Unit 8 Test

What are the three major zones of the ocean? How do they differ in sunlight and nutrient content?

The euphotic zone is the brightly lit upper zone where drifting phytoplankton carry out about 40% of the world's photosynthetic activity. Nutrient levels are low, and levels of dissolved oxygen are high. Large, fast-swimming predatory fishes such as swordfish, sharks, and bluefin tuna populate this zone. The bathyal zone is the dimly lit middle zone, which, because it gets little sunlight, does not contain photosynthesizing producers. Zooplankton and smaller fishes, many of which migrate to feed on the surface at night, populate this zone. The deepest zone, called the abyssal zone, is dark and very cold; it has little dissolved oxygen. Nevertheless, the deep ocean floor is teeming with life—enough to be considered a major life zone—because it contains enough nutrients to support a large number of species, even though there is no sunlight to support photosynthesis. Lots of life due to a large number of nutrients present that comes from dead and decaying organisms drifting down from upper layers.

Review units 1-7 study guides

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Know the possible source, effects and an example of these types of pollutants: Infectious agents

-Human and animal wastes -Cause diseases -Bacteria, viruses, protozoa, parasites

Know the possible source, effects and an example of these types of pollutants: Sediments

-Land erosion -Disrupt photosynthesis, food webs, other processes -Soil, silt

What ecological services are provided by the following ecosystems? rivers

-Provide habitats for wildlife -Deposit silt on floodplains -Deliver nutrients to wetlands and coastal ecosystems

Know the possible source, effects and an example of these types of pollutants: Oxygen-demanding wastes

-Sewage, animal feedlots, food processing facilities, pulp mills -Deplete dissolved oxygen needed by aquatic species -Biodegradable animal wastes and plant debris

Know the possible source, effects and an example of these types of pollutants: Plant nutrients

-Sewage, animal wastes, inorganic fertilizers -Cause excessive growth of algae and other species -Nitrates and phosphates

Helpful things to know from previous units: Groundwater, water table, aquifer

-There is a hydrological connection between surface water and groundwater because eventually most groundwater flows into rivers, lakes, estuaries, and wetlands. Thus, if we disrupt the hydrologic cycle by removing groundwater faster than it is replenished, nearby streams, lakes, and wetlands could dry up, resulting in degradation of aquatic biodiversity and various ecological services. -The spaces in soil and rock close to the earth's surface hold little moisture. Below a certain depth, in the zone of saturation, these spaces are completely filled with water. The top of this groundwater zone is the water table. It falls in dry weather, or when we remove groundwater faster than nature can replenish it, and it rises in wet weather. -Underground caverns and porous layers of sand, gravel, or bedrock through which groundwater flows. Groundwater normally moves from points of high elevation and pressure to points of lower elevation and pressure. Some caverns have rivers of groundwater flowing through them. But the porous layers of sand, gravel, or bedrock in most aquifers are like large elongated sponges through which groundwater seeps—typically moving only a meter or so (about 3 feet) per year and rarely more than 0.3 meter (1 foot) per day. Watertight layers of rock or clay below such aquifers keep the water from escaping deeper into the earth. Most aquifers are replenished naturally by precipitation that percolates downward through soil and rock, a process called natural recharge. Others are recharged from the side by lateral recharge from nearby rivers and streams. Most aquifers recharge extremely slowly. Because so much of the urban landscape has been built on or paved over, water can no longer penetrate the ground to recharge aquifers in some urban areas. Nonrenewable aquifers get very little, if any, recharge. They are found deep underground and were formed tens of thousands of years ago. Withdrawing water from these aquifers amounts to mining a nonrenewable resource. Such withdrawals will deplete these ancient deposits of liquid natural capital, and they represent an unsustainable use of this resource. (Lake can tell a lot; pore space filled with air above water table and pore space filled with water below water table.)

What is polyaquaculture? Why is it more sustainable?

Polyaquaculture is a more traditional method of aquaculture. It involves raising fish or shrimp with seaweed, shellfish, and algae. These systems mimic nature in that the wastes of one group feed the other so pollution is minimized.

Understand the basics of these alternatives to wastewater treatment: Wetland-based sewage treatment systems

A second alternative is wetland-based sewage treatment. These systems consist of artificial wetlands that perform the same tasks as a wastewater treatment plant, however most of the filtration and removal of waste material is performed by plants and animals living in the wetland ecosystem. This has been piloted in a number of US cities, including Arcata, CA. The cost of setting up one of these systems in Arcata cost less than it would to set up a conventional wastewater treatment plant, produces sludge that can be used as fertilizer and also serves as an Audubon Society bird sanctuary. (You can read more about these systems on pg 556)

Nekton

A second major type of organisms is nekton, strongly swimming consumers such as fish, turtles, and whales.

Where does most sewage go in developing countries?

According the Global Water Policy Project, most cities in developing countries discharge 80-90% of their untreated sewage directly into rivers, streams, and lakes.

Zooplankton

Sub-category of plankton. ("ZOH-uh-plankton," Greek for "drifting animals"), consist of primary consumers (herbivores) that feed on phytoplankton and secondary consumers that feed on other zooplankton. They range from single-celled protozoa to large invertebrates such as jellyfish.

What is the biggest cause of water pollution?

Agricultural activities

What ecological services are provided by the following ecosystems? Coral reefs

Although coral reefs occupy only about 0.2% of the ocean floor, they provide important ecological and economic services. They help moderate atmospheric temperatures by removing CO2 from the atmosphere, and they act as natural barriers that protect 15% of the world's coastlines from erosion caused by battering waves and storms. And they provide habitats for one-quarter of all marine organisms. Economically, coral reefs produce about one-tenth of the global fish catch—one-fourth of the catch in developing countries—and they provide jobs and building materials for some of the world's poorest countries. Coral reefs also support important fishing and tourism industries. Finally, these biological treasures give us an underwater world to study and enjoy. Each year, more than 1 million scuba divers and snorkelers visit coral reefs to experience these wonders of aquatic biodiversity.

Know the following methods of fishing and why they can be harmful: Purse-seine fishing

Another method, purse-seine fishing, is used to catch surface-dwelling species such as tuna, mackerel, anchovies, and herring, which tend to feed in schools near the surface or in shallow areas. After a spotter plane locates a school, the fishing vessel encloses it with a large net called a purse seine. Nets used to capture yellow fin tuna in the eastern tropical Pacific Ocean have killed large numbers of dolphins that swim on the surface above schools of tuna.

What are some ways that we can do aquaculture in a more sustainable way?

Another way to help maintain our ocean fisheries is to develop more sustainable methods of aquaculture which will take some of the stress off of ocean fisheries. There are several ways to do this. Open-ocean aquaculture is a method where large carnivorous fish are raised in underwater pens almost 200 mi offshore. This is an improvement over aquaculture operations closer to shore because it allows for some dilution of wastes. Shrimp can be raised in zero-discharge inland ponds to prevent damage to coastal ecosystems (mangroves, coastal wetlands) Another option for raising carnivorous fish is in recirculating systems. These are inland also so farmed fish cannot escape into the wild. Wastewater is also treated. Nevertheless, systems are expensive to operate. Eating lower on the marine food chain can also help because raising carnivorous fish can contribute to overfishing of species they eat. Raising herbivorous fish (carp, tilapia) produces more protein than it takes to raise them and doesn't contribute to overfishing. Polyaquaculture is a more traditional method of aquaculture. It involves raising fish or shrimp with seaweed, shellfish, and algae. These systems mimic nature in that the wastes of one group feed the other so pollution is minimized.

What is water recycling? What are the benefits of this process?

Another, cheaper option is to recycle water. This is being done already in El Paso, TX (40% of drinking water) and Singapore. Orange County (CA) uses recycled water to recharge groundwater. This is also similar to how astronauts get drinking water on the space station. The Silicon Valley Advanced Water Purification Center was opened in 2015 and works with the San JoseSanta Clara Regional Wastewater Facility to produce recycled water from wastewater that exceeds drinking water standards. After the water passes through tertiary treatment and disinfection at the wastewater treatment facility, it is pumped across the street to the Advanced Water Purification Center. There it is passed through microfilters and then reverse osmosis filters. Finally it is disinfected again with UV radiation. The resulting water exceeds state drinking water standards and is safe to drink. However, it is currently illegal to blend recycled water into the drinking water supply in California. Currently, this plant is acting as a "proof of concept" facility to show that our water can be recycled to these standards. Their hope is to start recharging groundwater with this recycled water soon and ultimately to use it for drinking water once the laws in California are changed.

Know what aquaculture is and some of the related environmental/ health concerns (pp 293, 305-306)

Aquaculture helps meet the demand for fish worldwide, however it requires lots of input of other fish/ plant proteins to produce one fish. Sometimes fish are fed grain which also has disadvantages. It takes lots of land, water, fertilizer to raise grain. If grain is grown industrially takes lots of energy to produce. Also reduces the health benefits of fish (such as the amount of omega-3 fatty acids), just like cattle fed grain don't have as many health benefits. Some farmed salmon are given dyes in addition to antibiotics to make sure their flesh is pink colored. Additionally, feed can be contaminated with carcinogenic PCBs and dioxins and concentrate in farmed fish like salmon. When fish are farmed in close quarters, there is a lot of waste in a concentrated area. It can leak out and pollute surrounding water. Disease & parasites can spread quickly from one fish to another, so lots of pesticides & antibiotics are needed. This leads to genetic resistance of pests, just like it does when given to cattle in feedlots. Diseases can also escape into any wild fish that are nearby and harm wild fish populations Shrimp farms are often located near tropical coasts, so mangrove forests can be removed to make room for them. This destruction of mangrove forests destroys habitats. It also degrades a natural system that can filter water and buffer the land from tsunamis and storms.

