speculated that this possibly accounted for the morphological simplicity of this section of the reef flat.
Outer living coral zone and reef slope
Live coral cover and biodiversity increases below mean
low water springs on the outer reef flat. Soft corals
(Lobophyton, Sinularia) and massive or head corals such
as Porites and Goniastrea dominate at the rear of this
zone, with Acropora becoming more abundant toward
the reef crest. Patch reefs seaward of the crest are sporadically distributed along the reef front.
The physical processes operating of fringing reefs are
covered in other entries and are not repeated here (see
Fringing Reef Circulation; Hydrodynamics of Coral Reef
Ecosystems; Reef Flats; Reef Front Wave Energy; Wave
Set-Up; Waves and Wave-Driven Currents). It is more
important to reemphasize that fringing reefs are exposed
to particular processes due to their proximity to land, such
as flood plumes (Devlin et al., 2001) and turbidity and sediment influx (Cortes et al., 1994; Wolanski et al., 2005),
which may complicate the marine processes that structure
reefs further offshore. Debate about the impacts of terrestrial exports on reef health is ongoing. It is, however, relevant to emphasize that many fringing reefs are (1) growing
at their environmental extremes, and (2) are relatively old
features at the “mature to senile end of the evolutionary
spectrum” (see Reef Classification by Hopley (1982)).
Although the pressures facing fringing reefs may have
increased during recent times due to anthropogenic
activities, it is critical to note that many fringing reef flats
have been largely dead for thousands of years due to late
Holocene sea-level fall (see section “Fringing reef growth
and sea level”), and the net calcium carbonate productivity
of most fringing reef reef-slope communities has been
insufficient to enable significant lateral accretion for several thousand years (e.g., Smithers et al., 2006). The vulnerability of fringing reef flat communities, natural
perturbations must be recognized when assessing the significance and causes of changes in reef flat community
status; for example, reef flat coral communities surviving
in moats at Holbourne Island, GBR suffered significant
mortality when the confining rampart was breached by
a cyclone in 1918 (Hopley and Isdale, 1977), lowering
water levels by 40 cm, and as discussed in section “Fringing reefs and terrestrial influence” of this entry, natural
movements in stream mouth position can directly impact
on fringing reefs as documented at Punta Islotes, Costa
Rica (Cortes et al., 1994).
Summary
Fringing reefs are shore-attached and are exposed to
a variety of pressures and processes related to this association that can affect their development. Although most
fringing reefs are morphologically simple, their morphologies may become more complex where they incorporate
reef flats formed at higher mid-Holocene sea levels, and
where terrestrial inputs and processes affect them. The
apparent geomorphological simplicity of many fringing
reefs masks development histories and internal structures
that can be complex and diverse – fringing reefs develop
over a range of foundations and are constructed of
a variety of materials deposited in numerous arrangements
(Figure 5). Of course, reefs are three-dimensional structures, and structural variation may occur within a single
fringing reef. Although geographical variation exists due
to differences in Holocene sea-level history and substrate
availability, most fringing reefs experienced a period of
active growth from 7,000 to 5,000 years ago when they
produced most of their structure. On many fringing reefs
living coral is now restricted to a narrow band near the seaward reef edge.
Bibliography
Adey, W. H., 1978. Coral reef morphogenesis: a multidimensional
model. Science, 202, 831–837.
Anthony, K. R. N., 2000. Enhanced particle-feeding capacity of
corals on turbid reefs (Great Barrier Reef, Australia). Coral
Reefs, 19(1), 59–67.
Anthony, K. R. N., 2006. Enhanced energy status of corals on
coastal, high-turbidity reefs. Marine Ecology – Progress Series,
319, 111–116.
Bellwood, D. R., Hughes, T. P., Folke, C., and Nystrom, M., 2004.
Confronting the coral reef crisis. Nature, 429(6994), 827–833.
Bird, E. C. F., 1971. The fringing reefs near Yule Point, North
Queensland. Australian Geographical Studies, 9, 107–115.
Bird, E. C. F., and Guilcher, A., 1982. Observations preliminaires sur
les recifs frangeants actuels du Kenya et sur les formes littorales
associees. Revue du Geomorphologie Dynamique, 31, 113–125.
