A Drowned Landscape
At the end of the last ice age, the coastline of Haida Gwaii looked very different. About 14,000 years ago, sea levels were approximately 150 meters lower than they are today. This exposed a large coastal plain that connected the islands to the mainland, an area with ancient riverbeds and grasslands that existed before the dense forests grew. As the massive Cordilleran and Laurentide ice sheets melted, the global sea level rose. Simultaneously, the land around Haida Gwaii, which had been pushed upward by the weight of nearby glaciers, began to subside. This combination of rising water and sinking land submerged huge areas of the coast where people lived. The Haida Nation's oral histories record this period, with stories of a great flood that forced people to move and dispersed tribes to new lands.
Archaeological and geological evidence supports these accounts. Over a period of about 3,000 years, the sea level rose around 165 meters, a change so rapid that a person could have witnessed the water rising by as much as three meters in their lifetime. This inundated the most resource-filled areas for coastal peoples, hiding years of human history beneath the waves of Hecate Strait.
Discoveries Beneath the Waves
For decades, archaeologists suspected that the earliest evidence of human occupation on the Northwest Coast was underwater. A multi-institutional project involving the University of Victoria, Parks Canada, and the Haida Nation set out to find it. Using an autonomous underwater vehicle (AUV) equipped with high-resolution sonar, researchers mapped the seafloor in Juan Perez Sound. The AUV, a robotic submarine, allowed them to survey depths impossible for divers to reach.
The sonar images revealed what appears to be a human-made structure at a depth of 122 meters (about 400 feet). The feature is a line of large stones arranged at a right angle to an ancient, submerged riverbed. Archaeologists, including Quentin Mackie from the University of Victoria, believe this is a fishing weir, a structure used to channel and trap migrating salmon. Based on the sea level at that time, the weir could be 13,800 years old, which would make it one of the earliest signs of human activity ever found in Canada. The oldest confirmed artifact previously found in the Gwaii Haanas National Park Reserve was dated to 12,700 years old. The underwater search also identified other formations on the seabed that may have been campsites.