Oceanography Merit Badge – In some way, the oceans touch every part of Earth. The oceans cover more than 70 percent of our planet and are the dominant feature of Earth.
Wherever you live, the oceans influence the weather, the soil, the air, and the geography of your community. Apollo astronauts hurtling toward the moon looked back at a blue sphere speckled with clouds. To study the oceans is to study Earth itself.
Since the world’s oceans are all connected, you could think of them as one great ocean. But people have given the various oceans names and have even debated their number.
They are, from largest to smallest, the Pacific, the Atlantic, the Indian, the Southern, and the Arctic Oceans.
That’s why for those of you who want to become a sea scout, it is very important to learn and also get the oceanography merit badge.
Oceanography Merit Badge Requirement
- Name four branches of oceanography. Describe at least five reasons why it is important for people to learn about the oceans.
- Define salinity, temperature, and density, and describe how these important properties of seawater are measured by the physical oceanographer. Discuss the circulation and currents of the ocean. Describe the effects of the oceans on weather and climate.
- Describe the characteristics of ocean waves. Point out the differences among the storm surge, tsunami, tidal wave, and tidal bore. Explain the difference between sea, swell, and surf. Explain how breakers are formed.
- Draw a cross-section of underwater topography. Show what is meant by:
- Continental shelf
- Continental slope
- Abyssal plain
- Name and put on your drawing the following: seamount, guyot, rift valley, canyon, trench, and oceanic ridge. Compare the depths in the oceans with the heights of mountains on land.
- List the main salts, gases, and nutrients in seawater. Describe some important properties of water. Tell how the animals and plants of the ocean affect the chemical composition of seawater. Explain how differences in evaporation and precipitation affect the salt content of the oceans.
- Describe some of the biologically important properties of seawater. Define benthos, nekton, and plankton. Name some of the plants and animals that make up each of these groups. Describe the place and importance of phytoplankton in the oceanic food chain.
- Do ONE of the following:
- Make a plankton net. Tow the net by a dock, wade with it, hold it in a current, or tow it from a rowboat.* Do this for about 20 minutes. Save the sample. Examine it under a microscope or high-power glass. Identify the three most common types of plankton in the sample.
- Make a series of models (clay or plaster and wood) of a volcanic island. Show the growth of an atoll from a fringing reef through a barrier reef. Describe the Darwinian theory of coral reef formation.
- Measure the water temperature at the surface, midwater, and bottom of a body of water four times daily for five consecutive days.* You may measure depth with a rock tied to a line. Make a Secchi disk to measure turbidity (how much-suspended sedimentation is in the water). Measure the air temperature. Note the cloud cover and roughness of the water. Show your findings (air and water temperature, turbidity) on a graph. Tell how the water temperature changes with air temperature.
- Make a model showing the inshore sediment movement by littoral currents, tidal movement, and wave action. Include such formations as high and low waterlines, low-tide terrace, berm, and coastal cliffs. Show how offshore bars are built up and torn down.
- Make a wave generator. Show reflection and refraction of waves. Show how groins, jetties, and breakwaters affect these patterns.
- Track and monitor satellite images available on the Internet for a specific location for three weeks. Describe what you have learned to your counselor.
- Do ONE of the following:
- Write a 500-word report on a book about oceanography approved by your counselor.
- Visit one of the following:
- Oceanographic research ship
- Oceanographic institute, marine laboratory, or marine aquarium Write a 500-word report about your visit.
- Explain to your troop in a five-minute prepared speech “Why Oceanography Is Important” or describe “Career Opportunities in Oceanography.” (Before making your speech, show your speech outline to your counselor for approval.)
- Describe four methods that marine scientists use to investigate the ocean, underlying geology, and organisms living in the water.
What Is Oceanography?
Oceanography covers all aspects of ocean study and exploration.
- Geological oceanography focuses on the topographic features and physical makeup of the ocean floor.
- Physical oceanography deals with the motions of seawater, such as waves, tides, and currents.
- Chemical oceanography concerns the distribution of chemical compounds and chemical reactions in the ocean and on the seafloor.
- Meteorological oceanography pertains to the study of the ocean’s interaction with the atmosphere and its effect on weather and climate.
- Biological oceanography concentrates on plant and animal life in the sea.
