Complex sentence: In 1857 the Thames Conservancy took over navigation responsibilities from the City of London and in 1909 assigned Oliver's Island to the Port of London Authority (PLA), wh used it as a storage depot and as a wharf for derelict vessels.
Split into simpler sentences: In 1857 the Thames Conservancy took over navigation responsibilities from the City of London and in 1909 assigned Oliver's Island to the Port of London Authority. The PLA used it as a storage depot and as a wharf for derelict vessels.