Zostera noltei Hornemann seagrass as the modulator of habitat within its canopy

Abstract

Seagrasses establish highly productive ecosystems within shallow coastal regions of tropical and temperate seas and modify optical and hydrodynamic conditions with their canopies. This study aims to elucidate the vertical distributions of water temperature, photosynthetically active radiation (PAR), and water mobility within the canopy of Zostera noltei Hornemann 1832, in the Black Sea and correlate these findings with biomass distribution of the seagrass in the water column. In absence of significant directed water flow, Z. noltei exhibits a unimodal biomass distribution, peaking in the lower half of the canopy. This distribution, primarily dictated by the plant's morphology and growth dynamics, optimally aligns with PAR distribution across the canopy. Furthermore, diurnal assessments indicate variability in temperature and PAR intensity profiles within the Z. noltei canopy. Additionally, water mobility, assessed via plaster ball measurements, exhibits a parabolic decline with increasing canopy depth. The discussion emphasizes the modulatory role of seagrasses in these processes.