What is the mesopelagic zone you may wonder? In short, the mesopelagic zone is a region of the ocean with insufficient light for photosynthesis, but sufficient for vision (200-1000 m depth). It is part of the pelagic zone that lies between the photic epipelagic and the aphotic bathypelagic zones. It is also sometimes referred to as the middle pelagic or twilight zone. The ecosystem of the mesopelagic zone offers potential opportunities for new sources of food and novel compounds for Blue Growth.
“Every time we think we understand the [deep ocean] ecosystem and the organisms, they manage to produce a new rabbit out of the oceanic hat, so that we are required to readjust our previous perspective.” – Peter Herring 
 Herring, P., The biology of the deep ocean2001: OUP Oxford.