Carl Reefs 3

Question 1

name the factors which shape the distribution of coral reefs ****
10!

Answer 1

• Salinity
• Hard Substrate
• Water Temperature
• Water depth
• Sedimentation
• Wave action
• Emersion
• Water
• Air
• Light

Question 2

Between what latitudes do coral reefs typically occur?

Answer 2

30N and 30S

Question 3

whats the scientific name for stony coral

Answer 3

Scleractinian

Question 4

What is the typical temperature restriction of corals?

• average
• upper range

Answer 4

• average of above 20*C year round
• greatest diversity in indo pac ~27*C
• lethal limits in range of 30-35*C

Question 5

what temperature events make corals vulnerable?

Answer 5

• atmospheric warming
• El Nino
• La Nina

Question 6

where are corals usually found on a global level due to GEOTROPIC ROTATIONAL PATTERS OF OCEAN CURRENTS respectively? (check out slide 5/39 to compare)

Answer 6

-Further North and South on the Eastern side of continents in the Northern and Southern hemispheres

Question 7

why do corals extend further north on Eastern side of continents?

Answer 7

the currents rise up along all eastern shores of continents save antartica

Question 8

what is the correlation between temperature and species tolerance?

Answer 8

-corals that live in warmer waters can typically tolerate warmer temperatures than those which live in cooler waters

Question 9

how does temperature tolerance of certain zooxanthellae in warmer waters forshadow future environmental hurdles?

Answer 9

some strains of zooxanthellae can handle appreciably warmer temperatures than others, and can therefore survive heating events better than those without. perhaps greater chance of tolerating climate change

Question 10

when do corals bleach?

Answer 10

when the coral animal host is stressed and expels the symbiotic zooxanthellae.

Question 11

what is the most significant cause of bleaching events?

Answer 11

sea surface temperatures that exceed the normal summer maxima by 1 or 2 degrees celcius for at least 4 weeks.

Question 12

what happens when the zooxanthellae are stressed by prolonged raised temperatures? (biologically)

Answer 12

excessive production of toxic compounds in the algae that are transferred to the host coral.

• coral expels algae
• coral is especially susceptible to death by starvation or disease

Question 13

what is the term associated with the death of coral? why?

Answer 13

phase shift.

-the environment has hit a new equilibrium, one that supports a markedly lower diversity of animals

Question 14

when was the warmest july on record globally, and by how much?

Answer 14

july 1998

temp was 0.84*I above the mean

Question 15

what happened to reefs in 1998?

Answer 15

global mass bleaching event where 50% of the reefs on the great barrier reef suffered bleaching

Question 16

aside from 1998, when was there another mass bleaching event? why?

Answer 16

2002, 60% of reefs were affected.
-two periods of hot weather resulted in sea surface temperatures a few degrees centigrade higher than the long-term summer maxima

Question 17

what drives hurricanes?

what do hurricanes cause? (environmentally)

Answer 17

thermal energy stored in water.

-great winds, large waves, and great coastal precipation

Question 18

what is the significance of two back-to-back record hot years? (historically)

Answer 18

historically only once in every 1500 pairs of years. now odds are one in 10.

Question 19

about how much percent are australia’s reefs affected by local threats, and what are these?
what percentage is high or very high threat?

Answer 19

15%

• coastal development, marine-based pollution and damage, overfishing, destructive fishing, watershed-based pollution
• ~2%

Question 20

what is the likely reason why there are no significant reefs off the coast of brazil?

Answer 20

large fresh water plumes into the ocean (Amazon)