Corals record persistent multidecadal SST variability in the Atlantic Warm Pool since 1775 AD

Abstract

[1] Accurate low-latitude sea surface temperature (SST) records that predate the instrumental era are needed to put recent warming in the context of natural climate variability and to evaluate the persistence of lower frequency climate variability prior to the instrumental era and the possible influence of anthropogenic climate change on this variability. Here we present a 235-year-long SST reconstruction based on annual growth rates (linear extension) of three colonies of the Atlantic coral Siderastrea siderea sampled at two sites on the northeastern Yucatan Peninsula, Mexico, located within the Atlantic Warm Pool (AWP). AWP SSTs vary in concert the Atlantic Multidecadal Oscillation (AMO), a basin-wide, quasiperiodic ($60-80 years) oscillation of North Atlantic SSTs. We demonstrate that the annual linear growth rates of all three coral colonies are significantly inversely correlated with SST. We calibrate annual linear growth rates to SST between 1900 and 1960 AD. The linear correlation coefficient over the calibration period is r = À0.77 and À0.66 over the instrumental record (1860-2008 AD). We apply our calibration to annual linear growth rates to extend the SST record to 1775 AD and show that multidecadal SST variability has been a persistent feature of the AWP, and likely, of the North Atlantic over this time period. Our results imply that tropical Atlantic SSTs remained within 1 C of modern values during the past 225 years, consistent with a previous reconstruction based on coral growth rates and with most estimates based on the Mg/Ca of planktonic foraminifera from marine sediments.

A Century of Ocean Warming on Florida Keys Coral Reefs: Historic In Situ Observations

“…In general, coral growth (annual linear extension) rates in the tropics are found to be negatively correlated with annual mean SST, and this relationship is often used to reconstruct past sea surface temperature (Saenger et al 2009;Cantin et al 2010;Vasquez-Bedoya et al 2012). However, manipulative experiments indicate a parabolic relationship between coral growth (calcification and/or linear extension) and SST (Jokiel and Coles 1977;Jokiel and Coles 1990), with highest growth rates found at temperatures 1 to 2°C below the mean annual maximum.…”

Calcification rates of the massive coral Siderastrea siderea and crustose coralline algae along the Florida Keys (USA) outer-reef tract

“…Using this approach of retrospectively calculating calcification rate, the evidence connecting in situ coral growth to environmental trends is equivocal. Correlation has been demonstrated in some cases, showing declines in coral calcification as the oceans have warmed and acidified (Cooper et al 2008;De'ath et al 2009;Tanzil et al 2009), but in some studies trends were not observed (Helmle et al 2011;Vasquez-Bedoya et al 2012) or observed only on certain reef types (Castillo et al 2011) or regions, with high-latitude reefs even showing increases in calcification with time (Cooper et al 2012).…”

Climate controls on coral growth in the Caribbean

“…In the Caribbean, SSTs have risen steadily for the past century (Hoegh-Guldberg, 1999) and according to a modeling study by On annual time scales, thermally induced bleaching and disease have been recognized as the major factors responsible for the large decline in live Caribbean coral cover (Bruckner & Hill 2009;Miller et al 2009) whereas the decline in architectural complexity has largely been associated with an increase in hurricane frequency (Alvarez-Filip et al 2011). On longer, decadal to centennial time scales, the decline in coral growth has been directly associated with the increasing trend in SST (Saenger et al 2009;Vasquez-Bedoya et al, 2012). Because, however, each of these drivers varies in scale, both temporally and spatially, there remains much uncertainty as to which are most responsible for the observed decline in coral …”

“…Caribbean, most of which find that coral growth rates are decreasing in concert with rising SSTs over the past several decades (Guzman et al 2008, Manzelo et al, 2010, Castillo et al, 2011, Castillo et al, 2012, Vasquez-Bedoya et al, 2012. In Belize, fore-reef colonies of Siderastrea siderea showed a significant decrease in linear extension from 1930-2000, whereas linear extension in colonies on the near shore and back reef showed almost no change (Castillo et al, 2011, Castillo et al, 2012.…”

“…Indeed, several studies of long-term Caribbean coral growth have indicated a significant relationship between coral growth and with the exception of the most recent part of the record, which is driven by a single coral from the Yucatan. Taking into account, however, that the growth-temperature relationship is inverse for the entirety of our corals records, the longest of which extends more than 200 years (Vasquez-Bedoya et al, 2012), it is unlikely that the temperature threshold was crossed at some point before this and corals have maintained the inverse relationship with temperature ever since. Instead, most long-term growth studies indicate that corals are able to adapt to their ambient temperature regimes over extended periods of time, often up to 30*C (Coles et al, 1976;Coles & Jokiel, 1978).…”