The Primary objective of the study was to analyze subsistence fishing harvests in the Yukon River drainage and see how they may correlate with temperature change from 1992 onwards. We hypothesize that warmer temperatures in Alaska are negatively impacting subsistence harvests by reducing salmon populations.

Harvest data for personal use subsistence fishing in the Alaskan portion of the Yukon River drainage in multiple reliant communities was analyzed using R and QGIS software. The climate variable of mean annual temperature (MAT) was analyzed using meteorological station data covering the period 1992 to 2019. A MAT increase of 2 degrees Celsius has been observed since 1992.

The amount of salmon harvested over the years between 1992 and 2022 of Chinook, Coho, Fall Chum, and Summer Chum salmon species showed visible declines during preliminary data exploration, and a slight increasing harvest for Pink Salmon. A Mann-Kendall test was executed and showed significant decreasing harvest for Chinook, Coho, Fall Chum, and Summer Chum. Pink salmon harvest show a weak and non-significant increasing trend. The increased harvest numbers for Pink Salmon may be due to other factors such as fishing restrictions placed on other salmon species.

Mean harvest levels were then compared to MAT between the years 1992 and 2019. A Pearson Correlation calculation was done and P-values were calculated. The results showed Coho and Summer Chum salmon harvests had significant negative correlations with MAT (P-value <0.05). Fall Chum also shows a fairly significant negative correlation (P-value = 0.05). Chinook salmon harvest with MAT are not statistically significant at the 0.05 level. Pink salmon harvest shows a non-significant positive correlation with MAT. It's essential to interpret these correlations cautiously and consider other environmental and human social factors that may influence salmon abundance.

Overall, the data suggests that there are decreasing subsistence harvest levels for most Salmon species along the Yukon River in Alaska. Whether due to climate change or other factors, subsistence harvest numbers are decreasing while number of households with fishing permits is generally increasing. This is a concern, especially for local Indigenous communities who not only rely on Salmon as a food staple, but also have deep cultural ties to Salmon (ANWA, n.d.; NOAA Fisheries, 2019; Rosen, 2023).