Know the sources and results of the following contaminants: Arsenic (As)

Arsenic (As) is a poisonous, naturally occurring substance that leaches into groundwater from surrounding rocks and soil in the aquifer. In some locations mining operations (ore processing) have also released As into drinking water. Chronic exposure can lead to skin, bladder, lung cancer. The safe level is 10 ppb, but many countries have As levels often up to 100 times safe level (particularly Bangladesh). Researchers are exploring ways to use nanotechnology to treat water for As, but not many other options are available for its removal.

Why is marine biodiversity higher on coasts/ocean bottom than in the open ocean surface?

Average primary productivity and NPP per unit of area are quite low in the open sea. However, because open sea covers so much of the earth's surface, it makes the largest contribution to the earth's overall NPP. Also, NPP is much higher in some open sea areas where winds, ocean currents, and other factors cause water to rise from the depths to the surface. These upwellings bring nutrients from the ocean bottom to the surface for use by producers.

What are barrier islands? How has human development resulted in the destruction of these ecosystems?

Barrier islands are sandy islands that form parallel to some coastlines. They tend to have one or more natural rows of sand dunes in which the sand is held in place by plant roots. These dunes are the first lines of defense against the sea. Seaside real estate is so scarce and valuable that coastal developers frequently remove the protective dunes or build behind the first set of dunes and cover them with buildings and roads. Large storms, like hurricanes, can then flood and sweep away seaside buildings. A more secure place for buildings would be behind the secondary dunes where there is more protection from the sea. The diagram shows the best locations for development in these areas.

Know what happens at each phase of wastewater treatment: Disinfection

Before discharge, wastewater is disinfected. This occurs whether the water goes through tertiary treatments or not. At our plant (and most plants in the US), chlorine is used to kill bacteria and then neutralized before the water leaves the plant. There are some concerns about carcinogenic compounds that can be produced when chlorine reacts in the water. Some places use UV or ozone to kill bacteria (both require a lot of energy and do not last as long as chlorine in the water).

Know what the following water quality tests measure: BOD

Biochemical oxygen demand (BOD) is a measure of the amount of oxygen consumed by organic matter and associated microorganisms in the water over a five-day period. In rivers with high BOD, much of the available dissolved oxygen is consumed by aerobic bacteria, robbing the other aquatic organisms of the oxygen they need to live. The input of nutrients, such as nitrates and phosphorus, into a river stimulates plant growth. When the aquatic plants fie, they are fed upon by aerobic bacteria. More plant growth, therefore, leads to more plant decay. Therefore, excess nutrients can be a prime contributor to increased BOD, and therefore decreased dissolved oxygen levels, in rivers. Natural sources of nutrients include organic matter entering lakes and rivers from swamps bogs and vegetation along the water, particularly leaf fall. Other sources of organic matter are animal waste and wood pulp from paper production. Water with a high BOD usually has a high bacteria count as well.

What is the NPP of an estuary/coastal wetland? The open ocean?

Coastal wetlands are found along the shores of estuaries, like the Elkhorn Slough. Coastal wetlands are areas that are covered by water for some part of the year. These include river mouths, the shores of bays and, in temperate zones, salt marshes. They are some of the earth's most productive ecosystems because of high nutrient inputs from rivers and nearby land, rapid circulation of nutrients from tidal flow and ample sunlight penetrating the shallow waters. Seagrass beds in coastal wetlands consist of plants that can grow underwater. Average primary productivity and NPP per unit of area are quite low in the open sea. However, because open sea covers so much of the earth's surface, it makes the largest contribution to the earth's overall NPP. Also, NPP is much higher in some open sea areas where winds, ocean currents, and other factors cause water to rise from the depths to the surface. These upwellings bring nutrients from the ocean bottom to the surface for use by producers. In 2007, a team of scientists led by J. Craig Venter released a report that dramatically challenged scientists' assumptions about biodiversity in the open sea. After sailing around the world and spending 2 years collecting data, they found that the open sea contains many more bacteria, viruses, and other microbes than scientists had previously assumed.

How can consumer choices lead to more sustainable fishing practices?

Consumers demanding sustainable seafood is one great way to help maintain fisheries. Buying sustainable seafood applies bottom-up pressure that encourages more responsible fishing practices. One important part of this is having fish labeled with where they are from and how they are caught. This information can help consumers make the most sustainable decisions The Marine Stewardship council, an international organization (more than 20 countries) started in London in 1997 to evaluate fisheries for sustainability. They certify certain fisheries as sustainable. Their logo indicates that the fish was caught in a sustainable manner. You can view lists of stores and brands that have been certified at www.msc.org so you know where to buy sustainable seafood. Currently you can buy MSC certified seafood at Safeway (only a few things), Target, Walmart and Whole Foods (bigger selection, including some fresh stuff). While MSC certification is a great tool for consumers, only about 6% of world's fisheries have been certified.

What is a coral reef? What are zooxanthellae? What is coral bleaching?

Coral reefs form in clear, warm coastal waters of the tropics and subtropics. These stunningly beautiful natural wonders are among the world's oldest, most diverse, and most productive ecosystems. In terms of biodiversity, they are the marine equivalents of tropical rain forests. Coral reefs are formed by massive colonies of tiny animals called polyps. They slowly build reefs by secreting a protective crust of limestone around their soft bodies. When the polyps die, their empty crusts remain behind as a platform for more reef growth. The resulting elaborate network of crevices, ledges, and holes serves as habitats for a variety of marine animals. Coral reefs are the result of a mutually beneficial relationship between the polyps and tiny single-celled algae called zooxanthellae ("zoh-ZAN-thel-ee") that live in the tissues of the polyps. In this example of mutualism, the algae provide the polyps with food and oxygen through photosynthesis, and help to produce calcium carbonate. Algae also give the reefs their stunning coloration. The polyps, in turn, provide the algae with a well-protected home and some of their nutrients. Although coral reefs occupy only about 0.2% of the ocean floor, they provide important ecological and economic services. They help moderate atmospheric temperatures by removing CO2 from the atmosphere, and they act as natural barriers that protect 15% of the world's coastlines from erosion caused by battering waves and storms. And they provide habitats for one-quarter of all marine organisms. Economically, coral reefs produce about one-tenth of the global fish catch—one-fourth of the catch in developing countries—and they provide jobs and building materials for some of the world's poorest countries. Coral reefs also support important fishing and tourism industries. Finally, these biological treasures give us an underwater world to study and enjoy. Each year, more than 1 million scuba divers and snorkelers visit coral reefs to experience these wonders of aquatic biodiversity. According to a 2005 report by the World Conservation Union, 15% of the world's coral reefs have been destroyed and another 20% have been damaged by coastal development, pollution, overfishing, warmer ocean temperatures, increasing ocean acidity, and other stresses. And another 25-33% of these centers of aquatic biodiversity could be lost within 20-40 years. One problem is coral bleaching. It occurs when stresses such as increased temperature cause the algae, upon which corals depend for food, to die off, leaving behind a white skeleton of calcium carbonate. Another threat is the increasing acidity of ocean water as it absorbs some of the CO2 produced by the burning of carbon-containing fossils fuels. The CO2 reacts with ocean water to form a weak acid, which can slowly dissolve the calcium carbonate that makes up the corals. The degradation and decline of these colorful oceanic sentinels should serve as a warning about threats to the health of the oceans, which provide us with crucial ecological and economic services.

Helpful things to know from previous units: Buffer Zone concept - how does it apply to marine reserves

Costa Rica is using a version of the buffer zone concept for their parks. In this model there is an inner core that is highly protected. Surrounding that are buffer zones that allow increasing levels of human disturbance as you move outwards. This allows people to extract resources (mining, logging) in a sustainable way, while still allowing the center of the reserve to remain untouched or at least only minimally disturbed. As you can see on the map, Costa Rica's reserves only have one buffer zone.

What two features define the zones of a lake?

Deep lakes normally consist of four distinct zones that are defined by their depth and distance from shore.

Know what the following water quality tests measure: Dissolved oxygen

Dissolved oxygen refers to the amount of free oxygen dissolved in the water. Dissolved oxygen describes what oxygen is available for use by aquatic organisms and does not include the oxygen atom in the water molecule H2O. If DO levels are too low, fish can drown. A DO that is too low is often an indicator of water pollution. It also shows a potential for further pollution downstream because the ability of the stream to self-cleanse will be reduced. Dissolved oxygen is expressed as percent saturation. However, it is often measured in parts per million. You will need to convert results obtained in ppm to a value for percent saturation.

