Seals we no longer see

Mammals have invaded the sea many times. (Interestingly, this never worked the other way: no pure sea mammal has evolved into a land-dweller.)  Mostly, they've been successful.

 The sea otters made themselves at home on seas, shores, and in kelp forests, and the sea mink was doing fine until humans exterminated it for the “mink” part. The sirenians, the manatees and dugongs, are threatened but not yet critical, unless you count Steller's sea cow, which lasted only a few decades after humans found it.  The cetaceans have produced some 90 living species, with one definite human-caused extinction (China’s baji dolphin), and one species reduced to a dozen animals or fewer (the vaquita, of which I’ve written elsewhere). 

The pinnipeds - the seals and sea lions – were mostly doing all right about a century ago despite longtime hunting of some species. The Guadalupe fur seal was even declared extinct twice and refused to leave the stage: it’s rebounding and well protected today.  It’s been suggested in a few papers and articles that we don’t know all the pinniped species yet, and cryptozoologists have many times hypothesized a long-necked seal as the cause of “sea serpent” stories.  (I once had some hope for this myself, but no longer think it plausible.)

What brings all this to mind? Just over 11 years ago, though, the Caribbean monk seal was declared extinct.

Monachus tropicalis survived the first pinniped driven extinct by humans, the Japanese sea lion (Zalophus japonicus), by a few decades. This species became commercially extinct in the late 1940s after decades of uncontrolled hunting in its range in and around the Sea of Japan to harvest skins, oil, and other parts. Its demise was likely assisted by fishermen who, like many fishermen around the world in those days, shot their “competitors” whenever the chance arose.   The animal may have been eliminated as early as 1951, although it seems to have lingered into the 1970s, and a few unconfirmed sightings occurred in the mid-80s.  That was it. A search announced by South Korea in 2007 produced nothing, An International Union for the Conservation of Nature (IUCN) Red List re-assessment in 2014 agreed with the consensus of extinction.     

The monk seal was the only pinniped endemic to the Caribbean, and the first New World mammal recorded by Christopher Columbus.  Columbus’ men killed eight of the abundant, large (up to 200 kg or more), curious animals they called “sea wolves.”   Unfortunately, other humans found them vulnerable too.  (Homo sapiens is not coming off well in this article.)

In 1911, the last large colony – about 200 seals on islands off Yucatan – was slaughtered.  A lone individual was killed near Key West, Florida, in 1933.  A small group of seals on islands off Jamaica was observed until the early 1950s, but vanished.  Except for scattered individual sightings, that was it, seemingly. The U.S. government, for one, lists no confirmed sightings after 1952.

In 1997, the last major survey effort was carried out. It offered some renewed hope. When 93 Haitian and Jamaican fishermen were interviewed about marine mammals, 21 included the monk seal, and 16 said they’d seen one within the last two years. 

Since then, however, there’s been nothing. The U.S. dropped it from the Endangered Species List in 2008 due to extinction. It’s been suggested some reports of Caribbean monk seals could be caused by California sea lions (Zalophus califonianus) from oceanic parks along Florida’s Gulf Coast. California sea lions are normally darker than monk seals, but their size ranges overlap, and the two could certainly be confused at a distance.  Some sightings may involve wayward members of other species.  In my first book (1996), I wrote hopefully of the Caribbean monk seal’s chances for survival.  In my second book (2006), I was still hopeful. But I’m convinced now it’s gone. In 2019, the expeditions have ended; the conservationists have long gone on to other species they can still save; the scientists, priests of knowledge, have written their obituaries.  The best way to honor this seal’s passing is to save its fellow marine mammals - while we still can. 

 References

Adam, Peter, and Gabriela Garcia. 2003. “New information on the natural history, distribution, and skull size of the extinct (?) West Indian Monk Seal, Monachus tropicalis,” Marine Mammal Science, 19:2, p.297.

Boyd, I.L., and M.P. Stanfield.  1998. “Circumstantial evidence for the presence of monk seals in the West Indies,” Oryx, 32, p.310.

IUCN, “Zalophus japonicus,” https://www.iucnredlist.org/species/41667/113089431, accessed 5 October 2019.

The Monachus Guardian (on-line journal) (2),  http://www.monachus.org/mguard02/02mguard.htm.

Naish, Darren. 2009. “Statistics, seals and sea monsters in the technical literature, Tetrapod Zoology blog, https://scienceblogs.com/tetrapodzoology/2009/03/statistics_seals_sea_monsters.php.

Rice, Dale. 1998.  Marine Mammals of the World.  Lawrence, KS: The Society for Marine Mammalogy.

Swanson, Gail.  2000. “Final Millennium for the Caribbean Monk Seal,” The Monachus Guardian 3(1), http://www.monachus.org/mguard05/05infocu.htm.

Walters, Mark.  1997. “Ghost of a Monk Seal,” Animals, November/December, p.23.

Seal image found Simithsonian.org, believed out of copyright