Calcite-filled borings in the most recently deposited skeleton in live-collected Porites (Scleractinia): Implications for trace element archives

Nothdurft, Luke D.; Webb, Gregory E.; Boström, Thor E.; Rintoul, Llewellyn

doi:10.1016/j.gca.2007.09.025

Cited by 64 publications

(52 citation statements)

References 104 publications

(164 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In times of environmental stress, however, corals may retract the polyp exposing the exterior of the corallite to corrosive waters and therefore to erosion and dissolution (Lazier et al, 1999), resulting in anomalous minor element ratios caused by differential leaching (Hendy et al, 2007). Endolithic borings could also be filled with aragonitic or calcitic cements (Nothdurft et al, 2007;Cusack et al, 2008). Post-mortem, dissolution, boring, and infilling may continue, and early marine aragonite cement may precipitate on the skeletal surface, altering the values of important geochemical proxies.…”

Section: Ablation Of Thick Sections Versus Exterior Of Septamentioning

confidence: 99%

Seawater nutrient and carbonate ion concentrations recorded as P/Ca, Ba/Ca, and U/Ca in the deep-sea coral Desmophyllum dianthus

Anagnostou

Sherrell

Gagnon

et al. 2011

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

As paleoceanographic archives, deep sea coral skeletons offer the potential for high temporal resolution and precise absolute dating, but have not been fully investigated for geochemical reconstructions of past ocean conditions. Here we assess the utility of skeletal P/Ca, Ba/Ca and U/Ca in the deep sea coral D. dianthus as proxies of dissolved phosphate (remineralized at shallow depths), dissolved barium (trace element with silicate-type distribution) and carbonate ion concentrations, respectively. Measurements of these proxies in globally distributed D. dianthus specimens show clear dependence on corresponding seawater properties. Linear regression fits of mean coral Element/Ca ratios against seawater properties yield the equations: P/Ca coral (lmol/ mol) = (0.6 ± 0.1) P/Ca sw (lmol/mol) -(23 ± 18), R 2 = 0.6, n = 16 and Ba/Ca coral (lmol/mol) = (1.4 ± 0.3) Ba/Ca sw (lmol/ mol) + (0 ± 2), R 2 = 0.6, n = 17; no significant relationship is observed between the residuals of each regression and seawater temperature, salinity, pressure, pH or carbonate ion concentrations, suggesting that these variables were not significant secondary dependencies of these proxies. Four D. dianthus specimens growing at locations with O arag 6 0.6 displayed markedly depleted P/Ca compared to the regression based on the remaining samples, a behavior attributed to an undersaturation effect. These corals were excluded from the calibration. Coral U/Ca correlates with seawater carbonate ion: U/Ca coral (lmol/ mol) = (À0.016 ± 0.003) ½CO 2À 3 (lmol/kg) + (3.2 ± 0.3), R 2 = 0.6, n = 17. The residuals of the U/Ca calibration are not significantly related to temperature, salinity, or pressure. Scatter about the linear calibration lines is attributed to imperfect spatialtemporal matches between the selected globally distributed specimens and available water column chemical data, and potentially to unresolved additional effects. The uncertainties of these initial proxy calibration regressions predict that dissolved phosphate could be reconstructed to ±0.4 lmol/kg (for 1.3-1.9 lmol/kg phosphate), and dissolved Ba to ±19 nmol/kg (for 41-82 nmol/ kg Ba sw ). Carbonate ion concentration derived from U/Ca has an uncertainty of ±31lmol/kg (for 60-120 lmol=kg CO 2À 3 ). The effect of microskeletal variability on P/Ca, Ba/Ca, and U/Ca was also assessed, with emphasis on centers of calcification, Fe-Mn phases, and external contaminants. Overall, the results show strong potential for reconstructing aspects of water mass mixing and biogeochemical processes in intermediate and deep waters using fossil deep-sea corals.

show abstract

Section: Ablation Of Thick Sections Versus Exterior Of Septamentioning

confidence: 99%

Seawater nutrient and carbonate ion concentrations recorded as P/Ca, Ba/Ca, and U/Ca in the deep-sea coral Desmophyllum dianthus

Anagnostou

Sherrell

Gagnon

et al. 2011

Geochimica et Cosmochimica Acta

View full text Add to dashboard Cite

show abstract

“…There were 3 anomalous results for samples OZO421 (HST1-PAVE), OZO422 (HST2-R3), and OZO426 (HST2-R9) with large, negative R values (Table 2). Low  13 C values present in these results may indicate exposure of sample material to freshwater (Southon et al 2002) and subsequent diagenetic effects and/or geological alteration-a common occurrence in emergent pavements and coral rubble ridges exposed above sea level (Nothdurft et al 2007;Nothdurft and Webb 2009). Nevertheless, low  13 C values seem not to consistently affect the AMS results, suggesting that poor sample quality is related to other forms of degradation or a combination of both.…”

Section: Resultsmentioning

confidence: 90%

“…In addition, there are several factors that limit the range of existing R values available for any chosen analysis. To avoid potential errors when selecting R values (or material to sample) for calculating site or regional averages, one must consider beforehand criteria such as: the trophic level and particular feeding habits of sampled organisms; the physicochemical nature of the aquatic environment and habitat of collection; the possibility of diagenetic alteration; and the dating/calibration methods, calculations, and corrections used (Reimer and Reimer 2001;Scholz et al 2004;Ulm 2006;Nothdurft et al 2007;Nothdurft and Webb 2009). …”

