The U.S. Fish and Wildlife Service this week reminded us, in a troubling way, of Hawaii’s unique place in the natural world. The agency on Tuesday published a final rule that adds three species of native damselflies and 20 species of native Hawaiian plants on Oahu to the federal list of endangered species.

One might ask: Why save them? After all, much of the lush wild greenery we associate with Hawaiian beauty came from foreign places; on Oahu, flora and fauna unique to Hawaii cling to life on the edges of the urban landscape, some nearly forgotten or unknown. This sorry state of affairs can be attributed to human intervention, and as such, we must do what we can to preserve Hawaii’s at-risk species. Their extinction would be not only a blow to biodiversity and its benefits, but an incalculable loss to the islands’ cultural and historical heritage.

The FWS’ addition of the 23 species brings the number of Hawaii species on the endangered or threatened list to 460 — the highest number of any state in the nation. This dubious distinction should not be a cause of despair, but a call to action. Among the biggest threats identified by the FWS are those that can, to a limited degree, be controlled: ungulates like feral goats and pigs, and nonnative plants.

In addition, the lovely and delicate damselflies, which live in streams, lowland swamps and marshes, face the loss of their habitat due to factors such as agriculture and urban development and stream diversion. Careful stewardship can help mitigate harm.

The FWS also designated a total of 42,804 acres on Oahu as "critical habitat" that at-risk species depend on for their survival. The designation generally restricts activities involving action, funding or permitting by federal agencies.

Nonetheless, the owners of the land — 89 percent of which belongs to the state, city or private owners — should engage in conservation-friendly practices to protect the species beyond the letter of the law.

It can be done. On Oahu, a predator-proof fence protects Laysan albatrosses at Kaena Point from rats, feral cats, mongooses and other threats. By all accounts, this once-devastated area is thriving again. Appropriate fencing can separate native plants from goats and pigs, which eat just about anything, native or not.

The neighbor islands already endure the wanton destruction wrought by mouflon sheep and axis deer on native forests and agricultural crops. These animals were introduced — a practice that, shockingly, seems to be continuing. The federal government prosecuted three men this year for transporting deer and sheep between Hawaii island and Maui, presumably for sport. Such law enforcement crackdowns against this practice are necessary and welcome. Also welcome is the response by farmers, ranchers and environmental groups, who have teamed up to campaign for the elimination or control of these invasive pests.

There are no easy ways to revive an already overwhelmed native ecosystem. Controlling invasive plants and propagating native ones can ease the pressure and can be done by just about anyone. Controlling destructive ungulates with extreme prejudice can help, too. But the best defense against the extinction of native Hawaiian flora and fauna lies in our own understanding and appreciation of the problem — and the desire and commitment to act accordingly.