New Zealand King Salmon says the expansion of its fish farming business in the Marlborough Sounds will create 1600 jobs in the region over the next decade - a claim disputed by a lobby group.
The company is applying for permission from the Environmental Protection Authority to treble the size of its six-hectare operation in Pelorus Sound.
It says an analysis by Market Economics Ltd shows the expansion will add $194 million of activity to the national economy by 2021.
The expansion is opposed by environmental groups and some local businesses which say it will cause pollution and prevent tourist operators and the public from using the area.
However, the Sustain our Sounds group says the expansion has a negative impact once the effects of pollution from the farms on commercial fishing and tourism are taken into account.
Submissions on the application close on Wednesday.