In the Antarctic, blue whales (Balaenoptera musculus) feed primarily on Antarctic krill (Euphausia superba), which feed primarily on under-ice algae. The retreat of the Antarctic ice shelf may pose potentially serious problems for blue whale populations by causing shifts in the abundance and distribution of sea ice and, hence, under-ice algae and Antarctic krill. Hence, the objective of this study is to evaluate the potential effects of Antarctic ice-shelf retreat on blue whale populations. We collected a comprehensive literature review to obtain data on the Antarctic ice-shelf retreat, abundance and distribution of Antarctic krill, and vital rates and population dynamics of blue whales. We then developed a simulation model representing the interactions among sea ice, Antarctic krill, under-ice algae, and blue whales, and used the model to explore the potential effects of Antarctic ice-shelf retreat on blue whale populations under various assumptions regarding the rate of retreat of the Antarctic ice shelf.
Results/Conclusions
When the ice decreases in an exponential manner, the ice effects would be 1.19×exp(-0.204×T) and the krill biomass declines as a lognormal curve which makes the whale population extinct in 16 years. When the ice decrease in a linear manner, the ice effect would be -0.0391×T+1.0391 and the krill biomass declines slower which makes the whale population extinct in 22 years. However, if we could keep the current sea ice level, the whale population could sustain itself and almost double the current population in 24 years.