Commuters face a major shake-up of Sydney's ferry services next year when the Taronga Zoo and Mosman Bay routes are merged, raising fears it will result in longer journeys for many passengers.

The private operator of Sydney Ferries, French company Transdev, is also proposing to terminate all Parramatta River ferries at Barangaroo, instead of Circular Quay.

Residents fear the Balmain East wharf will face a major increase in commuters due to proposed changes to the ferry network. Credit:Sam Mooy

The proposed changes mean Balmain East wharf will become a busy interchange point for people travelling on Parramatta River ferries who want to get to Circular Quay or the lower north shore, sparking concerns the wharf will struggle to handle a large increase in commuters.

The biggest change to the network will be a merger of the F2 Taronga Zoo and F6 Mosman Bay routes into a "one-loop route". Ferries on the merged routes will run anti-clockwise in the morning from Circular Quay to Taronga Zoo and Mosman, and then clockwise in the afternoon from 1pm.