Name: __________________________________________________ Date: ________ Pd: ____
Aquatic Bio Midpoint Assessment Study Guide - KEY
Test Date: _______
Unit 1: Marine Ecosystems, Bathymetry, and Ocean Zones
Part 1: Marine Ecosystems:
1. What is the average salinity of the oceans? __3.5%________
2. Why are phytoplankton so important on Earth? Provide 50% of the oxygen on Earth
3. List 3 biotic factors in the ocean a. _fish_ b. __phytoplankton______ c. _coral______________
4. List 3 abiotic factors in the ocean a. _sand__b. __temperature___ c. _oxygen______________
5. What is an ecosystem? Abiotic factors interacting with biotic factors in an area. Ex: Coral relying on
sunlight
6. What does the term “benthic” refer to? seafloor
7. Describe the characteristics of the following 8 ecosystems.
a. Coral Reef - colonial living structures that are found in equatorial areas in the photic zone (also there are deep water
corals but do not worry about these). Coral Reefs have very high biodiversity because of the vast availability of food and
nutrients.
b. Mangrove Forest - Line the coasts of mostly tropical regions. Consists of specific types of trees that are adapted to
exist in fluctuating salinities. Characterized by exposed roots. Serves as breeding grounds/nurseries.
c. Deep Sea - Mostly aphotic (without light), organisms are adapted to living in low to no light. Where we find our
most strange marine organisms.
d. Open Ocean - Most vast ecosystem dominated by pelagic fishes, large expanses of very low productivity. By far the
largest marine ecosystem.
e. Kelp Forest - Large protists that resembles large seaweed that is anchored on the seafloor. Found in coastal regions
of typically colder water. Serve as foraging/hunting grounds for a slew of large organisms.
f. Polar Sea – Arctic and Southern Ocean, extremely cold water and partially covered/insulated by thick layers of
ice/glaciers. High productivity due to plenty of upwelling.
g. Salt Marsh – Also known as estuaries with a wide variety of salinities depending on which end of the saltmarsh you are
measure. Dominated by marsh grasses that serve as our oceans nurseries/breeding grounds.
h. Rocky Shore – Found on coastlines where organisms living here are exposed to harsh conditions from frequent and
intense wave action against hard, rocky substrates.
8. Include the 3 types of organisms that are involved in the decomposition of a whale.
As a whale dies and sinks to the seafloor, background specialists begin to breakdown the flesh and tissue of the whale
until bone is exposed. Following are bone specialists which can extract oils from the bone and liberate them into the
water column. Lastly are species with unclear connections. Background specialists also reappear to feed on the osedax
(bone specialist). A whale fall is considered succession because it adds a tremendous amount of nutrients to a specific
area and can support growth of a tremendous amount of organisms in that specific area.
9. What is ecological succession?
10. Describe the important of Mangrove Restoration. As mangroves are destroyed, primary production and
biodiversity plummets in these areas. Therefore, affecting the rest of the surrounding ecosystems. Restoration
reestablishes the primary producers (trees and bushes) that create the basis of the food chain in this ecosystem. Also
provides a sink (removal) for carbon in the atmosphere.
11. What are National Marine Sanctuaries? NMS are America’s underwater treasures. They provide protection to
fisheries and safe passage way for migrating animals. There is a system of 14 Marine Protected Areas (MPAs) that
encompass nearly 25,000 square km. Marine and Great Lake waters from Washington State to Florida Keys and from
Lake Huron to American Samoa.
Part 2: Bathymetry – Seafloor Features
12. What type of technology do scientists use to study the seafloor? _sonar__________________
13. In a few words, define the following terms. Also, be able to label each structure on a seafloor diagram.
a. continental shelf - gently sloping land area along edges of continents
b. abyssal plain - flat, featureless plain with accumulated sediments
c. mid-ocean ridge - enormous mountain ranges on bottom of seafloor
d. guyot – a submerged flat-top peak from a subsided volcano
e. continental rise - hill of sediment at bottom of continental slope
f. continental slope - steep slope leading from edge of continent to ocean basin
g. trench - long, narrow canyon like structures
h. seamount – submarine volcano with a sharp peak
i. submarine canyon – steep sided underwater valley
14. Draw a simple representation of the following tectonic plate boundaries, and give an example of a
natural disaster that can result:
a. convergent boundary
ex: _tsunami________
b. divergent boundary
ex: _volcanism_________
c. transform boundary
ex: _earthquakes________
15. What is the deepest part of the ocean? _Marianas Trench_____ How deep? _11,000m________
16. What is the average depth of the oceans? _3,000m_____________________
17. In a sentence, explain the relationship between these two terms: hydrothermal vents, chemosynthesis.
Hydrothermal vents are structures at the very depths of ocean that spew chemicals from inside the Earth.
Organisms have adapted around the vents to use these chemicals to form organic materials to support life.
This process is called chemosynthesis.
Part 3: Ocean Zones
18. Draw a line to match the depth to the name of the ocean zone.
a. 0-200 m (c)
b. 200-1000m (b)
c. 1000-4000m (a)
d. 4000-6000m (e)
e. 6000-10,000m (d)
a. bathypelagic
b. mesopelagic
c. epipelagic
d. hadalpelagic
e. abyssalpelagic
19. What’s the difference between the supralittoral, littoral, and sublittoral zones?
Supralittoral – above tidal zone (beach)
Littoral – tidal zone (where high and low tide fluctuates – think where you dip your toes in the ocean)
Sublittoral – directly off the coast where water is always covering it
20. What zone is considered euphotic? __epipelagic_____________________
21. What zone is considered dysphotic? __mesopelagic_____________________
22. What zones are considered aphotic? __hadal, abyssal, bathy_____________________
23. Be able to label the following diagram:
Unit 2: Water Chemistry and Ocean Circulation
Part 1: Water Chemistry 24. Define/describe the following about Atoms:

