Ch 9

Question 1

What is the new stable state?

Answer 1

Shifting from coral dominated to algae.

Question 2

What is negative and positive feedback?

Answer 2

A cycle where to litlle grazing, reduces fish recruitment, which increases macroaglal cover, decreasing recruitment further, reducing coral cover, reducing structural complexity further reducing grazing and it keeps cycling. Positive feedback works similar but increases coral cover grazing and decreases algae cover

Question 3

How do alternate stable states occur?

Answer 3

Once pushed into a new threshold positive feedback maintain new state

Question 4

What is hysteretic?

Answer 4

a transition between two alternate stable states, showing two thresholds as the driver increases or decreases

Question 5

What is threshold?

Answer 5

a pronounced threshold at

particular conditions,

Question 6

Are any caribbean reefs recovering?

Answer 6

Jamaica’s

Question 7

What is one factor responsible for the shift?

Answer 7

Coral mortality folloed by increased nutrients/ algae growth, Decreased herbivory

Question 8

Is it a clear fact that driver act synergistically?

Answer 8

no, antagonism has been seen

Question 9

What is changing caribbean reefs?

Answer 9

Acropora die-off

Question 10

Why did acropora die so rapidly and before other corals?

Answer 10

White band disease

Question 11

Why are dead acropora palmata reeds not replaced by other species?

Answer 11

High wave action prohibits growth of other coral growth

Question 12

Acropora decline is unprecedented in which period?

Answer 12

Holocene

Question 13

In belize what species replace acropora?

Answer 13

Agaricia

Question 14

WHat species was strongly impacted by the bleaching event in 2005?

Answer 14

Montrastrea spp

Question 15

Warming trends are expected to continue and depend on what?

Answer 15

emissions

Question 16

Indo-Pacific reefs are also affected by ?

Answer 16

Crown of thrones

Question 17

Why are crown of thrones populations increasing?

Answer 17

decreased predation

Question 18

What species are coral reef communities changing to?

Answer 18

Siderestra siderea

Question 19

What fish group are also declining?

Answer 19

corallivores ie chaetodontids

Question 20

Why are herbivores decline with increased macroalgae growth?

Answer 20

overfishing, decreased architecture is important, juvenile grounds are being destroyed, bioerosion by parrotfish ro clionid sponges and wave action

Question 21

What is the breakwater effect?

Answer 21

Coral reefs absorb the impact of storms

Question 22

What does increased wave energy contribute too?

Answer 22

beach erosion

Question 23

How do corals assist in beach replenishment?

Answer 23

As corals eroid the calcareous debri wash on shore repleniching the sand. As more corals are lost the sand will stop being replaced.

Question 24

What else are reffs used for?

Answer 24

Building material

Question 25

What contributes to changing food webs in coral reefs?

Answer 25

fertilized algae, algae growing faster, algae prevents recruitment, phosphate inhibits coral calcification, overfishing

Question 26

What good news has been seen in coral reefs?

Answer 26

Jamaica recovery

Resilience of remote Pacific reefs

Bonaire and Dutch Antilles