This transport can be a key element in maintaining 'downstream' systems, including those in marine parks, and in allowing re-colonisation after natural or human induced disturbance. Mangrove-lined shores prevent coastal erosion and consequent silting of adjacent ecosystems. They are also nurseries for some juveniles of marine species that live in other habitats as adults. Coral reefs protect shores from violent wave action. From these examples alone, it is clear that damage to one part of tropical marine systems may affect other parts.
Tropical regions are annually subject to tropical cyclones.
These can cause massive disturbance and destruction to the coast and seabed habitats, and dramatically change marine life in their paths. The North West Shelf has the highest incidence of tropical cyclones anywhere along Australia's coastal regions and their influence on the marine environment accounts for a significant fraction of the interannual natural variability. However the effects of tropical cyclones on marine life is not well understood. The natural variability of the North West Shelf marine ecosystem caused by these and other natural phenomena is not well understood because of the absence of any long term, systematic monitoring programs. This means that we cannot properly assess the potential impact of industrial developments and other human activities on the shelf because of the lack of basic knowledge of the background natural variability.