3 subatomic particles - protons______, neutrons______, electrons__________________

Isotopes – same number of protons, different number of neutrons

How are isotopes used in science? – to carbon date fossils, ice core samples
25. Define/describe the following about water and density

Polarity – a property of a molecule in which the charges are unevenly distributed. Ex: Water (oxygen
end is negative, while hydrogen end is positive)

Polar covalent bond – bond in which electrons are unevenly shared

Hydrogen bonding – an attraction between the hydrogen of one molecule (+) and the negative end of
another molecule. In our purposes, they form between water molecules.

How does water’s hydrogen bonds change as you decrease temperature (below 4C)? – water’s hydrogen
bonds extend when water freezes, causing it to expand.

List the 3 phases of water in order from most dense to least dense.
Most dense: liquid, ice, gas :Least dense

Is this unique to water or common to all substances? _unique to water___________
26. Changing Phases of Matter

Label the following phase change diagram.
27. Define/describe the following about density and marine organisms

Buoyancy – The upward force exerted on an object.

Neutral buoyancy - The ability to maintain position in the water column. Jellyfish use this.
Part 2: Ocean Circulation
28. What mostly affects the layering of the ocean? _density____________________
29. What 2 factors control the density of ocean water?
a. _salinity_______________________________________________
b. _temperature_______________________________________________
30. What are the 3 zones of the stratified ocean in order from surface to depth?
a. upper
b. mixed
c. deep
31.
Pycnocline is the zone of rapid _density____ change.
32.
What 3 factors affect surface currents?
a. wind
b. bumping into land (deflection)
c. Coriolis Effect
33.
Circle the correct word to complete the statement. As
temperature increases, density (increases, decreases). As salinity
increases, density (increases, decreases).
34. What is another name for the global conveyor belt? Where does deep water form?
thermohaline circulation. Deep water forms in the North Atlantic.
35. Differentiate between upwelling and downwelling
zones. What important substances do each provide?
upwelling-nutrients
downwelling - oxygen
36. Explain what a surface convergence is. Does this
result in upwelling or downwelling?
downwelling
37. Explain what a surface divergence is. Does this
result in upwelling or downwelling?
upwelling
38. Describe the following convection cells (Use your global winds worksheet):
a. Polar cells – warm air rises at 60 deg latitude and moves to poles.
b. Ferrell cells – warm air rises at 60 deg latitudes and sinks at 30
c. Hadley cells - warm air rises at equator toward 30 deg latitudes
39. Circle the correct direction. Due to the Coriolis Effect water is deflected (right or left) of the driving
wind in the Northern Hemisphere and (right or left) of the driving wind in the Southern Hemisphere.
40. Explain a gyre. Which way does a gyre spin in the Northern and Southern Hemisphere?
Large circular current driven by winds, the ocean basin, and Coriolis effect. All gyres spin clockwise in
the northern hemisphere and counter clockwise in the southern hemisphere.
41. Define an eddie. You may draw this too!
A small circular current that spins off in the opposite direction as the gyre.
42. What is the difference between El Nino and La Nina?
Wind Belts
43. Label the following:
Convection cells
What happens to salinity
at the ITCZ?
Unit 3 – Waves, Tides, Migrations
Part 1: Waves
44. What is a medium? Anything through which energy flows.
