USING MACROALGAE AS FEED INGREDIENTS IN AQUAFEED, IMPROVING HEALTH WHILE CLOSING THE NUTRIENT CYCLE!

Macroalgae or seaweeds have the potential to replace many ingredients in aquafeeds from antiviral and antibiotics to colorants and other less desirable micro-ingredients. After decades of manipulating and optimising animal dietary needs in tandem with production and farming systems it seems the developed world has run into several issues in respect of antibiotic resistance and synthetic-compound use linked to cancer and other degenerative diseases.

Seaweeds or their constituents have great potential as products in the feed industry and in particular aquafeeds. Studies have shown that marine macroalgae are unrivalled sources of bioactive molecules with the potential to maintain and improve health through inclusion in feed.

Over the last five years Ocean Harvest Technology Ltd. (OHT) has developed, tested and trialled a seaweed-based salmon and shrimp feed ingredient "OceanFeed™". This is a proprietary blend of several algae, grown in tanks, in seaweed farms and harvested from wild resources. It has been demonstrated that it can replaces certain synthetic chemical additives that are currently used in salmon and shrimp feeds, while improving health and production and reducing mortality.

To increase sustainability, besides the fact of using seaweeds to replace chemicals in the first place, OHT cultivates specific seaweed species in tanks and seaweed farms to be used as part of their own seaweed feed ingredients. By cultivating these species in novel seaweed farms near fish cultivation sites, it allows partial recycling of N and P. By feeding the farmed seaweeds back to the fish or shrimp through their diet will help closing the nutrient cycle. The company has pioneered innovative seaweed cultivation systems to accomplish this and results on this will be presented. Results of the trials and future consequences for the Fish Farming Industry are discussed and an overview of potential seaweed bioactives in feed will also be presented.