They speculate that the ocean ecosystem has likely changed since the prewhaling era, making a return to prewhaling numbers infeasible.Several whales seen off Sakhalin and on Kamchatka Peninsula are confirmed to migrate towards eastern side of Pacific and join the larger eastern population.No new reproductive females were recorded in 2010, resulting in a minimum of 26 reproductive females being observed since 1995.Other than speculations, large portions of historical characteristic of migration and distribution are unclear such as locations of calving grounds, existences of resident groups, and occurrences within Black and Azov Seas.The gray whale is the sole living species in the genus Eschrichtius, which in turn is the sole living genus in the family Eschrichtiidae.
As of July 2013, the Namibian whale was still being seen regularly.
The subfossil remains of now extinct gray whales from the Atlantic coasts of England and Sweden were used by Gray to make the first scientific description of a species then surviving only in Pacific waters.
The gray whale has a dark slate-gray color and is covered by characteristic gray-white patterns, scars left by parasites which drop off in its cold feeding grounds.
In January 2011, a gray whale that had been tagged in the western population was tracked as far east as the eastern population range off the coast of British Columbia.
Recent findings from either stranded or entangled specimens indicate that the original western population have become functionally extinct and possibly all the whales appeared on Japanese and Chinese coasts in modern times are vagrants or re-colonizers from the eastern population.