Week 6 Flashcards
___________: 20-1000 um, many species 50-300 um
diatoms
___________: nitrogen fixers (most are cyanobacteria)
diazotrophs
Phytoplankton functional groups
Diatoms
Coccolithophores
Dinoflagellates
Diazotrophs
Picophytoplankton
nanophytoplankton
________, ___________, __________, and ___________ dominate phytoplankton blooms
diatoms
coccolithophores
dinoflagellates
diazotrophs
Grazing pressure keeps _________ and ___________ from blooming
picophytoplankton
nanophytoplankton
__________ is the limiting nutrient (blue) in the three high nutrient, low chlorophyll (HNLC) regions in the subarctic North Pacific, the equatorial Pacific, and the Southern Ocean
iron
The subtropical gyres tend to be ____ (maroon) or ___ limited (green)
N
P
3 types of microzooplankton: small protists, reproduce quickly, graze on small phytoplankton, heterotrophic bacteria, and small detrital particles
zooflagellates
heterotrophic dinoflagellates
ciliates
6 types of mesozooplankton-macrozooplankton: much larger, multicellular organisms, with longer reproductive time and more complicated life histories
copepods
krill (euphausiids)
gelatinous zooplankton
pteropods
radiolarians
foraminifera
Larger zooplankton (_____ um to cm)
200
__________: most common large zooplankton, type of crustacean, range in size from a few mm to several cm, important players in the biological pump
copepods
________________are the most common and often comprise more than 70% of the mesozooplankton biomass caught by nets
calanoid copepods
*2 types of zooplankton vertical migration
- Daily migration at low to mid-latitudes
- Seasonal migration in polar regions
In general there is an _______ relationship between _____ and _________ for the larger zooplankton
inverse
size
growth rates
4 ways to measure primary production
- changes in oxygen
- changes in CO2
- formation of organic matter
- consumption of light
Highly productive marine ecosystems have ____________ and ______________ by the biological pump
high export ratios
efficient export
Low productivity marine ecosystems have ____________ and ______________ (efficient recycling of nutrients and carbon within surface waters)
low export ratios
inefficient export
Short food chains lead to _________________
Long food chains lead to __________________ and _______________ in surface waters
efficient export
inefficient export
efficient recycling
The _________ is the export ratio (sinking POC/NPP), calculated over the euphotic zone depth, which varies from place to place
Ez-Ratio
The efficiency of the biological pump out of surface waters is a function of the ___________________
biological community
A community with ________________ species and abundant ___________________ will export organic matter out of the euphotic zone efficiently (___________________)
large phytoplankton
large zooplankton grazers
high export ratio
A community dominated by ____________________________ doing most of the grazing will not export organic material efficiently, most organic matter will be recycled within the euphotic zone (__________________)
small phytoplankton with microzooplankton
low export ratio
The ________________ refers to the upper ocean below the euphotic zone where most remineralization of sinking organic matter occurs
twilight zone
______________ refers to aggregations of particles often held together by sticky, fibrous polysaccharide-rich TEP (transparent exopolymeric) material
Marine snow
The mineral ballast components lead to more ________________________ by the biological pump
efficient downward transfer
Mineral components include:
dust particles- from the atmosphere
biogenic silica- from mostly diatoms, with some radiolarians
calcium carbonate (CaCO3)- from coccolithophores and some zooplankton (Pteropods and Formaminifera)
Plankton community composition can modify the ___________________
biological pump efficiency
More plasticity in ________ and ________ content
silicon
iron
4 proposed mechanisms of variation for ratios
-taxonomic differences: lower C:N:P in cyanobacteria
-nutrient supply ratio (reduce cellular quota of limiting nutrient)
-growth rate hypothesis: allocation to different growth strategies.
-accumulation of detritus (dead plankton material)
Diatoms
efficient carbon exporters
small phytoplanton
efficient uptake in Fe limited regions
diazotrophs
higher Fe quotas due to N-fixing metalloproteins
