Influence of upwelling on coral reef benthic communities: a systematic review and meta-analysis

Abstract

Highly competitive coral reef benthic communities are acutely sensitive to changes in environmental parameters such as temperature and nutrient concentrations. Physical oceanographic processes that induce upwelling therefore act as drivers of community structure on tropical reefs. How upwelling impacts coral communities, however, is not fully understood; upwelling may provide a natural buffer against climate impacts and could potentially enhance the efficacy of spatial management and reef conservation efforts. This study employed a systematic review to assess existing literature linking upwelling with reef community structure, and a meta-analysis to quantify upwelling impact on the percentage cover of coral reef benthic groups. We show that upwelling has context-dependant effects on the cover of hard coral and fleshy macroalgae, with effect size and direction varying with depth, region and remoteness. Fleshy macroalgae were found to increase by 110% on inhabited reefs yet decrease by 56% around one well-studied remote island in response to upwelling. Hard coral cover was not significantly impacted by upwelling on inhabited reefs but increased by 150% when direct local human pressures were absent. By synthesizing existing evidence, this review facilitates adaptive and nuanced reef management which considers the influence of upwelling on reef assemblages.

Mesoscale Eddies Influence Coral Reef Environments in the Northwest Gulf of Mexico

“…Physical dynamics including eddy influence and alteration to MLD influences biogeochemistry that can be significant to reef environments (i.e., cyclonic eddies enhancing nutrient availability through eddy pumping stimulating primary production in the upper water column) (Falkowski et al., 1991; Kealoha et al., 2020; McGillicuddy Jr, 2016; McGillicuddy Jr et al., 1998; Siegel et al., 1999; Spring & Williams, 2023). The increase in Biogeochemical‐Argo (BGC‐Argo) floats, launched in the Gulf of Mexico in late 2021, can provide a better understanding of the chemistry and trophic conditions of the water masses within the eddies through the measurement of oxygen, nitrate, chlorophyll‐a, pH, and particulate backscatter that pass over FGBNMS.…”

“…The increase in Biogeochemical‐Argo (BGC‐Argo) floats, launched in the Gulf of Mexico in late 2021, can provide a better understanding of the chemistry and trophic conditions of the water masses within the eddies through the measurement of oxygen, nitrate, chlorophyll‐a, pH, and particulate backscatter that pass over FGBNMS. The range of variability between the BGC parameters could be insightful for reef resilience as corals are mixotrophs, relying on nutrients from upwelling and particles in the water column for food as well as sunlight (Spring & Williams, 2023), and ocean acidification is a large threat to these calcifying organisms (Hoegh‐Guldberg et al., 2007).…”

Turbulent Characteristics of a Submerged Reef under Various Current and Submergence Conditions

“…Figure 5 shows the numerical results of the flow fields on three profiles and is in agreement with the experimental results (Figure 4). In our previous research, three turbulence models (Realizable k-ε, Standard k-ε, RNG k-ε) have been compared [29]. Realizable k-ε is the most suitable turbulence model for the simulation of complex flow field in the vicinity of the SR under the condition of limited computational capability in terms of the comprehensive model's computational accuracy and efficiency.…”

“…Furthermore, the interaction between the SR and the mainstream produces a wake behind the SR, i.e., back wake [25,26]. In particular, the upwelling transports nutrients from the bottom to the vicinity of the free surface [27][28][29][30], while the back wake promotes the deposition of nutrients in the rear of the SR [1], leading to the enhancement of water exchange [2]. Zooplankton, pelagic swimming 2 of 16 organisms, and benthic resources are augmented by food supply and habitat modification due to the cycling of materials in the watershed [30][31][32].…”

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

“…Upwelling is a process where cool deep waters are transported to shallow depths due to the displacement of a surface water mass by winds. This phenomenon can occur in the open ocean and along coastlines, and is characterized by a series of circulation cells that cause changes in pH, oxygen levels, and nutrient concentrations (Spring and Williams, 2023). Coastal upwelling in the Eastern Tropical Pacific (ETP) is initiated when wind jets exceed 10 m s −1 and pass from the Caribbean and Gulf of Mexico to the Pacific through topographic depressions at the gulfs of Tehuantepec (Mexico), Papagayo (Costa Rica), and Panama (D' Croz and O'Dea, 2007;Coria-Monter et al, 2019).…”