Bleaching Susceptibility and Recovery of Colombian Caribbean Corals in Response to Water Current Exposure and Seasonal Upwelling

Abstract

Coral bleaching events are globally occurring more frequently and with higher intensity, mainly caused by increases in seawater temperature. In Tayrona National Natural Park (TNNP) in the Colombian Caribbean, local coral communities are subjected to seasonal wind-triggered upwelling events coinciding with stronger water currents depending on location. This natural phenomenon offers the unique opportunity to study potential water current-induced mitigation mechanisms of coral bleaching in an upwelling influenced region. Therefore, coral bleaching susceptibility and recovery patterns were compared during a moderate and a mild bleaching event in December 2010 and 2011, and at the end of the subsequent upwelling periods at a water current-exposed and -sheltered site of an exemplary bay using permanent transect and labeling tools. This was accompanied by parallel monitoring of key environmental variables. Findings revealed that in 2010 overall coral bleaching before upwelling was significantly higher at the sheltered (34%) compared to the exposed site (8%). Whereas 97% of all previously bleached corals at the water current-exposed site had recovered from bleaching by April 2011, only 77% recovered at the sheltered site, but 12% had died there. In December 2011, only mild bleaching (<10% at both sites) was observed, but corals recovered significantly at both sites in the course of upwelling. No differences in water temperatures between sites occurred, but water current exposure and turbidity were significantly higher at the exposed site, suggesting that these variables may be responsible for the observed site-specific mitigation of coral bleaching. This indicates the existence of local resilience patterns against coral bleaching in Caribbean reefs.

Multi-scale processes drive benthic community structure in upwelling-affected coral reefs

“…Upwelling-related environmental changes in these parameters may, on the one hand, adversely affect coral growth (Antonius, 1972) and induce macroalgal blooms (Diaz-Pulido and Garzón-Ferreira, 2002). On the other hand, they may also cause a decrease in bleaching susceptibility of corals (Chollett et al, 2010) and facilitate recovery from coral bleaching (Bayraktarov et al, 2013). In addition, environmental changes also influence primary production of major benthic photoautotrophs (Eidens et al, 2014), thereby affecting benthic community composition.…”

The Physical Environment in Coral Reefs of the Tayrona National Natural Park (Colombian Caribbean) in Response to Seasonal Upwelling

“…Study locations were identical to sites from the coral bleaching survey in 2010/2011 in the same bay (see Bayraktarov et al, 2012Bayraktarov et al, , 2013. Coral community composition and appearance are different between opposing sides of the TNNP bays (Werding and Sánchez, 1989).…”

“…Coral community composition and appearance are different between opposing sides of the TNNP bays (Werding and Sánchez, 1989). Corals at the exposed site and a water depth of 10 m exhibited mainly massive to encrusting growth forms with colonies of Montastraea cavernosa, Diploria strigosa, D. labyrinthiformis, and Colpophyllia natans dominating the coral community (Bayraktarov et al, 2012(Bayraktarov et al, , 2013 and a low rugosity of 1.32 ± 0.13 (Corvin Eidens. Justus Liebig University Giessen.…”

“…As exposed, we characterize locations that due to orientation of the TNNP bays experience increased wave action and turbulence as compared to sheltered sites. In the studies of Bayraktarov et al (2012Bayraktarov et al ( , 2013, it was observed that during a coral bleaching event, the extent of bleached corals was three times lower at an exposed as at a sheltered site. This indicates that a key factor controlling coral reef ecosystem functioning in TNNP may reside in the water currents that act on different temporal and spatial scales.…”

Variables ambientales durante blanqueamiento coralino en el Caribe colombiano

“…Los eventos extremos, como los huracanes, también pueden estar indirectamente relacionados, ya que producen la fragmentación de la cobertura coralina (Van Woesik, et al, 1995;Gardner, et al, 2005). De otro lado, se ha sugerido que la nubosidad puede disminuir la alta radiación solar que reciben los corales (Mumby, et al, 2001) y la surgencia puede retardar el recalentamiento y permitir una rápida recuperación luego del blanqueamiento (Maina, et al, 2008, Bayraktarov, et al, 2013.…”