Marine fish populations have suffered the consequences of overfishing for a long time, leading to a loss in biodiversity. Traditional methods have been historically used to survey fish diversity but are limited to commercial species, particularly on the high seas. Environmental DNA (eDNA) has been successfully used to monitor biodiversity in aquatic environments. In this study, we monitored fish diversity in the Clarion-Clipperton Zone (CCZ) of the Eastern Pacific Ocean using eDNA metabarcoding. Our results identified 2 classes, 35 orders, 64 families, 87 genera. The genera Mugil, Scomberomorus, and Scomber had high relative abundance in the mesopelagic and demersal zone. Fish diversity were varied with sampling sites, and the greatest number of species were found at the depth of 2500 meters. Environmental changes driven fish aggregation, and our results indicated that Chla was negatively correlated with fish community, while DO was positively correlated with fish community. This study released the fish diversity pattern and the effected by the environment in the CCZ, which would provide useful information for biodiversity management and environment baseline for International Sea-Bed Authority.
 

Fish Diversity, Environmental DNA, Clarion-Clipperton Zone