The surface of seaweed serves as an interactive face between the seaweed and the surrounding environment. These microbial communities experience changes in response to environmental perturbations and seaweed physiology. The spatial and temporal variations may result in structural, functional, and behavioral changes in the host and consequently affect its fitness. In this study, the bacterial communities associated with Ulva lactuca Linnaeus 1753 (the most common seaweed in the Gulf of Aqaba, Jordan) were sampled over two sampling periods from three sampling sites with various levels of stress. The diversity of seaweed-associated bacterial communities was characterized using a 16S rRNA in order to investigate changes in the composition of seaweed associated bacterial communities in relation to seasonal environmental fluctuations