A 5,000 Year History of the North Pacific Marine Ecosystem

Sustainability, resource management, and the protection of endangered species on the north Pacific and southern Bering Sea suffer from the shifting baselines phenomena in that they are situated without any foundation for measurement except recent trends. Marine ecologists and fisheries biologists have thus no knowledge as to whether spatial and temporal patterns of the last 50 years are products of local marine system dynamics, a result of ecosystem engineering by human harvesters, or global marine cycles spanning decades or millennia. We further have no broad understanding of the effects of climate change and changes in marine productivity on these ecosystems, and how these changes affected the interactions between humans and other species on the marinescape. The archaeological analysis of over 100,000 mammal and fish bones from archaeological sites in the western Gulf of Alaska spanning 5000 years, analyses informed by local traditional knowledge and modern marine ecology, highlight major shifts in the abundance and distributions of keystone species. We find that some species are likely adapted to human harvesting to such an extent that their behavioral ecology can be considered a product of human ecosystem engineering. Conversely, some of the most widely harvested species show no evidence of human impacts at all, yet are very susceptible to minor variations in climate, marine productivity, and other hemispheric level phenomena. We further find that some of the most important commercial species of the last few decades were not present at certain times in the past. Finally, we show that both humans and climate have played key roles in the structure of the greater North Pacific ecosystem, and that a broad understanding of both top down and bottom up processes is critical to the long-term sustainability of the hemisphere’s last great fishery.