Carbonate production by calcareous red algae and global change

Abstract

The most important groups of modern red calcareous algae are the Mg-calcite secreting Corallinales and Sporolithales, and the aragonitic Peyssonneliales and Nemaliales. They are common on the world's shelves and are vulnerable to the global warming and the lowering of pH of sea water, caused by the ongoing increase in anthropogenic CO 2 . Among them, coralline algae are ecosystem engineers and major producers of carbonate sediment, of particular importance in temperate and cold seas. Corallines respond to marine acidification and rising temperature showing decreased net calcification, decreased growth and reproduction, as well as reduced abundance and diversity, leading to death and ecological shift to dominant non-calcifying algae. Despite their key ecological and sedimentological role, and because of their vulnerability to marine warming and acidification, our knowledge of the distribution of coralline-dominated habitats and the quantification of their carbonate production is not adequate to allow proper environmental management and confident modelling of a global carbon budget. Locating the algal carbonate factories around the world, then describing them, e.g., evaluating their extent and their production, are a priority for future research. résumé Production carbonatée par les algues rouges calcaires et changement climatique global.Les groupes les plus importants d'algues rouges calcaires actuelles sont, d'une part, les Corallinales et les Sporolithales, qui sécrètent de la calcite magnésienne, et d'autre part, les Peyssonnéliales et les Némaliales, qui produisent de l'aragonite. Abondantes sur les plates-formes actuelles, elles y jouent un rôle majeur

Rhodoliths in Brazil: Current knowledge and potential impacts of climate change

“…Meso-and small-scale distribution AMADO-FILHO et al (2007, 2012a RIUL et al (2009) PEREIRA- , 2012) MOURA et al (2013 Rhodolith bed structure TESTA;BOSENCE (1999) GHERARDI ( Contribution to global carbonate production BRASILEIRO et al (2015) KEMPF ( Influence of environmental factors on rhodolith bed habitats MEIRELLES et al (2015) RIUL et al (2008) MARINS et al (2012) VILLAS-BÔAS et al (2014b) FIGUEIREDO et al (2015) morpho-species (BRODIE; ZUCCARELLO, 2007;GUIRY;GUIRY, 2015). To date, 48 species of encrusting coralline red algae have been recognized in the Brazilian flora: 9 Sporolithaceae, 25 Corallinaceae, and 14 Hapalidiaceae (Table 2).…”

“…Calcified organisms can also act as buffers to OA, since they release CO 3 2-ions that bind with free H + protons to form HCO 3 -, thus neutralizing the acidification process (DONEY et al, 2009;SABINE;TANHUA, 2010;BASSO, 2012).…”

“…These features call the attention not only of phycologists, but also palaeontologists and geologists interested in the carbonate abundance of limestone deposits found since the Cretaceous (LITTLER, 1972;BASSO, 2012). It has been estimated that the Brazilian continental shelf carbonate stock holds 2 x 10 11 tonnes of CaCO 3 (MILLIMANN; AMARAL, 1974).…”

Maerl-bed mapping and carbonate quantification on submerged terraces offshore the Cilento peninsula (Tyrrhenian Sea, Italy)

“…In general, data on the growth rate of temperate species of algae are scarce and were obtained using a suite of discrete methods (Adey &Vassar 1975;Potin et al 1990;Garrabou & Ballesteros 2000;Frantz et al 2000;Rivera et al 2004;Basso & Caragnano 2007;Basso & Rodondi 2007;Caragnano & Basso 2009). Data on the accumulation and productivity of coralline algae in non-tropical areas are also scarce (Farrow et al 1984;Canals & Ballesteros 1997;Freiwald 1998;Bosence & Wilson 2003;Basso 2012).…”

“…It is distributed worldwide, and thus it contributes significantly to the global calcium carbonate budget. Maerl and other rhodolith beds are particularly important in temperate environments like the Mediterranean Sea, where other major carbonate (aragonite) producers, such as reef-building corals and green calcareous algae, are scarce or absent; -coralline algae respond to marine acidification due to increasing atmospheric CO 2 by decreasing calcification, inhibition of spore production and partial dissolution of the Mg-calcite thallus (Kuffner et al 2007;Cumani et al 2010;Basso 2012). erefore maerl is very sensitive to the ongoing global change; -maerl-beds have a high conservation value: both the main bed-forming species and the habitat itself are listed in the EC Habitats Directive because of their high level of biological diversity.…”