reefs. Where adults have been collected as a control
measure, coral has been saved from predation only over
relatively small areas (hectares). In the past, coral cover
has generally recovered within 10–15 years of an outbreak. However coral resilience in the face of future outbreaks is uncertain (Done, 1987). This is because the
size and frequency of other impacts that can effect coral
reefs (such as cyclones, coral bleaching, and ocean acidification) are predicted to increase in coming years due
to greenhouse gas emissions. Without full recovery,
repeated outbreaks will eventually lead to the degradation of the coral reef community.
Bibliography
Birkeland, C., 1982. Terrestrial runoff as a cause of outbreaks of
Acanthaster planci (Echinodermata: Asteroidea). Marine Biology,
69, 175–185.
Birkeland, C., and Lucas, S. L., 1990. Acanthaster planci: major
management problem of coral reefs. Boca Raton, Florida: CRC
Press.
Done, T. J., 1987. Simulation of the effects of Acanthaster planci on
the population structure of massive corals in the genus Porites:
evidence of population resilience? Coral Reefs, 6, 75–90.
Endean, R., 1969. Report on Investigations Made into Aspects
of the Current Acanthaster planci (Crown-of-thorns) Infestations of Certain Reefs of the Great Barrier Reef. Fisheries
Branch, Queensland Dept. of Primary Industries, Brisbane.
p. 35.
Lucas, J. S., 1982. Quantitative studies of feeding and nutrition during larval development of the coral reef asteroid Acanthaster
planci (L.). Journal of Experimental Marine Biology and Ecology, 65, 173–194.
Cross-references
Coral Reef, Definition
Corals: Environmental Controls on Growth
ACCOMMODATION SPACE
Tom Spencer
University of Cambridge, Cambridge, UK
Definition
The space available, in both a vertical and a lateral sense,
within which corals can grow, increase framework and
sediments accumulate.
Accommodation space
For corals, accommodation space is constrained vertically
by the water-air interface and its volume broadly determined by reef widths and slope angles. For sedimentary
accumulations on reef platforms, the lower boundary is
governed by reef margin position, reef flat elevation and
lagoon depth and the upper boundary set by the height
of wave run-up during storm events. The rate at which
accommodation space can be filled depends upon rates
of vertical coral growth, vertical framework accretion
and sediment supply, transport and accumulation; these
are all controlled by reef productivity and sediment generation processes which may themselves be constrained by
the environment processes (e.g., wave exposure locally
prevents coral growth from filling accommodation spaces
on Hawaii; Grigg, 1998), be periodically interrupted by
storms (see Tropical Cyclone/Hurricane) and modulated
by sea level change, which ultimately determines the
upper margin of the accommodation space (Figure 1).
Over the long-term, a subsiding reef basement results in
an increase in accommodation space. During glacial
periods, emergent reefs were subject to subaerial solution,
thus increasing the vertical accommodation space available
for reef re-growth on renewed inundation during interglacial periods. There has been debate over the subaerial
erosion rates involved, and thus the additional accommodation space generated, ranging from minimal downwearing
(e.g., Quinn and Matthews, 1990) to 6–63 cm of surface
lowering per 1,000 years (e.g., Gray et al., 1992). During
the stable sea-level of the late Holocene, there has been
“turn-off ” of both vertical and horizontal growth of some
reefs due to the progressive thinning of accommodation
space as reefs approached present sea level (which itself
may have fallen slightly in some Indo-Pacific locations,
thus further reducing accommodation space) and the difficulty of lateral expansion, and maintenance of reef front
volume and integrity, over relatively unstable reef front
talus deposits in increasing water depths. For example,
Smithers et al. (2006) attributed the shut-down of fringing
and nearshore reef progradation on the Great Barrier Reef
between 5.5–4.8 ka BP and 3.0–2.5 ka BP to the contraction of accommodation space caused by the reefs’ own
growth and the complete occupation of favorable reef foundations. In the short term, local accommodation space is an
outcome of local reef erosion and the re-configuration of
sedimentary accumulations resulting from hurricane and
Acanthaster Planci, Figure 1 A crown-of-thorns feeding
aggregation. Such outbreaks of the sea star are a major recurrent
cause of coral mortality on coral reefs throughout the
Indo-Pacific (photo: AIMS LTMP).
