OC 103 Final Study Guide

About 3/4ths of ocean water fall within what range of temperature and salinity?

0-5*C and 34-35% salinity.

Name and describe the six properties of ocean waves.

1. Wave crest is the peak of the wave · 2. Wave trough is the low point of the wave · 3. Wave height is the difference in height between the crest and the trough · 4. Wave length is the horizontal distance between the peak of one wave and the peak of the next (or one trough to the next) · 5. Wave period is the time interval between two crests (or two troughs) passing a fixed point · 6. Wave speed (celerity) of the wave can be calculated by dividing the wavelength by the wave period. Wavelengths are in meters, and wave periods are in seconds, so wave speed is in meters per second (i.e., meters divided by seconds equals m/s).

How many hours would it take for the 1700 tsunami to travel the distance from Oregon to Japan?

10 hours

How long does it take for a water mass to make the trip from the ocean surface to the deep ocean, and back to the surface?

1000-1500 years

A large earthquake off the coast of the Alaskan Peninsula in 1946 produced a deadly tsunami that reached Hawaii 6 hours later. How fast did the tsunami travel in km/hr?

710 km/hr

What is an ecosystem?

A biological community of interacting organisms and their physical environment.

What are tides? What causes them?

A tide is a broad, single wave that stretches across large areas of an ocean basin. Tides occur due to the gravitational pull of the Moon and Sun on the ocean water. Tides are caused by two principal factors: Gravity: The gravity field of the Moon pulls on Earth's ocean water and creates a bulge of water pointing toward it. The gravitational attraction of the Sun also creates a water bulge pointing toward it, but this bulge is much smaller because the Sun is so much farther away (which more than offsets the fact that the Sun is much larger than the Moon). • Centrifugal Force: Centrifugal force sends ocean water away from the center of rotation of Earth and the Moon, creating a tidal bulge pointing away from the center of rotation (and thus, away from the Moon). The centrifugal force between the Sun and Earth also creates a bulge pointing away from the Sun, but again, it is much smaller than the bulge pointing away from the Moon. The net result is 2 main bulges of ocean water caused by the Moon (1 from Gravitational Attraction + 1 from Centrifugal Force), plus 2 much smaller bulges caused by the Sun.

What is a tsunami, and what are its characteristics in deep water versus shallow water?

A tsunami is a wave caused by sudden shifting of the ocean floor due to an earthquake, volcanic eruption, or submarine slumping. In the open ocean, tsunamis have short heights (1 m or less), long wavelengths (>100 km), and long periods (20 minutes to 2 hours), and travel very fast in the deep ocean (usually at almost 500 mph!). When they reach shallow water their wave length shortens and their wave height increases dramatically as water piles up behind the front of the wave.

What is wave refraction, and how does it affect wave energy at headlands versus bays?

As a wave nears the coast, the end of the wave that encounters shallow areas first is slowed down by drag along the bottom, allowing the end of the wave still in deep water to catch up and make the wave bend so it is parallel to the shoreline. Wave energy is focused where the lines converge, such as on headlands; and spread out where the lines diverge, such as in bays.

What causes a wave to break?

As waves enter shallow water, bottom friction slows the wave down and alters its form. The wave speed decreases and its wavelength shortens, but its height increases, and it becomes steeper. When wave height ÷ wave length increases to greater than about 1/7 (i.e., when the height of the wave becomes more than one-seventh of the wavelength), the wave begins to break (collapse).

What is an example of how nutrients can be transported upriver?

Bodies of fish and other organisms contain nutrients, and as the fish move around they are essentially traveling packages of nutrients. A good example of this for western North America is the migration and life cycle of salmon, which ends up moving nutrients from the ocean to the rivers. Salmon hatch in freshwater streams and migrate to the ocean to feed on shrimp and smaller fish for 3-4 years. After they have grown much larger, they return to their birthplace stream to spawn and die, and their decaying bodies contribute their nutrients to the stream and river ecosystem where they were born.

Why are the O2 and CO2 contents of deep ocean water masses important?

