INTRODUCTORY OCEANOGRAPHY

Specific Reading Assignments for EXAM 4

Chapter 13	THE MARINE ENVIRONMENT; PHOTOSYNTHESIS AND BIOGOCHEMICAL CYCLING	ALL
Chapter 14	BIOLOGICAL PRODUCTIVITY - Energy Transfer	ALL
Chapter 15	ANIMALS OF THE PELAGIC ENVIRONMENT	ALL
Chapter 16	ANIMALS OF THE BENTHIC ENVIRONMENT	ALL

Key Elements to Study

Chapter 13. The Marine Environment

1. Define

• euryhaline/stenothermal/stenohaline/stenothermal
• Pelagic environment
• Benthic environment

2. Division of the Marine Environment

• What depth limits define the Neritic and Oceanic provinces of the Pelagic Environment
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• Be able to describe the subdivisions of the oceanic province on the basis of depth and on physical conditions.
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  • What is the mixed layer?
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  • At what depth is the permanent thermocline?
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• How do you differentiate the pelagic environment based on availability of light; i.e., Euphotic zone/Disphotic zone/Aphotic zone. Figure 14.4.

3. Benthic Environment

• Into what two provinces is the Benthic environment divided?
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• Be able to describe the subdivisions of the subneritic province on the basis of depth and on physical conditions.

4. Basic Marine Life-Styles

• What are the main differences between phytoplankton and zooplankton?
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• How do holoplankton differ from meroplankton and which has the larger number of organisms?
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• What differentiates plankton from nekton?

5. Diffusion

• Diffusion gradient - A concentrated substance (solute) placed in water (solution) will eventually become evenly distributed thoughout the water volume by diffusion. Along what gradient is the substance being moved and in what direction?
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  • Molecular diffusion - Over what mixing length distance and time scales is molecular diffusion involved?
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  • Turbulent diffusion - How do the mixing length distance and time scales of turbulent diffusion differ from molecular diffusion?
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6. Semipermeable cell membrane

• What is a semipermeable membrane and in which direction through it do substances diffuse? Figure 13.16.
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• What is osmosis and what kind of membrane is involved? In what direction will water diffuse?
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• What are the salinity/water differences and water movement diffusion directions for Isotonic, Hypertonic and Hypotonic conditions?
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  • Fresh water fish are Hypertonic. How do they keep from taking in so much water they burst? Figure 15.31 a.
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  • Salt water fish are Hypotonic. How do they control the loss of water from their cells? Figure 15.31 b.
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7. Photosynthesis

• Explain in detail how photosynthesis produces organic matter (carbohydrate).
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  • Describe the light reaction & dark reactions involved in photosynthesis
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  • What is ATP & NADP, and in which reaction are they created?

•  

  • What role does ATP play in photosynthesis?
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  • What role does ATP play in utilizing carbohydrate for metabolism and other cell functions of plants?
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• Do plants respire?
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8. Trophic Levels and Biomass Pyramids

• Transfer Efficiency of Trophic Levels
  • What is the average transfer rate of chemical energy through feeding (trophic) levels for an entire ecological system?
  •  
    • How does this rate compare with the rate with which light is absorbed by phytoplankton to begin with?
    •  
  • If you start with 10,000 units of phytoplankton, how many units remain after passing through two trophic levels? (Figure 14.3).
  •  
• Biomass Pyramid
  • What is the main difference between a food chain and a food web?
  •  
  • Why are animals that feed through a food web more likely to survive the disruption of the supply of food passed from lower trophic levels than those that feed in a linear chain? Figure 14.4.

9. Distribution of Life in the Ocean

• Why, generally, does the marine environment support fewer species that the terrestrial environment?
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• How does a variable and stressful habitat affect the evolutionary ability of an organism to survive in the ocean
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• What do we mean when we say that "organisms can survive where they live"?

10. Maintaining Marine Plants in Upper Sunlit Layer of Ocean

• How is surface area per unit mass related to the ease with which marine plants maintain their position at a desired depth and the efficiency with which nutrients and waste diffuse through the cell membrane? Figure 13.17.
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• Viscosity is a fluid's resistance's to flow. What is the proportionality relationship of viscosity to salinity and temperature, and in what temperature water do floating plants and animals have less need for extensions that aid them in floating in water?
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  • How are bony fishes disadvantaged by viscosity and how have they evolved to compensate? Figure 13.18.

