Nannochloropsis oculata

It is critical to clarify that Nannochloropsis oculata is not a plant pathogen or a disease agent. It is a genus of unicellular algae widely recognized in marine biotechnology and aquaculture. These organisms are highly valued for their nutritional profile, particularly their richness in lipids and essential fatty acids used to feed larvae in aquatic farming.

In agricultural settings, particularly in hydroponics or vertical farming, these microalgae are not considered parasites but can act as nuisance organisms. Under specific conditions involving excessive light exposure and nutrient-rich water, Nannochloropsis oculata can proliferate, causing water greening and forming biofilms on irrigation equipment and plant root zones.

The development of these algae is driven by photosynthesis. When external factors such as nitrogen/phosphorus availability and constant light sources are present, the population grows rapidly. While they do not infect plants with toxins or diseases, their physical presence can impede nutrient uptake and decrease the dissolved oxygen levels in water reservoirs.

Symptoms of an overgrowth include a noticeable green tint in water reservoirs, slime formation on surfaces, and potential clogging of emitters or fine-mesh filters. This leads to maintenance challenges for the grower, although the plants themselves remain physiologically healthy if the nutrient balance is maintained.

Effective management and prevention strategies include:

• ensuring tanks and pipes are light-proof;
• using UV sterilization for irrigation water;
• regular cleaning and flushing of irrigation lines;
• maintaining strict hygiene protocols in hydroponic setups.