CO2 content determines the CCD (Carbonate Compensation Depth is the depth below which carbonate shells dissolve faster than they can accumulate in the sediment), which determines how much CaCO3 is preserved on the ocean floor as sediments and how much dissolves back into the ocean to be used by other organisms. CO2 is also used for plant photosynthesis, but the deep ocean is too dark for plants to survive anyway. Animals in the deep ocean, rely on O2 content for respiration.

What are some of the complications that have made coastal management difficult in the past, and especially challenging for the future? What are some of the solutions that have been tried so far?

Complexity of ocean and coastal ecosystems and resources Ocean and coastal ecosystems are closely related, as are coastal and inland ecosystems, so a broad approach is required to manage them effectively. But the current management approach is often focused on specific areas with single-purpose objectives such as protecting a particular resource or species. •Fragmentation in ownership and control of coastal and ocean areas Property above the high-tide mark may be public or private. Property below the high-tide mark and out 3 miles into the ocean is managed by individual states. Beyond the 3-mile limit and out to 200 miles is managed by the federal government. Beyond 200 miles is international waters (although a country can claim out to more than 200 miles from their coastline if the area meets certain conditions). Marine organisms do not synchronize their habitat needs with these political boundaries, nor do resources start and stop at these boundaries, but management strategies and jurisdictions often do stop at political boundaries. • Jurisdictional conflicts among and within regions and agencies. The agency in charge of protecting a fish population may not have jurisdiction over protecting the seafloor habitat that is essential for successful breeding and survival of those fish.

What are coral reefs? How do they form? What is the fundamental difference between the coral reef food chain and that of most of the rest of the ocean?

Coral reefs are shallow, warm-water rock structures built by animals called coral polyps that secrete CaCO3. Instead of making shells out of CaCO3 the way clams and oysters do, communities of coral polyps secrete CaCO3 into massive structures called coral reefs. Coral reefs harbor the most biodiversity in the marine world, but occur only in areas of shallow water of about 20°-30°C. The coral polyps themselves are animals, but they usually harbor plant cells that use sunlight and the coral animal's waste products to photosynthesize, and in turn provide oxygen and nutrients to the coral animal that protects them. Many other animals live around coral reefs and graze on the coral itself, or hunt for other animals living around the reef. The energy pyramid for coral reefs is therefore different from most other places in the ocean

What is thermohaline circulation, and why is it called that?

Deep-water circulation is driven by density differences (as in heavier water sinks, and lighter water rises), and is called "Thermohaline Circulation" because temperature and salinity (T&S) together are what determine the density of seawater.

What are the good and bad things that plants and animals have to deal with to live in estuaries? What are some adaptations that organisms make to deal with life in estuaries?

Estuaries are semi-enclosed areas that are affected by ocean tides, but also have high input of freshwater from rivers. This results in sharp variations in salinity and temperature Few organisms can handle changing temperature and salinity well, so they either have to be ready to move if conditions change due to the tides or a flooding river, or have special mechanisms to tolerate the changes. These difficult salinity and temperature conditions mean that species diversity is low in estuaries because only a few species can tolerate it. There is not much competition from other species for the food supply, and few predators are able to tolerate the variable temperature and salinity conditions too, so it is a safer place for prey species to live.

What are some current and future issues in waste disposal and oil spillage that need to be managed?

