Evaluating Potential Effects of Antarctic Ice-Shelf Retreat on Blue Whale (Balaenoptera musculus) Populations: A Simulation Model of Interactions Among Sea Ice, Antarctic Krill (Euphausia superba), and Blue Whales

Abstract

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. Our results suggested that a decrease in ice-shelf extent would cause a decrease in blue whale populations due to a decrease in abundance of Antarctic krill.