by Ramona Young-Grindle, Courthouse News

WASHINGTON (CN) - The U.S. Fish and Wildlife Service has listed three tree snail species and 35 plant species on the island cluster of Maui Nui in Hawaii as endangered under the Endangered Species Act. The agency used an ecosystem-based approach for the listing regulation because "native species that occur in the same habitat types (ecosystems) depend on many of the same biological features and the successful functioning of that ecosystem to survive," the action said.

The listing is the result of a historic 2011 settlement between the USFWS and the Center for Biological Diversity (CBD) aimed at speeding listing decisions for 757 of the country's most vulnerable species, the group noted in its press release. The CBD first petitioned for protections for 20 of the Hawaiian species in 2004, nearly a decade ago.

The USFWS refers to the 38 listed species, plus two endemic Hawaiian plants already listed as endangered and reaffirmed in the current action, as the "Maui Nui species." Maui Nui is the term for the island cluster of Molokai, Lanai, Maui and Kahoolawe in the Hawaiian island chain.

Of the 40 total species, 37 are endemic plants, including exotic members of the sunflower, grass, pea, bellflower, African violet, mint, geranium, pepper, pittosporum, asparagus, sandalwood, and carnation families, as well as two shrub families, myrsine and akia, the action stated.

One purple-flowered member of the pea family, the 'awikiwiki, "survives droughts by producing bean seeds that can last decades in the lava rocks," the CBD noted.

The three endemic mollusks include two species of Lanai tree snail and the Newcomb's tree snail. The snails live only on wet cliffs on specific host plants and eat fungus and algae. The inch tall Lanai tree snails can live 20 years, and give birth to four to six live young per year, the CBD said.

The listed species are found in 10 of the 11 distinct ecosystems present in the unique Maui Nui islands, and some species have only one known surviving individual, the action said.

"The species are threatened primarily by habitat loss and by competition and predation from nonnative species such as feral pigs, goats, rats, axis deer and invasive plants and insects. They are also threatened by global climate change and extreme weather events," the CBD noted.

In addition, "over-collection for commercial and recreational purposes poses a serious potential threat to all three tree snail species," according to the action.

Each of the 40 endemic Maui Nui species is highly restricted in its range, and the USFWS found that all of the species are in danger of extinction throughout their entire ranges, "based on the immediacy, severity, and scope of the threats," the rule said.

The final critical habitat determinations for the Maui Nui species are still under development and review, but the USFWS plans to publish the determinations in the near future, the action noted.

The listing is effective June 27.

---30---

Link: Text of Listing