"Those would be Olive Ridley turtles, lepidochelys olivacea. They are the smallest marine turtles, and they have a unique nesting phenomenon called an Arribada, which translates to 'the arrival'. This species mass nests on beaches in Mexico, Costa Rica, and India, where a single mass nesting can see over 100,000 females laying eggs over the course of a few days.
The officer is there to detract egg poachers, but interestingly in some parts of Costa Rica they practice a inclusive conservation strategy where locals are allowed to harvest the eggs in the first two days, and in return they help to clean and protect the nesting sites for the remaining year.
Source: I did my masters dissertation on these turtles".