What ecological services are provided by the following ecosystems? Inland wetlands

Important part of the earth's natural capital. They absorb and slow the velocity of floodwaters from coastal storms, hurricanes, and tsunamis. Deposits of sediments and nutrients at the mouths of rivers build up protective coastal deltas. Wetland plants are highly productive because of an abundance of nutrients. Many of these wetlands are important habitats for game fishes, muskrats, otters, beavers, migratory waterfowl, and many other bird species. Inland wetlands provide a number of other free ecological and economic services, which include: -Filtering and degrading toxic wastes and pollutants -Reducing flooding and erosion by absorbing storm water and releasing it slowly and by absorbing overflows from streams and lakes -Helping to replenish stream flows during dry periods -Helping to recharge groundwater aquifers -Helping to maintain biodiversity by providing habitats for a variety of species -Supplying valuable products such as fishes and shellfish, blueberries, cranberries, wild rice, and timber -Providing recreation for birdwatchers, nature photographers, boaters, anglers, and waterfowl hunters

Know how the process of cultural eutrophication can reduce oxygen levels in a body of water. What is an oxygen-sag curve? (relate to cultural eutrophication)

During hot weather or drought, this nutrient overload produces dense growths or "blooms" of organisms such as algae and cyanobacteria and thick growths of water hyacinth, duckweed, and other aquatic plants. These dense colonies of plant life can reduce lake productivity and fish growth by decreasing the input of solar energy needed for photosynthesis by phytoplankton that support fish. When the algae die, they are decomposed by swelling populations of aerobic bacteria, which deplete dissolved oxygen in the surface layer of water near the shore and in the bottom layer. This can kill fish and other aerobic aquatic animals. This is what was happening to Lake Washington before scientists and citizens worked together to clean it up. If excess nutrients continue to flow into a lake, anaerobic bacteria take over and produce gaseous products such as smelly, highly toxic hydrogen sulfide and flammable methane. In a flowing stream, the breakdown of biodegradable wastes by bacteria depletes dissolved oxygen and creates an oxygen sag curve. This reduces or eliminates populations of organisms with high oxygen requirements until the stream is cleansed of oxygen-demanding wastes, at which place or time, such populations can recover. Similar oxygen sag curves can be plotted when heated water from industrial and power plants is discharged into streams, because heating water decreases its levels of dissolved oxygen.

Know what the following water quality tests measure: fecal coliform

Fecal coliform bacteria are found in the feces of humans and other warm-blooded animals. Fecal coliform bacteria occur naturally in the human digestive tract and aid in the digestion of food. These bacteria, by themselves, are usually not pathogens. Pathogenic organisms can be passed from an infected person's body in the feces along with fecal coliform bacteria. Pathogens are relatively scarce in water, making them difficult, costly, and time-consuming to monitor directly. Instead, fecal coliform levels are monitored because of the correlation between fecal coliform counts and the probability of contracting a disease from the water. If fecal coliform counts are high in a waterway, there is a greater chance that pathogenic organisms are also present. A person swimming or wading in such waters has a greater chance of being infected with disease-causing organisms. Diseases such as typhoid fever, hepatitis, gastroenteritis, dysentery and ear infections can be contracted in waters with high fecal coliform counts.

What is optimum sustained yield vs maximum sustained yield? Which is the best way to manage fisheries?

Fisheries can also be sustained through better management practices. Maximum sustained yield is the traditional approach to fishing. According to this approach, fisherman take as much as possible without decreasing population. It is calculated by estimating the carrying capacity of a species and then dividing by two. While this should work theoretically, it is not working because we are bad at estimating carrying capacities, particularly for marine species. Carrying capacities can change from year to year due to other environmental pressures, making an estimate too high in some years. It is also difficult to estimate reproductive rates of fish species. Finally, this calculation can be flawed if a large proportion of captured fish are young/ breeding individuals; removing these individuals will have a disproportionate effect on the population. The Optimum Sustained Yield method takes into account room for error in estimates and interactions with other species. As a result the allowed number of fish that can be caught according to this calculation is lower than the amount allowed by the maximum sustained yield calculation. This is the preferred method of determining the amount of fish that should be harvested from a particular fishery because it is more conservative.

Know the following methods of fishing and why they can be harmful: Longlining

Fishing vessels also use longlining, which involves putting out lines up to 130 kilometers (80 miles) long, hung with thousands of baited hooks. The depth of the lines can be adjusted to catch open-ocean fish species such as swordfish, tuna, and sharks or bottom fishes such as halibut and cod. Longlines also hook and kill large numbers endangered sea turtles, dolphins, and seabirds each year. Making simple modifications to fishing gear and practices can decrease seabird deaths.

Know some sources of groundwater pollution

Groundwater is a source of drinking water for many of the world's people. As a result, pollution of groundwater is a serious problem. Though data is limited, the data that we have about groundwater pollution is alarming. For example, aquifers in 90% of Chinese cities show some contamination. There are many ways that ground water can be polluted, both from surface pollution seeping into groundwater as well as from leaks from buried pollutants. Sources of Groundwater Pollution: 1. Runoff from: Fertilizers and pesticides, road salt (for de-icing roads) mining, people dumping or spilling contaminants like organic solvents (paint thinner) 2. Leaks from: Landfills (leacheate can leak out), Sewer pipes/ septic tanks 3. Leaks from waste lagoons used for industrial wastes (EPA found 1/3 of these had no linersmany were near drinking water wells) 4. Leaks from deep well disposal sites for hazardous waste (this is how we dispose of most hazardous waste in the US) 5. Leaks from underground tanks for Gasoline, toxic solvents, diesel fuel 6. Saltwater intrusion-when all the freshwater is pumped out of a coastal aquifer, salt water can intrude into the aquifer to replace the freshwater. This can contaminate wells.

Know what HIPPCO stands for

HIPPCO: Habitat destruction, degradation, and fragmentation; Invasive (nonnative) species; Population and resource use growth (too many people consuming too many resources); Pollution; Climate change; and Overexploitation

Hypereutrophic

Human inputs of nutrients from the atmosphere and from nearby urban and agricultural areas can accelerate the eutrophication of lakes, a process called cultural eutrophication. This process often puts excessive nutrients into lakes, which are then described as hypereutrophic.

What methods can be used to clean up oil spills? How effective are they?

If they are not too large, oil spills can be partially cleaned up by mechanical means including floating booms, skimmer boats, and absorbent devices such as large pillows filled with feathers or hair. Chemical, fire, and natural methods, such as using bacteria to speed up oil decomposition, are also used. But scientists estimate that current cleanup methods can recover no more than 15% of the oil from a major spill. (You can see the methods outlined here: http://bit.ly/2D2uEEw)

What are the pros/cons of dumping sewage sludge into the deep ocean

In deeper waters, the oceans can dilute, disperse, and degrade large amounts of raw sewage and other types of degradable pollutants. Some scientists suggest that it is safer to dump sewage sludge and most other harmful wastes into the deep ocean than to bury them on land or burn them in incinerators. Other scientists disagree, pointing out that we know less about the deep ocean than we do about the moon. They add that dumping harmful wastes into the ocean would delay urgently needed pollution prevention measures and promote further degradation of this vital part of the earth's life-support system.

How do most developed countries purify drinking water? How could cities in these countries save money by protecting watersheds?

In developed countries, surface water is stored in reservoirs and then reservoir water and groundwater are pumped to a treatment plant for purification to meet the standards. At the purifications plants it will be filtered and disinfected with chlorine, ozone or UV radiation (or some combination of the three). The cleaner the water when it is in the reservoir/ groundwater, the less treatment is needed. Some cities, like NYC, Boston, and Seattle, are focusing on keeping watersheds healthy and saving money. NYC paid $1.5 billion over 10 yrs (starting in 1997) to citizens and governments upstate to restore & maintain forests, wetlands, streams in watershed. This kept them from paying $6 billion (plus yearly maintenance costs) to build more water purification plants.

Commercial extinction

In most cases, overfishing leads to commercial extinction, which occurs when it is no longer profitable to continue fishing the affected species.

Know what happens at each phase of wastewater treatment: Tertiary (advanced)

In the tertiary stage (also called advanced treatment), a number of different techniques are used to remove other pollutants from the wastewater. At the San Jose plant, wastewater passes through fine filters in filter columns (2 stories tall). This step removes very small suspended solids and some pollutants. If a plant is going to remove nitrates and phosphates, it is done at this phase as well through different means.

Specific Locations to know: What are major threats to the Great Lakes ecosystem?

