Due to intensive coastal development, a combination of local (e.g. pollution, fishing) and global pressures (such as climate change) is affecting marine habitats worldwide. This is a pressing issue in Saudi Arabia, particularly considering the plans for the expansion of sea-related activities within the Saudi Arabia's Vision 2030 framework. Sustaining some of those activities, such as tourism, is dependent upon the maintenance of good ecosystem health. National monitoring programs in Saudi Arabia are scarce and a lack of sound knowledge on how marine organisms change in space and time and what the main factors driving their responses are, limits the contribution of scientists to the management and conservation of the Red Sea. Here we provide baseline knowledge, that can be critical for assessing changes associated with current and future coastal development as well as climate change by collecting data across multiple spatial (including multiple habitats) and temporal scales for the analysis of macroinvertebrate organisms and environmental drivers. One of the most striking findings is related to the low densities observed for macroinvertebrates, making populations potentially vulnerable to disturbance. We also highlight the contribution of different habitats within the seascape and the need to prioritize the features of the bottoms for management and conservation purposes. Each habitat has a unique ecological signature but they are connected to adjacent habitats through a subset of species able to utilize different biotopes within the seascape. Disrupting this ecological network may affect biodiversity patterns from local to regional levels. Within each habitat, temporal variability should be taken into account as patterns change on a seasonal and annual scale. The aim of the thesis is to contribute to the sustainable development of the Red Sea, a unique resource shared among several countries, which will result in a long-term benefit to the Kingdom of Saudi Arabia, and other countries. Information provided is critical as previous knowledge for the region was almost inexistent and allows for future studies to investigate and predict the impacts of intense coastal development and inform conservation and management decisions.