The State of Coral Reef Ecosystems of the Republic of the Marshall Islands
Coral Reef Ecosystems
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Coral Reef Ecosystems
description
Coral Reef Ecosystems. Our classical view of any ecosystem. Seen as systems which transform energy and process organic matter. Detritivores. Secondary consumers. Primary consumers. Detritus. Primary producers. Seen as systems which transform energy and process organic matter. - PowerPoint PPT Presentation
Transcript of Coral Reef Ecosystems
Coral Reef Ecosystems
Our classical view of any ecosystem• Seen as systems which transform energy and process
organic matter
Primary producer
s
Primary consume
rs
Secondary
consumers
Detritus
Detritivores
• Seen as systems which transform energy and process organic matter
Primary producer
s
Primary consume
rs
Secondary
consumers
Detritus
Detritivores
= pathway for material (or carbon)
• Seen as systems which transform energy and process organic matter
Primary producer
s
Primary consume
rs
Secondary
consumers
Detritus
Detritivores
= pathway for material (or carbon)
= pathway for energy
HeatHeat
HeatHeat
HeatHeat
Heat
Heat
Organic veneer of a reef
Net water flow
C, N, P, O
C
N
P
O
CN
P
O
Lagrangian Control Volume
Measuring Ecosystem Dynamics
C
N
P
O
CN
P
O
Time 1
Time 2
Eularian control volume
Measuring Ecosystem Dynamics
Useful measures of ecosystem ‘metabolism’
Pg = gross primary productivity (gC/m2/day)
P/R = community respiration ratio
E = excess production (gC/m2/day)
Ocean Outer reef slope Forereef
Reef crest
Back reef Lagoo
n
Water columnPg .2-.8 ? 2-7 2-7 2.6-27 .01-2.9-12.9
E .01-.65 ? -1-5.1 .3-1.5-8.7-7.3 -1.3-1.4-.5-3.4
P/R .9-1.38 ? .5-5.5 1-4 .7-3.2 .1-1.4.7-1.4
Ocean Outer reef slope Forereef
Reef crest
Back reef Lagoo
n
Water columnPg .2-.8 ? 2-7 2-7 2.6-27 .01-2.9-12.9
E .01-.65 ? -1-5.1 .3-1.5-8.7-7.3 -1.3-1.4-.5-3.4
P/R .9-1.38 ? .5-5.5 1-4 .7-3.2 .1-1.4.7-1.4
CoralsMacroalgaeAlgal turfs
0 2 46 810
MicroalgaeMacroalgaeSeagrass
0 2 46 810
How do coral reefs differ from this model?
1. Fluxes– nutrient and otherwise
2. Scales
4. The “unknowns”
3. Fate of the carbon
Cycles – nutrient and otherwise
The level of any nutrient depends partly on the flux between pools
-depends on the type of reef
Barrier reef
Water movement
Level of recycling
Cycles – nutrient and otherwise
The level of any nutrient depends partly on the flux between pools
-depends on the type of reef
Barrier reef Fringing reef
Water movement
Level of recycling
Cycles – nutrient and otherwise
The level of any nutrient depends partly on the flux between pools
-depends on the type of reef
Barrier reef Fringing reef Atoll
Water movement
Level of recycling
Cycles – nutrient and otherwise
Barrier reef Fringing reef Atoll
Degree of system closure
+ (factors increasing)
- (factors decreasing)
Water residence time,Nutrient recycling,Internal fluxes,Infilling
Exports,External connectedness,Boundary fluxes,N limitation
Scales
-nutrient level-inputs from ocean-species composition-heterotroph/autotroph composition
Scales
-nutrient level-inputs from ocean-species composition-heterotroph/autotroph composition
Fate of the carbon
Primary producer
s
Primary consume
rs
Secondary
consumers
Detritus
Detritivores
CaCO3
The Unknowns
The Unknowns
Microbial community
DetritusDissolved organics
Water (& nutrient flux) within a reef
The Unknowns
Water (& nutrient flux) within a reef
The Unknowns
?
