L9-primary production,climate change Flashcards
How much of primary productivity is algae?
50%
how much of anthropogenic CO2 is absorbed by ocean?
40% (maybe closer to 50%)
Which proportionally has more primary productivity land or sea?
land massively outsrtip oceans by surface area
How much carbon does macroalgae fix?
not much as most is released when it dies?
What is exceptional about current climate changes?
present-day
alterations in global climate is the rate at which the
various components are changing
What happens as carbon concentration increases in water?
It becomes harder for organisms to fix carbon
What are the three forms of inorganic oceanic carbon?
(~90%) of it is in the form of bicarbonate
~9% is carbonate
1% as carbon dioxide
Which form of inorganic carbon do organisms use mostly?
carbonate (the one organisms use mostly)
bicarbonate (the less biologically useful form)
What happens with increasing CO2?
release more H ions that ‘mop up’ the carbonate and
turn it into bicarbonate
What happens to organisms with higher CO2?
harder to make shells
organisms get smaller
What is the flow of events with increasing CO2?
Elevated CO2 Decreased oceanic pH (ocean acidification) Decreased carbonate availability for calcification Diminished calcification and growth of calcifying organisms
Where are the biggest changes in temperature?
the poles
What does increasing temperature do?
- Decreased O2 and CO2 solubility
- Direct effects of temperature on organisms
- Shoaling of thermocline
What are the direct temperature effects on organisms?
- Organisms have temperature optima for growth
- Warming ocean could be addressed by organisms moving to higher latitudes
- Extinction of high-latitude organisms
- Genetic adaptation if parts of the ocean become warmer than any extant organisms can tolerate
What other changes occur with higher temperature?
- Earlier spring blooms
- Stimulation of cyanobacterial growth
- Alterations in size of spring blooms (Keller et al 1999).
- Changes in grazing pressure
