Experimental thermocline deepening highlights the resilience of the seagrass Posidonia oceanica: An opportunity to investigate shoot adaptability

• Published in: Marine pollution bulletin Vol. 189; p. 114824
• Main Authors: Stipcich, Patrizia, Resaikos, Vasilis, Ceccherelli, Giulia
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2023
• Subjects: Adaptation, Physiological; Alismatales - physiology; Climate; Climate change; Growth rate; Leaf necrosis; Mediterranean Sea; Origin depth; Plant Leaves; Restoration; Temperature; Translocation; Water stratification; Mediterranean Sea; Translocation; Climate change; Leaf necrosis; Growth rate; Restoration; Water stratification; Origin depth
• ISSN: 0025-326X; 1879-3363
• DOI: 10.1016/j.marpolbul.2023.114824

The deepening of the thermocline, correlated to the rising temperature, can contribute affecting seagrass performance in a changing climate scenario. Here, the effect of the thermocline deepening on the seagrass Posidonia oceanica has been investigated in Cyprus through a manipulative experiment that allowed also testing the effects of the irradiance, origin depth and translocation. P. oceanica shoots were collected from 31 m of depth and transplanted at 12 m under a shading net, simulating the 31 m light conditions. Morphology (i.e. leaf area, leaf necrosis, number of leaves) and physiology (i.e. growth rate) were evaluated. Thermocline and origin depth effects were found with an increase of leaf necrosis, while a translocation effect was highlighted by a decrease in leaf area. No differences in shoot growth rate due to treatments were found. This experiment indicated an overall wide morphological and physiological acclimation of P. oceanica cuttings in coping with future thermocline conditions and it indirectly provides information for restoration efforts. •The effect of a field simulating thermocline lowering on P. oceanica was evaluated.•The effects of the irradiance, depth origin and translocation were also evaluated.•Conditions above the thermocline increase leaf necrosis.•No differences in shoot growth rate due to treatments were found.•Results indicated an overall acclimation of P. oceanica shoots to future conditions.