Bob Herbst, former director of the U.S. Fish and Wildlife Service and now head of Trout Unlimited, regards wildlife as the barometer by which dangerous environmental trends can be spotted before they get a foothold.

If a stream supports trout, he said recently, it's a solid indication water quality is good. When the trout start dying off, it spells trouble. Trout generally live in the cold headwaters of rivers, upstream from the most pernicious forms of industrial pollution. When even their pristine habitat is under siege, it bodes ill for an entire river system.

As trout are bellwethers for the changing state of rivers, so ducks serve the land, with one big difference. Trout stay put. Ducks travel the continent.

In the last month depressing news has unfolded on the waterfowl front -- ducks in Montana poisoned by Endrin, an agricultural pesticide; ducks in New York poisoned by polychlorinated biphenyls, industrial lubricants; birds and fish poisoned by the pesticide Mirex in Lake Ontario and by DDT in Alabama, 10 years after that chemical was banned.

In the two cases in which public health was thought to be jeopardized -- the Montana Endrin and New York PCBs -- the states issued warnings to hunters not to eat too much duck. In New York, where PCBs averaged twice the federal allowable maximum in 63 wild ducks tested, the state told hunters to trim the fat off birds they bag and not eat more than two a month.

I have a question. Where is the federal government in all this?

The Fish and Wildlife Service was helpful as all get-out in the Montana crisis. It offered its research facilities to test ducks for the presence of Endrin. The Environmental Protection Agency promised to check its regulations on use of Endrin to determine if they were too liberal.

But the crucial decisions on whether it was safe to hunt for and eat wild ducks was left to the states. If anyone is going to raise a stink in the courts over who was to blame for the debacle, it'll evidently have to be someone from the private sector. An EPA source said his agency is interested only in making sure it doesn't happen again.

This is not right. Ducks are not wards of any state or any private organization, no matter how well-intentioned. The ducks that are hatched in Montana and riddled with poison there are the same ducks that will fly to Wyoming and Colorado, New Mexico and Texas and across the border to Mexico. PCB-poisoned New York ducks will migrate through the Atlantic flyway. These birds are a national resource and decisions about them should not be left to the states and private organizations.

Dealing with problems like the New York and Montana poisoning is, as Herbst put it, "what we have a federal government for."

It was almost comical to watch on television the heralded final decision on the safety of hunting and eating ducks in Montana. It was handed down from a humble dais in a public building out in the woods somewhere, with a group of burly local officials joking and laughing with check-shirted hunters who assembled to find out whether to buy shells this year.

It's hard even to imagine all the complicated special interests that had a say in Montana's decision, which was used as a model for decisions in the 17 states throughout the flyway to which the Montana ducks would migrate.

Local hunters, farmers, bird-watchers, antihunters, naturalists and bureaucrats all would want a say.

Herbst thinks decisions like that should be the province of the federal government, whose giant protective agencies (Fish and Wildlife, Environmental Protection, Public Health) are beyond the grasping demands of interest groups.

"You remember the ban on DDT," he said. "Well, it was the federal government that had to step in because we had a problem that went beyond state lines. Here you have the same kind of problem.

"If the decisions are left up to the individual states, they're subject to the clamor of sportsmen who want to keep the hunting seasons."

When the Endrin problem in Montana came to light I expected to see a small army of federal biologists and agriculture specialists on the scene, monitoring testing of individual birds and inspecting farms to determine how it happened. But the army never showed.

Herbst thinks the U.S. should have stepped in and issued federal guidelines to the states in both instances, putting the power and prestige of national authority behind warnings on the dangers of eating poisoned ducks and against poisoning a natural resource.

Instead, there were meek warnings from two states, even though the affected birds will soon be distributed throughout two-thirds of the country and in foreign nations.

As I sat last week in a wilderness in Maryland, watching ducks cascade into a pond during the evening flight, it occurred to me what a treasure it is to see these secretive birds in their natural environment, existing exactly the way they did for hundreds of thousands of years before man invented PCBs and Endrin.

Now someone's tampering with a national treasure, and the keepers of the treasure are leaving its protection up to somebody else.