Studying the oceans tells us much about the land, rivers, lakes, and the air our entire planet.
This may help us to find new sources or supplies of food, fresh water, minerals, and energy, and a new understanding of weather and climatic patterns.
Earth and Sea
When you think of the ocean, you probably think of motion because the ocean is always moving.
As a free liquid on a spinning planet, it is constantly tugged and pushed by forces near and far. Much of the ocean’s motion takes the form of waves and tides.
1. Waves
The sea surface heaves and sighs as waves rise and fall. From earthquakes to ship wakes (waves created by boats), many forces create ocean waves. However, the most common force is wind.
As wind passes over the water, it pushes on the ocean’s surface, causing it to vibrate. That vibration creates a disturbance or ripple on the ocean surface.
The strength of the wind, the fetch (uninterrupted distance the wind blows), and the duration of the gust determine how big the ripples become.
During severe storms, the ripples can grow to waves 50 feet high. A wave has several distinct parts.
The crest is the portion above the still water line and the highest point on a wave; the trough, or valley between two waves, is the lowest point.
The horizontal distance between the crests or troughs of two waves is called the wavelength.
The vertical distance between the crest and the trough is the wave height. The wave period measures the period of time between two waves.
You can determine the wave period by picking a point, say a rock or pier or buoy, and counting the seconds it takes for two waves to pass by. There you’re an oceanographer already!
2. Storm Surges, Tsunamis, and Tidal Bores
The strong winds of a hurricane or storm push seawater toward the shore. This advancing water may combine with normal tides to create a storm surge, which can increase the tide level 15 feet or higher.
In addition, wind-driven waves roll in on top of the storm surge, adding to the destructive power. Storm surges can cause severe coastal flooding, especially if the storm surge happens at high tide.
Because so much of the U.S. population lives on the East and Gulf Coasts, many in locations just above sea level, the danger from storm surge is tremendous.
Occasionally, underwater disturbances such as volcanic eruptions, earthquakes, or landslides create monster waves called tsunamis. Reaching heights of 120 feet (37 meters) or more, tsunamis are the most dramatic and destructive of waves.
The larger the underwater disturbance, the larger the tsunami. They have been called tidal waves, but their formation has nothing to do with the tides.
In the open ocean, tsunamis are hard to spot. Their long wavelengths mask their monstrous size, but like smaller waves, tsunamis change when they enter shallow water.
Their wavelength shortens, and their crests rise to their full height. The
strength of the underwater disturbance, the tsunami’s wavelength, and the shape of the coastline all contribute to the tsunami’s height and destructiveness.
Tidal bores are waves or walls of water that race up an inlet as the tide comes in. While not completely understood, tidal bores usually occur in V-shaped inlets that shallow up along their length.
Wider at the opening and shallower at the head, these inlets force incoming water to collect in the middle. A wall of water then rushes up the inlet.
3. Waves and coastal Formation
Waves form and shape coastlines. Wave erosion creates some of the world’s most spectacular landforms, including sea caves, wave-cut notches, and coastal cliffs.
Often it smoothes sandy beaches and forms barrier islands like North Carolina’s
Outer Banks.
Breaking waves can deposit or carry away sand and soil. This is known as deposition or erosion of sediment. As waves batter the coast, they erode and grind away the shore.
Rocks and cliffs undercut by wave action fall into the sea and are ground and weathered into sand. The coastline’s resistance to erosion determines its shape.
The ocean constantly reshapes beaches and replenishes the sand. Sediment deposits move along the seashore as every wave hits. Since the wind blows from different directions, waves rarely approach the coast head-on.
As waves strike the shore, the swash (landward movement of water) carries sand to the beach at an angle. The backwash (seaward movement of water) returns straight out to the ocean.
Any sand carried by a wave that is not left on the beach is carried to the ocean by the backwash. There it settles on the seabed until another landward wave deposits it on the beach. This movement of sediment down the beach is called
beach drift.
When waves hit the coast, some of the water flows along the beach, creating a longshore or littoral current. The current moves beach sediment in the water, a movement known as longshore drift.
The combined movement of sediment via longshore drift and beach drift is called littoral drift. The strength of the longshore current increases as the size of the waves and the approach angle increase.
