Ancient communities in Patagonia were the subject of a new study that shows how an ancient population of humans effectively adapted to climate change, which can offer useful insights for today's environmental challenges.

The study examined fishing patterns of prehistoric Patagonian hunter-gatherers, located in South America's southern tip. The archaeologists used the remains of fish to reconstruct millennia of history in this region and paint a complete picture of the prehistoric societies there, and how they engaged with their natural environment.

French and Chilean archaeologists examined native tadpole codling bones to discover the area's ancient seasonal fishing habits. Tadpole codling is found on coastlines of rocky continental shelves in the southern part of Patagonia and the Strait of Magellan, the channel which connects the Pacific and Atlantic Oceans.

Fishing artifacts and remains of tadpole codling are abundant in the area, which indicates they were commonly used as food by ancient societies.

University of Magallanes Chile archaeologist and lead study author Jimena Torres said that evaluation of the seasonal fishing patterns would help researchers understand how prehistoric hunter-gatherers lived in the context of their time's ecological changes. Among the ways by which these prehistoric Patagonian communities flourished was through fishing.

The research team found bones of tadpole codling in various shell middens in sites in the Strait. These middens represent the discarded wastes of the food of prehistoric communities.

The study gathered samples for many periods over millennia. The bones are dated at several points from the middle to the late Holocene Epoch, suggesting that the communities of hunter-gatherers who ate the fishes most probably lived from 5,500 to 1,000 BCE. The majority of the bone samples are from the more recent period of the range.

These hunter-gatherers from Tierra del Fuego and Patagonia come from different groups and communities from the middle to the late Holocene. These include the fishing groups Kaweskar and Yaghan, as well as the Selk'nam, who were more reliant on land animals, such as the guanaco.

The team studied the bone's growth rings in order to estimate the organism's lifespan as well as the season during which the fishermen caught it. A fish caught during the summer had a larger measurement than the fish caught during colder seasons, during which growth was slower.

Four sites were analyzed, and the team found varied fishing patterns, which suggested year-round harvesting, and various activities during cold or warm seasons, depending on the area.

These varied patterns confirm how the region's communities have been reliant on tadpole codling. Fishing could have been done in cold periods due to scarcer marine mammals during winter. Other sites showed seasonal occupation, suggesting a nomadic lifestyle on the part of the human communities.

Prehistoric Patagonian peoples adapted to changing climatic conditions over millennia, modifying hunting strategies and dietary habits and adjusting to the cyclic advance and retreat of glaciers, cold periods, and varying productivity of marine resources.

Past studies show how roughly 2,500 years in the past, Patagonian seas have declined, and salinity decreased, probably due to heavy rainfall and more meltwater from the glacial advance. In this climate change, the people's reliance on tadpole codling and other fishes substantially declined; they then shifted to other species, which were still abundant.

Torres said that understanding human societies' relationship with the environment is essential. Prehistoric Patagonians reacted and adjusted to climate changes through millennia, and reconstructing such ecological and cultural history will also help us adapt to today's challenges for our long term survival.