The gigantic marine mammal, the blue whale, has long been under scrutiny for its size and eating habits. The humongous creature can grow up to 33 meters long and can weigh a staggering 181 metric tons. These sea mammals and some of their relative species had long been studied for their eating habits. However, until recently, the scientists did not have a true estimate of their appetite. A team of scientists led by Mathew Savoca of Stanford University carried out a study on how much the whales eat.
The team studied 321 whales belonging to varied species of blue whales and baleen whales including humpback, fin, bowhead, and arctic whales. All these whales were inhabitants of the Pacific, Atlantic, and Southern oceans. The scientists found out that the whales consume more than thrice the amount they were estimated to eat till then. On average, these whales eat 14.5 metric tons of krill in a day. Krill is a crustacean that has the appearance of a micro shrimp.
Nick Pyenson, a co-author of the study remarked that ‘The amount of food blue whales eat in a day is about the weight of a fully-loaded school bus’. Savoca believes that a blue whale measures and weighs more than the biggest dinosaurs and can grow to the size of a Boeing 737 airplane.
The team of scientists carried out the study by using special tagging devices which they attached to the mammals’ backs. Other equipment included cameras, microphones, GPS locator devices, and instruments that followed movements. The team used drone cameras to estimate the size of whales’ mouths and the amount of food they can engulf in one go.
Not all species of the studied whales consumed krill only. The largest whale species primarily ate krill while some smaller species such as humpback whales eat krill or fish. The majority of baleen whales do not feed all year. They eat for around 100 days of the year, usually during the mating season in the summer. The remainder of the year, they eat quite little. Based on daily consumption of 14.5 metric tons, blue whales consume roughly 1450 metric tons of food every year.