Blanchon, P., and Jones, B., 1995. Marine-planation terraces on the
shelf around Grand Cayman: a result of stepped Holocene sealevel rise. Journal of Coastal Research, 11(1), 1–33.
Blanchon, P., Jones, B., and Kalbfleisch, W., 1997. Anatomy of
a fringing reef around Grand Cayman: storm rubble, not coral
framework. Journal of Sedimentary Research A: Sedimentary
Petrology and Processes, 67(1), 1–16.
Braithwaite, C. J. R., Montaggioni, L. F., Camoin, G. F., Dalmasso,
H., Dullo, W. C., and Mangini, A., 2000. Origins and development of Holocene coral reefs: a revisited model based on reef
boreholes in the Seychelles, Indian Ocean. International Journal
of Earth Sciences, 89(2), 431–445.
Cabioch, G., Correge, T., Turpin, L., Castellaro, C., and Recy, J.,
1999. Development patterns of fringing and barrier reefs in
New Caledonia (Southwest Pacific). Oceanologica Acta, 22(6),
567–578.
Camoin, G. F., Colonna, M., Montaggioni, L. F., Casanova, J.,
Faure, G., and Thomassin, B. A., 1997. Holocene sea level
changes and reef development in the Southwestern Indian
Ocean. Coral Reefs, 16(4), 247–259.
Chappell, J., 1974. Geology of coral terraces Huon Peninsula New
Guinea: a study of Quaternary tectonic movements and sea level
changes. Geological Society of America Bulletin, 85, 553–570.
Chappell, J., Chivas, A., Wallensky, E., Polach, H., and Aharon, P.,
1983. Holocene palaeo-environmental changes central to north
Great Barrier Reef inner zone. BMR Journal of Australian
Geology and Geophysics, 8, 223–235.
Collins, L. B., Zhua, Z. R., Wyrwoll, K. H., and Eisenhauer, A.,
2004. Late Quaternary structure and development of the northern
Ningaloo Reef, Australia. Sedimentary Geology, 159, 81–94.
Cortes, J., Macintyre, I. G., and Glynn, P. W., 1994. Holocene
growth history of an eastern Pacific fringing reef, Punta Islotes,
Costa Rica. Coral Reefs, 13(2), 65–73.
444
FRINGING REEFS
Outer living coral zone and reef slope
Live coral cover and biodiversity increases below mean
low water springs on the outer reef flat. Soft corals
(Lobophyton, Sinularia) and massive or head corals such
as Porites and Goniastrea dominate at the rear of this
zone, with Acropora becoming more abundant toward
the reef crest. Patch reefs seaward of the crest are sporadically distributed along the reef front.
The physical processes operating of fringing reefs are
covered in other entries and are not repeated here (see
Fringing Reef Circulation; Hydrodynamics of Coral Reef
Ecosystems; Reef Flats; Reef Front Wave Energy; Wave
Set-Up; Waves and Wave-Driven Currents). It is more
important to reemphasize that fringing reefs are exposed
to particular processes due to their proximity to land, such
as flood plumes (Devlin et al., 2001) and turbidity and sediment influx (Cortes et al., 1994; Wolanski et al., 2005),
which may complicate the marine processes that structure
reefs further offshore. Debate about the impacts of terrestrial exports on reef health is ongoing. It is, however, relevant to emphasize that many fringing reefs are (1) growing
at their environmental extremes, and (2) are relatively old
features at the “mature to senile end of the evolutionary
spectrum” (see Reef Classification by Hopley (1982)).
Although the pressures facing fringing reefs may have
increased during recent times due to anthropogenic
activities, it is critical to note that many fringing reef flats
have been largely dead for thousands of years due to late
Holocene sea-level fall (see section “Fringing reef growth
and sea level”), and the net calcium carbonate productivity
of most fringing reef reef-slope communities has been
insufficient to enable significant lateral accretion for several thousand years (e.g., Smithers et al., 2006). The vulnerability of fringing reef flat communities, natural
perturbations must be recognized when assessing the significance and causes of changes in reef flat community
status; for example, reef flat coral communities surviving
in moats at Holbourne Island, GBR suffered significant
mortality when the confining rampart was breached by
a cyclone in 1918 (Hopley and Isdale, 1977), lowering
water levels by 40 cm, and as discussed in section “Fringing reefs and terrestrial influence” of this entry, natural
movements in stream mouth position can directly impact
on fringing reefs as documented at Punta Islotes, Costa
Rica (Cortes et al., 1994).
