coral_reefs_globalmarinetoxicology

Question 1

in what waters can you find coal reefs

Answer 1

shallow water up to 150 mdepth –> need light
close to the coast
warm water

Question 2

what is the temp. optimum of coral reefs?

Answer 2

narrow temp. optim (23-29°C) >18°C

Question 3

what are the threats to coral reefs?

Answer 3

unsustainable fishery --> overfishing 
pollution
tourism 
coastal developement 
qagriculture run off
storma 
predators (starfish)

Question 4

how does agriculture run off affects coral reefs?

Answer 4

turbidiyt –> corals need clear water for PS

– >hypoxic zones in coastal areas

Question 5

why does macroalgaae growth affect the coral reefs?

Answer 5

macroalgae = superioro competetiro for availab enutrinet

Question 6

what lead to intense macroalgae growth?

Answer 6

overfishing

Question 7

what are the 4 reef types?

Answer 7

fringe reef
platform reef
barriere reef
atol

Question 8

how many percent of the global prmiary production is produced in coral reefs?

Answer 8

50-70%

Question 9

with what organisms does polyps form a symbiosis

Answer 9

unicellular photosynthetic algae:
 like zooxanthella (which is a dionflagellate)

Question 10

what is the composition of a coral reef?

Answer 10

built mainly by hard corals and crustose coralline agae

–> aragonite and CaCO3

Question 11

how much of the earth surface is covered with c. r?

Answer 11

less than 1%

Question 12

what is the world largest coral reef?

Answer 12

great barriere reef (australia)

Question 13

coral are plants true or wrong?

Answer 13

wrong –> animals

polyps, who build themselfe a hard skeleto pout of CaCO3

Question 14

name the three coral types

Answer 14

hard corals
stony corals
hermtypic corals

Question 15

what does the symbiont gets from the coral what does the coral gets fromthe symbiont?

Answer 15

host receives excessive photosynthate, symbiont cannot use

symbiont receives nitrogen, that the host cannot use

Question 16

do deep water corals need the symbioses to survive?

Answer 16

no

Question 17

do soft corals need symbiosis the survive

Answer 17

yes they get the main part of their energy from the symbiont

Question 18

until what depth and what temp can you find codl/deep water corals?

Answer 18

surface down to 2 km depth

down to 4°C

Question 19

do all corals produce CaCO3 and from a skleteon?

Answer 19

no!- soft corals dont

Question 20

what is the name of the starfish that prededates coral reefs dramatcially?

Answer 20

COTS = crown-of-thorns starfish

Question 21

how does global change threat coral reefs?

Answer 21

1. more storms

2. increase of atmo. CO2

Question 22

how do storms (due to climate chnage ) affect coral reefs?

Answer 22

• more runoff

- more damage

Question 23

how does incresing atmopshericerc CO2 affect ,due to climate chnage affect coral reefs?

Answer 23

• ocean acidification
• rising lea levels
• increase in surface temperature

Question 24

what effects has ocean acidifacation?

2

Answer 24

• increase of pCO2
• -> leads to fertilization of PS
• -> competive advantage of macroalgae
• more H+ –> Co3 2- low
• biogenic calcifcation costs increase

–> acidification
problem for all calcifiers

Question 25

what is coral bleeching?

Answer 25

loss of symbionts, they die when the temperature is to high

Question 26

how many percent of the great barriere reefs died in 2016

Answer 26

betw 29-50%

Question 27

are coral totally dead after coral bleaching?

Answer 27

now they might sruvive if symbionts recolonize (in time (months))

Question 28

according to IPPC: how strong is the decline of coral reefs with global arming of 1.5 °C and how strong with 2°C

Answer 28

1.5°C –> 70-90 %

2°C –> >99 %

Question 29

wha do we care about reefs?

Answer 29

ecsystem services

Question 30

are all symbionts in the same way sensitive to increasing temp?

Answer 30

no they arent
different clades:
clade A =oldest
clade D and part of clade C more heat tolerant , but clade D provides less energy to the host
–> trade of bet. heat reisstant an denergetci benefits

Question 31

are fishes symbionts of coral reefs? what fish species?

Answer 31

yes:
corals feed on the excrete of the fish
fish will hide in the corals

Question 32

what is a coral? (systemaisch)

Answer 32

cnidaria –> anthozoa
colonie of polyps

hard corals
stony corals
hermatypic coral

Question 33

define symbiosis:

Answer 33

interaction/relationship betw. to different species, where both profit from this interaction

(e.g. resource sharing)

Question 34

finish this sentence:

thh more fish in the coral reef…

Answer 34

…. the more coral will grow