Invasions by nonnative species is a major threat to the biodiversity and ecological functioning of lakes, as illustrated by what has happened to the five Great Lakes, located between the United States and Canada. Collectively, the Great Lakes are the. world's largest body of fresh water. Since the 1920s, they have been invaded by at least 162 nonnative species, and the number keeps rising. Many of the alien invaders arrive on the hulls or in bilge water discharges of oceangoing ships that have been entering the Great Lakes through the St. Lawrence Seaway for almost 50 years. One of the biggest threats, the sea lamprey, reached the western lakes through the Welland Canal in Canada as early as 1920. This parasite attaches itself to almost any kind of fish and kills the victim by sucking out its blood. Over the years it has depleted populations of many important sport fish species such as lake trout. The United States and Canada keep the lamprey population down by applying a chemical that kills lamprey larvae in their spawning streams—at a cost of about $15 million a year. In 1986, larvae of the zebra mussel arrived in ballast water discharged from a European ship near Detroit, Michigan (USA). This thumbnail-sized mollusk reproduces rapidly and has no known natural enemies in the Great Lakes. As a result, it has displaced other mussel species and depleted the food supply for some other Great Lakes species. The mussels have also clogged irrigation pipes, shut down water intake pipes for power plants and city water supplies, and fouled beaches. They have jammed ship rudders and grown in huge masses on boat hulls, piers, pipes, rocks, and almost any exposed aquatic surface. This mussel has also spread to freshwater communities in parts of southern Canada and 18 U.S. states. Currently, the mussels cost the two countries about $140 million a year—an average of $16,000 per hour. Sometimes, nature aids us in controlling an invasive alien species. For example, populations of zebra mussels are declining in some parts of the Great Lakes because a native sponge growing on their shells is preventing them from opening up their shells to breathe. However, it is not clear whether the sponges will be effective in controlling the invasive mussels in the long run. Zebra mussels may not be good for some fish species or for us, but they can benefit a number of aquatic plants. By consuming algae and other microorganisms, the mussels increase water clarity, which permits deeper penetration of sunlight and more photosynthesis. This allows some native plants to thrive and could return the plant composition of Lake Erie (and presumably other lakes) closer to what it was 100 years ago. Because the plants provide food and increase dissolved oxygen, their comeback may benefit certain aquatic animals. In 1989, a larger and potentially more destructive species, the quagga mussel, invaded the Great Lakes, probably discharged in the ballast water of a Russian freighter. It can survive at greater depths and tolerate more extreme temperatures than the zebra mussel can. There is concern that it may spread by river transport and eventually colonize eastern U.S. ecosystems such as Chesapeake Bay and waterways in parts of Florida. In 2007, it was found to have crossed the United States, probably hitching a ride on a boat or trailer being hauled cross-country. It now resides in the Colorado River and reservoir system. The Asian carp may be the next invader. These highly prolific fish, which can quickly grow as long as 1.2 meters (4 feet) and weigh up to 50 kilograms (110 pounds), have no natural predators in the Great Lakes. In less than a decade, this hearty fish with a voracious appetite has dominated sections of the Mississippi River and its tributaries and is spreading toward the Great Lakes. The only barriers are a few kilometers of waterway and a little-tested underwater electric barrier spanning a canal near Chicago, Illinois.

Helpful things to know from previous units: Endangered Species Act

It arose from growing concern over declining wildlife populations. For instance, the bald eagle was endangered due to widespread DDT use and the whooping crane was endangered due to habitat loss which the species required in order to stop at overlong journeys. The goals of the act were to stabilize existing populations/help them recover. Species can be listed based on biological factors. It is illegal to hunt, kill, or collect the species. The government develops a recovery plan that designated critical habitat and it is illegal to damage the critical habitat. In a habitat conservation plan, landowners who can destroy a part of the critical habitat must do something for the species in return. Applies to both federal and private land. There are fines and possible jail time if broken. Has been very successful: 99% of all species are still surviving, more than 50% of listed species have stable/improving population, and some species have been moved off the list. There is some controversy over it: concerns over economic losses, the effectiveness of the law, putting the welfare of animals over people. There have been attempts to weaken it: private land voluntary, more difficult to list, stop protecting critical habitats, allow the government to exempt a state, country, or landowner from the law. There are also ways to strengthen it: increase funding and streamline the process of the conservation plan.

Specific Locations to know: What happened when Nile perch were introduced to Lake Victoria?

Lake Victoria, a large, shallow lake in East Africa, has been in ecological trouble for more than 2 decades. Until the early 1980s, the lake had 500 species of fish found nowhere else. About 80% of them were small fish known as cichlids (pronounced "SIK-lids"), which feed mostly on detritus, algae, and zooplankton. Since 1980, some 200 of the cichlid species have become extinct, and some of those that remain are in trouble. Several factors caused this dramatic loss of aquatic biodiversity. First, there was a large increase in the population of the Nile perch. This large predatory fish was deliberately introduced into the lake during the 1950s and 1960s to stimulate exports of the fish to several European countries, despite warnings by biologists that this huge fish with a big appetite would reduce or eliminate many defenseless native fish species. The population of this large and prolific fish exploded, devoured the cichlids and by 1986 had wiped out over 200 cichlid species. Introducing the perch had other social and ecological effects. The new mechanized fishing industry increased poverty and malnutrition by putting most small-scale fishers and fish vendors out of business. And because the oily flesh of the perch are preserved by use of a wood smoker, local forests were depleted for firewood. Another factor in loss of biodiversity in Lake Victoria was frequent algal blooms. These blooms became more common in the 1980s, due to nutrient runoff from surrounding farms and deforested land, spills of untreated sewage, and declines in the populations of algae-eating cichlids. Also, the Nile perch population is decreasing because it severely reduced its own food supply of smaller fishes—an example of one of the four scientific principles of sustainability in action—and it also shows signs of being overfished. This may allow a gradual increase in the populations of some of the remaining cichlids. This ecological story about the dynamics of large aquatic systems illustrates that there are unintended consequences when we intrude into a poorly understood ecosystem.

Why are lakes/reservoirs more vulnerable to pollution than streams?

Lakes and reservoirs are generally less effective at diluting pollutants than streams are, for two reasons. First, lakes and reservoirs often contain stratified layers that undergo little vertical mixing. Second, they have little or no flow. The flushing and changing of water in lakes and large artificial reservoirs can take from 1 to 100 years, compared to several days or weeks for streams. As a result, lakes and reservoirs are more vulnerable than streams are to contamination by runoff or discharge of plant nutrients, oil, pesticides, and nondegradable toxic substances, such as lead, mercury, and selenium.

Oligotrophic

Lakes that have a small supply of plant nutrients are called oligotrophic (poorly nourished) lakes. Often, this type of lake is deep and has steep banks. Glaciers and mountain streams supply water to many such lakes, bringing little in the way of sediment or microscopic life to cloud the water. These lakes usually have crystal-clear water and small populations of phytoplankton and fishes such as smallmouth bass and trout. Because of their low levels of nutrients, these lakes have a low net primary productivity.

What is the largest source of ocean oil pollution? Has it increased or decreased since 1980?

Largest source of ocean oil pollution is urban and industrial runoff from land, much of it from leaks in pipelines and oil-handling facilities. Some good news: according to a 2006 UNEP study, since the mid-1980s the amount of oil entering the marine environment from oil tanker accidents has decreased 75% and oil discharges from industry and cities have dropped by nearly 90%.

Helpful things to know from previous units: Keystone species/endangered species

Maintain balance in the ecosystem. Many other species within the ecosystem depend on them, so much so that drastic changes can occur if keystone species removed. Often plays a larger role than you would expect for the size of the population. No other species in the ecosystem is able to fill its niche. -Sea otters -Green-backed fire crown. Biologists classify species heading toward biological extinction as either endangered or threatened. An endangered species has so few individual survivors that the species could soon become extinct over all or most of its natural range (the area in which it is normally found). Like the passenger pigeon and several other bird species, they may soon disappear from the earth.

What ecological services are provided by the following ecosystems? Mangrove forests

Mangrove forests provide a number of ecological and economic services. Mangroves can filter toxic pollutants, excess plant nutrients, and sediments maintaining water quality. They provide food, habitats and breeding sites for a number of organisms. They can reduce storm damage and coastal erosion by absorbing much of the energy from waves. As a result they can help protect coastal areas from tsunamis and hurricane storm surges.

mesotrophic

Many lakes fall somewhere between the two extremes of nutrient enrichment. They are called mesotrophic lakes.

Understand the basics of these alternatives to wastewater treatment: Composting toilets

Modern wastewater treatment methods are effective but there are alternatives that can allow us to be more sustainable. One alternative is using composting toilets. These toilets can be installed in homes an businesses and are attached to a composting chamber below the building. These systems are odorless and waterless and create nutrient-rich compost. Periodically (approx. once each year), the composting chamber is emptied and the compost can be sold as a soil conditioner, returning nutrients to the soil and mimicing natural nutrient cycling. In addition to conserving water, these systems are also cheaper to install and operate because they do not require plumbing or wastewater treatment.

What are some drawbacks/issues to current wastewater treatment systems in the US?

Modern wastewater treatment methods are very effective at cleaning water and preventing pollution of surface waters. However, in some locations there are exemptions that jeopardize the effectiveness of these methods. For example, some cities can obtain exemptions from the federal law that requires secondary treatment if they can show that the cost of installing the system would present "undue financial burden." If cities are given this exception, they can discharge sewage following primary treatment. Another problem that occurs is that some cities have combined sewer & storm water systems. In the Bay Area, you can see signs by drains because our storm water and sewage treatment systems are not linked. (Anything going down these storm drains will be untreated.) When the systems are linked, heavy rains can cause the whole system to overflow. This will cause discharge of untreated sewage into local bodies of water (this has happened in the Great Lakes). This happens approx 40,000 times each year, according to the EPA. Sewage blending is a new practice that the EPA has allowed since 2005 to reduce wastewater treatment costs. During times of rain or snow, plants can bypass secondary treatment and blend partially treated sewage with fully treated wastewater. They can discharge this mixture into local waterways. This used to only be allowed in emergencies (ie hurricanes). This policy is expected to cause increased illness in people who swim in these waterways and ecosystem damage (harmful to fishing & tourism industries).

Bycatch

Most fishing boats hunt and capture one or a small number of commercially valuable species. However, their gigantic nets and incredibly long lines of hooks also catch nontarget species, called bycatch. Almost one-third of the world's annual fish catch, by weight, consists of these nontarget species, which are thrown overboard dead or dying. This can deplete the populations of bycatch species that play important roles in marine food webs. Marine mammals such as seals and dolphins can also become part of bycatch.

What factors determine the types and numbers of aquatic organisms found in the layers of aquatic life zones?