Garbage and Sewage - We already dump large quantities of garbage and sewage into the ocean, which covers the seafloor with trash and fills the nearby water with pollutants. Managing these dumps includes limiting the type of dumped materials to prohibit hazardous wastes, and regulating fishing nearby so that contaminated fish are not caught and eaten. • Nuclear waste - Burying nuclear waste within sediments on the seafloor may be a good way to isolate radioactive waste for the many thousands of years it takes for the most dangerous radioactive elements to decay away. But the technical challenges of working in the deep ocean, and designing and building containers with guaranteed integrity for thousands of years in saltwater at the tremendous pressures of the deep sea, are still daunting. Many of the deep, quiet areas of the ocean floor (the abyssal plains) that would presumably be safest for nuclear waste disposal are in international waters, and are poorly monitored and regulated under the current management structure. • Excess CO2 - Some scientists suggest that we can counteract some of the climate change caused by the industrial buildup of carbon dioxide and other greenhouse gasses by removing some of those gasses from the atmosphere and concentrating them in a stable form that we can then dump onto the ocean floor, effectively removing them from the ocean-atmosphere system for millions of years. Research into this is just beginning, but it seems likely that any operation of this scale would have implications for the health of the deep ocean. • Prevention and Clean-up of Oil Spills - Requiring safety equipment that lessens the likelihood of oil spills, such as double-hulls on oil tankers and blowout preventers on wellheads; and containment equipment on standby to be quickly available to respond to and contain oil spills, is expensive and difficult to justify financially and politically in the quiet, boring times between accidents; but are absolutely necessary no-brainers once an accident happens. The management challenge is to be constantly ready with the best equipment and people for an event that rarely occurs. Once a major spill does occur, such as the Exxon Valdez spill in Alaska or the Deepwater Horizon spill in the Gulf of Mexico, officials need to be able to make quick, well-informed decisions on how to mitigate the damage.

What limits how much marine plants can photosynthesize?

How much light the plants receive

What determines if methane that forms in decaying sediments stays locked up in the sediments, or escapes into the ocean and atmosphere? And why is that methane important?

If the deep water is cold enough, the methane remains frozen in the sediments. If the deep water warms up, the methane is released. If methane is released it heats up the water and acts as a greenhouse gas in the ozone.

What are some of the ocean resources that need managing now and in the future?

In San Francisco Bay, historic wetland losses have been huge. Because of the importance of wetlands for fish spawning grounds and wildlife habitat, and their ability to act as natural filters for water quality improvement, the San Francisco Bay Coastal Program was established to reduce wetland loss associated with development. Since 1987, only a few acres of wetlands per year are lost to development. Also since 1987, using mitigation and restoration, San Francisco Bay has actually been gaining more than 30 acres of wetland per year, to more than make up for the acreage lost to development. Most other coastal states have also been able to slow their rate of wetland loss through management and restoration. This has paid off in helping to maintain habitats that support local industries, such as shrimp fishing in Louisiana, and oyster farming in Oregon.

About how deep in the water can the affect of a surface wave be felt?

In deep water (defined as >1/2 the wavelength), most waves do not interact with the sea bottom, and the orbits of the water molecules are circular. But in shallow water (when water depths are less than about 1/20 the wave length), waves interact with the seafloor, causing the orbits of the water molecules to become elliptical.

What happens to the wavelength of a wave as it enters shallow water?

It decreases

What happens to the period of a wave as it enters shallow water?

It remains constant

Where does most oil pollution come from?

Most oil pollution is "standard operational discharge" related to pumping out bilges on ships. These small spills often go unnoticed or ignored, and are allowed to dissipate. Areas near ports and major shipping lanes are likely to experience these low-level spills fairly frequently, to the detriment of the health of the local shoreline and marine life. • A substantial amount of oil is dumped into the ocean by rivers that carry untreated domestic and industrial wastes to the sea. Some countries are more vigilant than others about how much waste oil they allow to be dumped untreated into the ocean. Because of federal clean water regulations, many U.S. cities now make an effort to sweep their streets regularly to capture some of the oily buildup before it washes into storm drains and into rivers.

How are oil spills cleaned up?

Oil spills gradually degrade over time. Marine life that makes it through the first few weeks after the spill often has a good chance of surviving, unless they experience lingering effects from petroleum residues or the harsh chemical dispersants and high-pressure hot-water hosing that are used on some oil spills that reach the coast. If the spill is in the open ocean, physically containing the oil with booms, and skimming it off of the surface or burning it away are also options, as are chemical dispersants and bioremediation using oil-munching bacteria.

What are some types of pollution?

Oil, Municipal and Industrial Effluent, Ocean Dredging and Mining

What adaptations are necessary on sandy shores where there are fewer places to attach?

On sandy shores, there is no fixed surface to attach to, so animals make different adaptations to protect themselves from predators and fluctuations in temperature, salinity, and water levels (so as not to dry out). Clams, worms, and sand stars will burrow into the sand for safety and to stay moist. The clams are suspension feeders, so they have to siphon seawater down into their burrows and filter out what food they can from the water. Worms and sea stars will feed on what they can scavenge from the sand, or some sea stars will eat clams or other animals they find in the sand.

