Sea Shelves Flashcards
What is the neritic zone?
the region up from 200m
what percentage of the global sea surface is continental shelf?
8%
What are tidal fronts and how do they form around the UK?
a tidal front is a horizontal gradient of density from differences in tidal strength, where weak tides (e.g. off cornwall) create vertical stratification and energetic tides (e.g. in the Irish sea) gives a well-mixed water column
Name a prokaryotic primary producer
cyanobacteria
Name 3 eukaryotic primary producers
dinoflagellata, bacillariophyceae, haptophyta
Give 2 similarities between prokaryotic and eukaryotic primary producers
both are unicellular and contain chlorophyll a
Which are smaller: prokaryotic or eukaryotic primary producers?
prokaryotic (picoplankton)
Describe the morphology and distribution of cyanobacteria
highest biodiversity in littoral tropical zones, found as single long filaments or clumps of filaments
Describe the morphology of the second most abundant phytoplankton group
dinoflagellates: can be autotrophic, heterotropic, or both. Motile (2 flagella), thecate or naked, may be toxic, form red tides
What is the most abundant phytoplankton group?
diatoms (main contributor to spring blooms)
describe the morphology of diatoms
silica frustule in 2 halves: epitheca and hypotheca. Non-motile, may be solitary or colonial
Briefly describe coccolithophores
formed of around 30 CaCO3 per cell. Coccolithophores reflect sunlight and heat back out of water. They are also highly sensitive to the effects of ocean acidification
What 4 resources are needed for autotrophs to grow?
light, carbon, oxygen, and nutrients
What is the redfield ratio?
the uptake ratio of carbon:nitrogen:phosphorus in healthy, actively growing cells - 106:16:1P
What is Fe needed for in cells?
enzyme activity
What are the 4 micronutrients needed for ion transport?
K, Ca, Mg, Na
Give the 4 sources of nitrogen in seawater
NO3, NO2, NH3 and N2
Give the 3 sources of phosphorus in seawater
HPO2-(4), PO3-(4) and H2PO-(4)
Give the 2 sources of sulphur in seawater
SO2-(4) and H2S
Give the 4 sources of carbon in seawater and the factors that effect their proportion
CO2, HCO-(3), CO2-(3), H2CO3, as governed by salinity, pH and temperature
What determines the light extinction coefficient of water?
wavelength, dissolved material and particles
What is the wavelength range of photosynthetically active radiation?
400-700nm
What is holoplankton?
permanent plankton
What is meroplankton?
temporary plankton