Most forms of aquatic life are found in the surface, middle, and bottom layers of saltwater and freshwater systems, which we explore later in this chapter. In most aquatic systems, the key factors determining the types and numbers of organisms found in these layers are temperature, dissolved oxygen content, availability of food, and availability of light and nutrients required for photosynthesis, such as carbon (as dissolved CO2 gas), nitrogen (as NO3 ), and phosphorus (mostly as PO4 3).

Know the sources and results of the following contaminants: Nitrates

Nitrates from fertilizers can soak into groundwater. When these are ingested they can be lethal for babies and small children, although they are not usually harmful to adults in the quantities found in drinking water. When the nitrates enter a baby's body, the body converts nitrates to nitrites and they can interfere with hemoglobin's ability to carry oxygen to organs. This will make the baby's extremities turn blue. Therefore this condition is called blue baby syndrome.

Know what an individual transfer rights system is and some associated problems

Once we know the appropriate sustainable yield of a fishery, market based controls can be used to manage that fishery. An Individual Transfer Rights (ITR) system is used by some countries to prevent overfishing. In this sort of a system, the government gives fishermen quotas or rights to catch a certain number of fish. The quotas can be sold or traded. This method has been used in NZ, Iceland, and Alaska with varying degrees of success. It was particularly successful in the Alaskan halibut fishery. Nevertheless, there are problems. Quotas are often too high and the ITR system does nothing to reduce bycatch. It also transfers fishery ownership to private citizens, but the public is still responsible for enforcement costs (fees could help). Small fishing companies can be pushed out, but limiting the number of quotas held by one company can help this problem.

What stresses do intertidal organisms need to deal with?

Organisms living in this zone must be able to avoid being swept away or crushed by waves and must deal with being immersed during high tides and left hot and dry at low tide. They must also survive changing levels of salinity when heavy rains dilute saltwater.

Know what the following water quality tests measure: TDS

Other than suspended solids, aquatic systems will also contain solids dissolved in the water. Theses solids are usually ions such as Na+, Mg2+, Ca2+, Cl-, HCO32- (bicarbonate) and SO42- (sulfate). Although most dissolved solids are salts, it is possible to find dissolved organic solids as well. A steady concentration of dissolved minerals is necessary for aquatic life- both as micronutrients and to maintain the osmotic balance within the cells of organisms. Rapid changes in TDS levels can lead to weakening of organisms or death. High levels of TDS can also affect photosynthesis and lead to a decline in the quality and taste of drinking water. Road salt, urban runoff, soil erosion and sewage can increase TDS levels.

eutrophic

Over time, sediment, organic material, and inorganic nutrients wash into most oligotrophic lakes, and plants grow and decompose to form bottom sediments. A lake with a large supply of nutrients needed by producers is called a eutrophic (well-nourished) lake. Such lakes typically are shallow and have murky brown or green water with high turbidity. Because of their high levels of nutrients, these lakes have a high net primary productivity.

Specific Locations to know: How did the collapse of the cod fishery in Newfoundland affect its economy? How did it affect the local ecosystem?

Overfishing usually results in only a temporary depletion of fish stocks, as long as depleted areas and fisheries are allowed to recover. But as industrialized fishing fleets vacuum up more and more of the world's available fish and shellfish, recovery times for severely depleted populations are increasing and can take 2 decades or more. In 1992, for example, Canada's 500-year-old Atlantic cod fishery off the coast of Newfoundland collapsed and was closed. This put at least 20,000 fishers and fish processors out of work and severely damaged Newfoundland's economy. This cod population has not recovered, despite the fishing ban. Such a collapse can create a domino effect, leading to collapses of other species. After the cod were fished out in the North Atlantic, fishers turned to sharks, which provide important ecosystem services and help to control the populations of other species. Since then, overfishing of big sharks has cut Atlantic stocks by 99%, according to a 2007 Canadian fisheries study. Scientists reported that with the large sharks essentially gone, the northwest Atlantic populations of rays and skates, which the sharks once fed on, have exploded and have wiped out most of the bay scallops.

How have people destroyed wetlands?

People have drained, filled in, or covered over swamps, marshes, and other wetlands for centuries to create rice fields and to make land available for growing crops, expanding cities, and building roads. Wetlands have also been destroyed in the process of extracting minerals, oil, and natural gas, and in order to reduce diseases such as malaria by eliminating breeding grounds for disease-causing insects. Wetlands serve as natural filters. Those around Lake Victoria have historically captured human and animal wastes and kept the lake water clean enough to be used as drinking water for millions of Africans. In 2006, the director of Uganda's wetlands program reported that extensive draining and building on Lake Victoria's coastal wetlands had led to serious water pollution that was killing fish and contaminating drinking water supplies for several countries. He noted that as the waste flow increases, still more wetlands are being destroyed. The Ugandan government is now working to protect its remaining wetlands. To make matters worse, coastal wetlands in many parts of the world will probably be under water during your lifetime because of rising sea levels caused by global warming. This could seriously degrade aquatic biodiversity supported by coastal wetlands, including commercially important fishes and shellfish and millions of migratory ducks and other birds. It will also diminish the many other ecological and economic services provided by these wetlands.

Know what happens at each phase of wastewater treatment: Primary

Primary treatment is where physical methods are used to remove solids from the wastewater. First, solids are physically separated from the liquid wastewater by pushing the water through a screen. Anything you flush is taken out at this step. Next grit chambers remove sediments (sand, gravel, dirt). Solids removed at this stage are sent to a landfill (there is one right next door to the San Jose plant) or to the digester (explained later). Finally, water is left to sit in settling tanks to allow any remaining solids to settle. Moving bars skim off fats & grease from the top and scrape solids off the bottom for removal. At the end of primary treatment, the water 50% cleaner than when it entered the plant.

Why is protecting marine biodiversity difficult?

Protecting marine biodiversity is difficult for several reasons. First, the human ecological footprint and fishprint are expanding so rapidly into aquatic areas that it is difficult to monitor the impacts. Second, much of the damage to the oceans and other bodies of water is not visible to most people. Third, many people incorrectly view the seas as an inexhaustible resource that can absorb an almost infinite amount of waste and pollution and still produce all the seafood we want. Finally, most of the world's ocean area lies outside the legal jurisdiction of any country. Thus, it is an open access resource, subject to overexploitation.

Know what the following water quality tests measure: pH

Pure water contains an equal amount of H+ and OH- ions Hydrogen ions are acidic and hydroxide ions are basic (or alkaline). pH measures the -log of the H+ concentration. Changes in the pH value of water are important to many organisms. Most organisms have adapted to life in water of a specific pH and may die if it changes even slightly. At extremely high or low pH values, the water becomes unsuitable for most organisms. Very acidic waters can also cause heavy metals, such as copper and aluminum, to corrode and release more readily in to the water. Heavy metals can come from pipes or metals waste dumped into streams. Heavy metals can then accumulate in the gills or aquatic organisms. They can also cause deformities in young fish, reducing their chance of survival.

Know the three zones of a stream/ river and how the speed of the water changes in each zone. How does the energy of the water influence the substrate size & dissolved oxygen in each zone?

Rivers have 3 main zones: the source zone, the transitional zone and the floodplain. The primary difference between these zones is the speed of the water. The source zone has the fastest speed of water, the transitional zone has an in-between speed of water, and the floodplain has the lowest speed of water. The primary difference between these zones is the speed of the water. This determines the size of the sediment in the stream bed. The substrate is made up of the particles on the bottom of the river. The size of these particles is directly determined by the rate of flow of the stream. If the river has enough energy it can keep particles suspended and they won't settle, so the speed of the river determines what will settle. This can also be shown graphically. Fast moving water will be too energetic to allow small particles to settle, so the substrate material will be fairly large boulders and pebbles. Slow moving water will allow smaller particles to settle, so substrate material will be sandy/muddy. This is interesting looking at rocks from ancient stream beds too, because geologists can use the size of the sediments left behind to determine the speed and possible aquatic environments that were present in earth's past. Substrate size matters for living things because it can change the available hiding places and change the types of plants that can grow in a particular location, influencing the consumers that can survive in that location.

What are red (or brown or green) tides? What are their effects?

Runoffs of sewage and agricultural wastes into coastal waters introduce large quantities of nitrate and phosphate plant nutrients, which can cause explosive growths of harmful algae. These harmful algal blooms are called red, brown, or green toxic tides. They release waterborne and airborne toxins that damage fisheries, kill some fish-eating birds, reduce tourism, and poison seafood. Each year, harmful algal blooms lead to the poisoning of about 60,000 Americans who eat shellfish contaminated by the algae.

Plankton

Saltwater and freshwater life zones contain several major types of organisms. One such type consists of weakly swimming, free-floating plankton, which can be divided into three groups: phytoplankton, zooplankton, and ultraplankton.

What percentage of the Earth's surface is covered with water?

Saltwater covers about 71% of the earth's surface, and freshwater occupies roughly another 2.2%. Yet, in proportion to the entire planet, it all amounts to a thin and precious film of water.

How are cruise ships responsible for some ocean pollution?