Why should we care what we are doing to the oceans?

Over half of our population lives within 50 miles of the coast We eat an average of 15 lbs. of seafood per person each year Many things we buy and sell are transported in cargo ships As much as half of the oil we burn arrives by sea Many world weather patterns originate over the oceans

One of the homeworks and at least one of the lessons mentioned the plight of Oregon fisheries, especially the groundfishing business. What are the causes and some potential solutions for this problem?

Overfishing and trawling boats taking over and putting small fishing boats out of business. Fishing passes for a designated percentage of fishing or no fishing areas to restore populations.

What is a red tide, and what can cause one?

Red tide is a phenomenon caused by algal blooms during which algae become so numerous that they discolor coastal waters (hence the name "red tide"). The algal bloom may also deplete oxygen in the waters and/or release toxins that may cause illness in humans and other animals. Usually caused by humans dumping waste into the ocean.

Between reflection, refraction, and diffraction, which process is the most likely to cause sand deposition at a beach flanked by rocky points?

Refraction

What are the ingredients and products of photosynthesis? And respiration?

Photosynthesis converts carbon dioxide and water into oxygen and glucose. Glucose is used as food by the plant and oxygen is a by-product. Cellular respiration converts oxygen and glucose into water and carbon dioxide. Water and carbon dioxide are by- products and ATP is energy that is transformed from the process.

What is primary productivity? How can it be measured by satellites?

Phytoplankton are the base of the marine food chain, so their growth is called primary productivity because they are the "primary" producers of complex sugars and oxygen that can be used by other marine organisms. In essence then, these satellite images show primary productivity. The satellite sensor is specially tuned to detect the wavelengths of light that are reflected by the chlorophyll in phytoplankton, so these images essentially show the abundance of plant life near the ocean surface, with the yellowish and reddish colors in the image signifying higher chlorophyll abundances, and thus, greater photosynthetic activity.

What are the different types and forms of fish fins and what are the advantages of each? Know the fins names, such as pectoral, caudal, etc., and the different types of caudal fins.

Rounded caudal fin (e.g., flounder): very flexible, slow-speed maneuvering. • Truncated caudal fin (e.g., angel fish, salmon): somewhat flexible for maneuvering. • Forked caudal fin (e.g., goatfish, herring): somewhat flexible, combination of maneuvering and speed. • Lunate caudal fin (e.g., blue marlin, tuna): very rigid, not good for maneuvering, but built for speed. • Heterocercal ("uneven") fin (e.g., shark): most of the surface area is in the upper part, which provides excellent thrust for speed, but limits maneuverability, so larger pectoral fins are needed for balance and maneuvering.

How do beaches change with the seasons?

Sand disappears from the beach when the backwash of the larger waves of winter moves the sand just offshore onto sandbars, leaving behind smaller, steeper beaches. The sand then reappears during the summer, when small waves pick the sand up from the sand bars and push it back onto the beach, depositing it as a wide, gradual, smooth slope

What affect will global warming have on sea level? What affect will that have on our coastal areas?

Sea levels will rise and coastal areas will be covered in water.

What are some of the bad things in sewage and how do they affect the oceans and marine life?

Sewage and fertilizer runoff contains an overabundance of nutrients, plus toxic chemicals, pesticides, and potential pathogens (disease-causing organisms) Nutrient Pollution - Sewage contains organic nutrients that can feed a phytoplankton population explosion if dumped into the ocean untreated, and when the plankton all die they decompose and use up all of the oxygen, so there is none left for animals living in the water. Also, some planktonic blooms contain large amounts of toxic algae. • Heavy Metals - Human and industrial wastes can contain heavy metals such as mercury, lead, and copper. High concentrations of metals are toxic to many organisms, especially when they accumulate up the food chain. • Biocides - Many pesticides, herbicides, and man-made chemicals are harmful to the environment. DDT (a pesticide now illegal to use in most countries, but still manufactured in India for use on mosquitoes), PCBs (used in electrical components), and CFCs (used in plastics) are not readily degraded, and animals can ingest them but can't excrete them, so they accumulate up the food chain the same way heavy metals do. Even small amounts of some of these chemicals can cause cancer and developmental or reproductive problems.

