Another extinction: The Caribbean monk seal

More than 50 years after it was last officially seen, the Caribbean monk seal has been formally declared extinct by the National Oceanic And Atmospheric Administration.

NOAA officials say it is the first species of seal driven into extinction by human activities, specifically overhunting.

The last confirmed sighting of a Caribbean monk seal was way back in 1952. A few sightings have been reported over the years, but none were ever confirmed. NOAA just completed a five-year review of the species, and were unable to find any evidence of its continued existence.

The IUCN has listed the Caribbean monk seal as probably extinct since 1986.

Meanwhile, the only other two species of monk seal remain endangered and highly at risk. Just 1,200 Hawaiian monk seals and 500 Mediterranean monk seals remain.

Plenty of other seal species also face troubling times. The Center for Biological Diversity recently filed a petition to protect ringed, bearded and spotted seals under the Endangered Species Act. It previously petitioned to protect the ribbon seal.

Around the world, more than 20 other seal species are currently considered threatened with extinction by the IUCN Red List.