Scientists also point to a little known problem of cruise ship pollution. A cruise liner can carry as many as 2,000 passengers and 1,000 crew members and generate as much waste as a small city produces. Much of this waste, including perchloroethylene from dry-cleaning and benzene from paint and solvents, is highly toxic. Cruise ships also generate huge amounts of plastic garbage and waste oil. For decades, cruise ships and other ocean vessels, which often sail through fragile ecosystems such as Florida's coral reefs, have been dumping their wastes at sea. In U.S. waters, such dumping is illegal, but some ships continue dumping secretively, usually at night. Ship owners can save large amounts of money by such illegal dumping.

Know what happens at each phase of wastewater treatment: Secondary

Secondary treatment uses biological methods to remove organic materials in the wastewater. After primary treatment, the wastewater is sent to aeration tanks which pump air into the wastewater. The oxygen nurtures the growth of aerobic bacteria. These bacteria are naturally occurring and reproduce under the right conditions, as in these tanks. The bacteria eat any organic materials in the water, like oxygen demanding waste (and plant nutrients), removing them from the wastewater. Blowing air into these tanks uses most of the San Jose plant's energy. After all the organic material has been decomposed, the water moves into clarifiers that allow the bacteria to settle to the bottom. Huge arms scrape sludge off the bottom to be taken to the digester. At the end of secondary treatment, the water is 95% cleaner than when it first entered the plant. Federal law requires only these first two steps, so only some plants go beyond this to tertiary (advanced) treatment.

Helpful things to know from previous units: CITES

Several international treaties and conventions help to protect endangered and threatened wild species. One of the most far reaching is the 1975 Convention on International Trade in Endangered Species (CITES). This treaty, now signed by 172 countries, bans hunting, capturing, and selling of threatened or endangered species. It lists some 900 species that cannot be commercially traded as live specimens or wildlife products because they are in danger of extinction. It also restricts international trade of roughly 5,000 species of animals and 28,000 plants species that are at risk of becoming threatened. CITES has helped reduce international trade in many threatened animals, including elephants, crocodiles, cheetahs, and chimpanzees. But the effects of this treaty are limited because enforcement varies from country to country, and convicted violators often pay only small fines. Also, member countries can exempt themselves from protecting any listed species, and much of the highly profitable illegal trade in wildlife and wildlife products goes on in countries that have not signed the treaty.

Know how economic incentives can help protect aquatic biodiversity (ex: Samaná, Dominican Republic and Playa Junquillal, Costa Rica)

Some coastal communities have an interest in maintaining the ban on whaling because they can provide jobs and income through increasingly popular whale watching. For example, The Nature Conservancy promoted whale watching in the town of Samaná in the Dominican Republic and has trained fishermen to work as whale-watching guides. The once run-down town has become a tourist hotspot, with spruced up houses, hotels, and inns, largely because of the popularity of whale watching. Local residents now have an economic interest in protecting the whales. On Costa Rica's northwest coast in the community of Playa Junquillal, an important leatherback nesting area, residents learned that tourism can bring in almost three times as much money as selling turtle products can earn. Biologists working with the World Wildlife Fund there directed a community-based program to educate people about the importance of protecting leatherbacks and to create revenue sources for local residents based on tourism instead of on harvesting turtle eggs. Volunteers were enlisted to find and rescue nests before they could be poached and to build hatcheries to protect the eggs. For the leatherback turtles, this program was a success. In 2004, on the local beaches, all known nests had been poached. The following year, all known nests were protected and none were poached. The leatherback had become an important economic resource for all, not for just a few, of the residents of Playa Junquillal.

How is a marine protected area different from a marine reserve? What are the benefits of a marine reserve?

Some countries are attempting to protect marine biodiversity and sustain fisheries by establishing marine sanctuaries. Since 1986, the IUCN has helped to establish a global system of marine protected areas (MPAs)— areas of ocean partially protected from human activities. There are more than 4,000 MPAs worldwide, 200 of them in U.S. waters. Despite their name, most MPAs are only partially protected. Nearly all allow dredging, trawler fishing, and other ecologically harmful resource extraction activities. However, the U.S. state of California in 2007 began establishing the nation's most extensive network of MPAs where fishing will be banned or strictly limited. Conservation biologists say this could be a model for other MPAs. Many scientists and policymakers call for adopting an entirely new approach to managing and sustaining marine biodiversity and the important ecological and economic services provided by the seas. The primary objective of this ecosystem approach is to protect and sustain whole marine ecosystems for current and future generations instead of focusing primarily on protecting individual species. The cornerstone of this ecological approach is to establish a global network of fully protected marines reserves, some of which already exist. These areas are put off-limits to destructive human activities in order to enable their ecosystems to recover and flourish. This global network would include large reserves on the high seas, especially near highly productive nutrient upwelling areas, and a mixture of smaller reserves in coastal zones that are adjacent to well-managed, sustainable commercial fishing areas. This would encourage local fishers and coastal communities to support them and participate in determining their locations. Some reserves could be made temporary or moveable to protect migrating species such as turtles. Governments could use satellite technologies to update fishing fleets about the locations of designated reserves. Such reserves would be closed to extractive activities such as commercial fishing, dredging, and mining, as well as to waste disposal. Most reserves in the proposed global network would permit less harmful activities such as recreational boating, shipping, and in some cases, certain levels of small-scale, nondestructive fishing. However, most reserves would contain core zones where no human activity is allowed. Outside the reserves, commercial fisheries would be managed more sustainably by use of an ecosystem approach instead of the current approach, which focuses on individual species without considering their roles in the marine ecosystems where they live. Marine reserves work and they work fast. Scientific studies show that within fully protected marine reserves, fish populations double, fish size grows by almost a third, reproduction triples, and species diversity increases by almost one-fourth. Furthermore, this improvement occurs within 2-4 years after strict protection begins, and it lasts for decades. Research also shows that reserves benefit nearby fisheries, because fish move into and out of the reserves, and currents carry fish larvae produced inside reserves to adjacent fishing grounds, thereby bolstering the populations there. In 2008, the Pacific island nation of Kiribati created the world's largest protected marine reserve. This California-sized area is found about halfway between the Pacific islands of Fiji and Hawaii. In 2006, the United States created the world's second largest protected reserve northwest of the U.S. state of Hawaii. The area is about the size of the U.S. state of Montana and supports more than 7,000 marine species, including the endangered Hawaiian monk seal and the endangered green sea turtle. Still, less than 1% of the world's oceans are closed to fishing and other harmful human activities in marine reserves and only 0.1% is fully protected—compared to 5% of the world's land. Thus, we have reserved essentially 99.9% of the world's oceans to use as we see fit. Furthermore, many current marine reserves are too small to protect most of the species within them and do not provide adequate protection from illegal fishing or from pollution that flows from the land into coastal waters. In 2006, a statement signed by 161 leading marine scientists called for urgent action to create a global network of fully protected marine reserves. Many marine scientists call for fully protecting at least 30% of the world's oceans as marine reserves, and some call for protecting up to 50%. They also urge connecting the global network of marine reserves, especially those in coastal waters, with protected corridors. This would also help species to move to different habitats in the process of adapting to the effects of ocean warming, acidification, and many forms of ocean pollution. Establishing and managing a global network of marine reserves would cost an estimated $12-14 billion a year and create more than 1 million jobs, according to a 2004 study by the World Wildlife Fund International and Great Britain's Royal Society for Protection of Birds. This investment in protecting aquatic biodiversity and regenerating fisheries is roughly equal to the amount currently spent by governments on subsidies for the fishing industry, which conservationists say encourage overfishing.

Specific Locations to know: What happened in the Everglades? What has been done to try to restore this ecosystem?