Why do some organisms have more than one lifestyle? Think about the advantages of an attached coral having larvae that can float around. You might consider an analogy to land plants: seeds that can float off in the wind have a chance of dropping in some new area where they have a greater chance of success than a young plant that sprouts directly from its parents roots and has to fight for sunlight with its parents and neighbors. Many marine organisms also change lifestyles if it improves their chance of being successful.

Some fish change from pelagic to benthic as they mature. Also, many animals such as crabs, lobsters, and sea stars have a planktonic larval stage, but are benthic as adults. Planktonic larvae can drift much farther than the adult form can walk, so this provides a better way for that species to disperse and colonize new areas.

What are some of the natural and human-caused problems that coastal managers have to deal with?

Sprawl and its impacts: As human population increases, disproportionate numbers of people are settling in coastal areas, the added impact of all of these people can be mitigated by strict land use planning and zoning to control development. Controlling pollution runoff from land: 70-80% of marine pollution enters coastal waters through land-based runoff. Stricter anti-pollution regulations have cut back on the obvious sources of pollution, such as factories and sewage plants, but less obvious sources (called non-point sources) are still a significant problem. Protecting and restoring marine and coastal habitats and biodiversity. Reducing our vulnerability to natural and human-caused hazards. Adapting to climate variability and long-term global change. Providing public access to beaches and coastal waters. Developing nonrenewable ocean resources while protecting other resources.

What are the significant oil spills we mentioned and what were their effects?

The 1989 Exxon Valdez oil spill in Prince William Sound, Alaska was the largest tanker oil spill ever in U.S. waters. 11 million gallons were spilled, and the total death toll for wildlife due to the toxic effects of the oil or to disruption of their food supply will never be known (partly because pre-spill wildlife populations in that area were poorly known). Over $2 billion was spent on the Exxon Valdez cleanup. Over 1000 miles of shoreline were damaged (see map below right), and some of it has still not recovered. The cargo ship New Carissa ran aground near Coos Bay, Oregon in 1999 and spilled some of its fuel onto the nearby coastline. Its stern section remained on the beach for 9 years (see photo below left) until the Summer of 2008, when a salvage company positioned a jack-up barge next to it (see photo below right), and chopped up and removed it piece by piece. In April, 2010, the floating drilling platform Deepwater Horizon burned and sank while drilling a well in 5000 ft deep water in the Gulf of Mexico off of the coast of Louisiana. Oil gushed from the seafloor at the broken drillhead for three months. By the time the flow was stopped, an estimated 200 million gallons of oil had created the largest oil spill ever in the U.S. (see satellite image below, from May 24, 2010). Nearly all of the waters off of Louisiana, Mississippi, and Alabama were closed to fishing, and the coastal tourism industry was devastated by reports of oil on some of the beaches. It will take years to begin to understand the full impacts of the spill, and decades to recover.

What are the T&S properties of the densest water masses, and how did they get that way?

The densest water masses are cold and salty, and are made that way by freezing winds at high latitudes. The cold atmosphere in these regions causes the surface of the ocean to freeze, and since the structure of ice pretty much excludes salts, the freezing of sea ice removes fresh water from the fluid ocean, leaving behind salty, very cold (and thus dense) seawater.

What is a water mass, and how do they get their names?

The different packages or "tongues" of water with distinctive combinations of temperature and salinity are called water masses. Each water mass gained its unique characteristics when it formed at the surface in a particular area. Water masses are usually named for where they formed and/or where they flow in the ocean.

How do beaches and sandbars change with time?

The erosion of rock formations in the water, coral reefs and headlands create rock particles that the waves move onshore, offshore and along the shore, creating the beach. Continual erosion of the shoreline by waves also changes the beach over time

What is the importance of mangrove swamps and salt marshes for marine creatures?

