Chattonellaceae

The family Chattonellaceae belongs to the class Raphidophyceae. These microscopic marine organisms are not plant pathogens in the terrestrial sense, but they are recognized as a major biological hazard in global aquaculture due to their ability to form harmful algal blooms.

The biological agent of damage is the proliferation of these flagellated cells, which release potent neurotoxins and reactive oxygen species. These compounds directly target the respiratory and nervous systems of marine organisms, leading to severe physiological distress.

Commercial fish species held in high-density aquaculture systems, such as salmon or sea bream, are the primary casualties. Chattonellaceae blooms can cause massive mortality events within hours, leading to significant economic losses for the aquaculture industry.

Symptoms of affected fish typically include erratic swimming, loss of balance, and heavy mucus production on the gills, which causes physical asphyxiation. In severe cases, mortality rates can reach nearly 100% within the affected site if mitigation actions are not taken.

Outbreaks are heavily influenced by nutrient loading (eutrophication), water temperature, and water column stratification. To protect aquatic stocks, professionals employ several management practices:

• Regular microscopic analysis of water samples for early warning.
• Deployment of bubble curtains to prevent algal cell infiltration.
• Temporary cessation of feeding to reduce metabolic stress.
• Relocation of floating cages to deeper, colder waters.
• Use of clay flocculation to sink algal cells from the water column.