Pollution and the Health of the Oceans. Chapter 18

Transcription

1 Pollution and the Health of the Oceans Chapter 18

2 WHAT S GOING WRONG? Global Habitat Destruction Sensitive Marine Habitat Destruction Pollutants and Their Effects Toxic Pollutants Nutrient Pollutants Energy Pollutants Refuse Pollutants Efforts and Solutions Exit

3 Global Warming...our fault?? Donald Trump's stance on climate change The greenhouse effect Brainstorm with the person next to you whether you believe in global warming (based on what you currently know about it). Climate science: what you need to know

4 Global Warming Greenhouse gases like water vapor, carbon dioxide, methane and CFC's trap and hold solar heat, this keeps Earth's climate stable and inhabitable. The rate of warming has increased dramatically since the industrial revolution. This happens because the natural balance of these chemicals in the atmosphere is upset.

5 Data that supports global warming Increase in CO2 in the atmosphere Rise in the sea level (amount of ice in polar ice sheets controls the sea level) Glacial samples Tree rings

6 Global Warming Several data sources support scientists concerns that the Earth s average surface temperature is rising. Scientists estimate that carbon dioxide in the atmosphere was about 290 parts-per-million (ppm) in 1850 compared to the present 386 ppm in This is a 33% increase. It would be worse without the ocean absorbing a lot of the released carbon dioxide. 18-6

7 So What? What are the possible effects of global warming Why don t people believe in climate science?

8 Effects of global warming Coral reef bleaching Changes in weather patterns Habitat destruction from climate changes Increase in violent storms

9 Alternative energy sources: Nuclear Solar Wind Tidal and wave Hydrogen fuel cells What is the solution? Internal combustion fuels from biological sources (plants) Ethanol, biodiesel, cooking oil?

10 Damage to the Ozone Layer The stratosphere has an ozone layer that is vital to life on Earth because it protects us from ultraviolet radiation. Without this protection, life in its current form could not exist. Some chemicals (primarily CFCs) destroy ozone. This is thought by many scientists to have caused or contributed to the hole in the ozone layer above Antarctica. In September 2000, scientists recorded the largest hole there yet. It was about three times the size of the continental US.

11 Damage to the Ozone Layer Ozone is important because ultraviolet radiation (UV) damages DNA and protein. In June 1990, 53 nations agreed on an international ban of ozone-depleting chemicals

12 Non-Native Species Although non-native species sometimes enter a new environment by being carried there intentionally, today the most common method is unintentional transportation. The new species may have characteristics that allow it to out compete local organisms. The pace of species transplantation is so rapid and countermeasures have been so ineffective that many ecologists think the world could become a one large homogeneous ecosystem

13 Non-Native Species Although a marine species, the zebra mussel adapted to freshwater life in the Great Lakes, where they had neither competitors nor predators. They multiplied so quickly. The zebra mussel clogged water intake pipes, attached to ships, and grew thickly on docks and other structures. The species has actually improved the water clarity of the lakes by filtering out suspended matter

14 Non-Native Species The suspended matter removed by the zebra mussel is algae - the base of the food chain. The mussels are voracious secondary consumers - without natural predators. They re cutting off the supply to higher trophic levels. There are thousands of examples of non-native species damaging local environments

15 What can you do? Be a responsible pet owner The Exotic Pet Amnesty Program is an effort to reduce the number of nonnative species being released into the wild by pet owners who can no longer care for their pets or no longer wish to keep them. Another goal of the program is to foster responsible pet ownership. One-day-only Amnesty Day events are held around the state to provide the opportunity for people to surrender their exotic pets free of charge with no penalties.

16 Sensitive Marine Habitat Destruction Coastal Wetland Destruction The primary cause of coastal wetland destruction is the tendency for people to live near the coast. (About twothirds of the world population concentrates along the coast. ) Sewage and toxic materials pollute coastal waters. One of the most significant is that coastal areas are prime real estate. There s tremendous economic pressure to fill wetlands and use them for housing, commercial zones, and even airports

17 Coastal Wetland Destruction In South America and Southeast Asia, aquaculturists destroy large areas of mangrove to make shrimp ponds, or burn mangrove trees as firewood. In Ecuador, shrimp mariculture has displaced about a third of all mangrove forests. Philippines mangroves are in danger also. Worldwide, mangroves are disappearing more quickly than tropical rainforests

