Calcium carbonate production in the southernmost subtropical Atlantic coral reef

Author(s)

Randi, Caroline B. ^[1] ; Becker, Ana Clara ^[1] ; Willemes, Maria Julia ^[2] ; Perry, Chris T. ^[3] ; Salgado, Leonardo Tavares ^[2] ; de Carvalho, Rodrigo Tomazetto ^[2] ; Motta, Fabio S. ^[1] ; de Moura, Rodrigo Leao ^{[4, 5]} ; de Moraes, Fernando Coreixas ^{[6, 2]} ; Pereira-Filho, Guilherme H. ^[1]

Affiliation

^[1] Univ Fed Sao Paulo, Inst Mar, Lab Ecol & Conservacao Marinha, Rua Dr Carvalho de Mendonca 144, BR-110070 Santos, SP - Brazil

^[2] Inst Pesquisas Jardim Bot Rio de Janeiro, Rua Pacheco Leao 915, BR-22460030 Rio De Janeiro - Brazil

^[3] Univ Exeter, Coll Life & Environm Sci, Geog, Exeter, Devon - England

^[4] Univ Fed Rio de Janeiro, Inst Biol, Rio De Janeiro - Brazil

^[5] Univ Fed Rio de Janeiro, SAGE COPPE, Rio De Janeiro - Brazil

^[6] Univ Fed Rio de Janeiro, Dept Invertebrados, Museu Nacl, Rio De Janeiro - Brazil

• Document type: Journal article
• Source: MARINE ENVIRONMENTAL RESEARCH; v. 172, DEC 2021.
• Web of Science Citations: 0

Abstract

Emerging evidence have been supporting the idea that the better known South Atlantic coral reefs (located between 18 degrees S and 24 degrees S) are now essentially senescent structures that have experienced little or no additional vertical reef growth over the past millennia. This has often coincided with a shift to a dominance of non-coral calcifying organisms becoming the main CaCO3 producers in these high latitude and marginal marine settings. Here, we used Calcification Accretion Units (CAUs) and census-based methods to measure non-coral rates of CaCO3 production on the geologically senescent reef and adjacent rhodolith beds within the southernmost subtropical Atlantic reef (i.e., Queimada Grande Reef, QGR). The reef habitat is currently producing CaCO3 at rates of similar to 126 g m(-2) yr(-1). In contrast, fragments of dead corals skeletons deposited adjacent to the reef over the last similar to 2000 years are now colonized by crustose coralline red algae. These form a rhodolith bed that produces CaCO3 at rates of 858 g m(-2) yr(-1). Our results indicate that, whilst not sufficient to promote active net framework accumulation, CaCO3 production by coralline algae and bryozoans on the QGR appears to be sufficient to at least limit net large-scale erosion of the underlying reef structure, allowing the reef structure to persist in a state close to budgetary stasis. Finally, our results are also of relevance for providing insights regarding the balance of CaCO3 production/dissolution/erosion processes in coral reefs, especially in these less understood marginal reefs. (AU)

• FAPESP's process: 16/14017-0 - Assessment of determinating process in associated diversity and formation of rhodolith beds in different spatial scales
• Grantee: Guilherme Henrique Pereira Filho
• Support Opportunities: Regular Research Grants