GLG Final CH. 7 & 12
How many total species have been cataloged on Earth? How many marine species exist (both number and percentage of total)? Of marine species, how many are benthic vs. pelagic?
1.8 million. 250,000 or 14% Benthic- 98% Pelagic-2%
How many subtropical gyres exist worldwide? How many main currents exist within each subtropical gyre?
5 Generally, 4 - equatorial, western-boundary, northern or southern-boundary, eastern boundary currents
Describe the global effects of severe El Ninos
Alter the atmospheric jet stream and produce unusual weather patterns, can be drier or wetter than normal or warmer or cooler than normal.
List the subdivisions of plankton and benthos and the criteria used for assigning individual species to each.
Autotrophic- can photosynthesize and make their own food phytoplankton-
List the three major domains of life and the five kingdoms of organisms. Describe the fundamental criteria used in assigning organisms to these divisions
Bacteria- simple life-forms with cells that usually lack a nucleus Archae- simple, microscopic, bacteria-like creatures, often prefer environments with extreme temperatures and pressures Eukarya- complex organisms, multicellular plants and animals, fungi and protocists Monera- simple single-celled organisms that lack discrete nuclei and internal organelles Plantae- multicelled plants Anamalia- multicelled animals Fungi- mold and lichen Protocista- single and multi celled organisms that have a nucleus.
Describe western intensification, including the characteristics of western and eastern boundary currents of subtropical gyres.
Because the top of the hill formed within a rotating gyre is closer to the western boundary than the center of of the gyre, the western boundary currents of subtropical gyres are faster, narrower, and deeper than eastern boundary currents.
Explain why upwelling areas are associated with an abundance of marine life
Cold water is rich in nutrients creates high productivity (an abundance of microscopic algae), which creates the base of the food web and can support larger marine life.
List differences between cold and warm water species in the marine environment
Cold- more biomass because of plankton Warm- often have ornate plumage to increase surface area, are smaller, grow faster, have a shorter life expectancy and reproduce earlier and more frequently, more species but LESS biomass than cold
Why do scientists think there are many more undiscovered species on Earth?
Difficulty of discovery.
Describe the different ways in which currents are measured.
Direct- a floating device released into the current and tracked through time OR a propeller-type flow meter. Indirect- determine the internal distribution of density and the corresponding pressure gradient across an area of the ocean, radar altimeters (show lumps at ocean surface), a Doppler flow meter to transmit low-frequency sound signals through the water.
Describe several different oceanographic conditions that produce upwelling
Diverging surface water, winds from the north cause Ekman transport to move coastal water to the right of the wind direction, causing the water to flow away from the shoreline (Coastal upwelling), offshore winds, sea floor obstructions or a sharp bend in a coastal. Also occurs in high-latitude regions (because of no pycnocline)
Discuss how Ekman transport produces the "hill" of water within the subtropical gyres that causes geostrophic current flow.
Ekman transport deflects surface water to the right in the Northern Hemisphere, so a clockwise rotation develops within an ocean basin and produces the Subtropical Convergence of water in the middle of the gyre, causing water literally to pile up in the center of the subtropical gyre.
EC 7.4
El Nino is a combined oceanic-atmspheric phenomenon that occurs periodically in the tropical Pacific Ocean, bringing warm water to the east. La Nina describes conditions opposite those of El Nino
Describe the three zones based on the availability of sunlight. Which one is where most marine life exists?
Euphotic- where most marine life exists. extends from the surface to a depth where enough light still exists to support photosynthesis Disphotic- small but measurable qualities of light Aphotic- no light.
Explain why the oxygen minimum layer exists and why it coincides with the nutrient maximum?
Exists to show the depth range that possesses the highest levels of nutrients in the ocean
Compare the forces that are directly responsible for creating horizontal and deep vertical circulation in the oceans. What is the ultimate source of energy that drives both circulation systems?
Horizontal circulation- wind-driven, occur primarily in ocean's surface waters. Deep vertical circulation- density-driven, accounts for the thorough mixing of the deep masses of ocean water. Energy from the sun.
Discuss the origin of the thermohaline vertical circulation. Why do deep currents form only in high latitude regions?
