Whales, dolphins, and porpoises are categorized taxonomically in the order Cetacea. As mammals, cetaceans are warm-blooded, breathe air, give birth to live young, and nurse their offspring. They are also highly intelligent and social animals. There are over 80 extant species of cetaceans, categorized into two suborders: the toothed whales (odontocetes) and baleen whales (mysticetes). Sperm whales, orcas (killer whales), beaked whales, belugas, narwhals, porpoises, and dolphins are odontocetes, of which there are about 70 known species. Baleen whales are comprised of 14 species, including blue, fin, sei, Bryde’s, gray, right, bowhead, humpback, and minke whales.
Odontocetes use their teeth to catch their prey, whereas mysticetes use their baleen plates to filter vast quantities of water, straining out their much smaller prey, such as krill. Despite the smaller size of their prey, most mysticetes are much larger than odontocetes and are referred to as the "great whales." The largest of the toothed whales, the sperm whale (made famous by Herman Melville in Moby Dick), is also considered a great whale.
The hunting and killing of cetaceans by humans is termed "whaling" and is practiced on both odontocetes and mysticetes by several countries. Although whaling historically was for oil (rendered from whale fat or blubber) and spermaceti (from the head cavity of sperm whales used to make candles and cosmetics and as a fine lubricant), cetaceans are mainly hunted and killed today for food in both commercial (for profit) whaling operations and by indigenous peoples hunting for nutritional and cultural subsistence (known as Aboriginal Subsistence Whaling (ASW)). Cetaceans are also killed in a misguided effort to reduce competition for fish and several small cetaceans (small whale, dolphin, and porpoise species) are hunted for use as bait to catch fish. Odontocetes are hunted in some communities for their teeth, which are used as currency. Some small cetaceans (primarily bottlenose dolphins and belugas today but previously orcas, as well) are also captured live for sale to aquariums.
Generally, whaling can be split into two types—whaling on the great whales and the hunting of . While the ICRW includes definitions of some odontocetes and includes references to toothed whales in its schedule (the binding rules and definitions that implement the ICRW), the IWC has concentrated its management on the great whales, setting quotas and other restrictions on hunting. The IWC’s Scientific Committee, however, routinely works on conservation issues relating to all cetaceans.
The Animal Welfare Institute believes all whaling to be inherently cruel. Even the most advanced whaling methods cannot guarantee an instantaneous death or ensure that struck animals are rendered insensible to pain and distress before they die, as is the generally accepted standard for domestic food animals. Modern commercial whaling and many aboriginal whale hunts of great whales use harpoons fired from the bow of a whaling vessel (often a fishing boat). The harpoons are usually fitted with penthrite grenades that are supposed to penetrate about 12 inches into the body before they explode, releasing claw-like protrusions into the flesh. Death is intended to come from the percussive force of the explosion delivered near the brain but, depending on where the harpoon hits the whale’s body, can come from trauma (shock) or blood loss. Given that whales are only visible for a short period when they surface to breathe, the brain area offers only a small, briefly accessible target for a gunner standing on a moving platform on a shifting sea, sometimes under difficult weather conditions.
If the whale does not die instantaneously, a second harpoon grenade or rifle (depending on the size of the whale and the type of hunt) is typically used as a secondary killing method. After harpooning, the animal is hauled to the catcher ship using a line attached to the harpoon, with the grenade’s claws biting into the flesh. For animals who have not been stunned or killed by then, the pain and distress during hauling must be excruciating. A proportion of struck whales are lost (e.g., if the harpoon line breaks due to heavy seas or other causes), only to die of their injuries or suffer pain from infections.
Because of the difficulty of obtaining a clean, accurate strike or because of inadequately powered weapons, some whales can take minutes, sometimes even hours, to die, especially in ASW hunts. The IWC defines “humane killing” as death brought about “without pain, stress or distress perceptible to the animal. That is the ideal. Any humane killing technique aims first to render an animal insensitive to pain as swiftly as is technically possible, which in practice cannot be instantaneous in the scientific sense.” A significant problem though, is determining whether a struck whale is dead, conscious but paralyzed, or unconscious and insensible to pain. The IWC has spent decades trying to agree to criteria for determining the onset of death or irreversible insensibility. The current criteria, which the IWC agrees are inadequate, require the whaler to determine visually from the vessel whether a whale displays relaxation of the lower jaw and no flipper movement, or sinks without active movement. Despite the IWC prioritizing this issue, it has not been possible for the whaling nations and countries that oppose whaling to reach agreement on new criteria.
From a purely physiological standpoint, there are significant differences in the mass, length, and organ placement of whale species targeted by whalers. Unlike farm animals who have been bred for consistency in size and weight, individual whales of the same species might differ in length by 10 to 20 feet.
The IWC’s work to improve whale killing methods depends on the willingness of the whaling nations to share whaling data (on the time to death (TTD) of hunted whales, instantaneous death rate (IDR), and the number of whales struck and lost) and to respond to recommendations from other governments, nongovernmental organizations, and welfare or ballistic experts. Unfortunately, in recent years, Japan and Norway have stopped sharing their data regularly with the IWC. Since it resumed commercial whaling in 2002, Iceland has also declined to provide information on the welfare aspects of its hunts with the IWC. ASW whaling nations have also become more reticent to share data.
Despite this, the IWC has embarked on an ambitious program of work to improve the welfare of whales impacted by non-directed threats such as vessels strikes and entanglement in fishing gear and other marine debris.