Shared Flashcard Set

Details

Marine Biology
Test 3
76
Other
Undergraduate 2
04/03/2006

Additional Other Flashcards

 


 

Cards

Term
What is the net primary production?
Definition
The gross primary production minus the respiratory losses.
Term
What is the limiting factor for marine photosynthesis?
Definition
Light
Term
What is the limiting nutrient in freshwater photosynthesis?
Definition
Phosphorus
Term
What nutrient is necessary for diatoms to form their shells?
Definition
Silicon
Term
What are the 4 most important nutrients?
Definition
-Nitrogen
-Phosphorus
-Silicon
-Iron
Term
Hyperbolic curve
Definition
water absorbs 1/2 of the light that is available for every 10 meters
Term
Define Compensation Depth
Definition
The depth at which there is just enough light for photosynthesis to compensate for respiration but NO more.
Term
Define Critical Depth
Definition
The depth at which the organism can't be mixed below (they die)

*can be mixed shallower but not deeper
Term
What area of the water column contains the least amount of nutrients?
Definition
Near the surface...because there are lots of phytoplankton using them up
Term
What is necessary to prevent nutrient stratification?
Definition
Upwelling or other mixing (wind)
Term
Biogeochemical cycles
Definition
nutrient cycles from inorganic to organic form
Term
How are decomposers related to nutrient cycles?
Definition
Decomposers break down dead organisms and release nutrients into the water.
Term
Where are there high levels of nutrients in the euphotic zone?
Definition
-near river openings
-upwelling areas
-near continental shelf
Term
Where are there low nutrient levels in the euphotic zone?
Definition
-gyre openings
-low latitudes
-tropical surface water (no mixing)
Term
Which 2 seasons have less storms? What does the calm weather produce?
Definition
Spring and Summer; the lack of mixing allows a thermocline to form
Term
Why does the angle of light matter to photosynthesis?
Definition
A lower/smaller angle of light from the sun causes more light to be reflected off of the water's surface. Smallest angle in Winter
Term
How many peaks of phytoplankton abundance are there in a 12 month period? When?
Definition
2 peaks;
1 large in Spring; and 1 smaller in the fall
Term
What happens to the compensation and critical depth in the Spring? Why?
Definition
They become deeper because there is more light. (longer days and larger angle)
Term
What happens to the mixed layer in Spring? Why?
Definition
becomes shallower because there is less mixing (less storms)
Term
Where is the mixed layer depth in winter?
Definition
Deep
Term
Where is the critical depth in winter? How about the compensation depth?
Definition
Critical= near surface; Compensation= shallow
Term
What would a graph of yearly phytoplankton abundance in the tropics look like? WHY?
Definition
flat line; stable stratification, low nutrients near surface
Term
What would a graph of yearly phytoplankton abundance near Antartica look like?
Definition
a single large peak in the Summer; high nutrients all year long b/c of upwelling but NO sun in winter
Term
Which is more productive, the tropical or Antartic phytoplankton?
Definition
average out to be the same; tropics are constanty low and Antartic has none except for one large peak
Term
How is the seasonal phytoplankton abundance in the Pacific Ocean unique? WHY?
Definition
they maintain a relatively constant abundance because the pacific zooplankton has larva that is always ready to grow when there is food available (keep phyto pop. low)
Term
Why is there high phytoplankton abundance extending in an arrow-shape away from the West coast of South America?
Definition
High nutrients conc. are supplied b/c the upwelling is driven by trade winds into the Pacific Ocean from the west coast of South America.
Term
Where does the most primary production occur per meter squared (area)?
Definition
Upwelling areas
Term
What are the stages of a food chain?
Definition
primary producer-->primary consumer-->carnivore-->etc
Term
Where is animal biomass produced?(level)
Definition
consumer and predator trophic levels
Term
Define trophic level.
Definition
Each of the steps in a food chain
Term
What is an estuary?
Definition
A semi-enclosed area where fresh water and seawater meet and mix.
Term
Why are estuaries good nurseries?
Definition
LOW predator count and HIGH productivity
Term
What are 3 groups with important ecological roles in estuaries?
Definition
1. Infauna
2. Predators (few, but important)
3. Attached plants
Term
What are infauna?
Definition
Animals that burrow into the substrate.
Term
What are three estuarine macrophyte communities?
Definition
1. Saltmarshes; 2. Seagrass Meadows; 3. Mangals (more tropical)
Term
