Road bridge spans Spanish River estuary ria tidal flats dusk moody AERIAL

river estuary delta crossing tidal flats coastal wetlands ria low water moody atmospheric tidal channel road bridge fluvial river crossing wide expanse nightfall mud flats patterns sand banks mudbanks sediment nature sand landscape natural low tide tidal coastline environment dusk outdoors estuary ecosystem natural scenery dark wetlands estuarine patterns spain playa de isla nobody sunset coastal habitat brackish water river mouth tidal river coastal estuary estuarine landscape sundown aerial view evening aerial 4k