Scientists' hopes are now pinned on one walrus to help them understand where the animals of west Greenland migrate over the summer months.
Of the eight satellite tags the BBC saw attached to walruses in April, seven now appear to have stopped working.
Project leader Erik Born said the tags were probably expelled as the walruses' hides began to heal or they could have been knocked off by the thick sea ice.
The remaining working tag is attached to a female who has a calf in tow.
On the BBC News website's Walrus Watch map, she appears as walrus two (W2) and is thought to be between 10 and 12 years of age.
So far, she has remained close the area where she was tagged.
See where the walruses have gone
Dr Born, a biologist at the Greenland Institute of Natural Resources, said: "There is still a lot of ice in this area, and she will probably stay there until the ice begins to retreat.
"But we hope she begins to move soon while the tag is still working. She should begin migrating any day now, but we could be unlucky if the ice remains."
Dr Born said he was a little disappointed that the rest of the tags had stopped working.
He said: "This year we tried a new smaller tag that we were hoping would last for longer, but this does not seem to be the case.
"Walruses have a very rapid healing process, and I think the tags are being expelled as their hides are starting to mend. They might also have been knocked off as the walruses were hauling out on to the ice.
"There is a chance that some of the tags may start sending data again, but I am not so sure about this."
The tagging study is being run by the Greenland Institute of Natural Resources, in cooperation with the Danish National Environmental Research Institute and the Technical University of Denmark.