The first study to methodically calculate how much food blue whales and some of their close relatives eat has yielded a simple answer: a whole lot.
The blue whale, the largest animal in Earth’s history, eats about 16 tonnes of krill daily in the North Pacific, gobbling up these tiny shrimp-like crustaceans with a filter-feeding system in their mouths using baleen plates made of keratin, the substance found in people’s fingernails, scientists said on Wednesday.
“That is roughly the weight of one fully loaded school bus,” said study coauthor Nick Pyenson, curator of fossil marine mammals at the Smithsonian Institution’s National Museum of Natural History in Washington.
Photo: AFP / Stanford University
The researchers calculated daily food intake for seven baleen whale species, tracking 321 individual whales in the Atlantic, Pacific and Southern Oceans from 2010 to 2019. These gigantic marine mammals were found to eat up to three times more food than previous estimates that were based on stomach contents of hunted whales or extrapolations from smaller marine mammals.
The other species studied — humpback, fin, bowhead, right, Antarctic minke and Bryde’s whales — also devoured impressive amounts. North Pacific Humpback whales can eat 9 tonnes of krill daily, while fin whales consume 8 tonnes.
“It is an unimaginable amount of food, but large whales are themselves unimaginable. A blue whale is the size and weight of a Boeing 737,” said Stanford University marine biologist Matthew Savoca, who is lead author of the study published in the journal Nature.
Blue whales, larger than even the biggest dinosaurs, can reach 33m long and 200 tonnes.
The researchers determined how often each whale engaged in feeding behavior using electronic tag devices suction-cupped to the animal’s back, with a camera, microphone, GPS locator and an instrument that tracks movement. Drones were used to estimate the size of a whale’s mouth area and how much prey it could engulf. An acoustic method measured nearby prey biomass.
Baleen whales eat zooplankton: small prey including krill, fish or crustaceans called copepods. The largest species prefer krill. Smaller species such as humpback, Bryde’s or minke whales can eat schooling fish or krill.
Most baleen whales do not eat year-round, having a feast-or-famine annual cycle. They eat about 100 days annually, typically during a summer breeding season, while eating little the rest of the year. Based on eating 16 tonnes in a day, the blue whale would consume perhaps 1,600 tonnes annually.
Food intake varied based on species, location and prey type. Among three humpback populations studied, North Pacific krill specialists consumed 9 tonnes daily, North Pacific fish eaters 3.5 tonnes and Southern Ocean krill specialists 3 tonnes daily.
Among the other species, Arctic bowhead whales consumed 6 tonnes daily of copepods, North Atlantic right whales 5 tonnes of copepods, South Atlantic Bryde’s 1 tonne of fish and Southern Ocean minke 0.69 tonnes of krill.
As the whales eat more than previously known, they also produce more excrement, an important ocean nutrient source. By catching prey and defecating, they help keep nutrients suspended near the sea surface to generate blooms of carbon-absorbing microscopic organisms called phytoplankton that form the base of marine food webs.
Pyenson said the study’s calculations suggest that before baleen whale numbers were dramatically reduced by 20th century industrial whaling, they had consumed more food than all of the world’s current krill biomass and global fisheries combined.
“The implication of these numbers is that whales supported far more productive ocean ecosystems before whaling, and that promoting whale recovery in the 21st century may restore ecosystem functions lost in the past hundred years,” Pyenson added.
‘SHARP COMPETITION’: Australia is to partner with US-based Lockheed Martin to make guided multiple launch rocket systems, an Australian defense official said Australia is to ramp up missile manufacturing under a plan unveiled yesterday by a top defense official, who said bolstering weapons stockpiles would help keep would-be foes at bay. Australian Minister for Defence Industry Pat Conroy said the nation would establish a homegrown industry to produce long-range guided missiles and other much-needed munitions. “Why do we need more missiles? Strategic competition between the United States and China is a primary feature of Australia’s security environment,” Conroy said in a speech. “That competition is at its sharpest in our region, the Indo-Pacific.” Australia is to partner with US-based weapons giant Lockheed Martin to make
BEYOND WASHINGTON: Although historically the US has been the partner of choice for military exercises, Jakarta has been trying to diversify its partners, an analyst said Indonesia’s first joint military drills with Russia this week signal that new Indonesian President Prabowo Subianto would seek a bigger role for Jakarta on the world stage as part of a significant foreign policy shift, analysts said. Indonesia has long maintained a neutral foreign policy and refuses to take sides in the Russia-Ukraine conflict or US-China rivalry, but Prabowo has called for stronger ties with Moscow despite Western pressure on Jakarta. “It is part of a broader agenda to elevate ties with whomever it may be, regardless of their geopolitical bloc, as long as there is a benefit for Indonesia,” said Pieter
TIGHT CAMPAIGN: Although Harris got a boost from an Iowa poll, neither candidate had a margin greater than three points in any of the US’ seven battleground states US Vice President Kamala Harris made a surprise appearance on Saturday Night Live (SNL) in the final days before the election, as she and former US president and Republican presidential nominees make a frantic last push to win over voters in a historically close campaign. The first lines Harris spoke as she sat across from Maya Rudolph, their outfits identical, was drowned out by cheers from the audience. “It is nice to see you Kamala,” Harris told Rudolph with a broad grin she kept throughout the sketch. “And I’m just here to remind you, you got this.” In sync, the two said supporters
Pets are not forgotten during Mexico’s Day of the Dead celebrations, when even Fido and Tiger get a place at the altars Mexican families set up to honor their deceased loved ones, complete with flowers, candles and photographs. Although the human dead usually get their favorite food or drink placed on altars, the nature of pet food can make things a little different. The holiday has roots in Mexican pre-Hispanic customs, as does the reverence for animals. The small, hairless dogs that Mexicans kept before the Spanish conquest were believed to help guide their owners to the afterlife, and were sometimes given