Last week a high-seas mystery dramatized how the age-old tradition invites abuse. Over Easter weekend, officials in Benin reported that a Nigerian ferry had gone missing in the Gulf of Guinea with a cargo of more than 200 “child slaves” from Togo and Benin destined to work as maids or street vendors in oil-rich Gabon. But when the ship turned up again in Benin a few days later, none of the children aboard seemed to be there against their will, embarrassing human-rights groups that have launched a drive to fight the worst forms of child labor–which the United Nations says amount to slavery for about 200,000 West African children. But the mystery grew over the weekend; only one child onboard was picked up by relatives and 30 others were still under the care of relief agencies, arousing suspicions they actually were child slaves. Benin has asked UNICEF to take part in a criminal investigation into the ship, MV Etireno, and international warrants have been issued for the crew on suspicions of smuggling children.

Publicity has begun to disrupt the child trade down the West African coast to Gabon. Warned by their governments of the danger that their children may be forced to live in poor conditions and work for no pay, parents in Benin and Togo are seeking news of their expatriated offspring. In the past three years hundreds of the estimated 5,000 foreign children in Gabon have been sent home. And authorities are cutting off the trade at the source. Last year Togo blocked the transfer of 337 children, some as young as 6, and charged 30 adults with trafficking. “We have to do everything to eradicate this trade,” says Baba Apoudjac, a high-school philosophy teacher in Libreville who runs a transit center for Togolese children who want to go home. Apoudjac said hundreds of children have died at sea during the trip to Gabon by road and ship, which can take nearly a year. Others have been raped and contracted HIV, he said.

More recently, antislavery activists have taken aim at the chocolate industry. Investigations have demonstrated rampant abuse of child labor on the plantations of Cote d’Ivoire, the world’s largest cocoa producer. The victims mainly are from Mali, recruited at truck stops or markets and held captive while struggling to pay off inflated debts to plantation owners. Most are hired on the false promise of being given soft office jobs in the capital, Abidjan. Some are held for years without pay. Many have reported being brutally beaten after escape attempts, according to Malian officials. The Ivoirian government hasn’t done much to crack down, but the industry seems increasingly worried by exposes highlighting the problem. Last week the British chocolate manufacturer Cadbury called for an international effort to stamp out child slavery on plantations. However, the firm said most of its own cocoa comes from Ghana, which hasn’t been implicated in the child-labor abuse.

Improving labor standards won’t be easy in countries like Cote d’Ivoire. The real evil is the poverty that makes ordinary people desperate for work, parents willing to part with preteen children and officials pliable. Sounding the alarm about modern-day slavery is a useful stopgap.