Three little keys, one of them under water, that are claimed by Nicaragua have added to its troubles with the United States since Congress ratified a treaty last month ceding to Colombia a U.S. claim to the pinpoints off this country's east coast.

For more than 110 years the United States used bird droppings as the basis for a claim to Quitasueno, Serrana and Roncador. When it exchanged that claim for Colombia's guarantee of U.S. fishing rights in the area, Nicaraguans were furious.

There were rumblings in Managua about breaking relations. The treaty was seen as yet another blow by the United States against the leftist government here and possibly a reward to Colombia, which has recently blasted Cuba diplomatically and warmed considerably to the United States, even to the point of committing its troops to the Sinai peacekeeping force.

At low tide, more than three feet of water cover Quitasueno. Its name, which in Spanish means "loses sleep," comes from the concern of sailors who might unknowingly crash into it.

"What is at stake here really is 84,000 square kilometers about 32,000 square miles of our continental shelf," said Nicaraguan Foreign Minister Miguel D'Escoto. If Quitasueno and the rest belonged to Nicaragua then its territorial waters -- replete with rich fishing grounds and perhaps mineral wealth -- would stretch almost twice as far as they would if Colombia's claim stands.

But there is also an emotional side to the issue. Nicaragua signed an accord with Colombia in 1928 recognizing Colombian sovereignty over the more substantial islands of San Andres and Providencia, and arguably over the keys. But in 1928 Nicaragua was occupied by the United States, which pushed Nicaragua's government to sign. When the "anti-imperialist" Sandinistas ousted dictator Anastasio Somoza and his National Guard -- another U.S. creation -- in 1979, one of their first acts was to declare the 1928 treaty null and void.

Washington's claim on the three pinpoints was based on the Guano Act of 1856 in which Congress said basically that the United States could claim little islands covered with bird dung valuable as fertilizer.