Competitive Interactions on a Reef

Coral Coral

Coral Algae

Competition and Recruitment

Benthic Cryptofauna

Fish and Territory

Topics

Death

recruitment

Clonal Life History

FissionFissionFission

Kinds of Competition between Corals

Connell (‘73)

Contact and interaction between soft tissues of coral

No contact between coral colonies

Direct Competition Indirect Competition

Kinds of Competition between Corals

Direct Competition

1. Mesenterial Filaments

Kinds of Competition between Corals

Direct Competition

2. Sweeper Tentacles

Kinds of Competition between Corals

Direct Competition

3. Sweeper Polyps (Goniopora)

Kinds of Competition between Corals

Direct Competition

4. Mucous Secretion (Fungia)

Kinds of Competition between Corals

Direct Competition

5. Histoincompatibily

Kinds of Competition between Corals

Direct Competition

6. Overgrowth

Kinds of Competition between Corals

Indirect Competition

1. Overtopping

Mechanisms for Algal Effects on Corals

Microalgae

Filamentous

Foliose

Crustose

Calcareous

Branching Digitate Tabulate Encrusting Massive Mushroom

O, C O, C O, C O, C O, C -

O, C O, C O, C O, C O, C -

O, O, O, O, O, -

O, - - O, O, -

O, - - - - -

Macrophytes S, C S, C S, C S, A S, A -

O = OVERGROWTH, C = CHEMICAL, S = SHADING, A = ABRASION

Competition and New Recruits

Vermeij, ‘06

Competition and New Recruits

Vermeij, ‘06

3 m

Competition and New Recruits

Vermeij, ‘06

Availablespace

Time

Competition and New Recruits

Vermeij, ‘06

Overgrowth

Competition and New Recruits

Vermeij, ‘06

Unoccupied

Coralline algaeMacroalgaeSponges

%Cover

%Cover

Time

Time

Competition and New Recruits

Vermeij, ‘06

50

40

30

20

10

0

%Mortality

Competition and New Recruits

Vermeij, ‘06

Greatest contributors to recruit mortality

1. Sponges

2. Bivalves

Competition among Cryptic Metazoa

Competition among Cryptic Metazoa

Jackson (‘92) - artificial substrates

% Cover

Time

Free space

Colonials

Solitary

Competition among Cryptic Metazoa

Jackson (‘92) - artificial substrates

Abundance

Time

% suspended cellsretained

Sponges

Bryozoans

Competition among Reef Fish

3 spot territory

Dusky territory

Acropora

3-spot

Dusky

Williams ‘78

Competition among Reef Fish

Robertson ‘96

Species

A

B

C

D

E

F

Aggressive territory holders - defend and eat algae

Less aggressive territory holders - wide variety of foods

Competition among Reef Fish

Roberston ‘96

Species

A

B

C

D

E

FPopulations doubled in size & moved from periphery to centre of reef

Competition among Reef Fish

Roberston ‘96

Species

A

B

C

D

E

F

- little effect - space allocated randomly

KARST SHORE

KARST SHORE - ZONATION

KARST SHORE - ZONATION

White ZoneGray Zone

Black ZoneYellow Zone

Pink ZoneELW

EHW

MLW

MHW

KARST SHORE - ZONATION

WHITE ZONE

KARST SHORE - ZONATION

GRAY ZONE

KARST SHORE - ZONATION

BLACK ZONE

KARST SHORE - ZONATION

YELLOW ZONE