Seasonal Growth Dynamics of Posidonia oceanica in a Pristine Mediterranean Gulf

• Published in: Ocean science journal Vol. 57; no. 3; pp. 381 - 397
• Main Authors: Mutlu, Erhan, Olguner, Cansu, Gökoğlu, Mehmet, Özvarol, Yaşar
• Format: Journal Article
• Language: English
• Published: Seoul Korea Institute of Ocean Science & Technology and The Korean Society of Oceanography 01-09-2022; Springer Nature B.V
• Subjects: Aquatic plants; Aquatic Pollution; Biometrics; Biometry; Calcite; Density; Depth; Dynamics; Earth and Environmental Science; Earth Sciences; Growth; Leaves; Limiting factors; Marine & Freshwater Sciences; Meadows; Mortality; Oceanography; Optical properties; Organic carbon; Physics; Posidonia oceanica; Rhizomes; Seasons; Shoots; Surface temperature; Surface water; Survival; Total organic carbon; Waste Water Technology; Water Management; Water Pollution Control; Water temperature; Width; Biometrics; Levantine Sea; Ecology; Seasonal growth dynamics; Meadows
• ISSN: 1738-5261; 2005-7172
• DOI: 10.1007/s12601-022-00078-8

Seasonal growth dynamics and ecology of
Posidonia oceanica
were studied in a space alongshore a pristine Mediterranean gulf in 2011–2012. About one-third of the present study surface area was occupied meadows where only calcite rocks were found on bottoms between 0.5 and 29 m. Shoot density was not significantly different among seasons, and was above 364 ± 27 shoots m
−2
, but was different among the depths. The density variables decreased along the bottom depth gradient along which the number of leaves per shoot, inter shoot distance and the morphometrical variables tended to increase. Inferring the dynamics of biometrics (length and width of leaf, orthotropic rhizomes and leaf sheath) and density (LAI, leaf biomass and the number of leaves per shoot), the biometrics of the meadow grew seasonally between growth by March and mortality by August–September, regardless of the coverage area. Mortality occurred due to the highest annual salinity in late summer. A transition depth in space and month in time was assessed as 15 m and as August for variation of the biometrics, respectively. Rhizome related-biometrics (length, thickness, weight, sheath length and width) were dynamically initialized mainly by water nitrogen content which was high by winter-spring. A PAR in the range of 10–32%, and surface water temperature up to 28.8–29.3 °C corresponding to up to ~ 40 PSU were critical limiting factors for
P. oceanica
to survive in space. Water physics, chemistry, and optical properties governed the annual course of biometrics. Total organic carbon was also negatively affecting the seasonal dynamics of the rhizome.