11. Factors Affecting Distribution of Life in the Ocean

• How do inorganic nitrates and phosphates initially enter the ocean?
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  • What kinds of organisms use nutrients and how are nutrients converted into organic substances?
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  • Are nutrients food for plants or for animals?
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• What part does solar radiation play in the distribution of life in the ocean?
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• Where are the most biologically productive regions of the ocean?
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  • What role does upwelling play in this productivity?
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  • How does upwelling differ from the vertical convection in the water column caused by cold air and wind at the surface?

12. Transfer of Biological Energy

• Define:
  • Ecosystem, including Producers, Consumers (herbivores, etc.), and Decomposers
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  • Symbiosis, including Commensalism, Mutualism, and Parasitism
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  • Autotroph
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  • Heterotroph
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• Constituents of organic compounds
  • Three major constituents of organic compounds are Carbon, Oxygen & Hydrogen.
    • From what two abundant compounds in the ocean do we get these elements?
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  • The other two major constituents are Nitrogen & Phosphorous. From what two sources are these found?
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  • Are all elements in the list of secondary constituents found in sufficient concentrations in the ocean?
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  • Why do so some scientists suggest we sprinkle iron fillings into the ocean?
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• Generalized Noncyclic Energy Flow
  • Most energy is introduced into the biotic community by what process?
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  • How is this energy passed through the biotic community and by what processes is energy lost?
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  • What is the final state of this energy?

11. Biogeochemical Cycling

• Describe the general processes for recycling matter in the energy flow in the biotic community?
  • In general, how are inorganic compounds converted to organic matter?
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• What new role do bacteria play as primary grazers of phytoplankton.
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  • Does the organic matter grazed by bacteria reenter the food web that supports fish populations?
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    • How do zooplankton create munchates from phytoplankton, and how are exudates obtained from phytoplankton?
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    • What is the 'microbial loop' of bacteria in grazing and how do they involve munchates and exudates?
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• Carbon Cycle
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  • Describe the two main processes involved in the uptake of carbone dioxide by plants and the return of carbon dioxide to oceanwater. (Figure 13.3)
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• Nitrogen Cycle - involves the uptake of nitrogen in production of amino acids and the return of nitrogen from dead animal tissue by bacteria. (Figure 13.4).
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  • What are the major forms of nitrogen in the ocean?
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  • What role do heterotrophic bacteria play in this process?
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    • How long does it take to break down organic nitrogen and in what way can the total breakdown process limit the availability of inorganic nitrogen for plant productivity?
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  • What role do nitrogen-fixing bacteria and denitrifying bacteria play in this cycle?
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• Phosphorus Cycle - Figure 13.5
  • Why is the rate of breakdown of organic phosphorus compounds more rapid than the breakdown of organic nitrogen compounds?
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Chapter 14. Biological Productivity & Energy Transfer

1. Primary Production

• Gran Method of Measuring Primary Productivity - Figure 14.7
  • What is the reasoning behind the use of oxygen as a measure of the amount of organic carbon synthesized in photosynthesis?
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  • Explain why Net Primary Production (NPP) can be measured in the clear bottle?
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  • Explain why clear and dark bottle are hung in pairs & how can we use a pair of bottles to obtain
  •  
    • Gross Primary Production (GPP)
    •  
    • Oxygen compensation depth

2. Macroscopic Plants

• Bull Kelp are the largest members of what kind of algae?
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• Which algae is the most abundant in the ocean?
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3. Microscopic Plants

• Golden Algae
  • Diatoms 
    • What is the chemical composition of their protective coverings?
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    • How does the degree of transparency of the diatom's protective coverings correlate with where geographically these organisms are found?
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  • How does the diatom reproduce itself?
    • What are the frustule, the epitheca and hypotheca and auxospore and how are they involved in reproduction?
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• Dinoflagellate Algae
  • What constitutes the protective shell of dinoflagellates ?
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  • How does the degree of transparency of the dinoflagellate's protective covering correlate with where geographically these organisms are found?
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  • What are Red Tides and when during a year do they most often occur?
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4. Patterns of Biological Production

• In addition to supplying the energy required for photosynthesis, sunlight may also hamper PP. How?
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• Explain how seasonal conditions, the availability of nutrients and sunlight, and the strength of the thermocline affect PP for the following geographic regions:
  • Polar Regions - which is the main restriction to PP in this region and during which season does the most productivity occur?
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    • Why is there only one phytoplankton and zooplankton bloom?
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  • Tropical Regions - what is main (and constant) deterrent to the return of nutrients to the surface layer?
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    • How and where is this deterrent overcome?
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  • Temperate Regions - explain how the supply of nutrients and sunlight interact to create two phytoplankton and zooplankton blooms.
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    • When during the year do these blooms occur?
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    • Explain why the second bloom is smaller than the first?
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Chapter 15 Animals of the Pelagic Environment