18 Pollutants and Their Effects Definition of Pollution With respect to the marine environment, pollution is: products of human activities that have harmful or objectionable effects to the water quality or affect the physical, chemical or biological environment. This definition includes organic or natural compounds, as well as unnatural, manufactured substances like sound and hot water discharge. It began with the belief in the late 1800s and early 1900s that The solution to pollution is dilution. THIS IS NOT TRUE!!! 18-18

19 Sources of Pollution Researchers have growing data about the types and quantities of pollution. This is the estimated breakdown of marine chemical pollution: 18-19

20 Sources of Pollution Sources can be from a known Point source location or from NonPoint sources Nonpoint source pollution is difficult to control because it comes from many different sources and locations. As the runoff moves, it picks up and carries away natural and human-made pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters and ground waters. These pollutants can harm fish and wildlife populations, kill native vegetation, foul drinking water, and make recreational areas unsafe and unpleasant.

21 Sources of Pollution Pollutants don t simply damage the sea because they don t necessarily stay there. Through natural processes, they can return to the atmosphere or enter the food web. The global conveyor belt circulates all the world s water - eventually pollutants go everywhere. Since the conveyor belt circulation is slow, it means that pollutants entering it today may be carried for more than 1,000 years before we know all their effects

22 Toxic Pollutants Excluding oil, each year more than 5 trillion gallons of potentially toxic waste, including heavy metals, hydrocarbons, industrial chemicals, and radioactive materials enter the ocean. Heavy Metals lead, mercury, cadmium, arsenic, copper Heavy metals damage organisms by interfering with cellular metabolism and cannot be easily eliminated from their bodies. There are many compounds that include heavy metals. Anti-fouling paints for boats and ship, etc

23 Some things don t go away.. Bioaccumulation is the concentration of heavy metals, synthetic organic chemicals, and natural organic chemicals that gradually accumulates in an organism s body throughout its lifetime. Sometimes the concentration of a heavy metal or other substance increases as it moves up the food web - biomagnification.

24 Heavy Metals Because of bioaccumulation and biomagnification, predators high on the food web tend to have high levels of heavy metals. This presents more risk of heavy-metal poisoning from consuming high-level organisms, such as tuna, swordfish and king mackeral. Heavy metals present significant risks for humans. Metal poisoning leads to birth defects, brain damage and behavior disorders 18-24

25 Synthetic Organic Chemicals In addition to heavy metals, synthetic chemicals capable of interacting with organic processes enter the ocean. Known as synthetic organic chemicals because they re human-made but based on organic molecule structures, these substances are particularly dangerous because they can be toxic in small quantities. Many can persist in the environment because bacteria and other processes don t break them down.

26 Synthetic Organic Chemicals Synthetic organic chemicals normally exist in very low concentrations in seawater. This is a problem because: Organisms bioaccumulate them, just as they do heavy metals

27 Oil The primary cause of oil in the ocean is the users, not the producers. Oil enters aquatic environments through runoff from parking lots and streets and as waste from sewage treatment plants. It s estimated that US treatment plants alone add about 900 million liters (237.8 million gallons) of oil to the sea annually. That s 22 times the famous 1989 Exxon Valdez spill in Alaska

28 Oil Petroleum in Ocean Water 18-28

29 Fate of an Oil Spill Volatile compounds evaporate, leaving heavier oil components Some of the oil dissolves in water Wave action helps accumulate the oil into tar balls and emulsified oil sinks to seafloor Benthic organisms consume these hydrocarbons or they get incorporated into sediments Eventually the oil becomes part of the Carbon cycle

30 Oil Another consideration is that an oil spill can involve either crude oil or refined oil. Crude oil spills have so far been the more frequent and larger spills. Crude oil is biodegradable and some components evaporate quickly. Refined oil has chemicals added to it that make it more toxic

31 Oil Recent analysis of the Exxon Valdez oil spill suggests that the cleaned areas fared worse than those left alone. Cleaners used water heated to 65 C (149 F) and high pressure jets to remove oil from rocks. The high temperatures killed plankton and other organisms at the base of the food web. The jets smothered others with mud and sand. The effort cost more than $3.5 billion

32 Radioactive Waste You may not realize it, but seawater is naturally radioactive. BUT Radioactive material enters the ocean primarily from people dumping it there. Dumping is banned, however, radioactive waste remains a concern for several reasons - primarily lots has been dumped and they remain for a long time