When the current grows strong enough to overcome the force of incoming waves,
the water will flow seaward in a riptide, or rip current. A rip current can carry large amounts of sand and sediment away from the beach.
If incoming waves do not return the sand, the beach gradually will wear away.
4. Tides
The gravitational pull of the moon (and, to a smaller degree, the sun) on the sea
causes ocean tides. In most parts of Earth, this pull produces two high tides and two low tides each day.
As Earth rotates beneath the bulging waters, a high tide occurs, then a low tide, then another high tide, and another low tide. The tilt of the moon’s orbit gives the two daily high tides and the two daily low tides different heights.
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5. Upwelling
Because the oceans have so much mass, they resist moving. Thus, only winds blowing over the water for long distances and for long periods of time are capable of generating ocean currents.
The Gulf Stream is a warm current that flows from the Caribbean toward northern Europe on the western side of the Atlantic Ocean. Winds in the central part of the Atlantic drive this current.
Along the eastern sides of the Atlantic, winds blowing in the direction of the equator push surface water offshore replacing colder, deeper ocean water.
This process is called oceanic upwelling, and the nutrient-rich water that rises to the surface with the cold water helps support the abundant marine life of the Atlantic.
Zones of Life in Sea
The sea is so vast that scientists have divided it into zones. The pelagic zone includes all the environments of the ocean above the bottom, or living in open
oceans or seas rather than in waters next to land or inland waters.
It is divided into an inshore neritic zone (the zone of shallow water adjoining the seacoast) and the open-sea oceanic zone. The boundary between them occurs at the edge of the continental shelf.
The oceanic zone is divided further according to how deep sunlight penetrates.
Planktonic plants occur only in the neritic and epipelagic zones but provide food to animals living in the water and on the bottom. Open-ocean life forms are called pelagic; bottom-dwelling life forms are called benthic.
The benthonic zone is subdivided into three bottom zones: the littoral, bathyal, and abyssal. Plants grow only in the sunlit zone, the only ocean layer that absorbs enough sunlight for photosynthesis.
Animals live in all the oceanic zones, although because of the availability of
food, more of them are found near the ocean’s surface. The sunlit zone is very shallow compared to the bathyal or abyssal zones.
Life Near the Surface
Food is most abundant in the sunlit zone. There, the majority of ocean life finds the food sources needed to survive mostly in the form of microscopic algae.
1. The Intertidal Zone and Intertidal Invertebrates
Abundant and varied plant and animal life thrive in intertidal communities between the high and low tides of marine coasts.
Factors such as the type of rock, type of sand or soil, water temperature, protection from waves, and the interactions between organisms determine what an intertidal community is like.
Intertidal communities are rich in life, especially in invertebrates animals such as clams, mussels, starfish, and others that do not have a backbone or spinal column.
The invertebrate group is one of two general categories of animals. The other
group, vertebrates, includes those animals that do have backbones (fishes, amphibians, reptiles, birds, and mammals).
Invertebrates occupy all habitats, even deep-sea trenches, and are found in all types of sea-bottom sediments, from soft oozes to rocky bottoms.
Swimming invertebrates survive at all depths and include forms developed to
live in the sunless waters of the deep sea as well as near the surface.
Invertebrates exist in fresh, brackish (slightly salty), and marine environments. Some specialized forms also thrive in extremely salty seawater such as lagoons along tropical coasts and pools high in the intertidal zone.
2. Splash and the Upper Intertidal Zones
In the intertidal zone, the area highest above the waves is the splash zone, which is just reached by the ocean’s salty spray.
Animals living in this zone, such as shore crabs and sand fleas, are primarily adapted to life above the waves. Only a few hardy animals live in splash pools, which dry up in summer and flood with freshwater runoff in winter.
Below this zone lies the upper intertidal zone with its scattered covering of green and brown seaweed. Here, snails and limpets scour rocks in search of microscopic algae.
Barnacles cover the rocks except where predators and winter storms have cleared them away. Because barnacles cement themselves to the rocks and close when the tide is out, they are welladapted to this zone.
3. Mid and Low Intertidal Zones
Below these two zones, in the mid-intertidal zone, a broadband of mussels often forms a bed several inches thick.
The common starfish continually feeds on mussels, which would otherwise abound throughout all the available mid-intertidal space.
