Diatoms
about .1 mm- on the larger side
2 groups- centric and pennate
often form long chains
Dinoflagellates
.5 mm- largest phytoplankton
2 flagella for motion
half photosynthetic, half heterotrophic
Cyanobacteria
.00005 mm-.04 mm
photosynthetic
3 important genera- synechococcus, trichodesmium, and prochlorococcus
Microflagellates
.01 mm
many other groups of flagellated phytoplankton
radiolarian
silica shells
foraminifera
calcium carbonate shells
copepods
Grazers of phytoplankton, “smell” chemical plumes
euphasids
a type of krill, they have eyes- light sensitive
chaetognaths
predatory worms
ctenophores
collect prey using their sticky cells or engulf prey
Salps
tunicates- enclosed in a tunic with openings at either end
pump water thru gelatinous bodies
Appendicularians (oikopleura)
mucus house builders
Crab larvae
polychaete larvae
Barnacle cyprid
ichthyoplankton
barnacles
mussel
sea stars
anemones
sea urchin
chitons
hydrothermal vent giant tubeworms
pompeii worms
hagfish
Osedax
bone boring worm
brain coral
branching coral
continental shelf
Continental slope
continental rise
submarine canyon
abyssal plain
mid-ocean ridge
transform fault
deep-sea trench
seamount
guyot
atoll
ring of coral left behind after island sinks
geological forces that drive plate tectonics and seafloor spreading
pieces of the lithosphere are constantly in motion because of heating/gravity, they move the asthenosphere along with them but gravity is the main force that drives tectonics
pressure gradients
caused by sea slope (barotropic) or difference in density (baroclinic)
Coriolis effect
objects in motion appearing to be thrown off course because of Earth’s rotation, North=right and South=left
wind
net average flow is 90 degrees to the right of the wind in the North, left in the South
friction
180 degrees to the direction of motion, slows things down and prevents them from going too fast
gyres
tend to circulate around mounds- indicate high pressure
equatorial currents
north and south equatorial gyres
equatorial counter currents
goes right through the middle
Antarctic circumpolar current
upwelling
caused by 2 currents crashing into each other, mixes all layers of the ocean and brings nutrients + cold water to the surface
generation of great ocean conveyor belt
caused by temperature and salinity in deep ocean, and wind driven currents on the surface, helps mix the water so there are nutrients at the top and phytoplankton to feed the deep
deep water chemistry changes in the conveyor
they lose salinity and gain temperature and sometimes the reverse, and nutrients get pushed up to the surface for phytoplankton
average salinity
35%
average temp
20 degrees C
average density
1.03 g/cm^3
thermocline
steep temperature gradient in water, usually has a layer where the temperature is different above/below it
halocline
steep salinity gradient in water, has a layer where the salinity sharply increases
pycnocline
steep density gradient in water, density goes up with depth- there’s a layer where there’s a sharp decrease
nutricline
a sharp decrease in nutrients as the depth increases
stratification
separation of things into different groups/layers- reduces mixing, traps phytoplankton at the top with light
limiting factor of productivity in open ocean ecosystems
light is highest at the top, nutrients are highest at the bottom, phytoplankton (the base of the food web) need both to thrive
Redfield ratio
C:N:P=106:16:1
diatom life cycle
asexual or sexual repro possible
dinoflagellate life cycle
usually asexual reproduction w mitosis
gross production
overall production of phytoplankton
net production
production of phytoplankton minus the energy it takes for them to be able to produce
respiration
opposite of photosynthesis
phytoplankton diversity
different phytoplankton thrive in different conditions- small ones use energy more efficiently but large ones are harder to eat
small phytoplankton are better
they use energy more efficiently, sink slower, grow/divide faster
why are large phytoplankton common in Puget Sound?
there are 2 different areas for stratification and mixing so it’s easier to grow larger
primary basins in Puget Sound
Hood Canal, whidbey basin, south sound, main basin
sills in Puget Sound
admiralty inlet sill, hood canal sill, tacoma narrows sill
why is puget sound so productive?
highly nutritious environment due to many mixing areas and various rivers flowing into the sound
paralytic shellfish poisoning
humans eat mussels and clams that have consumed dinoflagellates that produce neurotoxins
how do oceanographers create maps of phytoplankton from space?
they measure color/certain wavelengths that indicate phytoplankton
Limiting nutrients
N, P, Fe
holoplankton
spend their entire lives as plankton
meroplankton
spend part of their lives as plankton- usually a larval stage for a larger fish/invertebrate
Reynold’s number
The ratio of inertial forces to viscous forces (predicts whether flow is laminar or turbulent), copepods need low numbers to graze effectively
how to estimate phytoplankton and zooplankton grazing per capita with the dilution method
increased dilution of the seawater spreads out the phytoplankton and zooplankton so that it’s harder for the zooplankton to graze on phytoplankton.
Why do zooplankton perform diel vertical migration?
they go to the surface at night so they can eat, and they go to the bottom during the day to avoid predation by seeing predators
what causes vertical zonation patterns- intertidal rocky benthos
as you go down the layers, physical stress decreases due to proximity to the water but biological stress goes up due to more predators
competition between chthamalus, balanus, and mytilus
chthamalus grows first/fastest, then balanus arrives and begins to take over the lower areas of chthamalus. then mytilus arrives and overgrows both of them as high as it can go.
where are hydrothermal vents found?
spreading centers
energy source for hydrothermal vents
mantle heats fluid and reduces their density
4 stages of whale falls
1-mobile scavenger phase
2-enrichment opportunist phase- bone worms
3- sulphophilic phase
4- reef stage
food source during sulphophilic stage
anaerobic respiration in bones produces sulfide
how do whale falls serve as stepping stones for dispersal of hydrothermal vent species?
hydrothermal vent species shoot out larvae, they find a whale fall to attach to so they can shoot out more larvae to look for a new hydrothermal vent
stages of coral reef succession
fringing reef- reef surrounding an island
barrier reef- the reef forms a barrier far out from the island
atoll- the island is below the water but there’s still a ring of reef
high diversity in deep sea benthic communities
long lived, stable habitats, large habitat area, high levels of food production/energy, intermediate predation, highly complex habitat, heterogeneous food resources