by vehicles with a low wheel loading such as dune buggies or agricultural vehicles with large tyres. A foliage ramp should require minimal maintenance if initially formed to follow the beach profile, and not overused. Gravel ramp A gravel ramp is formed by excavating the underlying loose sediment and filling the excavation with layers of gravel of graduated sizes as defined by John Loudon McAdam. The gravel is compacted to form a solid surface according to the needs of the traffic. Gravel ramps are less expensive to construct than concrete ramps and are able to carry heavy road traffic provided the excavation is deep enough to reach solid subsoil. Gravel ramps are subject to erosion by water. If the edges are retained with boards or walls and the profile matches the surrounding beach profile, a gravel ramp may become more stable as finer sediments are deposited by percolating water. Longest beaches Amongst the world's longest beaches are: Eighty Mile Beach () in north-west Australia; Praia do Cassino () in Brazil; Padre Island beach (about ) in Gulf of Mexico, Texas. Ninety Mile Beach, Victoria () in Victoria, Australia; Cox's Bazar, Bangladesh ( unbroken); Playa Novillera beach (about ) in Mexico. 90 Mile Beach in New Zealand (); Fraser Island beach (about ) in Queensland, Australia; Troia-Sines Beach () in Portugal; the Jersey Shore, 204 km/127 miles; and Long Beach, Washington (which is about ). Wildlife A beach is an unstable environment that exposes plants and animals to changeable and potentially harsh conditions. Some animals burrow into the sand and feed on material deposited by the waves. Crabs, insects and shorebirds feed on these beach dwellers. The endangered piping plover and some tern species rely on beaches for nesting. Sea turtles also bury their eggs in ocean beaches. Seagrasses and other beach plants grow on undisturbed areas of the beach and dunes. Ocean beaches are habitats with organisms adapted to salt spray, tidal overwash, and shifting sands. Some of these organisms are found only on beaches. Examples of these beach organisms in the southeast US include plants like sea oats, sea rocket, beach elder, beach morning glory (Ipomoea pes-caprae), and beach peanut, and animals such as mole crabs (Hippoidea), coquina clams (Donax), ghost crabs, and white beach tiger beetles. See also Beach advisory Beach ball Beach cleaner Beach evolution Beach polo Coast List of beaches Sand art and play Shore Smart