Wednesday, August 5, 2009

PS 43-32: Understanding recent changes in Arctic pond ecosystems by re-sampling historic research sites

Gilda Victorino and Vanessa L. Lougheed. University of Texas at El Paso

Background/Question/Methods

The Arctic tundra ponds at the International Biome Project (IBP) site in Barrow, AK were studied extensively in the 1970’s; however, very little research has occurred there since that time. Due to the sensitivity of this region to climate warming, understanding any changes in the ponds’ structure and function over the past 35 years can help identify any potential climate-related impacts. The purpose of this project was to re-sample ponds in a historical research site last sampled in the 1970’s and compare their physical, chemical and biological characteristics to present time  and to newly established and protected research sites at the Barrow Experimental Observatory (BEO).  

Results/Conclusions

Preliminary data indicate that the IBP ponds in 2008 had significantly higher Dissolved Reactive Phosphorus (DRP) concentration and epipelic algal biomass than the same ponds in the early 1970s. On average, BEO sites had significantly lower epipelic algal biomass and exhibited lower biomass accumulation on acrylic rods compared to IBP sites. In summary, these data suggest that the IBP sites may be more productive in 2008 than in the 1970s and that the IBP sites may be more productive than the BEO sites, which are from the village of Barrow. Increased nutrients may be present due to the greater proximity of the IBP sites to an urban setting, or released from warming permafrost. Results from this and further study could help understand the implications of climate change on Arctic tundra pond ecosystems.