There are plenty of candidates. The deep-diving, plankton-feeding megamouth shark was discovered as recently as 1976 and is only known from 40 or so specimens. A group of species called “river sharks” seem pretty rare. Some have been described from just a single collected specimen. There are many deep sea sharks that have only been caught a handful of times. Does that make them rare? Maybe we’re just lousy at finding them?
What is clear is that many species are much rarer than they used to be. One study finds shark populations in the Mediterranean Sea down 97%. Another found oceanic whitetips in the Gulf of Mexico down 99% since the 1950s. Large predators are naturally uncommon as it is. It takes a lot of energy in an ecosystem to support them. It’s up to us to make smart decisions when it comes to seafood and coastal development to keep them from becoming even rarer.
But we’ve only scratched the surface here. Check back often at http://www.beachchairscientist.com for more insight about your favorite beach discoveries.
Vice President, Education Division, Director, Center for School and Public Programs, Mote Marine Laboratory