Upwelling, climate change, and the shifting geography of coral reef development

Abstract

The eastern tropical Pacific is oceanographically unfavorable for coral-reef development. Nevertheless, reefs have persisted there for the last 7000 years. Rates of vertical accretion during the Holocene have been similar in the strong-upwelling Gulf of Panamá (GoP) and the adjacent, weak-upwelling Gulf of Chiriquí (GoC); however, seasonal upwelling in the GoP exacerbated a climate-driven hiatus in reef development in the late Holocene. The situation is now reversed and seasonal upwelling in the GoP currently buffers thermal stress, creating a refuge for coral growth. We developed carbonate budget models to project the capacity of reefs in both gulfs to keep up with future sea-level rise. On average, the GoP had significantly higher net carbonate production rates than the GoC. With an estimated contemporary reef-accretion potential (RAP) of 5.5 mm year−1, reefs in the GoP are projected to be able to keep up with sea-level rise if CO2 emissions are reduced, but not under current emissions trajectories. With an estimated RAP of just 0.3 mm year−1, reefs in the GoC are likely already unable to keep up with contemporary sea-level rise in Panamá (1.4 mm year−1). Whereas the GoP has the potential to support functional reefs in the near-term, our study indicates that their long-term persistence will depend on reduction of greenhouse gases.

Can upwelling regions be potential thermal refugia for marine species during climate warming? The case of Mexico

“…The scenario is presently inverted, with seasonal upwelling in the Gulf of Panama cushioning the thermal stress of climate change. Indeed, the Gulf of Panama reefs produce significantly more carbonate than those in the Gulf of Chiriqui [26].…”

“…Similar to the studies above, collaborators modelled potential changes in thermal habitat based on thermal physiological data finding that besides the migration to higher latitudes well reported by the literature, the upwelling regions of the Campeche Bank and Western Baja California in Mexico might act as thermal or climate refugia [21]. Even though latitudinal shift reports may be the dominant observation, literature relates to the CC effect and the role upwelling regions could play as a climatic refugium [15,22–26]. In the context of this study, climate refugia are regions where the majority of species stay or retreat to endure and possibly expand in the face of changing climatic conditions [25,27,28] – in this case, endure temperature increases.…”

“…Evidence has demonstrated that upwellings regions worldwide are intensifying as a product of CC related mainly to the land-sea pressure difference that could strengthen wind patterns [30,31]. That process could partially buffer coastal upwelling ecosystems from CC temperature increases [26,30]. Indeed, if upwellings regions can act as potential climate refugia, it would be worthwhile to prioritize the management of these regions for diversity or resource protection.…”

Synergistic and antagonistic interactions of oxybenzone and ocean acidification: new insight into vulnerable cellular processes in non-calcifying anthozoans

“…A 4 h exposure was arbitrarily chosen as an initial timeframe since environmental BP-3 is associated with anthropogenic beach activity. The 96 h timeframe of OA exposure was chosen since some coastal upwellings are known to have periodicities of fluctuation ( Murray et al, 2015 ; Rodriguez-Ruano et al, 2023 ). Dynamic environments such as an acute 96 h exposure of OA followed by a 4 h pulse of BP-3 will challenge organisms to adapt to physiologically demanding conditions ( Evans and Hofmann, 2012 ).…”

Physiological responses of Pocillopora corals to upwelling events in the Eastern Tropical Pacific

“…Upwelling has been suggested to reduce warm thermal stress during El Niño events and provide a thermal refuge from ocean warming (Randall et al, 2020), and warming associated with El Niño can counteract the negative effects of low temperature on coral growth during upwelling (Vargas-A ́ngel et al, 2001;Jimeńez and Corteś, 2003a). However, some discrepancy exists regarding trends in bioerosion and future persistence of reefs at upwelling sites (Manzello et al, 2008;Manzello, 2010a;Enochs et al, 2021;Rodriguez-Ruano et al, 2023). It has been proposed that to effectively reduce thermal stress during warming events, upwelling must occur simultaneously and provide sufficient cooling, phosphate levels must increase to alleviate nutrient starvation of Symbiodiniaceae, or corals must actively feed during plankton blooms (Chollett et al, 2010;Riegl et al, 2019).…”