A century of warming on Caribbean reefs

Abstract

The world’s oceans are warming at an unprecedented rate, causing dramatic changes to coastal marine systems, especially coral reefs. We used three complementary ocean temperature databases (HadISST, Pathfinder, and OISST) to quantify change in thermal characteristics of Caribbean coral reefs over the last 150 years (1871–2020). These sea surface temperature (SST) databases included in situ and satellite-derived measurements at multiple spatial resolutions. We also compiled a Caribbean coral reef database identifying 5,326 unique reefs across the region. We found that Caribbean reefs have been warming for at least a century. Regionally reef warming began in 1915, and for four of the eight Caribbean ecoregions we assessed, significant warming was detected for the latter half of the nineteenth century. Following the global mid-twentieth century stasis, warming resumed on Caribbean reefs in the early 1980s in some ecoregions and in the 1990s for others. On average, Caribbean reefs warmed by 0.18°C per decade during this period, ranging from 0.17°C per decade on Bahamian reefs (since 1988) to 0.26°C per decade on reefs within the Southern and Eastern Caribbean ecoregions (since 1981 and 1984, respectively). If this linear rate of warming continues, these already threatened ecosystems would warm by an additional ~1.5°C on average by 2100. We also found that marine heatwave (MHW) events are increasing in both frequency and duration across the Caribbean. Caribbean coral reefs now experience on average 5 MHW events annually, compared to 1 per year in the early 1980s, with recent events lasting on average 14 days. These changes in the thermal environment, in addition to other stressors including fishing and pollution, have caused a dramatic shift in the composition and functioning of Caribbean coral reef ecosystems.

The past, present, and future of coral reef growth in the Florida Keys

“…For most reefs around the world, the increasing frequency and intensity of thermal extremes has been the dominant driver of coral mortality in recent decades (Bove et al, 2022; Bruno et al, 2019; Hughes et al, 2018). The shallow‐water habitats of the FKRT have warmed by ~0.8°C over the last century (Kuffner et al, 2015), with an estimated 0.57°C increase from 1993 to 2020 alone (Bove et al, 2022).…”

Global change differentially modulates Caribbean coral physiology

“…Indeed, while P. strigosa was previously classified as a stress-tolerant species based on trait assessment [45], it has more recently been identified as a more thermally sensitive coral species [35,72,73]. This response is likely representative of the overall deterioration of coral condition in response to thermal stress, which may lead to mortality under chronic or extreme exposure as is being seen more frequently on Caribbean coral reefs [5]. Thermal events on coral reefs are generally considered to be acute stress events (on the scale of hours to weeks) [74].…”

“…Human-induced global change is driving unprecedented challenges for ecosystems globally, from increases in terrestrial droughts [1] and severe storm activity across lower latitudes [2] to altering species' distributions globally [3,4]. Coral reefs are a prime example of an ecosystem heavily impacted by global change, particularly by ocean warming and acidification [5][6][7][8]. Ocean acidification and warming are predicted to affect many marine ecosystems by reducing ecosystem complexity and function, especially for organisms with longer generational times and thus fewer opportunities to adapt to changing conditions [9].…”

Exposure to global change and microplastics elicits an immune response in an endangered coral

“…Coral reef ecosystems are experiencing major declines under global change stressors, especially ocean warming that causes the breakdown of the symbiosis between the coral host and dinoflagellate algae (family Symbiodiniaceae; (Muller-Parker et al, 2015; LaJeunesse et al, 2018)). These declines are particularly evident across the Caribbean where reefs have experienced significant coral loss since the late 20th century, largely due to major disease outbreaks, overfishing leading to macroalgal blooms, and thermal stress events (Contreras-Silva et al, 2020; Bove et al, 2022b; Randazzo-Eisemann et al, 2022). In addition to warming, ocean acidification represents a significant challenge to reef-building corals that can lead to reduced growth rates, dissolution of existing reef framework, and reduced holobiont physiology and metabolic rates (Anthony et al, 2008; Aichelman et al, 2021; Cornwall et al, 2021).…”