South Florida's Everglades (USA) was once a 100-kilometer-wide (60-mile-wide), knee-deep sheet of water flowing slowly south from Lake Okeechobee to Florida Bay. As this shallow body of water—known as the "River of Grass"—trickled south it created a vast network of wetlands with a variety of wildlife habitats. Since 1948, a massive water control project has provided south Florida's rapidly growing population with a reliable water supply and flood protection. But is has also contributed to widespread degradation of the original Everglades ecosystem. Much of the original Everglades has been drained, diverted, paved over, ravaged by nutrient pollution from agriculture, and invaded by a number of plant species. As a result, the Everglades is now less than half its original size. Much of it has also dried out, leaving large areas vulnerable to summer wildfires. And much of its biodiversity has been lost because of reduced water flows, invasive species, and habitat loss and fragmentation from urbanization. Between 1962 and 1971, the U.S. Army Corps of Engineers transformed the wandering 166-kilometerlong (103-mile-long) Kissimmee River into a straight 84-kilometer (56-mile) canal flowing into Lake Okeechobee. The canal provided flood control by speeding the flow of water but it drained large wetlands north of Lake Okeechobee, which farmers then turned into cow pastures. To help preserve the wilderness in the lower end of the Everglades system, in 1947, the U.S. government established Everglades National Park, which contains about a fifth of the remaining Everglades. But this protection effort did not work—as conservationists had predicted—because the massive water distribution and land development project to the north cut off much of the water flow needed to sustain the park's wildlife. As a result, 90% of the park's wading birds have vanished, and populations of other vertebrates, from deer to turtles, are down 75-95%. Florida Bay, south of the Everglades is a shallow estuary with many tiny islands, or keys. Large volumes of freshwater that once flowed through the park into Florida Bay have been diverted for crops and cities, causing the bay to become saltier and warmer. This, along with increased nutrient input from crop fields and cities, has stimulated the growth of large algal blooms that sometimes cover 40% of the bay. This has threatened the coral reefs and the diving, fishing, and tourism industries of the bay and the Florida Keys—another example of harmful unintended consequences. By the 1970s, state and federal officials recognized that this huge plumbing project was reducing wildlife populations—a major source of tourism income for Florida—and cutting the water supply for the 6 million residents of south Florida. After more than 20 years of political haggling, in 1990, Florida's state government and the federal government agreed on the world's largest ecological restoration project, known as the Comprehensive Everglades Restoration Plan (CERP). The U.S. Army Corps of Engineers is supposed to carry out this joint federal and state plan to partially restore the Everglades. The project has several ambitious goals. First, restore the curving flow of more than half of the Kissimmee River. Second, remove 400 kilometers (250 miles) of canals and levees blocking water flow south of Lake Okeechobee. Third, buy 240 square kilometers (93 square miles) of farmland and allow it to be flooded to create artificial marshes that will filter agricultural runoff before it reaches Everglades National Park. Fourth, create 18 large reservoirs and underground water storage areas to ensure an adequate water supply for south Florida's current and projected population and for the lower Everglades. Fifth, build new canals, reservoirs, and huge pumping systems to capture 80% of the water currently flowing out to sea and return it to the Everglades. Will this huge ecological restoration project work? It depends not only on the abilities of scientists and engineers but also on prolonged political and economic support from citizens, the state's powerful sugarcane and agricultural industries, and elected state and federal officials. The carefully negotiated plan has begun to unravel. In 2003, sugarcane growers persuaded the Florida legislature to increase the amount of phosphorus they could discharge and to extend the deadline for reducing such discharges from 2006 to 2016. The project had originally been estimated to cost $7.8 billion and to take 30 years. By 2007, the price tag had risen to $10.5 billion and was expected to go much higher, mostly because of an almost tenfold increase in land prices in South Florida between 2000 and 2007. Overall, funding for the project, especially federal funding, has fallen short of the projected needs, and federal and state agencies are far behind on almost every component of the project. Now the project could take 50 years to complete, or it could be abandoned because of a lack of funding. According to critics, the main goal of the Everglades restoration plan is to provide water for urban and agricultural development with ecological restoration as a secondary goal. Also, the plan does not specify how much of the water rerouted toward south and central Florida will go to the parched park instead of to increased industrial, agricultural, and urban development. And a National Academy of Sciences panel has found that the plan would probably not clear up Florida Bay's nutrient enrichment problems. The need to make expensive and politically controversial efforts to undo some of the ecological damage done to the Everglades, caused by 120 years of agricultural and urban development, is another example of failure to heed two fundamental lessons from nature: prevention is the cheapest and best way to go; and when we intervene in nature, unintended and often harmful consequences always occur.

Phytoplankton

Sub-category of plankton. ("FY-toe-plank-ton," Greek for "drifting plants"), includes many types of algae. They and various rooted plants near shorelines are primary producers that support most aquatic food webs.

Specific Locations to know: Where is the Columbia River? What environmental problem is this river system known for?

The Columbia River is a famous example of a river system that humans have interfered with. It is fed by an enormous watershed that stretches from Canada down to Nevada. The Columbia finally empties into the Pacific Ocean west of Portland, OR. It is a famous river system because of the number of dams (over 100) that have been built on the Columbia and its tributaries. These have has a number of negative effects on local ecosystems, as all dams do. The particular problem they have caused in this region is disruption of the native salmon populations. Salmon are a huge part of the Native American culture in this region and were very important to the economy. Since the dams were built, salmon populations dropped 94%. Fishermen & conservationists are pushing to have several dams on the Snake River (a tributary of the Columbia) removed to allow easier migrations for fish, but farmers and industry are opposed. While this may not happen, the government has moved to protect some rivers with the Wild and Scenic Rivers Act. This act, passed in the 1960s protects rivers that are already undeveloped from future development.

Understand how the EPA's discharge trading policy works and the concerns that some environmental scientists have about it

The EPA is experimenting with a discharge trading policy, which uses market forces to reduce water pollution (as has been done with sulfur dioxide for air pollution control, p. 490) in the United States. Under this program, a permit holder can pollute at higher levels than allowed in its permit if it buys credits from permit holders who are polluting below their allowed levels. Environmental scientists warn that the effectiveness of such a system depends on how low the cap on total pollution levels in any given area is set, along with how regularly the cap is lowered. They also warn that discharge trading could allow pollutants to build up to dangerous levels in areas where credits are bought. They call for careful scrutiny of the cap levels and for gradual lowering of the caps to encourage prevention of water pollution and development of better pollution control technology. Neither adequate scrutiny of the cap levels nor gradual lowering of caps is a part of the current EPA discharge trading system.

Know what the Clean Water Act does. How has the amount of water pollution changed in the US since this law was passed?

The Federal Water Pollution Control Act of 1972 (renamed the Clean Water Act when it was amended in 1977) and the 1987 Water Quality Act form the basis of U.S. efforts to control pollution of the country's surface waters. The Clean Water Act sets standards for allowed levels of key water pollutants and requires polluters to get permits limiting how much of various pollutants they can discharge into aquatic systems. But there is more work to be done. In 2006, the EPA, found that 45% of the country's lakes and 40% of the streams surveyed were still too polluted for swimming or fishing, and that runoff of animal wastes from hog, poultry, and cattle feedlots and meat processing facilities pollutes seven of every ten U.S. rivers. Even where sewage treatment plants are in place, treated wastewater can serve as a nutrient leading to algal blooms as it did in Lake Washington. Population growth and increasing levels of resource use and waste can overwhelm these sewage treatment systems. Fish caught in more than 1,400 different waterways and more than a fourth of the nation's lakes are unsafe to eat because of high levels of pesticides, mercury, and other toxic substances. Also, a 2003 study by the EPA found that at least half of the country's 6,600 largest industrial facilities and municipal wastewater treatment plants have illegally discharged toxic or biological wastes into waterways for years without government enforcement actions or fines. And according to a 2007 study by the U.S. Public Interest Research Group, more than half of the country's industrial and wastewater facilities exceeded the limits of their Clean Water Act pollution permits one or more times in 2005, with the average facility discharging close to four times its legal limit of water pollutants. Finally, the U.S. government reported in 2007 that tens of thousands of gasoline storage tanks are leaking, possibly affecting groundwater, and cleanup of most of these leaks has yet to begin. In 43 states, these numbers are expected to increase by thousands before 2020. The estimated cost of cleanup is $12 billion, but the government in 2007 was planning to spend about 3% of that amount on the problem.

Know what the Marine Stewardship Council and the Seafood Watch Program are & how they can help consumers make sustainable choices

The Marine Stewardship council, an international organization (more than 20 countries) started in London in 1997 to evaluate fisheries for sustainability. They certify certain fisheries as sustainable. Their logo indicates that the fish was caught in a sustainable manner. You can view lists of stores and brands that have been certified at www.msc.org so you know where to buy sustainable seafood. Currently you can buy MSC certified seafood at Safeway (only a few things), Target, Walmart and Whole Foods (bigger selection, including some fresh stuff). While MSC certification is a great tool for consumers, only about 6% of world's fisheries have been certified. Another way that consumers can stay informed is through the Seafood Watch program, which was started by Monterey Bay Aquarium in 1997. The program provides recommendations for the most sustainable types of seafood to eat. A lot of the evaluation is based on fishing methods. As you can see in the graph, most seafood is caught using trawl and purse seine methods, both of which are destructive. Trawling decimates the ocean bottom while purse seine fishing can have bycatch. Avoiding fish caught using these methods is a big step towards managing ocean fisheries more sustainably. To help consumers stay informed, Seafood Watch produce pocket guides as well as a free iPhone app. Their online guide also has lots of good information about different fisheries.

How can water be purified by purification plants?

The cleaner the water when it is in the reservoir/ groundwater, the less treatment is needed. Some cities, like NYC, Boston, and Seattle, are focusing on keeping watershed healthy and saving money. NYC paid $1.5 billion over 10 yrs (starting in 1997) to citizens and governments upstate to restore & maintain forests, wetlands, streams in watershed. This kept them from paying $6 billion (plus yearly maintenance costs) to build more water purification plants.

What is mitigation banking and what are some problems with it?

The stated goal of current U.S. federal policy is zero net loss in the function and value of coastal and inland wetlands. A policy known as mitigation banking allows destruction of existing wetlands as long as an equal area of the same type of wetland is created or restored. However, a 2001 study by the National Academy of Sciences found that at least half of the attempts to create new wetlands failed to replace lost ones, and most of the created wetlands did not provide the ecological functions of natural wetlands. The study also found that wetland creation projects often fail to meet the standards set for them and are not adequately monitored. Creating and restoring wetlands can be profitable. Private investment bankers make money by buying wetland areas and restoring or upgrading them, working with the U.S. Army Corps of Engineers and the EPA. They thus create wetland banks or credits that they can sell to developers. Currently, there are more than 400 wetland banks in the United States with a total of more than $3 billion a year in sales. It is difficult to restore or create wetlands. Thus, most U.S. wetland banking systems require replacing each hectare of destroyed wetland with 2-3 or more hectares of restored or created wetlands as a built-in ecological insurance policy. Wetlands restoration expert Ecologists argue that mitigation banking should be used only as a last resort. They also call for making sure that new replacement wetlands are created and evaluated before existing wetlands are to be destroyed. This example of applying the precautionary principle is often the reverse of what is actually done.

