The Sheffield-based firm reported a £73m pre-tax loss from continuing operations in the year to September 30 following a £45m impairment related to the firm's INVE business.
The firm said it will accelerate the restructuring of the group and it is speeding up the disposal and discontinuation of non-core activities.
Earnings from continuing operations fell 37 per cent to £12m and revenue from continuing operations fell 3 per cent to £127m.
Benchmark said weakness in the shrimp and sea bass/bream markets continues and while some recovery is expected it is unlikely to recover to 2018 levels next year. However, the outlook for the salmon market looks positive.
Executive chairman Peter George said: "Following these disappointing results, and the management changes announced in August, our priorities for the coming year are to deliver the programme of disposals and restructuring, to obtain regulatory approval and prepare for launch of BMK08 and CleanTreatÒ and to execute our strategy in our core business areas of genetics and advanced nutrition, including the launch of SPR shrimp and the expansion of our health and specialist diets segments in advanced nutrition."
He said there is a growing need for solutions that improve the sustainability of food production in aquaculture.
"Benchmark's focus on delivering products and solutions that improve animal health and welfare, and that reduce environmental impact, positions it as a leader in raising the sustainability standards in aquaculture," he added.
The group said it is making progress towards the commercial launch of some major products.
It said the next generation sea lice treatment showed show 99 per cent efficacy and "excellent" environmental and animal welfare credentials.
Production of specific pathogen resistant shrimp has started in Florida for export into Asia.