Final Report Final Reporton the Feeding Feeding Feeding Demonstration emonstration emonstrationConducted in Conducted in Conducted in Marsaxlokk, Malta Marsaxlokk, Malta Marsaxlokk, Malta, 2022
- Farm location: ~ 10 km NE of the port of Marsaxlokk (35°86’97.930″ N, 14°64’60.072″ E)
- Species: Adult Atlantic bluefin tuna, Species Thunnus thynnus
- Start date: Aug 12, 2022 End date Start date End date End date: Oct 21, 2022 (71 days total)
- Days fed: 55 (16 days missed due to poor weather co Days fed nditions)
- Survival: 100% on both formula and baitfish-fed Atlantic bluefin tuna. Fish number 168
- Note: 4, transfer-related mortalities occurred at the start of the feeding period (day 1)
- Initial average weight: 62.62 kg; initial biomass 10,269.7 kg (counting 164 fish)
- Final average weight: 102.63 kg; final biomass 16,831.3 kg
- Biomass increase: 6,561.6 kg
- Weight gain (%): 63.89%
- Feed efficiency (kg gained/kg fed): 0.2
- Feed conversion ratio (kg fed/kg gained): 4.8 : 1
- Additional advantages: Compound feed solved the significant slime problems
- Results of blind taste evaluation: Tuna buyers and guests preferred taste, color and texture of tuna fed IU’s compound feed
Dare to blind test tuna event: October 22, 2023; Café del Mar, Triq it-Trunciera, Malta An event was organized by MFF in which several government officials, Japanese tuna buyers and other guest attended. Only MFF owner, Salvu Elul knew that samples labeled as “A” were formula
fed and those labeled as “B” were baitfish fed. Several fish from each feeding regime were sampled and tasted.
Results:
- An informal survey was conducted and both guest and Japanese tuna buyers thought fish B were formula fed
- All Japanese buyers preferred flavor and color on fish A
- There were no measurable differences nor trends on fat level
- Japanese buyers mentioned they need the compound feed to be made available in Japan
- Malta’s Secretary for Fisheries, Aquaculture and Animal Rights, Dr. Alicia Bugeja understood that the only way for tourism and tuna farming (two of the most important revenue-generating industries) to co-exist harmoniously in Malta is to adopt the compound feed
Based on the data collected during the feeding demonstration the following inferences can be drawn:
1. IU’s formulated feed it is more cost-effective than frozen baitfish
2.This feed is available year-round with consistent quality and less price fluctuation
3. By adopting the use of feed tuna farmers do not tie up their cashflows nor incur in long-term cold storage costs
4. With less volume of feed farmers can produce the same amount of tuna biomass
5. Logistical advantages
- a. Smaller volumes need to be handled & dispensed into the marine environment. This results in savings in fuel and labor for the tuna farmer
- b.The feed is better for the marine environment because:
- It produces no fish slime
- It prevents leaching of valuable nutrients
- It results in no waste other than the tuna’s metabolic waste
- Allows retrieval and reuse of uneaten feed
- Results in a reduced organic load to the marine environment
- Decreases the number of re-provisioning trips, reducing fuel usage CO₂ emissions to the atmosphere. Also, less labor and wear-and-tear of vessels
6. Allows for management of stress in tuna.
7. Allows for management of diseases and parasites.
8. Prevents the occurrence of yake niku = lactic acidosis
9. Improves flesh color of tuna
10. Extends the shelf life and reduces the mercury footprint in tuna.
This experience demonstrates that the use of IU’s formulated feed provided suitable long-term nutrition for adult bluefin tuna, enabling management strategies that can optimize tuna performance. Therefore, this compound feed increases the return of the investment for tuna farms
At the end of both long-term feeding demonstrations, blind sensory evaluations were conducted. The pictorial documentations show the closing event at “Café del Mar”, a high-end restaurant in Triq it-Trunciera, Malta (October 21, 2022).
Atlantic bluefin tuna (Thunnus thynnus) were fed (starting July 2023) with either baitfish or IU’s balanced feed. Survival was 100% for both dietary treatments but, fish fed the compound feed were deemed to have better flavor and texture and better color than the baitfish fed tuna.
Ichthus Unlimited (IU), conducted two very successful commercial demonstrations of our formulated tuna feed in Spain and Malta (2021 and 2022 respectively).
Lipid deposition was the same in fish fed both diets. The assessment was conducted first buy Japanese buyers of tuna and then by honorary guests invited to the event.
Among them, Malta’s Undersecretary of Fisheries – Alicia Bugeja, Ph.D. – endorsed the compound feed as means to harmonize the coexistence of tourism and bluefin farming in Malta.
Presently, baitfish feeding of tuna causes severe pollution of Malta’s premier beaches. Tourists exposed to fish slime in the otherwise pristine waters have an awful experience while swimming.
The compound feed developed by IU makes possible for two of the main revenue-generating industries in Malta (tourism and tuna farming) to thrive in harmony with each other.
