(Littler and Littler, 2007); instead, the degree to which
they rise to dominance is largely controlled indirectly by
the factors influencing the abundances of other functional
groups, primarily the corals and fleshy macroalgae. The
key point is that crustose corallines dominate mainly by
default (i.e., under conditions of minimal competition),
where corals are inhibited (e.g., by elevated nutrients or
by strong wave action), and where fleshy algae are
removed by intense herbivory. The wave-pounded intertidal algal ridges are built predominantly by Porolithon
(Hydrolithon) onkodes, P. gardineri, P. craspedium, and
Lithophyllum kotschyanum in the Indo-Pacific and
P. pachydermum, and L congestum in the Atlantic; all
are coralline species that appear uniquely tolerant of aerial
exposure. The transition from frondose- to turf- to coralline-algal communities has been reported (Steneck,
1989) to closely correlate with increasing herbivory gradients on coral reefs.
In addition to their protective reef-building nature, coralline algae provide a number of other goods and services.
Since the eighteenth century, unattached corallines (maërl)
have been harvested as acid-soil pH conditioners. In
Britain and France, hundreds of thousands of tons of
Phymatolithon calcareum and Lithothamnion corallioides
continue to be dredged annually. Enormous maërl beds,
several km
2 in area, mainly composed of species belonging to the genera Lithothamnion and Lithophyllum, are
present off the coast of Brazil and have begun to be commercially harvested. Maërl is also used as a mineral food
additive for cows, hogs, and other livestock, as well as in
the filtration and neutralization of acidic drinking water.
Corallines are used in modern medical science in the preparation of dental bone implants (Shors, 1999). The cellular
carbonate skeleton provides an ideal matrix for the adherence and regeneration of bone and tooth structures. Coralline algal fossils have proven to be extremely beneficial in
deriving paleoecological and paleoclimatic information,
and also have been employed as stratigraphic markers of
particular significance in petroleum geology. As
a spectacularly colorful component of live rock for the
flourishing marine aquarium trade, coralline algae are
highly desired for their architectural and attractive aesthetic qualities. However, the most important contribution
of coralline algae worldwide may well prove to be in ameliorating the greenhouse carbon dioxide buildup associated with global climate change. It is the balance
between calcification and respiration – which produce
carbon dioxide – and the consumption of CO 2 by photosynthesis that will determine whether corallines act as
a “sink” (absorbing CO 2 ) or as a source of CO 2 . Experiments that studied how various calcifying systems take
up and give off carbon dioxide have shown that the rise
in CO 2 produced by calcification is mitigated by its
removal through increased photosynthesis (Ohde, 1995;
Iglesias-Rodriguez et al., 2008), with a net effect that is
unlikely to either contribute greatly or significantly reduce
the rise in atmospheric CO 2 . However, rising levels of
CO 2 and concomitant acidification of seawater inhibit all
reef builders, including coralline algae (Kleypas et al.,
1999). By binding vast accumulations of CaCO 3 during
calcification and photosynthesis, corallines may play
a role in slowing future acidification of marine habitats
such as coral reefs.
Bibliography
Agassiz, A., 1888. Three Cruises of the United States Coast and
Geodetic Survey Steamer “Blake.” Boston: Houghton, Mifflin
Co, Vol. 2, 220 p.
Aguirre, J., Riding, R., and Braga, J. C., 2000. Diversity of coralline
red algae: origination and extinction patterns from the Early Cretaceous to the Pleistocene. Paleobiology, 26(4), 651–667.
Bailey, J. C., 1999. Phylogenetic positions of Lithophyllum
incrustans and Titanoderma pustulatum (Corallinaceae,
Rhodophyta) based on 18S rRNA gene sequence analyses, with
a revised classification of the Lithophylloideae. Phycologia, 38,
208–216.
Bory de Saint-Vincent, J. B., 1832. Notice sur les polypiers de la
Grèce. Expédition Scientifique de Morée (Section des Sciences
Physiques), 3(1), 204–209, pl. 54.
Darwin, C. R., 1842. The Structure and Distribution of Coral Reefs.
Being the First Part of the Geology of the Voyage of the Beagle,
Under the Command of Capt. FitzRoy, R.N. During the Years
1832 to 1836. London: Smith Elder and Co, pp. i–xii, 1–214,
pls I–II.
Dawson, E. Y., 1961. The rim of the reef. Natural History, 70, 8–17.
