LIKE A FISHERMAN'S catch of menhaden adrift, legalized gambling can attract sharks unless officials move quickly to stop it. That is why most states that operate lotteries or other games of chance run these operations directly instead of farming them out to private operators. They also have tight rules to bar even anyone with friends who have ties to illegal gambling or the underworld from working for the official operations. But in the District of Columbia's lottery, the standards are not so stringent, which is good reason for reassessing the city's setup.

From the outset, there have been questions about the contract bidding and awarding process--some raised by Mayor Barry himself, others by members of the D.C. Council and still more by the firms competing for the jobs. Nothing illegal has been discovered, but there have been some troubling disclosures.

The latest, as reported Sunday in The Post by Tom Sherwood and Joe Pichirallo, have to do with people managing the city's instant lottery games and those involved in a contract to start a new daily numbers game here. One of the overseers of the instant lottery games was convicted in 1972 of operating an illegal lottery, a felony, and of maintaining a gambling establishment and possessing illegal numbers slips, both misdemeanors. Another man was arrested in 1973 on a charge of operating an illegal lottery--a charge that was dismissed.

None of this may affect the city's operations in any serious way--but is there more to be learned about what kind of system this city should have?

As we noted the other day, the D.C. Council, the D.C. Office of Inspector General and the independent D.C. Auditor are looking into these questions, and their findings are critical not just to the future of legalized gambling but also to the political franchise and financial integrity of the city itself. Each new report or troubling allegation should be thoroughly investigated.