Phytoplankton
Light & Photosynthesis
Other Controls of Phytoplankton
Global Distribution of Phytoplankton
Microbial Food Web
100
What size are nanoplankton?
20-20 um
100
Define photosynthesis
Autotrophic conversion of inorganic carbon to organic carbon using light as an energy source
Expressed as the rate per volume of the biomass produced or the biomass specific rate
100
Name 3 macronutrients & 2 micronutrients
Macronutrients: Nitrogen, Phosphorus, Silicon, Carbon
Micronutrients: Fe, Zn, Co, Mn, Mo, Cd, Se, Cu
100
Identify two areas of the ocean with high productivity
North Atlantic
North Central Pacific
Indian Ocean
Coastal Areas
Upwelling areas
100
Name 3 sources of DOM
Phytoplankton release
Autolysis
Zooplankton sloppy feed or excretion/egestion
Solubilization of particles
Cell lysis due to viral infection
200
What are the two groups of diatoms?
Centric and pennate
200
Name a phytoplankton pigment and what color light they absorb
Carotenoids - blue and green
Chlorophyll - blue and red
Phycobilins
200
What is the Redfield ratio? Why do we care?
106 C: 16 N: 1P
Atomic ratio of C,N,P found in plankton & dissolved in seawater
Can be used to determine the limiting nutrient for phytoplankton growth
200
Name one factor that can cause the decline of the spring bloom
Growth limited by nutrients
Losses to sinking
Losses to grazers
200
Why didn't scientists used to think there weren't a lot of bacteria in the ocean?
What is one discovery or technique that helped overcome these issues?
Great Plate Anomaly
Couldn't see them or grow them
Techniques: Epifluorescence microscopy
Flow cytometry
Immunological identification
PCR
300
Give 3 characteristics to describe dinoflagellates
Have two flagella - transverse & longitudinal
Common in warmer area
Most are mixotrophs
Have cellulose plates that make up their cell wall (theca)
Resting cysts
Asexual and sexual life cycle phase
Make red tides
Some are bioluminescent
Some are coral components
300
What is net primary productivity?
Rate per area of time of primary production - respiration
300
Where would you find phytoplankton with low half-saturation constants?
Low nutrient (oligotrophic) environments like Sargasso Sea
300
Draw or describe the seasonal phytoplankton & zooplankton cycle in the Tropics, Polar Regions or for the Chesapeake Bay.
300
What are the four major types of bacterial metabolic pathways?
Photoautotrophs
Photoheterotrophs
Chemoautotrophs
Chemoheterotrophs
400
What is nitrogen fixation and name a marine organism that can do this?
N2 -> NH4
Trichodesmium
Richelia
400
Draw a P-I curve
400
What is the f-ratio? Where would you find a high f-ratio? Where would you a low f-ratio?
The f-ratio of new production to total production
High: Upwelling & coastal zone
Low: Oligotrophic & open-ocean areas
400
Name 3 conditions that help facilitate a spring bloom
Increasing thermal stability- mixed layer above critical depth
Increasing solar radiation
Decreasing storms
High nutrients
400
Why do we care about marine viruses?
lead to new pathway of C,N cycling for primary producers and consumers (cell lysis releases cellular constituentsa0
algal bloom control
May “rob” larger grazers of food, more material into smaller forms
genetic exchange
regulate diversity of bacteria and phytoplankton- by effecting relative proportions of different species-since viruses are both density-dependent and species specific
shape global climate- virus attack on some DMSP –producing algae (e.g., Emiliaina Huxleyi, Phaeocystis) induces release of DMS- gas that influences cloud nucleation
500
Where can you find Synechococcus?
High productivity areas
500
Compare and contrast critical depth and compensation
Critical depth: water column respiration = water column photosynthesis
Compensation depth: individual cell respiration = individual cell photosynthesis
500
Name the three high nutrient low chlorophyll ecosystem
Equatorial Pacific
Southern Ocean
North Pacific
500
What are the four general steps of species succession in phytoplankton blooms?
1. Small cells with high growth rates- small flagellates/ diatoms
2. Larger diatoms
3. Slower growing forms - dinoflagellates
4. N depletion - N fixers and other pico/nano plankton
500
Do you think the microbial loop is a sink or a source? Why?
Source: Bacteria is able to return and repackage the lost DOM into the model
Sink: As carbon moves through the loop, some carbon is lost through the process because the loop is not efficient. A large amount just stays in the loop or is lost as DOM