Summary
Fringing reefs are shore-attached and are exposed to
a variety of pressures and processes related to this association that can affect their development. Although most
fringing reefs are morphologically simple, their morphologies may become more complex where they incorporate
reef flats formed at higher mid-Holocene sea levels, and
where terrestrial inputs and processes affect them. The
apparent geomorphological simplicity of many fringing
reefs masks development histories and internal structures
that can be complex and diverse – fringing reefs develop
over a range of foundations and are constructed of
a variety of materials deposited in numerous arrangements
(Figure 5). Of course, reefs are three-dimensional structures, and structural variation may occur within a single
fringing reef. Although geographical variation exists due
to differences in Holocene sea-level history and substrate
availability, most fringing reefs experienced a period of
active growth from 7,000 to 5,000 years ago when they
produced most of their structure. On many fringing reefs
living coral is now restricted to a narrow band near the seaward reef edge.
Bibliography
Adey, W. H., 1978. Coral reef morphogenesis: a multidimensional
model. Science, 202, 831–837.
Anthony, K. R. N., 2000. Enhanced particle-feeding capacity of
corals on turbid reefs (Great Barrier Reef, Australia). Coral
Reefs, 19(1), 59–67.
Anthony, K. R. N., 2006. Enhanced energy status of corals on
coastal, high-turbidity reefs. Marine Ecology – Progress Series,
319, 111–116.
Bellwood, D. R., Hughes, T. P., Folke, C., and Nystrom, M., 2004.
Confronting the coral reef crisis. Nature, 429(6994), 827–833.
Bird, E. C. F., 1971. The fringing reefs near Yule Point, North
Queensland. Australian Geographical Studies, 9, 107–115.
Bird, E. C. F., and Guilcher, A., 1982. Observations preliminaires sur
les recifs frangeants actuels du Kenya et sur les formes littorales
associees. Revue du Geomorphologie Dynamique, 31, 113–125.
Blanchon, P., and Jones, B., 1995. Marine-planation terraces on the
shelf around Grand Cayman: a result of stepped Holocene sealevel rise. Journal of Coastal Research, 11(1), 1–33.
Blanchon, P., Jones, B., and Kalbfleisch, W., 1997. Anatomy of
a fringing reef around Grand Cayman: storm rubble, not coral
framework. Journal of Sedimentary Research A: Sedimentary
Petrology and Processes, 67(1), 1–16.
Braithwaite, C. J. R., Montaggioni, L. F., Camoin, G. F., Dalmasso,
H., Dullo, W. C., and Mangini, A., 2000. Origins and development of Holocene coral reefs: a revisited model based on reef
boreholes in the Seychelles, Indian Ocean. International Journal
of Earth Sciences, 89(2), 431–445.
Cabioch, G., Correge, T., Turpin, L., Castellaro, C., and Recy, J.,
1999. Development patterns of fringing and barrier reefs in
New Caledonia (Southwest Pacific). Oceanologica Acta, 22(6),
567–578.
Camoin, G. F., Colonna, M., Montaggioni, L. F., Casanova, J.,
Faure, G., and Thomassin, B. A., 1997. Holocene sea level
changes and reef development in the Southwestern Indian
Ocean. Coral Reefs, 16(4), 247–259.
Chappell, J., 1974. Geology of coral terraces Huon Peninsula New
Guinea: a study of Quaternary tectonic movements and sea level
changes. Geological Society of America Bulletin, 85, 553–570.
Chappell, J., Chivas, A., Wallensky, E., Polach, H., and Aharon, P.,
1983. Holocene palaeo-environmental changes central to north
Great Barrier Reef inner zone. BMR Journal of Australian
Geology and Geophysics, 8, 223–235.
Collins, L. B., Zhua, Z. R., Wyrwoll, K. H., and Eisenhauer, A.,
2004. Late Quaternary structure and development of the northern
Ningaloo Reef, Australia. Sedimentary Geology, 159, 81–94.
Cortes, J., Macintyre, I. G., and Glynn, P. W., 1994. Holocene
growth history of an eastern Pacific fringing reef, Punta Islotes,
Costa Rica. Coral Reefs, 13(2), 65–73.
444
FRINGING REEFS