Ecological responses of macroalgae vegetation to seasonal variations and environmental changes in the Suez Canal District

Abstract

The noticeable lack in macroalgae number and their vegetation composition in the Suez Canal district may refer to the importance of studying and following the temporal and spatial patterns that are in change in space and time. Therefore, we have to follow regular biodiversity monitoring to elucidate the changes to seaweed vegetation in the Suez Canal area that might occur as seasonal variations or anthropogenic impacts. The present study extended from summer 2020 to spring 2021 along the Suez Canal district, including eight sites at Port Said on the Mediterranean Sea, Timsah Lake in Ismailia and Suez Bay in the Red Sea. Distribution of seaweeds is usually affected by environmental factors as temperature, salinity, pH, and water chemistry. Most of the chemical parameters recorded very high concentrations (high significant) at the sites in the Suez Bay area during all seasons, excluding nitrogen and phosphorus, which were elevated recordings in the Port Said area. El-Timsah Lake area recorded an increase in salinity which was considered as a brackish stratification type. The taxonomic groups of the recorded species showed a total of 39 macroalgal taxa (20 Chlorophyta, 16 Rhodophyta and 3 Phaeophyta). Port Said area recorded the highest significant number of Chlorophyta and Rhodophyta communities. The relative abundance of macroalgal divisions was Chlorophyta, which formed the main coverage. Enteromorpha-Ulva community was characterized during all the study seasons. Multivariate analysis showed the great relation between seaweed distribution, physicochemical parameters and seasonal variations.