Why Lighting Matters More Than You Think in Fish Farming

When we think about fish farming improvements, we often focus on feed types, tank design, or oxygen levels. But one factor that's quietly influencing everything beneath the surface: Lighting. 

Fish respond to light in profoundly different ways than humans. They don’t just “see” light - they feel it biologically.

At HATO, we’ve spent decades understanding how to apply lighting to improve animal welfare and productivity, and our expansion into aquaculture builds on this legacy.

Fish perceive light differently 

Fish have specialized photoreceptors in their eyes, pineal gland, and deep brain cells. These receptors detect brightness, color, and track daily and seasonal light patterns, which in turn influence: 

• Feeding behavior 

• Stress levels 

• Reproductive development 

• Circadian rhythm 

A mismatch between lighting and the fish’s biological expectations can disrupt growth, feeding, and even immunity. 

The link between light and performance 

Modern research shows how finely tuned lighting can lead to: 

• Better tank or seacage distribution (avoiding crowding) 

• Improved feed conversion rates 

• Reduced maturation in salmon 

Lighting is not a “nice to have.” It’s a biological input that, when applied correctly, leads to measurable gains. 

What smart lighting looks like in aquaculture 

It’s not just about adding more light—it's about the right spectrum, intensity, distribution, and control: 

• Gradual dimming mimics sunrise/sunset and reduces stress 

• Uniform distribution avoids shadowy hideouts and crowding 

• Blue/green wavelengths align with the sensitivity of the photoreceptors of the fish 

At HATO, we call this precision lighting. It's animal-focused, energy-efficient, and easy to manage. 

Wrap-Up 

Lighting is more than visibility: it's functionality, biology, and efficiency rolled into one. And when you get it right, everything from growth rates to welfare indicators improve.