Article: During the last interglacial period, the Red Sea coast of Eritrea was occupied by early anatomically modern humans. It is believed that the area was on the route out of Africa that some scholars suggest was used by early humans to colonize the rest of the Old World. In 1999, the Eritrean Research Project Team composed of Eritrean, Canadian, American, Dutch and French scientists discovered a Paleolithic site with stone and obsidian tools dated to over 125,000 years old near the Bay of Zula south of Massawa, along the Red Sea littoral. The tools are believed to have been used by early humans to harvest marine resources like clams and oysters.

Question: What were the tools believed to have been used for by early humans?
to harvest marine resources like clams and oysters