Benthos

The third type, benthos, consists of bottom dwellers such as oysters, which anchor themselves to one spot; clams and worms, which burrow into the sand or mud; and lobsters and crabs, which walk about on the sea floor

Specific Locations to know: Know how the oxygen-depleted zone in he Gulf of Mexico has formed

The world's third largest oxygen depleted zone (after those in the Baltic Sea and the northwestern Black Sea) forms every spring and summer in a narrow stretch of the northern Gulf of Mexico off the mouth of the Mississippi River. The low oxygen levels suffocate fish, crabs, and shrimp that cannot move to less polluted areas. The Mississippi River basin drains all or parts of 31 U.S. states and two Canadian provinces. Its watershed contains almost two-thirds of the continental U.S. land area and more than half of all U.S. croplands; it is one of the world's most productive agricultural regions. According to a 2005 study of sediment cores by geologist Lisa Osterman, seasonal oxygen-depleted zones in the northern Gulf of Mexico existed as long ago as the 1800s. But since 1950, when fertilizer use began increasing sharply, the sizes of the zones and levels of oxygen-depletion have been increasing on average, even though it shrank in some years. In many years, it covers an area larger than the U.S. state of Connecticut. In 2007, scientists projected that the 15% increase in the size of the heavily fertilized U.S. corn crop, resulting from increased demand for corn to make ethanol fuel for cars, would cause the zone to grow in size. They later found that the zone was larger that summer than it had been in the previous 22 years. Thus, despite a commitment in 2001 by state and federal governments and Native American tribes to reduce the size of the zone by 75% by 2015, it is still growing.

How do dissolved oxygen, turbidity and temperature affect each other?

Turbidity is the condition resulting from suspended solids in the water, including silts, clays, industrial wastes, sewage and plankton. Such particles absorb heat in the sunlight, thus raising water temperature, which in turn lowers dissolved oxygen levels.

How can the amount of nonpoint-source pollution released in agriculture be reduced?

There are a number of ways to reduce nonpoint-source water pollution, most of which comes from agriculture. Farmers can reduce soil erosion by keeping cropland covered with vegetation. They can also reduce the amount of fertilizer that runs off into surface waters and leaches into aquifers by using slow-release fertilizer, using no fertilizer on steeply sloped land, and planting buffer zones of vegetation between cultivated fields and nearby surface water. Organic farming techniques also offer ways to prevent water pollution. For example, organic farmers use manure for fertilizer, in which nitrogen is contained within organic matter that clings to the soil. Industrialized agriculture applies fertilizer as granules to cropland, which can more easily wash into streams. Applying pesticides only when needed and relying more on integrated pest management (p. 300) can reduce pesticide runoff. Farmers can control runoff and infiltration of manure from animal feedlots by planting buffers and locating feedlots and animal waste sites away from steeply sloped land, surface water, and flood zones. Tougher pollution control regulations for U.S. livestock operations are spurring scientists to come up with better ways to deal with animal waste. They are exploring techniques for converting it to natural gas, recycling undigested nutrients in manure back into animal feed, and extracting valuable chemicals from manure to make plastics or even cosmetics. For example, Smithfield Foods, a large pork producer, plans to build a facility in the state of Utah to convert the wastes from 500,000 hogs into renewable biodiesel fuel for vehicles.

How can cultural eutrophication be prevented/cleaned up?

There are several ways to prevent or reduce cultural eutrophication. We can use advanced (but expensive) waste treatment to remove nitrates and phosphates before wastewater enters lakes. In Lake Washington, this approach, plus diversion of lake water to nearby Puget Sound, were used to reduce eutrophication. We can also use a preventive approach by banning or limiting the use of phosphates in household detergents and other cleaning agents and by employing soil conservation and landuse control to reduce nutrient runoff. There are several ways to clean up lakes suffering from cultural eutrophication. We can mechanically remove excess weeds, control undesirable plant growth with herbicides and algicides, and pump air through lakes and reservoirs to prevent oxygen depletion, all of which are expensive and energy-intensive methods.

What ecological services are provided by the following ecosystems? Estuaries & coastal wetlands

They are some of the earth's most productive ecosystems because of high nutrient inputs from rivers and nearby land, rapid circulation of nutrients by tidal flows, and ample sunlight penetrating the shallow waters. Seagrass beds in coastal wetlands consist of plants that can grow underwater. These plants help to stabilize shorelines and reduce the impact of waves on the shore. Also water storage basins and filter pollutants. Support species and good for commercial and residential housing.

Sustainable yield

Today 75% of the world's commercial fisheries are being fished at or beyond their estimated sustainable yields, according to the U.N. Food and Agricultural Organization.

Know the following methods of fishing and why they can be harmful: Trawler fishing

Trawler fishing is used to catch fishes and shellfish—especially shrimp, cod, flounder, and scallops—that live on or near the ocean floor. It involves dragging a funnel-shaped net held open at the neck along the ocean bottom. It is weighted down with chains or metal plates and scrapes up almost everything that lies on the ocean floor and often destroys bottom habitats—somewhat like clearcutting the ocean floor. Newer trawling nets are large enough to swallow 12 jumbo jet planes and even larger ones are on the way.

Know what the following water quality tests measure: Turbidity

Turbidity is a measure of how light is scattered in the water column due to solids that do not dissolved but are small enough to be suspended in the water. The higher the turbidity, the murkier the water will appear. High turbidity reduces light penetration into the water column, reducing photosynthesis. Suspended solids can clog gills and, in the case of sand and clay settling to the bottom, can smother larvae and eggs. High turbidity can come from soil erosion, runoff, organisms that stir up bottom sediments and algal growth.

What are the ecological & economic impacts of an ocean oil spill?

Volatile organic hydrocarbons in oil immediately kill many aquatic organisms, especially in their vulnerable larval forms. Other chemicals in oil form tar-like globs that float on the surface and coat the feathers of birds (especially diving birds) and the fur of marine mammals. This oil coating destroys their natural heat insulation and buoyancy, causing many of them to drown or die of exposure from loss of body heat. Heavy oil components that sink to the ocean floor or wash into estuaries can smother bottom-dwelling organisms such as crabs, oysters, mussels, and clams, or make them unfit for human consumption. Some oil spills have killed coral reefs. Research shows that populations of many forms of marine life recover from exposure to large amounts of crude oil within about 3 years. But recovery from exposure to refined oil, especially in estuaries and salt marshes, can take 10-20 years. Oil slicks that wash onto beaches can have a serious economic impact on coastal residents, who lose income normally gained from fishing and tourist activities. In 2006, some 17 years after the Exxon Valdez spill, researchers found patches of oil remaining on some parts of the shoreline of Prince William Sound. These areas continue to be hazardous for sea otters, shore birds, and other wildlife.

Helpful things to know from previous units: Tragedy of the Commons- how does it apply to fishing? Water pollution?

Wasteful resource use. The idea of the "tragedy of the commons" was first articulated in 1968 by a Biologist named Garret Hardin. It usually applies to common property, not private property, because people have more incentive to protect private property. The tragedy of the commons works like this: In the short run, people have more to gain from exploiting the resource than from protecting it. In the long run, people have more to gain by protecting it. But, most people think short term, particularly if their livelihood depends on it and they know that others will probably exploit the resource if they don't. Examples: Air, water, forests, grazing lands, ocean fisheries, groundwater. To fix, protect natural capital, live sustainably, don't use resources faster than sustainable yield. Poverty major factor.

What is a septic system?

Wastewater (or sewage water) from households and businesses can be disposed of in a couple of different ways. Some houses (particularly in rural areas) will have their own septic system which consists of a septic tank and a drain field. In the septic tank, the solids settle to the bottom and the liquid and oils move through to the drain field. In the drain field the liquid is able to slowly soak into the soil being filtered as it goes.

Know the difference between point and non-point source pollution (thinking of some examples may help you)

Water pollution can come from single (point) sources, or from larger and dispersed (nonpoint) sources. Point sources discharge pollutants at specific locations through drain pipes, ditches, or sewer lines into bodies of surface water. Examples include factories, sewage treatment plants (which remove some, but not all, pollutants), underground mines, and oil tankers. Because point sources are located at specific places, they are fairly easy to identify, monitor, and regulate. Most developed countries have laws that help to control point-source discharges of harmful chemicals into aquatic systems. In most developing countries, there is little control of such discharges. Nonpoint sources are broad, and diffuse areas, rather than points, from which pollutants enter bodies of surface water or air. Examples include runoff of chemicals and sediments from cropland, livestock feedlots, logged forests, urban streets, parking lots, lawns, and golf courses. We have made little progress in controlling water pollution from nonpoint sources because of the difficulty and expense of identifying and controlling discharges from so many diffuse sources.

Know the following methods of fishing and why they can be harmful: Drift net fishing

With drift-net fishing, fish are caught by huge drifting nets that can hang as deep as 15 meters (50 feet) below the surface and extend to 64 kilometers (40 miles) long. This method can lead to overfishing of the desired species and may trap and kill large quantities of unwanted fish, marine mammals, sea turtles, and seabirds. Since 1992, a U.N. ban on the use of drift nets longer than 2.5 kilometers (1.6 miles) in international waters has sharply reduced use of this technique. But longer nets continue to be used because compliance is voluntary and it is difficult to monitor fishing fleets over vast ocean areas. Also, the decrease in drift net use has led to increased use of longlines, which often have similar harmful effects on marine wildlife.