A new study has revealed that humans in Southeast Asia were not just surviving 40,000 years ago—they were venturing into deep seas to hunt large, fast-moving fish such as tuna and sharks.
At the time, organic materials like boats and ropes were perishable, leaving little direct evidence. However, researchers have reconstructed the picture of ancient maritime skills through surviving tools, fish bones, and microscopic wear marks on stone implements.
Researchers Rizgar Fuentes and his team from De La Salle University in Manila, Philippines, have analyzed wear patterns on stone tools to infer the use of plant fibers in boat construction. These fibers were used to create strong ropes, nets, and joints for boats, highlighting sophisticated marine technology. This analytical method, known as traceology, examines microscopic wear on tools to understand their use.
Fuentes emphasized the importance of these findings, saying, “Direct or indirect evidence of boat-building materials is crucial to understanding mobility among islands.”
Why Ancient Maritime Skills Matter
Crossing narrow waterways between islands required more than just floating; it demanded planning, timing, and precise control. Consistently reaching specific locations indicates organized effort, teamwork, and technical expertise rather than mere chance.
Sue O’Connor, a researcher at the Australian National University, noted that deep-water fish bones, including tuna and sharks, were found in Jerimalai Cave in Timor-Leste dating back 42,000 years. The same study uncovered the oldest shell-based fish hooks, dating between 23,000 and 16,000 years ago. In total, 38,687 fish bones from 2,843 individual fish were analyzed.
A Network of Maritime Activity
Findings from Timor-Leste and the Mindoro Island caves in the Philippines suggest that seafaring and fishing persisted for at least 30,000 years. By examining which species were caught and when, researchers have reconstructed patterns of deep-sea fishing, demonstrating a planned and systematic lifestyle. Knowledge was learned, taught, and passed down through generations.
How Boats Were Made
Boats were constructed using wooden planks, sewn connections, and strong plant fibers for binding. Stone tool wear indicates that fibers were cut and twisted into ropes or nets. Similar twisted plant fibers found in France’s Abri du Maras, dating 40,000 years ago, suggest that rope-making knowledge developed independently in different regions. With ropes, humans could weave nets, build boats, and engage in deep-sea fishing, unlocking organized maritime activity.
Obsidian Trade Indicates Communication
Obsidian exchanges between islands in Southeast Indonesia and Timor-Leste indicate a continuous network of communication. These were not one-time events but regular interactions, part of maritime knowledge and seasonal routines.
Rewriting History
These discoveries suggest that history is not made solely by monumental finds in famous regions. Technological expertise included collective labor, planning, and maintenance. From boat-building to fiber cutting, rope-making, net-weaving, and fishing, every step was organized. Rapid repairs were essential in saltwater and sunlight to maintain boats.
The study collectively shows that humans in Southeast Asia were skilled and organized seafarers long before previously believed. Future analyses of plant-fiber ropes, stone tool wear, and coastal excavations could uncover even more details about ancient maritime practices.
The research has been published in the Journal of Archaeological Science.