1. Staying Near the Surface using Buoyancy - Zooplankton & Nekton

• Rigid gas chambers. Where is the gas chamber located on the Nautilus and what keeps them from diving below about 250m? Figure 15.13.
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• Flexible swim (gas) bladder. Some slow-moving bony fish keep neutrally buoyancy by filling a swim bladder with gases in the following ways:
  • Air duct - how is the bladder filled
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    • can animals with air ducts change depth rapidly?
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    • can they make themselves more buoyant after they dive?
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  • Gas gland - how are their swim bladders filled?
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    • what could happen if these fish are at least 200 m below surface and brought rapidly to the surface?
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• Gas float. The "Portuguese man-of-war" is a Siphonophore that has a gas float which acts as a sail and allows the wind to move it across the water.
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  • Can it move up and down vertically in the water column?
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  • What is the function of the colony of medusae and polyps suspended beneath the float?
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• True jellyfish.
  • How do true Jelly fish (Scyphozoans) differ from Siphonophores.
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  • How do jelly fish change depth and how do they know "which way is up"?

2. Staying Near the Surface by Expending Energy - Nekton

• Squid. The three genera of swimming squid do not have hollow air chambers like the deep-sea squid.
  • How do they maintain their depth?
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• Fish. Locomotion of fish is much more complex than that of squid.
  • How does a fish provide thrust to move forward.
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  • Explain how adaptations to the pectoral fin benefit the flying fish, stingray and Gurnard.
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  • The tail or caudal fin is the most important fin in propelling high-speed fish. Tails flair dorsally and ventrally for what purpose?
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    • What defines the aspect ratio (AR), and why is the lunate fin (AR ~10) effective for high speed fish such as the blue marlin?
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    • What is the AR of the rounded fin and what kind of fish has this tail?
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      • How maneuverable are these fish?
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    • What is the shape of the Heterocercal fin and what added benefit does it give to the blue shark?
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      • How maneuverable are these fish?

3. Muscular Structure of Fish and Their Swimming Behavior

• Muscle Tissue Type
  • Contrast and compare concentration of myoglobin in, and size of white and red muscle tissue.
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• Lungers
  • What is the predominate muscle fiber in a lunger?
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    • What consequence does this have for the muscle?
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  • What is the feeding behavior of lungers?
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  • What is the AR range of lungers?
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• Cruisers
  • What is the predominate muscle fiber in a cruiser?
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    • What consequence does this have for the muscle?
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    • How does this tissue achieve a high metabolic rate?
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  • What is the AR range for cruisers?
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  • What other kind of muscle tissue to cruisers have and when do they use it?

4. Metabolic Rates of Fish

• Warm-blooded fish. Although most fish are considered to be cold-blooded (body temperature same as environment), many fast swimming cruisers can elevate or maintain their body temperature (warm-blooded).
  • By what mechanism is blood entering the muscle tissue from the cutaneous artery warmed?
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  • What is the advantage to the fish of using muscle to maintain a high body temperature? Isn't it counter-productive?

5. Marine Mammals

• What characteristics define a mammal?
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• Whales, porpoises and dolphins (cetaceans)
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  • How does the tail fin of cetaceans differ from those of fish in orientation and purpose?
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  • Contrast and compare toothed whales and baleen whales.

6. Modifications to Cetaceans to Increase Abilities

• Increased swimming speed
  • In addition to streamlining, what other modification to the bodies of cetaceans allow them to swim so fast?
  •  
• Deep diving. Cetaceans make deep dives and stay down for a long time using several mechanisms:
  • Breath control
    • What in the concentration of capillaries surrounding the lung alveoli and how does it help cetaceans exchange gases with the blood?
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    • What percentage of the oxygen is captured by these lunges in each breath?
    •  
      • Contrast and compare the efficiency of this gas exchange with that of terrestrial animals.
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      • Contrast and compare the structure of the lungs with those of terrestrial animals.
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  • Strategies to utilize this large amount of Oxygen
    • Store it
      • Contrast and compare the number of red blood cells per unit volume and the amount of myoglobin of Cetaceans muscle tissue and those of terrestrial mammals.
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    • Reduce its use
      • How do Cetacean's muscles, which start the dive with adequate supply of oxygen continue to function when the oxygen is used up?
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      • For most cetaceans, how does the circulation to the digestive tract and kidneys change during a dive?
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  • Reduced absorption of gases into tissues
    • How does a cetacean prevent nitrogen narcosis?
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• Use of Sound. Cetaceans do not have vocal chords.
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  • How do they use sound?

