Coral macrobioerosion is accelerated by ocean acidification and nutrients

DeCarlo, Thomas M.; Cohen, Anne L.; Barkley, Hannah C.; Cobban, Quinn; Young, Charles W.; Shamberger, Kathryn E. F.; Brainard, Russell E.; Golbuu, Yimnang

doi:10.1130/g36147.1

Cited by 127 publications

(145 citation statements)

References 29 publications

Supporting

Mentioning

134

Contrasting

Unclassified

Order By: Relevance

“…With one exception [40], previous studies of bioerosion from naturally high-CO 2 systems have focused on the prevalence of macroborers colonizing live Porites coral [15,16,17,32]. While these studies are highly informative, bioeroding communities within living coral skeletons are different than those occupying dead coral substrates, where the majority of coral reef bioerosion occurs [41].…”

Section: Discussionmentioning

confidence: 99%

Enhanced macroboring and depressed calcification drive net dissolution at high-CO ₂ coral reefs

et al. 2016

View full text Add to dashboard Cite

Ocean acidification (OA) impacts the physiology of diverse marine taxa; among them corals that create complex reef framework structures. Biological processes operating on coral reef frameworks remain largely unknown from naturally high-carbon-dioxide (CO2) ecosystems. For the first time, we independently quantified the response of multiple functional groups instrumental in the construction and erosion of these frameworks (accretion, macroboring, microboring, and grazing) along natural OA gradients. We deployed blocks of dead coral skeleton for roughly 2 years at two reefs in Papua New Guinea, each experiencing volcanically enriched CO2, and employed high-resolution micro-computed tomography (micro-CT) to create three-dimensional models of changing skeletal structure. OA conditions were correlated with decreased calcification and increased macroboring, primarily by annelids, representing a group of bioeroders not previously known to respond to OA. Incubation of these blocks, using the alkalinity anomaly methodology, revealed a switch from net calcification to net dissolution at a pH of roughly 7.8, within Intergovernmental Panel on Climate Change's (IPCC) predictions for global ocean waters by the end of the century. Together these data represent the first comprehensive experimental study of bioerosion and calcification from a naturally high-CO2 reef ecosystem, where the processes of accelerated erosion and depressed calcification have combined to alter the permanence of this essential framework habitat.

show abstract

Section: Discussionmentioning

confidence: 99%

Enhanced macroboring and depressed calcification drive net dissolution at high-CO ₂ coral reefs

et al. 2016

View full text Add to dashboard Cite

show abstract

“…Understanding the magnitude of reef carbonate budget changes, and how they have changed within and between reef-building regions has thus been a focus of considerable recent research interest. This has encompassed assessments of both reef framework carbonate production (Perry et al, 2014a;Pratchett et al, 2015) and bioerosion rates (Perry et al, 2014a;Weinstein et al, 2014), and considerations of how rates of both may respond to future climate change drivers (e.g., Fang et al, 2013;Barkley et al, 2015;DeCarlo et al, 2015;Januchowski-Hartley et al, 2017;Schönberg et al, 2017). In addition, there has been considerable effort aimed at improving the understanding of how net reef carbonate budget states vary between reefs and how they may respond to ecological change, these being based on either census (e.g., Stearn et al, 1977;Scoffin et al, 1980;Hubbard et al, 1990;Eakin, 1996;Mallela and Perry, 2007;Perry et al, 2012Perry et al, , 2013b or hydrochemical (e.g., Smith and Kinsey, 1976;Gattuso et al, 1996;Andersson and Gledhill, 2013;Shaw et al, 2016) in-situ measurements.…”

Section: Introductionmentioning

confidence: 99%

Reef Habitat Type and Spatial Extent as Interacting Controls on Platform-Scale Carbonate Budgets

2017

View full text Add to dashboard Cite

A coral reefs carbonate budget strongly influences reef structural complexity and net reef growth potential, and thus is increasingly recognized as a key "health" metric. Despite this, understanding of habitat specific budget states, how these scale across reef platforms, and our ability to quantify both framework and sediment production values remains limited. Here, we use in-situ census data from an atoll rim reef platform in the central Maldives to quantify rates of both reef framework and sediment production and loss within different platform habitats, and then combine these data with high-resolution habitat maps to quantify contributions to platform wide carbonate budgets. The net reef framework budget for the entire platform is extremely low (0.12 G, where G = Kg CaCO 3 m −2 year −1 ), with a very high proportion (143,745 kg or 65.1%) of total framework production generated within the platform margin reef zones, despite these comprising only ∼8% of platform area. Net platform-scale sediment budgets are higher (1.04 G), but most is produced in the reef and platform margin hardground habitats, of which ∼80% derives from parrotfish bioerosion. Significant quantities of new sediment (up to ∼1 G derived from the calcareous green algae Halimeda) are produced only in one habitat. All lagoonal habitats have negative or neutral net carbonate budgets. These data demonstrate the marked inter-habitat differences in reef carbonate budgets that occur across reef platforms, and the major dampening effect on overall platform scale budgets when rates are factored for habitat type and size. Furthermore, the data highlights the disproportionately important role that relatively small areas of reef habitat can have on the maintenance of net positive platform scale budgets. Because of the intrinsic link between carbonate production rates and reef-associated landform development and maintenance, these findings also have implications for understanding reef-associated landform stability. In this context the reef island at this site has been highly mobile over the last ∼40 years, and we hypothesize that such instability may be being exacerbated by the measured low overall rates of framework and sediment generation.

