Anthropogenic climate change

Question 1

Physical effects

Answer 1

Warming, includes marine heatwaves
deoxygenation
melting ice caps
sea level rise
increased storminess and extreme weather
ocean acidification

Question 2

Temperature Influence

Answer 2

Influences biological processes in individuals and ecosystems
Sets threshold for species performance, abundance and distribution
Responsible for massive shifts in ecosystem structure and function

Question 3

Southern Ocean Temperature Trends, 55-88

Answer 3

Air temps rising more rapidly than anywhere else in the world, >5deg in winter since 1955
Much greater than rate of warming of circumpolar Sern Ocean
Strongly surface installed

Question 4

Deoxygenation

Answer 4

Atlantic is more oxygenated but has lower nutrients than Pacific due to the age of the water and how it is used by the PPs

Question 5

Eutrophication and dead zones

Answer 5

Excess nutrient inputs stimulate algal blooms which then die off and sink
Bacterial decomposition of the bloom uses up oxygen leads to hypoxia

Question 6

Hydrological cycle

Answer 6

Poleward freshening
Higher salinities at low latitude

Question 7

Ocean acidification

Answer 7

Pteropods cant form shells

Question 8

Zooplankton as indicators

Answer 8

Poikilothermic, sensitive to temperature
Short lived, most <1 year
Not commercially exploited, except krill
Planktonic
Most marine organisms have a planktonic life stage

Question 9

Response of poikilotherms to temperature

Answer 9

Temps at which ectotherms thrive set the upper and lower thermal window for different physiological processes

Question 10

Poikilotherm thermal window amplitude

Answer 10

Amplitude inversely related to complexity of the animal and physiological processes
- short term tolerance has greater TW than the LT maintenance

Question 11

Unimodal response to temperature

Answer 11

Metabolic rate increases with temperature to thermal optimum through the rising trait
Past optimum falls at the same rate through monotonic fail

Question 12

Arrhenius plot of temp response

Answer 12

y axis metabolic rate
x = 1/KT
Upper thermal limit at lower left, rise to arrhenius breakpoint temperature, TO just below and falls to Lower thermal limit
Ea is gradient of falling slope

Question 13

Thermal window and organismal fitness

Answer 13

Fitness giverned by Eg = EI - ER
Different physiological processes can respond differently to temp change
A mismatch in response of Ei and Er to similar temperature sets the threshold in performance

Question 14

TW and life stages

Answer 14

Width of TW changes with life stage
Seasonal acclimitization, limited shift in TW due to change in functionality or endurance
Stenothermal (narrow) and eurythermal (wide) acclimatized windows
Biogeographies can overlap in species with different TWs
Warming leads to mismatch between seasonal cues (temp) and constant cues (light)

Question 15

Impacts of temperature on zoop

Answer 15

Species distributions (biogeographic range shifts)
Biodiversity
Body size
Phenology
Abundance