33 Radioactive Waste Today radioactive substances come primarily from nuclear-reactor cooling water and nuclear-power vessel discharges. Dumping has been banned since 1975 but radioactive waste is still a concern. The amount already dumped into the sea previously by the US and more currently by Russia is a threat to local marine resources. Despite the obvious danger radiation poses to living organisms, so far no widespread effects have been noted. It appears that marine organisms have a high tolerance to radioactivity. It is just a matter of time though before measurable effects become evident probably genetic damage

34 Munitions The concerns for the environment regarding lost munitions range from minor up: The detonation of unexploded bombs is more of a safety concern for ships and divers than it is a long-term, wide-ranging environmental hazard. Leakage of chemical weapons, on the other hand, could pose a major threat by contaminating and killing local wildlife. Even though banned, some countries are probably still coastal dumping.

35 Eutrophication Excessive nutrients that throw the local ecosystem out of balance is called eutrophication. Eutrophication can hurt ecosystems: Can create dead zones on the bottom. Areas that have low oxygen (hypoxic) and no oxygen (anoxic). Low-oxygen either kills fish, shrimp, etc. or causes those that can to flee. This can ruin local fisheries. Some nontoxic algae blooms can cause lethal conditions in surface waters by clogging the gills of some species and consume all the free oxygen. Red tides and similar algae blooms are called HABs Harmful Algae Blooms. Today, anoxic and hypoxic events cause more massive fish kills than any other single cause including oil spills

36 Sound Pollution A rising concern is sound pollution. Human-produced sounds ranging from ship engines to sonar may be detrimental to marine species. Concerns include noise interfering with whale communications and high-intensity sound injuring marine organisms.

37 Seismic Airguns Seismic airguns are towed behind ships and shoot loud blasts of compressed air through the water and miles into the seabed, which reflect back information about buried oil and gas deposits. These blasts harm marine mammals, sea turtles, fish and other wildlife. Impacts include temporary and permanent hearing loss, abandonment of habitat, disruption of mating and feeding, and even beach strandings and death. For whales and dolphins, which rely on their hearing to find food, communicate, and reproduce, being able to hear is a life or death matter.

38 Heat Pollution Heated water is a pollutant because hot water can raise temperatures above the tolerance level for many species, causing a die-off or decline in the immediate areas where the warm-to-hot water is. Most thermal pollution comes from power plants, which draw water from the sea for cooling. By using heat exchangers the discharged hot water remains free of radiation and contamination. Usually the heat is the only pollutant. Some industrial discharges do pollute with both heat and substances

39 Plastic Plastics get into the marine environment primarily by being lost or dumped there. Including fishing gear, bags, packing materials, balloons, bottles and syringes. Plastics are a hazard in the marine environment because they look like food to some predators. Sea turtles and sea birds commonly die when they swallow plastic bags and similar items that resemble jellyfish, their natural prey. Larger marine animals can swallow small pieces as food. Once swallowed, the plastic can cause internal blockage and a swift death. Or, it can accumulate in the gut, inhibiting feeding, resulting in slow starvation. Plastics are a hazard through entanglement and entrapment. Biodegradable plastic in the marine environment is one answer Recycling the best solution is to keep plastic out of the ocean altogether.

40 Dredge Spoil and Industrial Solids A major pollution source is spoil. Spoil is the soft bottom material removed during the dredging of harbors and ports. More often than not this is dumped at sea. The bottom of harbors tend to contain toxic chemicals from shipping and development. These chemicals damage the benthic communities when dumped with the spoil at sea and does damage even without toxins. Benthic organisms die when buried in the spoil. Suspended particles carried from spoil cloud the water and clog the feeding and respiratory organs of organisms

41 International Conservation Efforts 1972 Ocean Dumping Convention resulted in an international agreement that prohibited marine dumping of persistent (nonbiodegradable) plastic Marine Pollution Convention (London International Convention for the Prevention of Pollution from Ships) established regulations that limit and control oil pollution, packaged substances, sewage, and garbage dumped from ships International Convention for the Prevention of Pollution (MARPOL) took place. It regulates discharge from ships and has been adopted by more than 80 countries UN Environment Program, the International Union for the Conservation of Nature and Natural Resources, and the World Wildlife Fund released the World Conservation Strategy. It provides a strategy and procedures by which nations can develop their economic potential without destroying their resources. It recommends that countries with common seas work together to find common solutions to shared marine problems. This led to the Regional Seas Programmes, which have establish zones for international cooperation around the world