Increase in seawater density can be caused by decrease in temperature or increase in salinity. Originate in high latitudes at the surface when surface water becomes cold and its salinity increases as sea ice forms. Form only in high latitude regions because the water is the same at the surface as it is down below
How is La Nina different from El Nino? Describe the pattern of La Nina events in relation to El Ninos since 1950.
La Nina conditions commonly occur following an El Nino.
EC 12.2
Marine organisms can be classified according to their habitat and mobility as plankton (drifters), nekton (swimmers), or benthos (bottom dwellers)
Describe the process of osmosis. How is it different from diffusion? What three things can occur simultaneously across the cell membrane during osmosis?
Osmosis is the process of water molecules moving from LESS concentrated solution to MORE concentrated solution. It is diffusion that produces a net transfer of water molecules through a semipermeable membrane from the side with the greatest concentration of water molecules to the side with the lesser concentration of water molecules. Diffusion is the molecules of soluble substances moving from areas of HIGH concentration to LOW concentration. 1. Water molecules moe through the semipermeable membrane toward the side with the lower concentrator of water. 2. Nutrient molecules or ions move from where they are more concentrated into the cell, where they are used to maintain the cell. 3. Waste molecules move from within the cell to the surrounding seawater.
List the subdivisions of the pelagic and benthic environments and the physical factors used in assigning their boundaries.
Pelagic- Neritic province- extends from the shore seaward and includes all water less than 200 m deep. Oceanic province- where depth increase beyond 200 m epipelagic zone- enough sunlight to support photosynthesis in the upper half mesopelagic- Benthic-
Describe the lifestyles of plankton, nekton, and benthos. Why does plankton account for a much larger percentage of the ocean's biomass than benthos and nekton combined?
Plankton- all organisms that drift with ocean currents (can be algae, animals and bacteria). Nekton- all animals capable of moving independently of the ocean currents by swimming or other means of propulsion. Benthos- organisms living on or in the ocean bottom. Because they are abundant.
What is the problem requiring osmotic regulation faced by hypotonic fish in the ocean? What adaptation do these animals have to overcome this problem?
Saltwater fish are hypotonic compared to the surrounding seawater, so without regulation they would lose water from their body into the ocean and dehydrate. The loss is counteracted by drinking ocean water and secreting the salts through special chloride releasing cells in their gill and also through urination.
Explain why the subtropical gyres in the Northern Hemisphere move in a clockwise fashion while the subpolar gyres rotate in a counterclockwise pattern.
Subtropical- Subpolar-
How does water temperature affect the water's ability to hold gases? How do marine organisms extract dissolved oxygen from seawater?
The amount of gases that dissolve in seawater increases as the temperature of seawater decreases, so cold water dissolves more gas than warm water. Gills exchange oxygen and carbon dioxide directly with seawater.
What factors account for the fact that most marine species inhabit the benthic environment?
The ocean floor contains numerous benthic environments such as rocky, sandy, muddy, flat, sloped, irregular, and mixed bottoms that create different habitats to which organisms have adapted.
EC 12.5
The pelagic environment includes the water column and the benthic environment includes the sea bottom. Subdivisions of pelagic and benthic environments are based on depth, which influences the amount of sunlight.
EC 7.2A
The principal ocean surface current pattern consists of subtropical and subplot gyres that are large, circular-moving loops of water powered by he major wind belts of the world.
EC 7.5
Thermohaline circulation describes the movement of deep currents, which are created at the surface in high latitudes, where they become cold and dense, so they sink.
EC 7.3
Upwelling and downwelling cause vertical mixing between surface and deep water. Upwelling brings cold, deep, nutrient-rich water to the surface, which results in high productivity.
EC 7.2B
Western intensification is a result of Earth's rotation and causes the western boundary currents of all subtropical gyres to be fast, narrow, and deep.
Essential Concept 7.1
Wind-induced surface currents are measured with floating objects, by satellites, and by other techniques. Density-induced deep currents are measured using submerged floats, water properties, and chemical tracers.
What are thought to be the ancestors of the three domains of life?
a community of early primitive cells.
Discuss some adaptations other than size that organisms use to increase their resistance to sinking.
streamlining allows marine organisms to overcome water's viscosity and move more easily through water.
What characteristics should be included in a good working definition of life?
use energy, reproduce, adapt and change through time.
