. Given this problem and rising demand, the role of global fisheries management is to prevent the day coming when there will be nothing to catch. Many fisheries scientists think that, unfortunately, we’re not off to a very good start. 17 - 73 Menu Previous Next Chapter 17 Pages 17-39 to 17-40 The State of the World’s Fisheries - A Bleak Picture Maximum Sustainable Yield, Overfishing and Ecosystem-Based Management The concept of maximum sustainable yield lies at the heart of fisheries management. Maximum sustainable yield is the greatest yield (catch) of a target species that fisheries can take without jeopardizing future catches. Overfishing occurs when the quantity of fish taken exceeds the amount of fish that can be resupplied by the growth and reproduction of the remaining population. This is what has happened to the cod fishery off the north Atlantic US coast, for example. 17 - 74 Menu Previous Next Chapter 17 Pages 17-39 to 17-40 The State of the World’s Fisheries - A Bleak Picture Maximum Sustainable Yield, Overfishing and Ecosystem-Based Management Maximum sustainable yield isn’t an easy number to establish. Scientists and fisheries managers debate the number for different species, often with widely differing estimates. Pollution and other environmental changes complicate the issue by affecting the reproductive rates of target species. 17 - 75 Menu Previous Next The State of the World’s Fisheries - A Bleak Picture Chapter 17 Pages 17-39 to 17-40 Maximum Sustainable Yield, Overfishing and Ecosystem-Based Management Whatever the maximum sustainable yields are, however, the evidence indicates overfishing in virtually all the world’s fisheries. Fleets catch less than in previous years, yet have to range farther. Indications are that half the marine fisheries are overfished or already commercially extinct. The FAO estimates that 50% of the worldwide fish stocks are fully exploited/overfished and 25% are depleted. The National Marine Fisheries Service estimates that half of the fish stock in US waters is overfished. This estimate is based on species with known status—with data lacking on most fish stocks, the picture could be much worse. 17 - 76 Menu Previous Next Chapter 17 Pages 17-40 to 17-42 The State of the World’s Fisheries - A Bleak Picture The Problems with Overfishing Clearly, the evidence shows that the world’s fisheries can’t sustain the present catch levels. Responding to declining species in the face of continued or rising demand, however, the fishing industry has become more efficient. By refining technology and methods, the fishing fleets are taking ever larger proportions of declining stocks. This response worsens the problem, as you might expect. Already several fisheries show the longterm consequences of this response. 17 - 77 Menu Previous Next Chapter 17 Pages 17-40 to 17-42 The State of the World’s Fisheries - A Bleak Picture The Problems with Overfishing There are many problems with overfishing. In Canada, the Cod levels became so low that the government closed the fishery in 1992. Putting 35,000 people out of work. In 1993, the National Marine Fisheries Service closed large parts of the New England cod fishery. Another example is the North Atlantic swordfish. Between 1982 and 1990, the US catch declined 70%. The average fish weight fell from 52 kilograms (115 pounds) to 27 kilograms (60 pounds). The Atlantic bluefin tuna declined by 80% in just three years (1990 to 1993). This fish may be doomed to extinction. 17 - 78 Menu Previous Next Chapter 17 Pages 17-40 to 17-42 The State of the World’s Fisheries - A Bleak Picture The Problems with Overfishing Besides becoming more efficient, fisheries also respond by turning to new, unexploited fisheries. These are fish that are usually lower in the trophic pyramid, leading to a problem called fishing down the food chain. Creates problems with overfishing species such as the herrings, sardines and anchovies. These species are prey fish – food for higher species. Fishing down the food chain also allows the proliferation of other organisms low on the food web. For example, overfishing in the Black Sea removed fish species that feed on plankton. This allowed rapid plankton growth. 17 - 79 Menu Previous Next Another problem results when commercial fishing disregards how fast species reproduce. Orange roughy example. Chilean seabass example. Another indirect problem is bycatch. Bycatch is the unintentional capture of organisms. Chapter 17 Pages 17-40 to 17-42 The State of the World’s Fisheries - A Bleak Picture The Problems with Overfishing 17 - 80 Menu Previous Next Chapter 17 Pages 17-42 to 17-43 The State of the World’s Fisheries - A Bleak Picture Recommendations for Sustaining the World’s Fisheries Given the state of the world’s fisheries, it is not surprising that many environmental groups are disappointed with government fishery management. The Pew Ocean Commission made four recommendations to restore US fisheries as sustainable biological resources: Make the principal objective of US fisheries policies the protection of marine ecosystems. Create an independent government agency responsible or managing ocean resources. Invest in more marine research over the next five years. The commission recommended doubling current funding. Establish a network of marine reserves or protected areas. 