Olivia - diatom rhizaria lecture 15 Flashcards
pelagic ocean
largest part of ocean
diatoms
carbon sequestration
fatty acids for humans and nutrients for other organisms
oil extraction
primary producers
silicon and carbon
silicon (diatoms) dissolve in ocean - determines which nutrients are avail and then determines which phyto are most dominant and then determines how much carbon is sequestered
– important for long term climate mitigation
silicate and carbonate rocks store nutrients
biology of silicon - important for cycles
rhizaria
taking up silicon
very large and sink
- can contribute v large amounts of carbon sequestration
- abt 10%
primary production in oligotrophic zones
preserved in sedimentary record bc dont dissolve as quickly
rhizaria
dissolved silicon
rhizaria - live in surface - taking up silicon here
diatoms - important for silicon cycling
competition between rhizaria and diatoms
in mesopelagic - the ONLY silicifies here
bringing silicon and all carbon to sea floor
Olivia research
look at growth rate and silicon uptake on ship
correlation between higher diatoms but lack of rhizaria – could be bc of competition
what type of plot could show us how the environment impact community composition?
multigrade analysis
rhizaria vs diatom silicon uptake
rhizaria daily uptake insignificant compared to diatoms
rhizaria take up silicon over months scales – important for long time scales
main findings
Rhizaria are impacted by temperature, heatwaves and dissolved Si – might see increase in these when warming
Diatoms might outcompete Rhizaria
Rhizaria are less “important” to daily Si uptake - but could contribute to longer timescales
summary (take homes)
Silicon and carbon are linked (cant study carbon cycles without)
Siliceous creatures can greatly impact global biogeochemistry - temperatures, climate change etc
