Giant South American River Turtles Hatch in Mass

When Pokey and I read stories like this one, where 15,000 of 210,000 hatchlings were marked and released in Brazil, several questions come to mind.  One, how do they mark these turtles "so they [can] be easily identified in future surveys" without hurting them?  Two, is the 'mark and recapture' process more traumatic when experienced in your first day(s) of life?  Three, in a country that doesn't regulate the consumption of turtle meat or eggs, should we be focused on studying the other threats to the species or lobbying to institute restrictions on the most obvious source of harm?