By Alex Kirby BBC News Online environment correspondent in Atyrau, Kazakhstan

In the autumn rain, the featureless steppe that stretches to the Caspian shore turns to near-impenetrable glutinous brown mud.

We slipped and slid for kilometres across it to visit Oleg, a fisherman who lives near the river Ural.

Some of the people responsible for protecting the sturgeon are doing pretty well out of them

Kazakh environment campaigner

He might well know something about the poachers, they told us in Atyrau. But whatever he did know, he certainly was not inclined to share it with us.

Oleg (not his real name) and his family were hospitality itself. Breakfast was tea from a samovar, bread, cheese, bream sausage, and a half-bottle of vodka among the four of us.

He vividly described his hunting expeditions along the reed-fringed Caspian shores, killing the wild boar that make their homes there.

"I shoot wolves, too", he said. "In fact, I shot one the day before yesterday. Would you like to see the skin? I get a bounty for every one I kill."

Mum's the word

Tentatively, we broached the subject of "illegal fishing", as poaching is always called here.

"I can't tell you anything about that," Oleg said, constantly twisting the ring on one of his huge fingers. "I really don't know anything about it."

Was it a dangerous subject to discuss, we asked him. "No. It's not dangerous to talk about it. But... " And his voice trailed off.

Every wolf skin pays a bounty

Atyrau is an oil town, in the heart of the old Soviet Union's Wild East. The Ural is traditionally reckoned the border between Europe and Asia, and the city's cracked and potholed streets jostle with Kazakhs, west Europeans and Americans, all intent on securing a slice of the action.

Oil is 98% of the local economy. The remaining 2% comes from caviar, or has done: the plummeting numbers of wild sturgeon suggest the trade's days are strictly numbered.

The trade is monitored and controlled, of course, but the way it happens does not always inspire confidence.

We had an appointment to meet the chief fisheries inspector in his brand-new office building in an Atyrau suburb.

Muck and money

When we arrived, there was no sign of him. Come back this afternoon, they told us - he'll probably be here by then.

Shrinking Caspian leaves ships stuck

Back we dutifully went a few hours later, to find he still hadn't shown up. His deputy was in, but sent a message to say he didn't want to speak to us.

I told an environmental campaigner, "Vassili", about our wasted journeys. "What did you expect?," he asked. "Some of the people responsible for protecting the sturgeon are doing pretty well out of them."

It isn't just the poachers that are the problem, of course. The oil industry imposes its own strains on anything that lives in the Caspian, an unpredictable body of water where a previously rising sea level has now given way to a steady fall, stranding ships and leaving shoreside settlements several kilometres inland.

Atyrau is a strange place, set 30 metres below sea level in a shallow depression in the steppe.

Its muddy streets brim with new buildings - brilliant glass and chrome towers for the oil companies, a gold-domed Orthodox cathedral, an elegant footbridge arcing over the Ural to link the continents.

There is plenty of money pouring into Atyrau. And, for the time being, there is a lot pouring out as well, into some strictly anonymous pockets.