Section: Introductionmentioning

confidence: 99%

A Marine Reservoir Correction for the Houtman-Abrolhos Archipelago, East Indian Ocean, Western Australia

et al. 2013

View full text Add to dashboard Cite

ABSTRACT. High-precision analysis using accelerator mass spectrometry (AMS) was performed upon known-age Holocene and modern, pre-bomb coral samples to generate a marine reservoir age correction value (R) for the HoutmanAbrolhos Archipelago (28.7S, 113.8E) off the Western Australian coast. The mean R value calculated for the Abrolhos Islands, 54 ± 30 yr (1) agrees well with regional R values for Leeuwin Current source waters (N-NW Australia-Java) of 60 ± 38 yr. The Abrolhos Islands show little variation with R values of the northwestern and north Australian coast, underlining the dominance of the more equilibrated western Pacific-derived waters of the Leeuwin Current over local upwelling. The Abrolhos Islands R values have remained stable over the last 2896 cal yr BP, being also attributed to the Leeuwin Current and the El Niño Southern Oscillation (ENSO) signal during this period. Expected future trends will be a strengthening of the teleconnection of the Abrolhos Islands to the climatic patterns of the equatorial Pacific via enhanced ENSO and global warming activity strengthening the Leeuwin Current. The possible effect upon the trend of future R values may be to maintain similar values and an increase in stability. However, warming trends of global climate change may cause increasing dissimilarity of R values due to the effects of increasing heat stress upon lower-latitude coral communities. INTRODUCTIONSurface ocean radiocarbon levels are largely representative of the proportionate contributions of atmospheric CO 2 and 14 C-depleted subsurface water DIC, thus making them lower than atmospheric and terrestrial 14 C. The influence of the "older" 14 C-depleted carbon source incorporated by marine organisms creates a differential between the marine organism's 14 C age and the 14 C age of its terrestrial contemporary. The average offset between the marine and terrestrial 14 C age (~400 yr) is referred to as the marine reservoir age (R) and is described and accounted for by the application of atmospheric modeling. The marine reservoir age also has regional variation referred to as the marine reservoir correction or R value and represents the local influence of ocean and atmospheric mixing due to currents, gyres, upwelling and climatic variations, which vary on seasonal to multidecadal scales (Stuiver and Reimer 1986;Stuiver and Braziunas 1993;Reimer and Reimer 2001).Around the Australian coastline, especially towards the remote north and northwestern regions and along the East Indian Ocean, there are many gaps in the record of R values with low spatial resolution (Reimer and Reimer 2001;Southon et al. 2002;Ulm 2006). In addition, there are several factors that limit the range of existing R values available for any chosen analysis. To avoid potential errors when selecting R values (or material to sample) for calculating site or regional averages, one must consider beforehand criteria such as: the trophic level and particular feeding habits of sampled organisms; the physicochemical nature of the aquati...

show abstract

“…following CCA mortality) Webster et al, 2011). These algae are mainly filamentous and coccoid green algae and cyanobacteria (Tribollet and Payri, 2001), and their metabolic activity causes primary dissolution not only of calcitic but also aragonitic substrates (Ramírez-Reinat and Garcia-Pichel, 2012b;Nothdurft et al, 2007). Ocean acidification and warming conditions can enhance the biomass and respiration rates of endolithic algae, which in turn appear to decrease the interstitial pH and increase dissolution of coral skeletons (Reyes-Nivia et al, 2013;Tribollet et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Relative roles of endolithic algae and carbonate chemistry variability in the skeletal dissolution of crustose coralline algae

Reyes-Nivia

Díaz-Pulido²,

Dove³

2014

Biogeosciences

View full text Add to dashboard Cite

Abstract. The susceptibility of crustose coralline algae (CCA) skeletons to dissolution is predicted to increase as oceans warm and acidify. Skeletal dissolution is caused by bioerosion from endolithic microorganisms and by chemical processes associated with undersaturation of carbonate minerals in seawater. Yet, the relative contribution of algal microborers and seawater carbonate chemistry to the dissolution of organisms that cement reefs under projected pCO 2 and temperature (pCO 2 -T) scenarios have not been quantified. We exposed CCA skeletons (Porolithon onkodes) to four pCO 2 -T treatments (pre-industrial, present-day, SRES-B1 "reduced" pCO 2 , and SRES-A1FI "business-as-usual" pCO 2 emission scenarios) under natural light cycles vs. constant dark conditions for 8 weeks. Dissolution rates of skeletons without photo-endoliths were dramatically higher (200 %) than those colonized by endolithic algae across all pCO 2 -T scenarios. This suggests that daytime photosynthesis by microborers counteract dissolution by reduced saturation states resulting in lower net erosion rates over day-night cycles. Regardless of the presence or absence of phototrophic microborers, skeletal dissolution increased significantly under the spring A1FI "business-as-usual" scenario, confirming the CCA sensitivity to future oceans. Projected ocean acidity and temperature may significantly disturb the stability of reef frameworks cemented by CCA, but surficial substrates harbouring photosynthetic microborers will be less impacted than those without algal endoliths.

show abstract

Calcite-filled borings in the most recently deposited skeleton in live-collected Porites (Scleractinia): Implications for trace element archives

Cited by 64 publications

References 104 publications

Seawater nutrient and carbonate ion concentrations recorded as P/Ca, Ba/Ca, and U/Ca in the deep-sea coral Desmophyllum dianthus

Seawater nutrient and carbonate ion concentrations recorded as P/Ca, Ba/Ca, and U/Ca in the deep-sea coral Desmophyllum dianthus

A Marine Reservoir Correction for the Houtman-Abrolhos Archipelago, East Indian Ocean, Western Australia

Relative roles of endolithic algae and carbonate chemistry variability in the skeletal dissolution of crustose coralline algae

Contact Info

Product

Resources

About