17 - 81 Menu Previous Next Chapter 17 Pages 17-44 to 17-48 Commercial Fishing Commercial Fishing 17 - 82 Menu Previous Next Chapter 17 Pages 17-44 to 17-46 Commercial Fishing Commercial Fishing Methods Commercial fisheries primarily use five methods for taking their catch. Gill nets. Drift net. Longline fishing. Purse seine nets. Trawling. 17 - 83 Menu Previous Next Chapter 17 Pages 17-44 to 17-46 Commercial Fishing Commercial Fishing Drift Nets 17 - 84 Menu Previous Next Chapter 17 Pages 17-44 to 17-46 Commercial Fishing Commercial Fishing Longlining 17 - 85 Menu Previous Next Commercial Fishing Chapter 17 Pages 17-44 to 17-46 Commercial Fishing Purse Seining 17 - 86 Menu Previous Next Chapter 17 Pages 17-44 to 17-46 Commercial Fishing Commercial Fishing Trawling 17 - 87 Menu Previous Next Chapter 17 Pages 17-46 to 17-48 Commercial Fishing The Economics of Commercial Fishing Compared to the industries involved with other marine resources, the worldwide fishing industry is unique in that, according to economic estimates, the worldwide fish catch sells for less than it costs to catch. Despite the apparent illogic, it’s not hard to understand why governments do this. Loss of jobs. Although commercial fishing in its present state appears unsustainable and very damaging to the environment, it would be wrong to characterize everyone in that trade as uncaring or unethical. 17 - 88 Menu Previous Next Chapter 17 Pages 17-48 to 17-52 Who Owns the Sea? Who Owns the Sea? 17 - 89 Menu Previous Next Chapter 17 Pages 17-48 to 17-49 Who Owns the Sea? The Origin of Territorial Waters The foundations of western legal views of the ocean can be traced back to the 1490s. The Treaty of Tordesillas in 1493. Mare Liberum Defended the concept of a free ocean–access to the high sea by every nation. By the early 18th century, Mare Liberum was internationally recognized. The limit of territorial waters was 5 kilometers (about three miles) from shore. 17 - 90 Menu Previous Next Chapter 17 Pages 17-49 to 17-50 Who Owns the Sea? The Truman Proclamation To protect US interests, President Harry Truman issued the Truman Proclamation of 1945. It declared that “The U.S. regards the natural resources of the subsoil and sea bed of the continental shelf beneath the high seas but contiguous to the coasts of the United States as appertaining to the United States, subject to its jurisdiction and control.” 17 - 91 Menu Previous Next Chapter 17 Pages 17-50 to 17-52 Who Owns the Sea? Exclusive Economic Zones In 1953, the Outer Continental Shelf Lands Act solidified the Truman Proclamation. It granted control of the seabed and subsoil of the outer continental shelf to the US federal government. Was in response to a Declaration of Maritime Zone signed by Chile, Ecuador, and Peru in 1952. Extended jurisdiction to 350 kilometers from coastline. Iceland followed. International controversy ensued. 17 - 92 Menu Previous Next Chapter 17 Pages 17-50 to 17-52 Who Owns the Sea? Exclusive Economic Zones UNCLOS - UN Convention on the Law of the Sea. UN conference in Geneva to settle issues. UNCLOS established the concept of the Exclusive Economic Zone (EEZ). A nation’s EEZ extends 370 kilometers (about 200 nautical miles or 230 statute miles) from the shoreline. Within the EEZ, a nation has complete control of all resources, economic activity, and environmental protection. Areas beyond the EEZs are the high seas or international waters. 17 - 93 Menu Previous Next Chapter 17 Pages 17-50 to 17-52 Who Owns the Sea? Exclusive Economic Zones 1983 Ronald Reagan established for the United States an Exclusive Economic Zone within 200 nautical miles of its coasts. This doubled the size of the U.S. Omits shared resources in international waters. Other countries have EEZs of their own. May help to effectively maintain the ocean’s resources. 17 - 94 Menu Previous Next Chapter 17 Page 17-53 Biodiversity and the Future Biodiversity and the Future 17 - 95 Menu Previous Next Chapter 17 Page 17-53 Biodiversity and the Future The Ultimate Resource Biodiversity raises the question of the importance of a single species. It’s often hard to point to the importance of a single organism. Biologist Paul Eherlich’s Airplane Analogy. The importance of biodiversity is that every organism is a biological resource. In the end, the ultimate resource we get from the sea is life itself. 17 - 96 Menu Previous Next
