A story of whales and krill:
The last two weeks numerous humpback whales have been sighted near Palmer Station. On day 46 I mentioned that about 2 million of these majestic creatures had been killed. Humans can have such a dramatic impact on marine life. However, with the ban on whale hunting, it is obvious (at least in this area) that there is some rebound of the population - but not yet to the same extent as before the massive killing period. Below is a photo by Marissa from January 22nd that she took near Palmer Station (Palmer Station is in the background).
Why would there be a lot of whales here? It seems that their main food source: the Antarctic krill (Euphasia superba) is abundant this season. Antarctic krill look like small versions of shrimp with beady eyes - but they are not shrimp; in fact they are in a different order. The zooplankton group (Leigh West, Jack Conroy and Dr. Debbie Steinberg) is studying where krill are likely to be abundant and why. They work with the whale and penguin researchers also so that a more complete picture emerges regarding the Antarctic foodweb. Krill are near the base of the foodweb in Antarctica. This means that most other animals eat them and thus Antarctic marine life really is dependent on the krill, from penguins to seals to whales.
Researchers measure the lengths of krill and also perform bioacoustic surveys (more about that in a later blog). Meauring the lengths (see photo below) gives an indication of how old they are and thus whether the whales and other animals are feeding on older or younger krill.
The estimated biomass of krill in the Southern Ocean is about 500 million tonnes! They congegrate in enormous swarms - lucky for the animals that eat them! Their combined biomass is highest of any multicellular animal on this planet.
Krill are actually pretty cute….. And now we know they are a very important food source for many other marine species, such as whales. They are in essence the fuel of marine life.
