Well, it's a health concern. As fishermen we are expose to skin cancer causing uv-rays all the time. Plus there is the threat of heat stroke in the summer and hypothermia amid winter. It'd be a threat to your health to try and produce one fishing video per day. So, our content is produced at a much slower rate compared to a gaming channel for instance.
It's much like a mountain climber. That mountain doesn't take to kindly to people climbing all over it's face, plus altitude sickness, and they have uv problem being that high on the mountain in such thin air. The health risk for a outdoors channel is significantly higher the more content we output.