7. Group Behavior

Many species of animals inhabiting the open ocean have developed patterns of group behavior that give them more efficiency in their environment.

• Schooling
  • What does the term "schooling" mean and which marine organisms school?
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    • Does it include zooplankton? Why or why not?
• Behavior
  • How do they know when and in what direction to move?
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• Advantages
  • What two advantages are thought to accrue from schooling?

8. Migration

Many oceanic animals migrate from their feeding grounds various distances to spawn, lay their eggs on land, or give live birth to their young.

• How do they know where they are and where they are to go and how do they know it is time to migrate?
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• Not all animals spend their adult life in the same place they were spawned
  • Catadromous. What distinguishes catadromous fish such as the Atlantic eel?
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  • Anadromous. What distinguishes anadromous fish, such as salmon.
  •  
    • How do Atlantic and Pacific Salmon differ in their spawning behavior?

Chapter 16. Animals of the Benthic Environment

1. Composition and Characteristics of Supralittoral & Intertidal Zones

In most benthic habitats, fauna predominates over flora, and benthic fauna are strongly influenced by bottom type -- some require a solid space on which to attach while others need a soft bottom in which to burrow. In general, biomass decreases with depth below the surface.

• Rocky Shores (Hard Bottom)
  • Animals that live on hard bottoms are of what main type?
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  • For those that attach to the bottom, is the composition of the hard bottom material more or less important than the need for space to which they may attach?
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• Sediment Covered Shores (Soft Bottom) - Sediment grain size greatly affects the type of infauna found there. This correlates to the following inter-related soft bottom features:
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  • Mobility of sediment. The degree of movement of sediments determines the type of benthic animals that can live there.
    • Sand beaches are dynamic and are home to what kind of infauna?.
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    • Mud flats have very little sediment mobility and are home to what kind of infauna?
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  • Permeability, and organic & bacterial content of bottom material. Explain how and why breaking waves determine the bacterial content of the two following types of soft bottom:
  •  
    • Sand beaches
    •  
    • Mud flats

2. Vertical Zonation

The vertical zonation of fauna is dramatic at the surface and progressively less so with increasing depth. Compare this vertical zonation of fauna for three zones, and the physical conditions and types of fauna found there.

• Supralittoral and Intertidal Zones
  • What wave features define the supralittoral zone?
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  • What wave and tidal features define the intertidal or littoral zone?
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  • Rocky Shores. How do these and other physical features result in zonation on rocky shores in the following three zones?
    • Supralittoral zone. What epifauna give birth to live young and breath air like their terrestrial cousins, and need only saltwater spray for their connection to the sea?
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    • High-tide zone. Why can't buckshot barnacles abandon the sea for dry land?
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    • Middle-Tide Zone.
      • What is the gooseneck barnacle, and how does it overcome the most important limitation of a rocky shore?
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      • Even more successful in competing for space are the various species of mussels -- given time they will eventually overgrow all other sessile forms. The mussel bed thickens near the bottom of the zone until it reaches an abrupt bottom limit. What determines this lower limit?
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      • Describe the sea anemone and the method it uses to attach to the bottom. Is it a sessile animal?
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  • Sediment-covered shore. Most animals on these shores burrow.
    • Sandy Beach
      • Explain how deposit feeders eat and dispose of these waste matter.
      •  
      • How do suspension feeders feed?
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      • Upon what do Sand Stars feed and how do they find their prey?
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    • Mud Flat
      • Mud flats support even fewer species than sandy beaches. Why?
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      • Fiddler crabs live in burrows and filter feed. They have an aversion to seawater, so that every time the tide rises they do what?
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• Deep-Ocean Floor
  • The subzones here become very broad and diffuse and are determined largely by what?
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  • Does biomass increase or decrease with depth. Why?
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  • In what locations on the deep-ocean floor does biomass increase dramatically?
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    • Describe the conditions that support this increase?
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    • How is energy for life obtained where there is no sunlight, and what role do bacteria play in this process? Explain.
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