The Twilight Zone is between the depths of 200-1,000m where no sunlight penetrates the water. The combined biomass of fishes, crustaceans and squids far surpasses that of all the world's current fisheries and it is suspected that the twilight zone contains roughly ninety percent of the world's fish biomass. It is also said that there may be more than one million species of the twilight zone that have not been discovered. There are so many creatures that it would be equivalent to 1.3 tons of fish biomass per person on Earth.
|Image from Science Daily's News regarding Twilight Zone|
The animals of the twilight zone possess a large amount of fishmeal and Omega 3 fatty acids. Both of these are needed to feed people, but can only be found in parts of the twilight zone, called "no man's water," that cannot be accessed due to a lack fishing rules. Because there is a lack of understand behind the biological processes that occur in this zone, researchers cannot assess the resiliency of the communities. Therefore, they would be no way of knowing how to develop a maintenance program should the animals be fished.
The Problem & Solution
It is known that the mesopelagic creatures play major roles in the regulation of the climate. When they travel to the upper levels at night to feed they release carbon. This allows for a mechanism for fast transport of carbon, which dampens CO2 's contributions to global warming. By fishing these animals more, this mechanism could be destroyed.
The solution, however, would be in better understanding the twilight zone's biodiversity. Things like population controls on recruitment success and each species' role in the food web would need to be learned before this habitat is to be exploited in such a big manner.
As of right now, there are no major efforts being made to begin fishing in the twilight zone. With a growing demand for the Omega 3 fatty acids, however, the idea becomes more and more viable. Professor Michael St. John, from DTU Aqua in Denmark states that as the coastal resources are being used up, this idea of fishing in the twilight zone will be of growing interest. He fears that there will be a "gold rush" of sorts that will be detrimental to the twilight zone communities. Without knowledge of the communities' resiliencies, this gold rush could lead to completely wiping out entire species. It would throw off not only local food webs, but could ultimately reduce the species' abilities to help regulate the climate.