Research

I use a combination of zooarchaeological, ancient DNA, and isotopic analyses to study the impact of human harvesting and climate change on marine mammal populations throughout the Holocene. 

Historical Ecology of Japanese Sea Lions in Hokkaido

The Japanese sea lion is an extinct pinniped, most closely related to the California sea lion, that inhabited the waters surrounding the Japanese archipelago. Japanese sea lions were hunted by people in Hokkaido dating at least as far back as the Early Jomon period (~7000 – 5500 cal BP). I am sampling approximately 50 Japanese sea lions from 12 archaeological sites around Hokkaido. These sites include the three different coastlines of Hokkaido (Sea of Okhotsk, Sea of Japan, and Pacific Coast) and date from ~5000 BP through the Satsumon period. I will use target capture to sequence the mitogenomes of the samples, then model the estimated effective population size through time and calculate population diversity measures. I will also use bulk carbon and compound-specific stable isotopes of nitrogen in amino acids to gain insight into variation in marine productivity and shifts in trophic position and niche breadth of the sea lions.

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Steller Sea Lions in the Kuril Islands and Russian Far East

To better understand the demographic history of both Steller sea lions and humans inhabiting this region, I am sequencing the mitogenomes of 47 archaeological, historic and modern Steller sea lions from the Kuril Islands, Tjulenij Island, and Bering Island. Estimates of population size from the historic period to the early 2000s are largely based on observations and historical records. I add to the robusticity of this data by using Bayesian demographic models to track past population fluctuations and trace haplotype continuity through time. I will then compare this Steller sea lion population data to human demographic curves of the region which indicate two human population crashes in the middle of the Epi-Jomon period (~2000 BP) and during the Okhotsk period (~1000 BP). These events are hypothesized to have been caused by long-interval climatic and oceanographic oscillations in the Northern Pacific and economic entanglements with the expanding world systems. The sea lion data serves as an environmental proxy for understanding marine environmental conditions throughout this period and provides insight into human harvesting pressure on the species. This data will be useful for developing policies to conserve this threatened population.

Porpoise Hunting at the Par-Tee Site, Seaside, Oregon AD 100-800

Small cetaceans are understudied compared to whales and pinnipeds even though they represent a high -ranking prey choice when available in the environment. This research works to fill an important gap in the literature understanding how humans interacted with small cetacean populations in the past and the role that these animals played in the diet of coastal communities.​Building upon previous faunal analyses at the Par-Tee site, Seaside, Oregon that investigated whaling, my analysis of dolphin and porpoise remains suggested that people were hunting small cetaceans between AD 100–800 on the Oregon coast, especially harbor porpoise, which was found significantly more than any other cetacean species at the site.

​Here is a PDF of my paper on the Par-Tee small cetaceans:
​loiselledolphinporpoise2020.pdf