Long term photoacclimation responses of the coral Stylophora pistillata to reciprocal deep to shallow transplantation: photosynthesis and calcification

Abstract

Reciprocal transplantation of Stylophora pistillata coral fragments between deep (30 m) and shallow sites (3 m) was conducted gradually and resulted with 100% survival. Photoacclimation of transplants at both depths showed two distinct phases: at the first phase, within 2 weeks, zooxanthellae density decreased below (at 3 m) and increased beyond (at 30 m) these of the control values at the new depth, while chlorophyll a per zooxanthellae cell remained as in the original depths, thereby fully adjusting areal chlorophyll concentration. On the second phase, after 6 months, zooxanthellae chlorophyll and their quantum yield (Fv/Fm) were adjusted at both new depths. Such regulated acclimation was also observed in the maximal photosynthesis rate of both transplants, whereas respiration adjustment was rapid. These results differ from previously reported rapid shade and light acclimation strategies hence we suggest that acclimation mechanism changes when certain symbiont type is exposed to depth out of its boundary zone. Despite seemingly having become physiologically acclimated, calcification at both new depths was only half the rate achieved by the controls, suggesting that the coral host requires even longer time than the symbionts to acclimate.

Considerations for maximizing the adaptive potential of restored coral populations in the western Atlantic

“…Our current understanding is that local adaptation in corals happens most prominently with respect to depth (Bongaerts et al. , Prada and Hellberg , Cohen and Dubinsky ). But other factors can play a role in adaptation such as temperature (Howells et al.…”

“…Ideally, as part of a climate-adjusted provenance strategy, some of these sites would feature projected future conditions, such as elevated temperature, more variable temperature regimes, and/or lower aragonite saturation state. Our current understanding is that local adaptation in corals happens most prominently with respect to depth (Bongaerts et al 2011, Prada and Hellberg 2013, Cohen and Dubinsky 2015. But other factors can play a role in adaptation such as temperature (Howells et al 2013), especially its daily range , Kenkel et al 2015a.…”

Resolving coral photoacclimation dynamics through coupled photophysiological and metabolomic profiling

“…Titlyanov et al, 2001;Anthony and Hoegh-Guldberg, 2003a;Hennige et al, 2008). Most of these studies to date have predominantly focused on 'steady-state' properties of photoacclimation (reviewed in Warner and Suggett, 2016), via photophysiological measurements from corals acclimated to longterm exposure to different light intensities that occur naturally (Anthony and Hoegh-Guldberg, 2003b;Frade et al, 2008;Winters et al, 2009;Hennige et al, 2010) or are imposed experimentally (Hennige et al, 2008;Schutter et al, 2011;Jeans et al, 2013;Langlois and Hoogenboom, 2014;Cohen and Dubinsky, 2015). However, repeated photophysiological measurements during photoacclimation are needed to provide insight on the fine-scale physiological changes that occur following dynamic alterations in light availability.…”

Utility of Photochemical Traits as Diagnostics of Thermal Tolerance amongst Great Barrier Reef Corals

“…Symbiodinium photoacclimation to changes in light availability (photosynthetically active radiation, PAR) has been particularly well-studied in hospite of corals distributed along natural spatial light gradients (Iglesias-Prieto et al, 2004), and shallow to mesophotic (Frade et al, 2008;Lesser et al, 2010;Cooper et al, 2011) and clear to turbid (Hennige et al, 2008;Suggett et al, 2012) waters, complimented with reciprocal transplants of coral species across these habitats (Cohen and Dubinsky, 2015). Here, upon moving Symbiodinium to darker or deeper habitats, light-harvesting efficiency is altered through adjustment of light-harvesting capacity (Frade et al, 2008).…”