Warm Water Marine Fish (Seabass, Sea bream, Barramundi, Yellowtail)
What’s important for warm water marine fish?
- High water quality
- Correct water temperature
- Sufficient tidal movement (if cage farming)
- Optimal pH levels (If operating a recirculating system)
- Sourcing strong fingerlings
- Stable environmental conditions
- Optimal oxygen conditions
- Slow growth: This is often due to being raised in small ponds.
- Spread of pathogens: Viruses, bacteria and parasites are often spread via other fish, which are being used to help cut costs.
- Anemia: This can be caused by leeches and contributes to lethargy and poor performance.
- Streptococcus bacteria: A viral infection that can affect major organs such as liver, pancreas and heart if not treated and managed correctly.
For sea bream:
- Edwardsiella tarda: Local strains of this bacteria do not cause high peaks of mortality but can slowly kill fish during the cycle. A common cause is stress. Affected fish do not always die, but they cannot be harvested due to apparent injuries to the skin, eyes and head, or a noticeably “off” smell.
- Henneguya pagri: A myxospora that affects internal organs and oxygen absorption of younger fish.
- Iridovirus: This is the most severe disease for barramundi, causing mortality of up to 80–90%.
- Parasites: Neobenedinia commonly affects newly stocked barramundi in open ocean cages — fish may develop skin and tail rot and mortality rates can go as high as 30–40%.
- Streptococcus iniae: This is the most serious bacterial disease to Barramundi, causing acute mortality with a cumulative mortality of up to 70%.
- Lactococcus type 2: Spikes of mortality may occur, especially during the summer months.
- Fishmeal replacement: Yellowtail are highly carnivorous and have higher protein requirements than salmonids.
- Benedenia seriolae and Neobenedenia girellae (skin flukes): These parasites appear year-round but are especially prevalent during the summer months.
Tips for maximizing health and performance
- Optimize feed and water quality
- Reduce stocking density (to prevent cannibalism and stress)
- Minimize stress during transportation
- Improve gut health
- Formulate stress-resistant nutrients in feed to help enhance immunity
- Provide proper ventilation, such as in the case of air-breathing catfish species
- Apply correct feeding levels (just below satiation)