Fish farming treatment shows promise for tackling parasites in kelp hatcheries

A treatment first developed for fish farming could help kelp growers tackle one of the problems that can affect young seaweed cultures, according to new research by the Universities of British Columbia and Alaska Fairbanks.

The study, published in the Journal of Phycology, looked at whether Biokos, a product made by biotechnology firm Sundew, could control marine ciliates in cultures of Saccharina latissima, or sugar kelp. Ciliates are tiny organisms that can contaminate hatchery cultures and create problems during early-stage seaweed production.

“Seaweed farming is an increasingly important industry, with around 40 million tonnes produced annually. As well as food and feed, seaweed has many applications including agricultural inputs and bio-degradable plastics,” co-founder of Sundew Andy Gardiner told WeAreAquaculture, via email.

“Ciliate contamination is an important bottleneck in seaweed farming. These latest findings highlight the potential of Biokos® to improve reliability and yield in kelp aquaculture,” Gardiner added.

In the study, the Sundew product was found to destroy ciliates within 24 hours and did not appear to affect the normal growth of the early life stage of kelp used in hatcheries.

The company said the product, which it produces at scale using fermentation, is extracted from a naturally occurring aquatic microbe and was originally developed as an alternative to chemical use in fish farming.

The study’s authors said it could be useful for controlling ciliate contamination in kelp hatcheries, but recommended that cultures are buffered to maintain pH during treatment, with further testing required before use in commercial hatcheries and with other kelp species.

The full study can be accessed online here.