Deepwater sharks batoids and chimaeras (Class Chonddrichthyes)

Almost half of the known chondrichthyans are deep-sea species, but most of these belong to the groups squaloid dogfishes, scyliorhinid catsharks, skates, and holocephalans. The bulk of our knowledge of deep water chondrichthyans comes from only a handful of species. The literature on chimaeras is limited. For species where data are available, productivity and rebound potential decrease with depth of occurrence. For a suite of deep-sea species studied, their productivity was on average less than half that of shelf and pelagic species. At present, about 17 species of sharks are fishery targets, and most are depleted or collapsed. On the other hand, some shelf sharks, such as houndsharks and sharpnose sharks might be fished sustainably since they are more productive than most deep-sea shark species. The major issues in assessing the status of deep-sea shark stocks include lack of time series data, lack of species-specific data, poor understanding of stock structure, and the unresolved taxonomy of several groups