The mangrove's network of stilt-like roots provides excellent cover and habitat for crabs and juvenile shrimp and fish. Fallen leaves from the mangroves also provide food for animals living in mangrove swamps. In sheltered, low-energy environments along coastlines, enough sediments can build up that saltwater-tolerant grasses can take root, creating saltwater marshes of grassy mud flats that are covered and uncovered by the tides. Dead and decaying bits of grass provide food for filter feeders, and the grassy flats and small tidal creeks provide refuge for juvenile crabs and fish.

Where does pollution tend to concentrate?

The most seriously polluted areas are coastal zones that border large urban centers, but even the open ocean is showing signs of pollution, especially along major shipping lanes. Pollution tends to concentrate in 3 parts of the ocean o The sea bottom because pollutants chemically attach to silt and clay particles in the sediments. Along pycnoclines, especially in estuaries because the particles and pollutants are trapped by the density contrast. At the sea surface where air pollution and polluted water dumped by rivers and ships tends to accumulate.

What were our past expectations of the oceans, and what are some of the present realities about those expectations?

The ocean and fish was a limitless resource. Effects; Harmful plankton blooms Reductions in fish and shellfish populations from over-harvesting or pollution Coral reef bleaching and die-off Near extinctions of some marine mammals Coastal erosion and flooding

What are the different lifestyle classifications, and some examples of each? Know the meaning of terms such as plankton, nekton, etc.

The plankton: very weak swimmers, essentially drifters. They usually just go wherever the currents take them, although they can move up and down in the water by changing their buoyancy. They are usually very small or even microscopic, and are subdivided into phytoplankton (planktonic plants) and zooplankton (planktonic animals). • The nekton are organisms that are active swimmers capable of overcoming currents and moving wherever they want. Consequently, there are no plants, only animals, in this group. Common examples include fish, squid, reptiles, birds, and mammals. • The benthos are the bottom-dwellers that live attached to, on, or in the sea bottom. This group includes both plants and animals Benthic plants occur only in shallow areas because of their dependence on light for photosynthesis. Benthic animals occur everywhere from shallow environments to the deep sea. Benthos are further divided up into organisms that live on the sea bottom (either attached or mobile), and those that live in the sea bottom, such as in burrows in the sediment (of course, plants can't live in the bottom because they need sunlight).

Do most ocean creatures live on the bottom or up in the water?

Up in the water.

What determines what beaches look like: their sand types, slopes, etc?

The shape, texture, and color of a beach depends on: • Types of waves: Low wave energy (e.g., Gulf Coast U.S.) - gentle beach, fine sand High wave energy (e.g., West Coast U.S.) - steep beach, coarse sand or pebbles • Types of sediments - Not all sand is the same -- The type of sand that makes up a beach is determined by a combination of source and "aging"

Habitats on the rocky shore are usually divided into vertical zones. Why? What are the zones and what lives in each?

There are 4 zones of distinct biological communities on rocky shores. They are distinguished by their vertical position relative to the tides. • Spray Zone: mostly dry, submerged only during storms. Periwinkle snails, rock louse, and sea roaches scavenge for organic debris here. • High Tide Zone: fairly dry, covered only by the highest high tides. Limpets and buckshot barnacles filter-feed seawater. They have planktonic larvae that depend on high tides to disperse. • Middle Tide Zone: exposed and covered during tide changes. Goose barnacles, mussels, sea stars are common here. This zone has much variety, but also a lot of competition for space. • Low Tide Zone: always wet, except during the lowest low tides. Dominated by plants such as surf grass, but some animals such as sea urchins and sea anemones. Some animals roam more than one tidal zone, such as shore crabs scavenging on seaweed and dead animals.

What are some of the techniques or types of appendages that plankton use to move through the water?

They increase their drag on the water with pores or spines, which increase their surface area.

What causes a storm surge, and why should it be taken seriously?

This is a dangerous condition where a strong storm such as a hurricane pushes a low, broad mound of water against the shoreline. Low atmospheric pressure in the storm leads to a rise in sea level, plus persistent strong winds drive water onto shore, flooding low-lying areas. This flooding is what causes many of the deaths in hurricanes and typhoons.

Why do different plants and animals live in different zones on rocky coasts?

