Construction of a so-called 'fish habitat skirt' began around the Vancouver Convention Centre on Saturday.
Slabs of concrete, each weighing 36,000 kilograms, were hoisted by cranes and lowered into Coal Harbour to build a bench-like extension of the natural shoreline.
Engineering consultant Richard Sims said the 'habitat skirt' is a new concept designed to give the fish a seemingly natural environment.
"Basically, the shoreline continues along, so that fish can move along, and other marine organisms have the continuity that exists in a natural environment," he told CTV News.
Coal Harbour has "exceptional" marine habitat values, he added, and there have been a lot of measures to ensure there is no environmental damage to the harbour during the project.
Construction of the concrete bench should be completed by Tuesday.
The project was created by a team of engineers, architects, government agencies and other specialists.
