WWF Scotland issued the warning following analysis of data on landings and discards, scientific advice, and quotas for the giant fishing area off the west coast that stretches to almost 100,000 square miles.
According to scientists at the International Council for the Exploration of the Seas (ICES), in 2011 discards of haddock, cod and whiting were all at unsustainable levels. WWF argues that neither the marine environment nor fishing industry could sustain this level of inefficiency.
WWF is calling for action that will build on existing measures by introducing more selective fishing gear such as the use of "flexible grids" to help prevent juvenile fish being caught and ensure that the existing Cod Recovery Plan is adapted to the needs of the fisheries on the west of Scotland.
Dr Mireille Thom, the charity's senior marine policy officer, said: " We are calling on all stakeholders to work together to agree a way forward. We know this joint approach has started to work in the North Sea, with cod discards by Scottish vessels more than halved since 2008."
Fisheries Secretary Richard Lochhead said: "In 2012 we have worked with the industry to introduce new conservation measures. We also provided incentives for west coast vessels to fish further south, helping cut cod discards."