Various ways of eating/hunting, breeding and survival. The organisms living on rocky shores are playing a constant balancing game between competition for food, the risk of predation, and the risk of drying out if they get too far from the water in their search for food and a safe haven from marine predators.

Why is upwelling important for primary productivity and fishing?

Water that rises to the surface as a result of upwelling is typically colder and is rich in nutrients. These nutrients "fertilize" surface waters, meaning that these surface waters often have high biological productivity. Therefore, good fishing grounds typically are found where upwelling is common.

How do animals usually find food when living in soft versus hard bottoms?

Wave activity prevents the accumulation of soft sediments near the shores so plants can't grow and feed animals.

How does this promote sand deposition on the beaches?

Wave energy focuses on the rocky points thus weakening wave energy on the adjacent beach, allowing for sand deposition.

What are the food chain and energy pyramid and what are they based upon?

When animals graze on the primary producers (plants), and convert the nutrients contained in the plant cells into their own energy, that energy moves up the food chain. The "energy pyramid" shows how the energy created by plants (mainly phytoplankton, but also seaweed, kelp, etc.) forms the base of the food chain, but the amount of available energy decreases as it works its way up the food chain because only 10% of energy makes it up each step.

Once bits of food fall to the ocean floor, what happens to them? How can they be recycled back up into the upper ocean where they can be used again? How significant is this for fisheries?

When dead plant and animal matter sinks out of the upper water column and settles to the bottom, it becomes available to the benthic scavengers such as brittle stars and deep-sea crabs that are experts at finding tiny bits of edible organic matter scattered on the seafloor. Abundant benthic scavengers almost exactly coincide with the high primary productivity areas. This is because in areas of high surface productivity there is much more organic matter available to sink to the bottom and provide food for the benthic scavengers. Once plants and animals that die sink below the photic zone, the nutrients contained in their bodies are lost to the deep sea and are no longer available for primary productivity near the surface. In some areas, however, upwelling (remember how this happens when wind-driven Ekman Transport pushes surface water away from a coastline?) brings deep water back up to the surface, returning nutrients to the photic zone. Surface waters in areas of upwelling have very high productivities because of this influx of nutrients; in essence these areas are being continually fertilized with nutrient-rich deep water. Many of the very high primary productivity areas seen in the map several slides ago are there because of upwelling. Upwelling occurs at only 0.1% of the Earth's ocean surface, but supports ~50% of marine fishes.

What are some examples of tracers that have been used to measure the movement of water masses?

byproducts of above-ground nuclear weapons testing during the Cold War, such as carbon-14 (14C) and hydrogen-3 (3H or tritium). lead (from when most gasoline contained lead), chlorinated fluoro-carbons (CFCs), which are byproducts of plastics manufacturing and other industrial processes, and have only become abundant in the atmosphere and oceans in the last 70 years or so.

What are some examples of how tides are significant to biology?

important for many marine organisms that depend on the high tide for ventilation and flushing, or on low tides to expose areas for feeding. Fiddler crabs are one type of animal that scavenges for food on beaches and rocks exposed at low tide, so the daily activity cycle of the fiddlers is synchronized with the low tides. There are other examples of marine organisms synchronizing their habits to take advantage of tidal cycles. Some types of fish and turtles time their spawning and egg laying behavior to coincide with the tides so that their young, which hatch under the sand, will emerge during high tide so they are more likely to make it to the safety of the water before being spotted by predators.

Understand the issues related to population pressure and the changes to the coastlines.

population pressure - people like to live and vacation near the ocean Steady rise of sea level - Sea level is currently rising by 3-4 mm/yr. increasing storm activity - Climate change and periodic phenomenon such as El Niño bring with them more and larger unusual events such as storms and floods. Increasingly common and expensive erosion and damage.

