Abstract
<title>Abstract</title> <p> The reef-crest coral <italic>Acropora palmata</italic> thrived under changing climatic conditions during the Holocene and played a key role in controlling accretion in shallow Caribbean reefs. Despite this legacy, the species has recently experienced a significant regional decline and potentially faces extinction. While anthropogenic factors associated with global warming are considered to be one of the main drivers of this decline, the impact of natural climate variability on its population trajectory over the Holocene remains uncertain. Here, we use a Generalised Additive Model to assess the impact of regional paleoclimate on a 6000-year-long trajectory of <italic>A. palmata</italic> across the Caribbean. We find that the relationship between abundance and climate is non-linear and geographically divergent. Cooler and wet conditions associated with frequent hurricanes coincide with distinctive fluctuations in acroporid abundance. In the Caribbean Warm Pool, the Little Ice Age cooling interval between ~ 725 and 175 year ago coincides with rising abundance. Whereas warmer intervals, like the Caribbean Warm Period-Medieval Warm Anomaly between ~ 1950–750 year ago coincide with low or declining abundance. A notable exception to this trend occurs at the edge of the Warm Pool, where acroporid decline coincides with cooler Little Ice Age conditions. Such regional differences are likely related to thermal variability and relatively intense hurricane activity. Although ecological mechanisms underlying abundance variation are uncertain, these findings underscore the influence of paleoclimatic drivers on reef-building acroporids. Although correlative, our analysis ultimately finds that acroporid abundances were prone to local extirpations and instability long before the onset of anthropogenic induced global warming. ● Generalized Additive Modelling of <italic>A. palmata</italic> density over the last 6 ka shows consistency with major climate anomalies. ● Rising thermal trends in the Caribbean Warm Pool coincide with declining density consistent with population reduction. ● Falling temperatures during the Little Ice Age coincide with stable or rising density consistent with population increase. ● At well sampled sites Acroporid density is consistent with population dynamics, implying recent decline forced by anthropogenic stressors is not unprecedented. </p>