New research indicates that shark species may be under greater threat from human activity than previously thought. Results just published in Proceedings of the Royal Society by Professor Monty Priede, Director of Aberdeen University’s Oceanlab, suggest that sharks haven’t adapted to depths of more than 3,000 metres – making them absent from over 70% of the world’s oceans, and, crucially, mostly present at depths within the reach of human fisheries. This research raises the interesting question of why there are no really deep water species of shark when many species of bony fish are adapted to far deeper waters.
News of this research has been reported widely: see e.g. Guardian and BBC coverage.
Sharks, Rays and Chimaeras: The Status of the Chondrichthyan Fishes and the forthcoming Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date, Volume 1 FAO are key references for those interested in the status of shark species from a conservation viewpoint.
For more general information Collins Field Guide: Sharks of the World is hard to beat (see also the previous edition Collins Sharks and Rays) or Shark. Sharks, Skates, and Rays The Biology of Elasmobranch Fishes provides comprehensive coverage on the biology and ecology of sharks.
The Grey Nurse shark or sand tiger Odontaspis taurus, apparently has dropped to a little as 400 individuals on the Great Barrier Reef. This harmless shark was destroyed in the hundreds of thousands after Jaws was released, due to its menacing appearance. This species is a prime example of sharks maturing late in their life and when finally giving birth, only to a few young. They are thus extremely vulnerable to fishing. This shark is now critically endangered. Does anyone have any comment on its appearance in most public aquariums across the globe?