2
ACCOMMODATION SPACE
measure, coral has been saved from predation only over
relatively small areas (hectares). In the past, coral cover
has generally recovered within 10–15 years of an outbreak. However coral resilience in the face of future outbreaks is uncertain (Done, 1987). This is because the
size and frequency of other impacts that can effect coral
reefs (such as cyclones, coral bleaching, and ocean acidification) are predicted to increase in coming years due
to greenhouse gas emissions. Without full recovery,
repeated outbreaks will eventually lead to the degradation of the coral reef community.
Bibliography
Birkeland, C., 1982. Terrestrial runoff as a cause of outbreaks of
Acanthaster planci (Echinodermata: Asteroidea). Marine Biology,
69, 175–185.
Birkeland, C., and Lucas, S. L., 1990. Acanthaster planci: major
management problem of coral reefs. Boca Raton, Florida: CRC
Press.
Done, T. J., 1987. Simulation of the effects of Acanthaster planci on
the population structure of massive corals in the genus Porites:
evidence of population resilience? Coral Reefs, 6, 75–90.
Endean, R., 1969. Report on Investigations Made into Aspects
of the Current Acanthaster planci (Crown-of-thorns) Infestations of Certain Reefs of the Great Barrier Reef. Fisheries
Branch, Queensland Dept. of Primary Industries, Brisbane.
p. 35.
Lucas, J. S., 1982. Quantitative studies of feeding and nutrition during larval development of the coral reef asteroid Acanthaster
planci (L.). Journal of Experimental Marine Biology and Ecology, 65, 173–194.
Cross-references
Coral Reef, Definition
Corals: Environmental Controls on Growth
ACCOMMODATION SPACE
Tom Spencer
University of Cambridge, Cambridge, UK
Definition
The space available, in both a vertical and a lateral sense,
within which corals can grow, increase framework and
sediments accumulate.
Accommodation space
For corals, accommodation space is constrained vertically
by the water-air interface and its volume broadly determined by reef widths and slope angles. For sedimentary
accumulations on reef platforms, the lower boundary is
governed by reef margin position, reef flat elevation and
lagoon depth and the upper boundary set by the height
of wave run-up during storm events. The rate at which
accommodation space can be filled depends upon rates
of vertical coral growth, vertical framework accretion
and sediment supply, transport and accumulation; these
are all controlled by reef productivity and sediment generation processes which may themselves be constrained by
the environment processes (e.g., wave exposure locally
prevents coral growth from filling accommodation spaces
on Hawaii; Grigg, 1998), be periodically interrupted by
storms (see Tropical Cyclone/Hurricane) and modulated
by sea level change, which ultimately determines the
upper margin of the accommodation space (Figure 1).
Over the long-term, a subsiding reef basement results in
an increase in accommodation space. During glacial
periods, emergent reefs were subject to subaerial solution,
thus increasing the vertical accommodation space available
for reef re-growth on renewed inundation during interglacial periods. There has been debate over the subaerial
erosion rates involved, and thus the additional accommodation space generated, ranging from minimal downwearing
(e.g., Quinn and Matthews, 1990) to 6–63 cm of surface
lowering per 1,000 years (e.g., Gray et al., 1992). During
the stable sea-level of the late Holocene, there has been
“turn-off ” of both vertical and horizontal growth of some
reefs due to the progressive thinning of accommodation
space as reefs approached present sea level (which itself
may have fallen slightly in some Indo-Pacific locations,
thus further reducing accommodation space) and the difficulty of lateral expansion, and maintenance of reef front
volume and integrity, over relatively unstable reef front
talus deposits in increasing water depths. For example,
Smithers et al. (2006) attributed the shut-down of fringing
and nearshore reef progradation on the Great Barrier Reef
between 5.5–4.8 ka BP and 3.0–2.5 ka BP to the contraction of accommodation space caused by the reefs’ own
growth and the complete occupation of favorable reef foundations. In the short term, local accommodation space is an
outcome of local reef erosion and the re-configuration of
sedimentary accumulations resulting from hurricane and
Acanthaster Planci, Figure 1 A crown-of-thorns feeding
aggregation. Such outbreaks of the sea star are a major recurrent
cause of coral mortality on coral reefs throughout the
Indo-Pacific (photo: AIMS LTMP).
2
ACCOMMODATION SPACE