Lecture 9 Flashcards
What is biomass?
How much stuff there is
What is productivity?
How much stuff accumulates over time
What does “stuff” refer to?
Mass, Carbon, Nitrogen
Mussel productivity _____ with phytoplankton biomass
increases
What is primary productivity?
growth at the base of the food chain
What is secondary productivity?
growth at higher trophic levels
What is a food chain?
a linear diagram that uses a single organism at each trophic level to illustrate the main pathway of carbon through a system
What is a trophic level?
A species or group of species that feeds on one or more other species
What are organisms refered to in a food chain?
Primary produces, primary consumers, secondary consumers
What is a food web?
a diagram that shows the overall feeding relationships between organisms in an ecological community
What is the bottom- up perspective?
This is how available biomass at the base of the food chain determines abundances of organisms at higher trophic levels
What effect did El NIno have on fisheries?
Causes a change in temperature in the water
How does El Nino affect phytoplankton?
it causes phytoplankton to migrate to different places
How does El NIno affect fish population?
Fish populations no longer have food because the phytoplankton migrated
How does El Nino affect people?
There are fewer fish available for humans to feed on because the fish don’t have any energy sources.
Where does El NIno originate from?
It comes from the South American coast
-winds blowing from the south
-coriolis force moves the surface water offshore
-deep, cold, nutrient-rich water replaces it
What happens during the El NIno years?
-trade winds decline
-warm water sloshes back across the Pacific
-the thermocline moves deeper
-upwelling no longer brings in cold nutrient-rich water to the surface
What is the top-down perspective?
predator abundances can determine abundances of organisms at lower trophic levels
What happens to urchin density where otters are present?
Urchin density will decrease
What happens to kelp density?
Kelp density will increase
What is a top-down perspective example?
Orca food has declined which leads to orcas eating sea otters
What are the types of primary productivity?
gross primary production and net primary production
What is GPP?
the total amount of carbon fixed by photosynthesis
What is NPP?
the total amount of carbon fixed by photosynthesis minus the loss associated with respiration
How do you measure primary productivity?
-measure carbon (uptake and assimilation)
-measure oxygen
-surrogates; electron transport rate, change in chlorophyll concentration over time
What does a radiocarbon do?
measures radioactivity of phytoplankton as index of carbon assimilated
Pulse Amplitude Modulated Fluorometry
Shines a light on an autotroph, then measures the rates of electron transport
Remote sensing
measures ocean color based on satellite images, can determine rate of change, global scale estimates
More productive pools were characterized by ?
-increase in pH over time
-decline in pCO2 over time
-increased in calcification over time
Pools with more ___ abundances were more ___
seaweed, productive
Where is productivity the highest?
In the hotspots
What occurs in the “hotspots” of productivity?
-upwelling and coastal areas
What does the coastal upwelling do?
-the equatorward winds along the west coasts of continents
-coriolis effect shifts surface waters offshore
-deep, cold, nutrient-rich water to the surface