Many worms, snails, and crabs live within the mussel bed. The mid-intertidal zone is covered and uncovered twice a day by the tides.
Animals in this zone have adapted to being immersed in air and seawater. The diverse plants and animals of the low intertidal zone include red algae and large kelp, which clings to the rocky bottom with holdfasts.
The kelp’s large leaves move with the waves, and the kelp beds protect the sea urchins, worms, snapping shrimp, and porcelain crabs preyed upon by the giant sunflower starfish.
Sandy beaches, while fun for sunbathers, provide limited habitat for marine and shore animals. Those that are there, though, are often found in abundance, especially crabs, clams, and beach hoppers.
Plankton
The term plankton comes from the Greek word planktos, which means “wanderer.” Plankton includes marine plants and animals that drift with the currents.
Because they drift, plankton differ from nekton, animals that actively swim or lie on or burrow into the seafloor, such as clams and worms.
They also differ from marine plants such as large seaweeds. Plankton cells are seldom larger in diameter than a few tenths of an inch. Plankton forms the basis of all major ocean food chains.
Plankton is denser than water and tends to sink. However, because of their small size, long spines, shell extension, and the ability to float, these drifters have adapted in different ways to slow this sinking.
Some planktonic animals rise toward the surface at night and then sink to deeper waters during the day. This vertical migration is probably tied to feeding strategies as well as to the avoidance of predators.
When plankton dies, it sinks and contributes to the rich sediments at the bottom of the sea.
1. Phytoplankton
Plant plankton, or phytoplankton, consists of single-celled algae. Through photosynthesis, plankton supports the rest of all marine life.
Photosynthesis is the process plants use to convert sunlight into food and release oxygen from carbon dioxide and water. The amount of available light and nutrients affects phytoplankton production.
Besides sunlight, phytoplankton needs nutrients to survive. Ocean mixing brings these nutrients up from the seafloor.
Levels of plankton tend to remain low and constant year-round in the clear open ocean and tropical waters. Light can penetrate deeper there, but storms have trouble churning up nutrient-rich bottom sediments in deepwater.
The most productive areas are where surface currents lead away from land and mix with deep currents, like the west coast of Ecuador and Peru and off western Africa.
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2. Zooplanton
Planktonic animals, or zooplankton, are divided into two groups. Holoplankton spend their entire life cycle as plankton.
These include small crustaceans such as crabs, krill (the principal food of baleen whales), and jellyfish.
Meroplankton are plankton only during the larva stage (the earliest stage of an animal, before it changes and becomes an adult).
These species, which include shrimp, barnacles, worms, and marine fish such as herring and anchovies, change dramatically as they grow. As many as 50,000 zooplankton may inhabit one gallon of seawater!
To complete the 8th requirement you can read about Career Opportunities in Oceanography.
Career Opportunities in Oceanography
To become an oceanographer, you will need a background in science and mathematics, and a solid knowledge of at least one basic science such as biology, chemistry, geology, or physics.
In college, oceanography courses help an undergraduate student learn how science applies to the study of the ocean. Your education should include an undergraduate degree (four years) and at least a master’s degree (two more years).
You may need a doctorate (three more years). An oceanographer may choose from several types of careers after completing training.
Colleges and universities provide teaching and research opportunities. The government employs oceanographers in areas such as the Department of Commerce and the Environmental Protection Agency.
The private sector offers the most opportunities. Engineering businesses, oil and
gas extraction companies, and metals mining firms need oceanographers, geologists, and geophysicists.
Oceanographers may detect and track ocean-related weather events, investigate ocean pollution, look for minerals on the seafloor, or study the migration of aquatic animals.
Marine engineers design, construct, and repair ships, submarines, and port facilities.
Ocean engineers design and install equipment used in the ocean, including oil rigs and other offshore installations, and design breakwater systems to prevent beach erosion.
Plenty of other ocean-related career opportunities exist, including:
- Coast Guardsman
- Ocean tour or dive operator
- Commercial fisherman or diver, kelp harvester
- Sailor, ship’s captain, boat operator
- Conservationist or fish and game officer
- Lifeguard
- Longshoreman
- Mariculturist
- Offshore oil worker
- Meteorologist
- Ship builder
- Underwater photographer
