Lagos Lagoon empties into the Atlantic Ocean via Lagos Harbour, a main channel through the heart of the city, 0.5 km to 1 km wide and 10 km long. The principal ocean
port of Lagos is located at
Apapa in a broad western branch off the main channel of the harbour. Another branch off the main channel that is narrower and longer separates
Lagos Island from
Victoria Island, the broad
sand spit which forms the coastline. The city spreads along more than 30 km of the lagoon's south-western and western shoreline.
Pollution by urban and
industrial waste is a major problem as a large amount of
wastewater is released into the lagoon daily. The 11-km-long
Third Mainland Bridge was built off the western shore to by-pass congested mainland suburbs. To its north-east the lagoon is connected by a channel passing south of the town of
Epe to the
Lekki Lagoon. Narrow winding channels connect the system through a broad band of coastal swamps and rivers, as far away as
Sapele, 250 km to the east. The areas around west-Lagos Lagoon are not well provided with roads and many communities there traditionally rely on water transport. In the middle of the lagoon are the Palaver Islands. == Pollution and degradation due to human activities ==