Esteban, M., 1996. An overview of Miocene reefs from Mediterranean areas: general trends and facies models. In Franseen, E.,
Esteban, M., Ward, W. C., and Rouchy, J. M. (eds.), Models
for Carbonate Stratigraphy from Miocene Reef Complexes of
the Mediterranean Regions. Society of Economic Paleontologists and Miner, Concepts in Sedimentology and Paleontology
Series, Vol. 5, pp. 3–53.
Halfar, J., and Mutti, M., 2005. Global dominance of coralline redalgal facies: a response to Miocene oceanographic events. Geology, 33(6), 481–484.
Halfar, J., Godinez-Orta, L., Mutti, M., Valdez-Holguin, J., and
Borges, J., 2004. Nutrient and temperature controls on modern
carbonate production: an example from the Gulf of California,
Mexico. Geology, 32(3), 213–216.
Harrington, L., Fabricius, K., De’Ath, G., and Negri, A., 2004.
Recognition and selection of settlement substrata determine
post-settlement survival in corals. Ecology, 85, 3428–3437.
Iglesias-Rodriguez, M. D., Halloran, P. R., Rosalind E. M.,
Rickaby, R. E. M., Hall, I. R., Elena Colmenero-Hidalgo, E.,
Gittins, J. R., Green, D. R. H., Tyrrell, T., Gibbs, S. J., von
Dassow, P., Rehm, E., Armbrust, E. V., and Boessenkool, K. P.,
2008. Phytoplankton Calcification in a High-CO 2 World. Science, 320(5874), 336–340.
Johnson, C. R., and Mann, K. H., 1986. The crustose coralline alga,
Phymatolithon Foslie, inhibits the overgrowth of seaweeds without relying on herbivores. Journal of Experimental Marine Biology and Ecology, 96(2), 127–146.
Kleypas, J. A., Buddemeier, R. W., Archer, D., Gattuso, J. P.,
Langdon, C., and Opdyke, B. N., 1999. Geochemical consequences of increased atmospheric CO 2 on coral reefs. Science,
284(5411), 118–120.
Littler, M. M., 1973. The population and community structure of
Hawaiian fringing-reef crustose Corallinaceae (Rhodophyta,
Cryptonemiales). Journal of Experimental Marine Biology and
Ecology, 11, 103–120.
Littler, M. M., and Kauker, B., 1984. Heterotrichy and survival
strategies in the red alga Corallina officinalis L. Botanica
Marina, 27, 37–44.
ALGAE, CORALLINE
29
they rise to dominance is largely controlled indirectly by
the factors influencing the abundances of other functional
groups, primarily the corals and fleshy macroalgae. The
key point is that crustose corallines dominate mainly by
default (i.e., under conditions of minimal competition),
where corals are inhibited (e.g., by elevated nutrients or
by strong wave action), and where fleshy algae are
removed by intense herbivory. The wave-pounded intertidal algal ridges are built predominantly by Porolithon
(Hydrolithon) onkodes, P. gardineri, P. craspedium, and
Lithophyllum kotschyanum in the Indo-Pacific and
P. pachydermum, and L congestum in the Atlantic; all
are coralline species that appear uniquely tolerant of aerial
exposure. The transition from frondose- to turf- to coralline-algal communities has been reported (Steneck,
1989) to closely correlate with increasing herbivory gradients on coral reefs.
In addition to their protective reef-building nature, coralline algae provide a number of other goods and services.
Since the eighteenth century, unattached corallines (maërl)
have been harvested as acid-soil pH conditioners. In
Britain and France, hundreds of thousands of tons of
Phymatolithon calcareum and Lithothamnion corallioides
continue to be dredged annually. Enormous maërl beds,
several km
2 in area, mainly composed of species belonging to the genera Lithothamnion and Lithophyllum, are
present off the coast of Brazil and have begun to be commercially harvested. Maërl is also used as a mineral food
additive for cows, hogs, and other livestock, as well as in
the filtration and neutralization of acidic drinking water.
Corallines are used in modern medical science in the preparation of dental bone implants (Shors, 1999). The cellular
carbonate skeleton provides an ideal matrix for the adherence and regeneration of bone and tooth structures. Coralline algal fossils have proven to be extremely beneficial in
deriving paleoecological and paleoclimatic information,
and also have been employed as stratigraphic markers of
particular significance in petroleum geology. As
a spectacularly colorful component of live rock for the
flourishing marine aquarium trade, coralline algae are
highly desired for their architectural and attractive aesthetic qualities. However, the most important contribution
of coralline algae worldwide may well prove to be in ameliorating the greenhouse carbon dioxide buildup associated with global climate change. It is the balance
between calcification and respiration – which produce
carbon dioxide – and the consumption of CO 2 by photosynthesis that will determine whether corallines act as
a “sink” (absorbing CO 2 ) or as a source of CO 2 . Experiments that studied how various calcifying systems take
up and give off carbon dioxide have shown that the rise
in CO 2 produced by calcification is mitigated by its
removal through increased photosynthesis (Ohde, 1995;
Iglesias-Rodriguez et al., 2008), with a net effect that is
unlikely to either contribute greatly or significantly reduce
the rise in atmospheric CO 2 . However, rising levels of
CO 2 and concomitant acidification of seawater inhibit all
reef builders, including coralline algae (Kleypas et al.,
1999). By binding vast accumulations of CaCO 3 during
calcification and photosynthesis, corallines may play
a role in slowing future acidification of marine habitats
such as coral reefs.
