Guest essay by Eric Worrall
The University of Western Australia, former home of Professor Lewandowsky, has published a new report which claims that whales are suffering, because their food sources are being depleted by melting Antarctic sea ice.
According to the press release;
“If the ice declines in the area that these forage in, then that will reduce krill and that will reduce how much food they have,” Ms [Janelle] Braithwaite said.
“Whales live this feast and fast lifestyle.
“Over the summer they’re feasting up on krill down in the Southern Ocean but once they leave, they’re pretty much fasting during their migration journey.
“It’s a bit like a car, if there’s not enough petrol at the petrol station, then you’re setting off with three quarters of a tank and you might not be able to make it.
“If these whales run out of petrol before they get back to the Southern Ocean, then there’s no safety net, they will die from exhaustion.”
The abstract of the study:
Krill (Euphausia superba) are fundamentally important in the Southern Ocean ecosystem, forming a critical food web link between primary producers and top predators. Krill abundance fluctuates with oceanographic conditions, most notably variation in winter sea ice, and is susceptible to environmental change. Although links between local krill availability and performance of land breeding, central place foragers are recognised, the effects of krill variability on baleen whales remain largely unclear because concurrent long-term data on whale condition and krill abundance do not exist. Here, we quantify links between whale body condition and krill abundance using a simple model that links krill abundance to sea ice extent. Body condition of humpback whales (Megaptera novaeangliae) caught in west Australian waters between 1947 and 1963 was estimated from oil yields in whaling records. Annual estimates of krill abundance in the Southern Ocean where those whales foraged (70°–130°E) were correlated significantly with contemporary annual winter sea ice extent. We hindcast sea ice extent for the whaling period from reconstructed temperature data and found that whale body condition was significantly correlated with hindcasted winter sea ice extent, supporting the hypothesis that variations in body condition were likely mediated by associated krill fluctuations. As humpback whales migrate and breed on finite energy stores accrued during summer foraging in the Antarctic, changes in sea ice and concomitant changes in krill abundance have long-term implications for their condition and reproductive success.
The question in my mind is, since rising CO2 levels have been correlated with the record busting growth of Antarctic sea ice, for at least the last few decades, shouldn’t we burn as much coal as possible to help the whales?