What plant is VERY common in Atlantic saltmarshes?
Definition
Spartina (cordgrass and salt hay)
Term
What is one reason that snails like marshgrass?
Definition
their Structure; snails can climb up stalks when the tide goes out to avoid predators(crabs)
Term
What is a long term effect of seagrass structure?
Definition
They trap sediment carried in the wind and water which builds up and extends coastline/makes islands, etc
Term
What do estuarine macrophytes excrete into the water column?
Definition
extra Phosphate
Term
What is detritus?
Definition
dead particulate organic matter
Term
Most algae and sea grasss spend their whole life in seawater; how are they different?
Definition
Sea grass is a true vascular plant; algae isn't
Term
How does seagrass reproduce?
Definition
Asexually (rhizomes) and sexually (flowers)
Term
What species is characteristic of tropical seagrass meadows?
Definition
Turtle grass, Thalassia
Term
Is turtle grass productive? Who eats it?
Definition
VERY productive; Few heribvores except sea turtles and manatees
Term
What is an epiphyte?
Definition
A photosynthetic organism that lives on algae or plants. ex: diatoms live on sea grass
Term
What is the primary killer of seagrass meadows?
Definition
Algal blooms caused by nutrient overload (Non-point pollution). Algae blocks light
Term
What is a halophyte?
Definition
A salt-tolerant terrestrial plant. ex: mangrove
Term
Which species of mangrove has prop roots?
Definition
Red mangrove
Term
Which mangrove species has pneumatophores?
Definition
Black Mangrove
Term
Which mangrove species is known as the "pioneer" species?
Definition
Red Mangrove
Term
What is unusual about mangrove reproduction?
Definition
viviparity...seeds germinate while it is still on the parent plant
Term
Why aren't mangroves seen upstream?
Definition
They are out-competed by other plants
Term
How do red mangroves effect the underwater scenery?
Definition
their prop roots form inverted islands; nursury ground for larva b/c benthic predators can't reach
Term
What type of food web are mangrove habitats driven by?
Definition
detritus-driven
Term
Which of the 3 estuary macrophytes degrades the quickest?
Definition
Seagrass
Term
Which of the 3 estuary macrophytes degrades the slowest?
Definition
spartina and mangroves; contain lots of silica
Term
Why is detritus bad food?
Definition
1. little nutrients; 2. too much carbon; ad 3. hard for animals to digest
Term
How does detritus change over time?
Definition
becomes easier to digest; and becomes higher in nutrients
Term
How is most energy exported from estuary ecosystems?
Definition
by living organisms
Term
When does the spring tide occur?
Definition
full or new moon; sun and moon are aligned
Term
When do neap tides occur?
Definition
1/4 moons; smaller tides;
Term
What are some biological consequences of tides?
Definition
Salinity changes; osmotic concentration changes; temperature changes; nutrient mixing, etc
Term
What are general body characteristics of rocky intertidal organisms?
Definition
adaption for attachment; flexible; or hard and stream-lined
Term
What is the difference in the tidal zone between a cove and a peninsula?
Definition
tidal zone will be higher on the peninsula because the waves "run-up" rock and spray higher
Term
What is unique about European rocky intertidal zones?
Definition
Lichen zone
Term
Is it harder to live higher or lower in the rocky intertidal zone?
Definition
Higher; b/c of environment extremes
Term
In rocky intertidal zones, where is the maximum level of diversity located?
Definition
level of lowest tide
Term
How do New England rocky intertidal zones compare to those on the Californian coast?
Definition
NE shores are Less diverse b/c the coasts freeze (organisms die)
Term
What 6 factors lead to intertidal zonation?
Definition
1. reproductive factors; 2. physiological challenges; 3. climate; 4. competitive abilities; 5. grazing; 6. predation
Term
Describe a urchin barren.
Definition
Lots of urchins and almost no macrophytes and algae bc urchins grazed all of the plant larval forms
Term
What is an example of a physical disturbance?
Definition
logs crash into mussels by the waves, logs knock off a chunk of mussels
Term
What is an example of a biological disturbance?
Definition
starfish eats mussels
Term
What is a keystone predator?
Definition
A predatory species whose effects on its community are proportionatley much greater than its abundance. ex: starfish
Term
What are pneumatocysts?
Definition
gas filled cells in see weed (and kelp)
Term
What will the ecosystem look like underwater if there are lots of sea otters?
Definition
Lots of KELP
Term
What will the ecosystem look like underwater if there are few sea otters?
Definition
Lots of URCHINS
Supporting users have an ad free experience!