vegetation, known as a fragmented or decoupled gradient, can create weak points in the dune that limit its effectiveness against floods and even its continued existence. Publicly owned beaches, found in U.S. states such as California and Hawaii and in other jurisdictions, present the opportunity to systematically manage—or mismanage—beaches and their accompanying dunes. Coastal sand dune management Coastal sand dunes fringe thousands of Kilometres of coastline around the world. They are made up of continuous, hummocky hills of sand that are held together by specially adapted sand dune vegetation. See Figure 1. These plants have adaptations that allow them to survive in sand dune habitats, these include adaptations to a moving substrate which covers and uncovers its roots, adaptation to desiccation, to strong winds carrying salt and sand and to wildly changing temperatures. Coastal sand dunes formed during a time of low sea level where sand and sediments on the foreshore became exposed and in conjunction with sufficient winds, this sand was transported up the beach face via a process known as saltation. Once sufficient wind (>15 km/hr) mobilises sand particles they become trapped in vegetation or drift wood at the back of the beach, sand then continues to accumulate among the vegetation and over time slowly builds up the dunes we see today. Sand dunes serve an important purpose by protecting inland areas from coastal water intrusion. They are able to absorb the impact and protect inland areas from high energy storms and act as a resilient barrier to the destructive forces of wind and waves. Human impacts It is generally observed that coastal dunes are highly sensitive to any number of human activities. It is also understood that coastal dunes need to have limited interaction with humans in order for their protection and survival. Around the world coastal dunes are eroding and under pressure due to increased sediment loss because of increased coastal human activities. For example, in the last 30 years, mainly because of tourism, nearly 75% of the Mediterranean's coastal dunes have been damaged or destroyed. Human impacts can expand from minor to highly significant adverse effects. Minor effects include pedestrian trampling, constructing footpaths, and off-road vehicle tracks, to the highly more significant which includes the construction of roads, car parks, houses, and the use of sand dunes for ground water extraction, the conversion of sand dunes to land for farming, forestry, waste disposal and sand