Protected too late: US authorities report more than 20 extinctions


Freshwater mussels are among the most endangered groups in North America, but scientists don’t know enough about the eight species on the list to say for sure why they have gone extinct. The extinctions are likely linked to reservoirs humans have built over the past 100 years, federal biologists have said, essentially turning rivers from mussels to lakes.

Has the change of habitat affected any aspect of their carefully choreographed life cycle? Were the filters also injured by sediment or water pollution?

Freshwater mussels depend on adaptations developed over countless years of evolution. Females attract fish with an appendage that resembles a minnow, crayfish, snail, insect or worm, depending on the species. The mussels then shed their larvae, which attach themselves to the fish, forcing it to take cover and eventually distribute them.

Perhaps the mussels became extinct because their host fish moved or itself disappeared.

“I don’t think we fully understand what we’ve lost,” said Tyler Hern, a Fish and Wildlife Service biologist whose job includes recovering freshwater mussels. “These mussels had secrets we will never know.”

The mussels proposed for extinction are the flat pig, the green-flowered pearl mussel, the southern acorn shell, the stirrup, the mussel-flowered pearl mussel, the turgid-flowered pearl mussel, the upland coomb and the pearl mussel with yellow flowers.

Hawaiian birds are the Kauai akialoa, Kauai nukupuu, Kauai O’o, Kauai great thrush, Maui akepa, Maui nukupuÊ»u, creeper Molokai, and poÊ»ouli.

The only plant on the list is also native to Hawaii, Phyllostegia glabra var. lanaiensis.

From Guam, there is the white-eyed flanged bird and the fruit bat Little Mariana. From Texas, there is the San Marcos gambusia fish. From Ohio, the crazy fish Scioto.

Bachman’s Warbler and Ivory-billed Woodpecker have been found in the southeast.


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