Types of sharks that also sound like heavy metal band names.

Great White*

Tiger*

Hammerhead*

Thresher*

Leopard*

Megamouth*

Not sure if there are any academic papers that monitor the decline of heavy metal, but there is certainly a wealth of research that examines the decline of shark populations. Thanks mostly to the work of Ransom A. Myers, who sadly passed away last week. Condolences to his family and colleagues.

As an aside, I can't help but think that (in keeping with the above list), "Ransom Shark" sounds pretty good as well.