Effects of penguin colonies on water quality and algal biomass near tourist landing sites on the Antarctic Peninsula

Background/Question/Methods

Penguins returning from the open ocean after feeding deposit marine-based nutrients on Antarctic terrestrial ecosystems, which may subsequently run-off into nearshore waters due to snowmelt. In the Antarctic peninsular area, many penguin colonies are currently being visited by an ever increasing number of tourists and the impact of tourism on penguin colonies is largely unknown. Any resulting changes in algal biomass and composition due to changes in penguin densities may impact the trophic composition of the Antarctic marine ecosystem as a whole. The focus of the study is to examine the relationship between penguin colony densities and the concentration of nutrients and algae in the nearshore of Antarctic peninsular sites commonly visited by tourists.  Water and phytoplankton samples were collected from the nearshore areas of 8 sites in the South Shetland Islands and Antarctic Peninsula areas in December 2007.  The number of nesting pairs of penguins was estimated from prior surveys. Chlorophyll-a biomass and phytoplankton cell counts were used as an indicator to determine algal abundance. 

Results/Conclusions

Water column nutrients, including total phosphorus and ammonia, and algal biomass as estimated by chlorophyll-a, increased significantly with the total number of penguin pairs in colonies (p<0.05). GIS-based maps will be used to examine the spatial distribution of tourist landing sites and water chemistry in the area. These results not only have implications for understanding the impact of changes in penguin densities due to ecotourism in Antarctica, but may also serve to indicate any food web impacts due to changes in penguin distributions due to climate change in the region.