Yes
For the most part blue whales are too large to have any known natural predators. In fact the only known predators to attempt to attack a blue whale is a group of killer whale. While these instances are rare there have been people who have confirmed witnessing such attacks and even a few videos have been recorded showing a group of killer whales attacking a blue whale. As far as other predators are concerned humans still remain the primary threat to blue whales. Most countries have adopted rules that ban whale hunting, however there are also several countries that still endorse this type of activity. While these instances are rare there have been people who have confirmed witnessing such attacks and even a few videos have been recorded showing a group of killer whales attacking a blue whale. The sperm whale (Physeter macrocephalus), or cachalot, is the largest of the toothed whales and the largest toothed predator. It is the only living member of genus Physeter, and one of three extant species in the sperm whale family, along with the pygmy sperm whale and dwarf sperm whale of the genus Kogia.  Blue whales have few predators but are known to fall victim to attacks by sharks and killer whales, and many are injured or die each year from impacts with large ships. Blue whales are currently classified as endangered on the World Conservation Union (IUCN) Red List. When a blue whale exhales, the spray from its blowhole can reach nearly 30 ft (9m) into the air. Size relative to a bus: Blue whales are the largest animals ever known to have lived on Earth. These magnificent marine mammals rule the oceans at up to 100 feet (30 meters) long and upwards of 200 tons (181 metric tons). Their tongues alone can weigh as much as an elephant. Their hearts, as much as an automobile In these attacks a large pod of killer whales are usually spotted working cooperatively in an attempt to try to successfully take down a blue whale by surrounding it from the front, sides and bottom to hopefully prevent it from escaping. While these instances are rare there have been people who have confirmed witnessing such attacks and even a few videos have been recorded showing a group of killer whales attacking a blue whale. Killer whales have no natural predators (they are the top predators of the oceans) and can live to about 50-80 years old. Killer whales have been hunted by humans but not with enthusiasm as it takes 21 killer whales to produce the same amount of oil as 1 sperm whale. Orcinus. Species: orca. Though killer whales, also called orcas, are considered whales by most people, they are actually members of the Delphinidae (dolphin) family. Killer whales are excellent hunters that a wide range of prey, including fish, seals, and big whales such as blue whales. Blue whales are the largest predator to ever inhabit this planet, though it is thought to feed almost exclusively on tiny, shrimp-like creatures called euphausiids or krill. Feeding is usually at depths less than 100 m; harpooned animals have dived as deep as 500 m. Blue whales, Balaenoptera musculus (Linnaeus, 1758), like all rorquals (Family Balaenopteridae, the family that includes the blue whale, Bryde's whale, fin whale, humpback whale, minke whale, and sei whale), are long, slender whales that are much more streamlined than other large whales. Whale Dangers and Predators. Whales have no natural predators in the water so they have been able to live for many years in the water if the conditions are right. However, there are plenty of dangers to whales that you may not be aware of. Some of these dangers are so significant that they have lead to some being classified as endangered species. Others hunt whales to eat for food or for a sport. They are enormous mammals so the thrill of the hunt is one that may people are interested in. With the increase in the number of boats in the waters, whales are in danger of being hit and killed by them.
http://www.whalefacts.org/do-blue-whales-have-predators/ http://www.whalefacts.org/do-blue-whales-have-predators/ https://en.wikipedia.org/wiki/Sperm_whale http://animals.nationalgeographic.com/animals/mammals/blue-whale/ http://www.whalefacts.org/do-blue-whales-have-predators/ http://www.afsc.noaa.gov/nmml/education/cetaceans/killer.php http://marinebio.org/species.asp?id=41 http://www.whale-world.com/whale-predators/
do blue whales have a predator