ESCI 204 midterm

Diatoms

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