Bibliography
Agassiz, A., 1888. Three Cruises of the United States Coast and
Geodetic Survey Steamer “Blake.” Boston: Houghton, Mifflin
Co, Vol. 2, 220 p.
Aguirre, J., Riding, R., and Braga, J. C., 2000. Diversity of coralline
red algae: origination and extinction patterns from the Early Cretaceous to the Pleistocene. Paleobiology, 26(4), 651–667.
Bailey, J. C., 1999. Phylogenetic positions of Lithophyllum
incrustans and Titanoderma pustulatum (Corallinaceae,
Rhodophyta) based on 18S rRNA gene sequence analyses, with
a revised classification of the Lithophylloideae. Phycologia, 38,
208–216.
Bory de Saint-Vincent, J. B., 1832. Notice sur les polypiers de la
Grèce. Expédition Scientifique de Morée (Section des Sciences
Physiques), 3(1), 204–209, pl. 54.
Darwin, C. R., 1842. The Structure and Distribution of Coral Reefs.
Being the First Part of the Geology of the Voyage of the Beagle,
Under the Command of Capt. FitzRoy, R.N. During the Years
1832 to 1836. London: Smith Elder and Co, pp. i–xii, 1–214,
pls I–II.
Dawson, E. Y., 1961. The rim of the reef. Natural History, 70, 8–17.
Esteban, M., 1996. An overview of Miocene reefs from Mediterranean areas: general trends and facies models. In Franseen, E.,
Esteban, M., Ward, W. C., and Rouchy, J. M. (eds.), Models
for Carbonate Stratigraphy from Miocene Reef Complexes of
the Mediterranean Regions. Society of Economic Paleontologists and Miner, Concepts in Sedimentology and Paleontology
Series, Vol. 5, pp. 3–53.
Halfar, J., and Mutti, M., 2005. Global dominance of coralline redalgal facies: a response to Miocene oceanographic events. Geology, 33(6), 481–484.
Halfar, J., Godinez-Orta, L., Mutti, M., Valdez-Holguin, J., and
Borges, J., 2004. Nutrient and temperature controls on modern
carbonate production: an example from the Gulf of California,
Mexico. Geology, 32(3), 213–216.
Harrington, L., Fabricius, K., De’Ath, G., and Negri, A., 2004.
Recognition and selection of settlement substrata determine
post-settlement survival in corals. Ecology, 85, 3428–3437.
Iglesias-Rodriguez, M. D., Halloran, P. R., Rosalind E. M.,
Rickaby, R. E. M., Hall, I. R., Elena Colmenero-Hidalgo, E.,
Gittins, J. R., Green, D. R. H., Tyrrell, T., Gibbs, S. J., von
Dassow, P., Rehm, E., Armbrust, E. V., and Boessenkool, K. P.,
2008. Phytoplankton Calcification in a High-CO 2 World. Science, 320(5874), 336–340.
Johnson, C. R., and Mann, K. H., 1986. The crustose coralline alga,
Phymatolithon Foslie, inhibits the overgrowth of seaweeds without relying on herbivores. Journal of Experimental Marine Biology and Ecology, 96(2), 127–146.
Kleypas, J. A., Buddemeier, R. W., Archer, D., Gattuso, J. P.,
Langdon, C., and Opdyke, B. N., 1999. Geochemical consequences of increased atmospheric CO 2 on coral reefs. Science,
284(5411), 118–120.
Littler, M. M., 1973. The population and community structure of
Hawaiian fringing-reef crustose Corallinaceae (Rhodophyta,
Cryptonemiales). Journal of Experimental Marine Biology and
Ecology, 11, 103–120.
Littler, M. M., and Kauker, B., 1984. Heterotrichy and survival
strategies in the red alga Corallina officinalis L. Botanica
Marina, 27, 37–44.
ALGAE, CORALLINE
29