Fish food seller Ridley will be testing its feed on fish grower Tassal’s salmon.

Two trials will use Tassal freshwater nursery facilities and seawater ponds to test the feed on hatchery ponds and larger fish.

Ridley (ASX:RIC) says it will be selling about 3300 tonnes of feed at market rates over the next two years to Tassal, rather than having to sell it at a discount.

Chief Tim Hart says the trial is to test Ridley’s food against other diets with the aim of having the most growth in the safest possible way.

“What’s important for us is we’re building a new mill in Tasmania. Clearly I’d like to win some more work for that, and this is a sizeable piece of work for us,” he told Stockhead.

Ridley shares over the last year.

“The object is to become a bigger supplier to Tassal down the track.”

Ridley is expecting to commission its new plant in Westbury, Tasmania, in the middle of 2019.

Ridley’s fish food consists of carbohydrates but also mushed-up chickens — a process that caused a few problems in April after its chicken supplier went into administration.

Tassal has four hatcheries around Tasmania and four “marine farming zones”.

Tassal was recently in the news after a report by Tasmania’s Environment Protection Authority (EPA) revealed this week that 1.35 million salmon have died in Macquarie Harbour since October last year at farms owned by Tassal, Huon Aquaculture and Petuna.

Tassal shares slipped 0.24 per cent to $4.10 at midday on Friday.