Clean Seas Seafood (ASX:CSS) detected the presence of the species karenia mikimotoi in its Arno Bay hatchery in South Australia for the first time, coinciding with elevated mortalities of fish contained in the hatchery, according to a Monday ASX filing.

It added that with the current number of viable fingerlings in the hatchery and the contingency plans in place, there will be no material reduction in future harvests or sales.

The species is associated with algal blooms reported in the waters off South Australia, which has affected marine life across the region.

Currently, the mortalities are most concentrated among the smallest fingerlings, while the broodstock appears to be less impacted, per the filing.

Arno Bay holds both Kingfish broodstock and the first of four planned intakes of Clean Seas' Year Class 26.