45. What is a wave? What is the source of energy for most waves?
A disturbance caused by a transfer of energy through a medium. The source of energy for
most waves is wind.
46. Be able to label the parts of a transverse wave  1- wavelength, 2- amplitude, 3- crest, 4 - trough
47. Draw a longitudinal wave, orbital wave, and transverse wave below.
Longtudinal wave
Transverse wave
Orbital wave
48. How do you calculate period of the wave? Frequency?
Count the time of 1 wavelength. The frequency is 1/period.
49. What type of wave is found at a gentle slope? Steep slope? Very steep slope?
gentle – spilling
steep – plunging
very steep - surging
Part 2: Tides
50. What 3 things cause the tides?
a. _moon’s gravity_______ b. centrifugal force_ c. _sun’s gravity______
51. Describe the position of the moon, sun, and Earth during high tide and during low tide.
51. How do you calculate tidal range?
Subtract low tide from high tide. Largest tidal range is found in the bay of fundy, Maine (52 ft).
52. What is a flood vs. ebb tide? Flood – incoming tide Ebb – outgoing tide
53. Label the following 3 types of tidal patterns:
54. Describe how the tide reacts during a spring tide? Neap tide?
Spring tide brings the highest highs and the lowest lows. Neap tides brings the lowest highs and the highest
lows.
55. What moon phases create a spring tide? Neap tide?
Part 3: Migrations in the Sea
Migrating Animals
56. What is a baleen? Broom-like plates found in the mouths of some whales used to filter tiny organisms.
57. Describe the migration pattern of the gray whale. Gray whales migrate south from the Bering Sea to Baja,
California during the winter to breed. Then return north in the summer to forage.
58. In general, why do whales migrate to warmer waters? Why to colder waters? To warmer water to breed, and to
cold waters to feed.
59. Compare the migration distances of gray whales to humpback whales. Gray whales migrate on the west coast of
U.S. an average of 5600miles, while humpback whales migrate on the east coast of U.S. an average of 2800 miles.
Satellites and Tracking
60. What is an uplink? Downlink? Transmitting signal sent up to a satellite. Transmitting signal sent down from a
satellite to a ground station.
61. Differentiate between a polar and a geostationary satellite. Polar circles the Earth at about 833km and scan
portions of the Earth’s surface as the Earth rotates underneath it. Geostationary is approx. 36,000 km away from
Earth and is at a fixed position over the Equator.
Polar satellites orbit the Earth in 100 minutes, does this 14 X per day. Collects data from Earth’s surface like
volcanoes, polar ice, bodies of water, etc. Geostationary satellites record Earth images more often than polar so
scientists can view images with more frequency. Also, can collect data over an entire hemisphere. Tracks
weather systems.
62. Describe the difference in data collection of a polar satellite vs. a geostationary satellite. See above.
63. What is a SPOT? Smart Position or Temperature Tag What types of animals are they used for? A type of tag that
is used with animals that breathe at surface.
64. What is a Pop-up Archival tag? What type of animals are they used for? A type of tag that is used with animals
that do not come to the surface often. The tag is programmed to be released from the organism after a few months
and float to the surface for retrieval.
65. What is a SRDL? Satellite Relay Data Logger What type of animals are they used for? A type of tag that is used
for large marine animals that dive to great depths. In addition, it can gather and retain a great deal of data like
salinity, temperature, and depth.