WELCOME

The only way to survive is if they can find

Jan. 12, 2019 by Devin Jones

The only way to survive is if they can find the right spot, said Peter P. Lomax, a marine biologist at the University of Massachusetts, who led the study from the U.S. Department of Agriculture. He and colleagues have identified a new type of marine mammal known as "neotropical blue" that can live only in the deepest parts of the ocean, where the ocean is warmer and the crustaceans are less prevalent. But it is not clear yet whether that means its survival is up to snuff.

As Lomax and his colleagues reported in April, blue whales in the northeastern United States are the closest of these mammals to humans, and their populations have been declining for a decade or more. The study suggests, thus, that blue whales have the potential to continue their decline, even if they can't find any reliable feeding grounds.

So why do blue whales remain the most frequently hunted species on Earth? The researchers speculate that blue whales, in particular, rely on their memory in order to get their food. Indeed, they are able to use that memory to make the right choices. When we hunt whales, we see whales, who are often highly territorial and will do anything to get what they want in any given moment, such as snagging prey as they move along the coast, but who rely on memory in the same way that whales rely on their brain for a good meal. But when we're hunting blue whales, we see blue whales from different locations, and those are the only areas that blue whales find new food sources, even though they are highly territorial. Blue whales are also more susceptible to predators, which means that blue whales are often more likely to attack individuals that are more vulnerable to predatory attacks.

As an example, the researchers noted that blue whales are known to eat the same number of crustaceans a year, but there is one significant difference between the two: the numbers of crustaceans are lower. As a result, the researchers have hypothesized that when blue whales have more food, they will eat more crustacean crustaceans. But blue whales, the researchers note in their paper, have far fewer predators in the deepest parts of the ocean, so their food is even more limited from its source. This, they say, is why they don't hunt blue whales. To test whether that pattern is true for blue whales, the researchers took the crustaceans from the same location as the blue whales. The researchers then analyzed their data to find out if blue whales eat more