BIO 105 Set 4: Primary Producers

challenges plankton face

need light to live so have to stay in the photic zone. they can’t move very well. reproducing sexually is more difficult but required for diveristy

plankton adaptations

can form symbiotic relationships. adapt to high or low light conditions. silica frustule in diatoms. dinoflagellates have 2 flagella.

groups of phytoplankton

cyanobacteria, diatoms, dinoflagellates, coccolithophores

cyanobacteria traits

prokaryotes, have thylakoids, some form symbiotic relationships, extremely important in open ocean. reproduce through binary fission

thylakoid

pouch-like sacs within chloroplasts that contain chlorophyll

prochlorococcus

genus of cyanobacteria. most abundant photosynthetic organism

synechococcus

genus of cyanobacteria. require lots of light. live in nutrient rich environment. important in upwelling zones

diatoms traits

eukaryotes. larger than cyanobacteria. solitary or chain-forming. circular or elongated shape. silica based frustule. divide rapidly and can form blooms. reproduce asexually and each generation becomes smaller until it sexually reproduces and gametes fertilize and become and auxospore.

dinoflagellates traits

eukaryotes. 2 flagella. “eye” spot. naked or armored with cellulose. can be autotrophic or not. more common in coastal areas. specialize in low nutrient areas. diel vertical migration. asexual reproduction through binary fission. sexual reproduction through fusion of two individuals into a planozygote

ex: cyanobacteria

diel vertical migration

swim up during the day and down at night (dinoflagellates). they do this to access the nutrients in the deeper waters

coccolithophores traits

eukaryotes. exclusively marine. exterior made of CaCO3 coccoliths. form large blooms. shell sequesters CO2. produce dimethyl sulfide (DMS) which controls cloud formation

green macroalgae

chlorophyta. dominant pigment is chlorophyll. tolerate wide range of salinities

red macroalgae

rhodophyta. have red pigment called phycobilin. resistant to grazing (crustose coralline algae)

brown macroalgae

phaeophyta. dominant pigment is fucoxanthin. largest and most complex algae

what conditions do kelp need to grow?

hard bottom for holdfasts. sunlight (depth around 60m but can be deeper). >1 uM nitrate. <20 degrees C

how do El Nino cycles impact kelp?

the warmer water brought to the western coasts of the americas negatively impacts kelp growth in those areas

surface area to volume ration importance

plankton that are smaller have a larger surface area to volume ratio so they can specialize in low-nutrient areas (dinoflagellates) opposite is diatoms

what role do phytoplankton play in the marine environment

foundation of the food web, and are extremely important primary producers