Why do tides look different at different places, and even at one place are not the same everyday?

the orbit of the Moon is not aligned with Earth's Equator, but is tilted at about 28.5 degrees, so the tidal bulge is also at a 28.5° angle to the Equator. As the solid Earth rotates once around every 24 hours beneath this double-bulged cloak of ocean water, most points on Earth rotate through some part of both bulges (each causing a high tide) and both low areas between the two bulges (each causing a low tide), thus causing 2 high tides and 2 low tides per day (almost). Earth does not quite rotate completely through both bulges in 24 hours because the Moon moves forward in its orbit each day, taking its water bulges with it, so it takes 50 additional minutes for a spot on Earth's surface to catch up with the water bulges caused by the Moon. That is why it takes 24 hours and 50 minutes, instead of an even 24 hours, for Earth to rotate through both bulges and get through two complete tidal cycles. Some locations have only one tidal cycle per day (called diurnal tides). Diurnal tides usually occur in areas in the far north and south because those areas encounter only one of the water bulges during a rotation, and completely miss the other bulge. So many locations near the poles have only 1 tide per day. Many locations on Earth have two unequal tides each day (called mixed tides). For mixed tides, locations at mid-latitudes rotate directly under one of the bulges, but only catch the edge of the other bulge, so at those locations one of the daily tidal cycles of a mixed tide has higher high tides and lower low tides than the other daily cycle. Some areas rotate under parts of both bulges that are about equal in magnitude, so those places have two nearly equal tides per day (semidiurnal tides). Oregon, being at mid-latitudes, has mixed tides.

Why do waves often travel in sets?

the size of a wave and its speed is one of the reasons that waves often travel together in trains of 5-10 similar-sized waves that surfers call "sets".

What are hydrothermal vents and what is special about them compared to the main ocean food chain?

vents of very hot water issuing from cracks in the seafloor near where there has been volcanic activity The hot water is rich in metals and chemicals that it picked up from the hot volcanic rocks deep beneath the seafloor. Chemosynthetic bacteria have adapted to this harsh environment, and can make chemical energy by oxidizing the metals in the hot water. These bacteria form the basis of an entirely separate food chain of bizarre animals that graze on, or even "farm", the bacteria, and other animals that prey upon those animals. There is no need for sunlight in this ecosystem, and most of these hot vents are 1000-4000 m deep, far below the photic zone anyway.

How fast do water masses move, and what is the most common way to measure their movements?

water masses move very slowly about 1 km/day, which is a speed of about 0.025 knots. chemical tracers in the water masses such as human-made chemicals that have only been around for a known amount of time. If these tracers can be found in the deep water, we can see how far they have traveled since they were produced and released into the oceans and atmosphere

What causes most waves on the ocean surface, and what determines those waves' sizes?

waves on the ocean surface are caused by winds pushing the water surface into a wave form. Wind velocity (stronger winds make bigger waves) · Wind duration (longer storms make bigger waves) · Fetch (distance over which the wind blows; longer distances make bigger waves) · Simply put, wave size increases as you increase the strength and duration of the wind, and distance over which it blows.

What are the differences between sea, swell, and surf?

· Sea - irregular, chaotic waves in the area of generation, such as within a storm · Swell - more regularly spaced and shaped waves that have traveled beyond their area of generation and have sorted themselves into a uniform size and wavelength · Surf - waves as they reach the coast, grow in height and break

What are the two basic motions associated with a surface wave, and which one actually travels a significant distance?

· The forward movement of the wave energy. · The orbital motion of water particles within and beneath the wave. The water moves in a back-and-forth or circular motion It is wave energy, not water molecules, that travels across the sea surface

What are the two types of wave interference, and which one causes rogue waves?

• Constructive wave interference, which occurs when two wave crests or two wave troughs coincide. The crests build up and the troughs build down Constructive interference occasionally causes massive waves called rogue waves. • Destructive wave interference occurs when the crest of one wave coincides with the trough of another wave, resulting in partial cancellation of both waves

What are the 5 different ways that animals feed?

• Grazers - consume plants (e.g., copepods that eat diatoms, snails that eat seaweed) • Predators - hunt other animals (e.g., sharks that hunt other fish) • Scavengers - search for dead organic matter (e.g., crabs and snails that scavenge on the seafloor) • Suspension feeders - filter seawater for food particles (e.g., barnacles and oysters) • Deposit feeders - search through or ingest mud to extract food particles (e.g., worms and sand dollars that eat mud)