show abstract

“…Sr-U is conceptually based upon a forward biomineralization model that correctly predicts the concentrations of skeleton Sr/Ca and U/Ca [DeCarlo et al, 2015]. While coral skeleton Sr/Ca is sensitive to DeCarlo et al [2016] showed that Sr-U values in a set of 14 modern…”

Section: Coral Paleoceanographymentioning

confidence: 99%

“…In situ logged temperatures are available for Jarvis Island, Palmyra, Palau, Pacora Island and the Red Sea sites [Pineda et al, 2009;Cantin et al, 2010;Barkley et al, 2015;Alpert et al, 2016]. At other sites, logger data were available but discontinuous or not covering the same time period as the coral records.…”

Section: Temperature Data For the Calibrationmentioning

confidence: 99%

Little Ice Age climate in the Western Tropical Atlantic inferred from coral geochemical proxies

Alpert¹

2016

View full text Add to dashboard Cite

Paleoclimate archives place the short instrumental record of climate variability in a longer temporal context and allow better understanding of the rate, nature and extent by which anthropogenic warming will impact natural and human systems. The ocean is a key component of the climate system and records of past ocean variability are thus essential for characterizing natural variability and quantifying climate sensitivity to radiative forcing. Coral skeletons are high-resolution archives of tropical sea surface temperatures (SSTs), but inconsistencies call the accuracy of existing coral proxy records into question.In this thesis, I first quantify the errors associated with the traditional coral thermometer, Sr/Ca, by comparing in situ logged SST with Sr/Ca-derived SST in four corals on the same reef. I show that intercolony disparities in mean Sr/Ca, amplitude of variability, and trend are not due to differences in water temperature, but rather to "vital effects" that result in a ± 2 C uncertainty on reconstructed SST.I then expand, refine, and test a new paleothermometer, Sr-U, across multiple coral species and through time. I show that Sr-U captures spatial SST variability with an uncertainty of ± 0.6 C. When applied to two corals outside of the calibration, Sr-U accurately captures the mean SST and the 20 th century trend in the Western Tropical Atlantic.Finally, I apply Sr-U to a coral from the Little Ice Age (LIA) to address uncertainties in the magnitude of western tropical Atlantic cooling during a 95-year period spanning 1465-1560. Results suggest the region was 1.1 C±0.6°C cooler than the 1958-1988 mean, but within error of early 20 th century SST at this site. Critically, several periods of warmth, equivalent to the 1958-1988 mean, occurred during a solar minimum that is widely believed to have been a cool period of the LIA. My results indicate that Sr/Ca exaggerates the actual cooling by almost 3 °C. My record demonstrates the value of Sr-U and highlights the need for continuous accurate SST records to better constrain the amplitude, drivers, and mechanisms of LIA tropical climate change.

show abstract

Coral macrobioerosion is accelerated by ocean acidification and nutrients

Cited by 127 publications

References 29 publications

Enhanced macroboring and depressed calcification drive net dissolution at high-CO ₂ coral reefs

Enhanced macroboring and depressed calcification drive net dissolution at high-CO ₂ coral reefs

Reef Habitat Type and Spatial Extent as Interacting Controls on Platform-Scale Carbonate Budgets

Little Ice Age climate in the Western Tropical Atlantic inferred from coral geochemical proxies

Contact Info

Product

Resources

About

Coral macrobioerosion is accelerated by ocean acidification and nutrients

Cited by 127 publications

References 29 publications

Enhanced macroboring and depressed calcification drive net dissolution at high-CO 2 coral reefs

Enhanced macroboring and depressed calcification drive net dissolution at high-CO 2 coral reefs

Reef Habitat Type and Spatial Extent as Interacting Controls on Platform-Scale Carbonate Budgets

Little Ice Age climate in the Western Tropical Atlantic inferred from coral geochemical proxies

Contact Info

Product

Resources

About

Enhanced macroboring and depressed calcification drive net dissolution at high-CO ₂ coral reefs

Enhanced macroboring and depressed calcification drive net dissolution at high-CO ₂ coral reefs