Seagrasses are generally known for their significant role in marine and estuarine ecosystems. The growth in human population along the coastal regions, where the seagrass live, makes them very vulnerable to the human-induced disturbances. Large-scale seagrass decline has been reported worldwide due to this problem. There is an evident need to monitor seagrass population to predict future changes and to protect coastal ecosystems from further degradation. The decline of seagrass beds results in their fragmentation and appearance of smaller patches of seagrass isolated from each other. This reference provides a synthesis on how fragmentation of seagrass beds influence their role in the ecosystem. The other part of this book specifically deals with the effect of heavy metal contamination on seagrass and associated fauna. Despite the well- publicised issue of metal contamination of highly urbanised marine systems and its effect on seagrasses, this is the first synthesis on the contamination effect on the seagrass community using a range of bioindicators and biomarkers in order to obtain an integral picture of the contamination effect.