In addition, several factors threaten their populations. Sperm whales were a major objective of the commercial whaling industry from to Whaling greatly reduced this population. Although whaling is no longer a major threat, its population is still recovering. The females only have one calf every 3 or 4 years, so, with a low number of them, it becomes difficult to increase the numbers.
Your gestation period is 16 months. They are very protective of their offspring and work together to ensure that they are well cared for. One or two females submerge to bring food to the younger ones, while the others take care of all of them. The young can not dive deeply due to their need to surface frequently to take air. It is estimated that the historical population all over the world totaled 1. Currently, there is no accurate accounting of the total number of sperm whales worldwide.
The best estimate of the world sperm whale population is between , and , individuals. Ship traffic around the world is increasing. That increases the risk of collisions.
Sperm whales spend long periods of time on the surface between deep dives. As a result, it makes them more vulnerable to collisions with ships. Many different types of fishing gear, including trap lines, pots, and gillnets. These mammals can swim long distances by dragging the attached equipment. That can result in fatigue, compromised eating ability or serious injuries that can lead to death.
Underwater noise pollution can interrupt the normal behavior of sperm whales, which depend on sound to communicate. Debris in the deep-scatter layer where sperm whales feed can be confused with prey and incidentally ingested, which could result in injury or death.
Blue whales are among the longest living animals on Earth. Your average life is estimated at around 80 to 90 years. The gestation period is approximately 10 to 12 months. The average interval of delivery is probably 2 to 3 years. It was estimated that the total world population was between 5, and 12, specimens in It continued with that status until At least 1, blue whales died before the s in the waters of eastern Canada. In the North Pacific, whaling of this species was prohibited in In the Antarctic region, the most optimistic estimates show a significant annual increase of 7.
It appears as an endangered species in the IUCN Red List of endangered species and has been so since the creation of the list. In the case of the Antarctic subspecies, the larger one, its situation is even worse. It is rated as critically endangered. The highest known concentration of the species, with about individuals. This is the Northeast Pacific population of the northern blue whale. It is estimated that the total population of the North Atlantic is between and individuals.
In the Southern Hemisphere there seem to be two distinct subspecies, the Antarctic blue whale and the little-studied pygmy blue whale. This is found in the waters of the Indian Ocean. Estimates of a work done in resulted in pygmy whales only in a small area south of Madagascar. If this is true, the global populations would be higher than those given by the initial forecasts.
The average life of a gray whale is 30 to 60 years. Gray female whales usually give birth every two or three years, and their pregnancies last twelve months. According to an investigation in that population is individuals. Once closed, blue whales then push the trapped water out of their mouth with their tongue and use their baleen plates to keep the krill trapped inside.
Blue whales are found in all oceans except the Arctic. They generally migrate seasonally between summer feeding grounds and winter breeding grounds, but some evidence suggests that individuals in certain areas might not migrate at all. Information about distribution and movement varies with location, and migratory routes are not well known.
In general, distribution is driven largely by food availability—they occur in waters where krill are concentrated. Blue whales have been sighted in the waters off eastern Canada and in the shelf waters of the eastern United States. They likely feed during summer off the U. Blue whales with young calves are regularly observed in the Gulf of California Sea of Cortez from December through March.
It is believed that this area is an important calving and nursing area for the species. In the northern Indian Ocean, there is a "resident" population.
Blue whale sightings, strandings, and acoustic detections have been reported from the Gulf of Aden, Arabian Sea, and across the Bay of Bengal.
The migratory movements of these whales are largely unknown but may be driven by oceanographic changes associated with monsoons. In the Southern Hemisphere, Antarctic blue whales occur mainly in relatively high latitude waters south of the "Antarctic Convergence" and close to the ice edge in summer. They generally migrate to middle and low latitudes in winter, although not all whales migrate each year. Pygmy blue whales Balaenoptera musculus brevicauda —a subspecies—are typically distributed north of the Antarctic Convergence and are most abundant in waters off Australia, Madagascar, and New Zealand.
An unnamed subspecies of blue whale is found in the southeastern Pacific Ocean, particularly in the Chiloense Ecoregion, and migrates to lower latitude areas, including the Galapagos Islands and the eastern tropical Pacific. Scientists can estimate the age of whales by counting the layers of wax-like earplugs collected from deceased animals. Scientists know little about the life history of the blue whale. The best available science suggests the gestation period is approximately 10 to 12 months.
Weaning probably occurs at around 6 to 7 months on, or en route to, summer feeding areas. The age of sexual maturity is thought to be 5 to 15 years. Most reproductive activity, including births and mating, takes place during the winter. The average calving interval is probably 2 to 3 years. Vessel strikes can injure or kill blue whales. Vessel strikes have killed blue whales throughout their range, but the risk is much higher in some coastal areas with heavy vessel traffic, like ports and in shipping lanes, and from larger vessels and vessels traveling at high speeds.
Blue whales can become entangled in fishing gear, either swimming off with the gear attached or becoming anchored. Blue whales can become entangled in many different gear types, including traps, pots, and nets. Once entangled, whales may drag the attached gear for long distances, ultimately resulting in fatigue, compromised feeding ability, or severe injury, which may lead to reduced reproductive success and death. Additional possible threats to blue whales that are less understood include ocean noise , habitat degradation, pollution, vessel disturbance, and climate change.
Our work strives to protect blue whales by:. Our research projects have helped us better understand blue whales and the challenges they face. Our work includes:. Be responsible when viewing marine life in the wild. Observe all small whales from a safe distance of at least yards by sea or land. In Washington State inland waters, it is illegal to approach a killer whale within yards. Please visit Be Whale Wise for more specific instructions.
Learn more about our marine life viewing guidelines. Report a sick, injured, entangled, stranded, or dead animal to make sure professional responders and scientists know about it and can take appropriate action. Numerous organizations around the country are trained and ready to respond. Never approach or try to save an injured or entangled animal yourself—it can be dangerous to both the animal and you. Learn who you should contact when you encounter a stranded or injured marine animal.
Vessel collisions are a major cause of injury and death for whales. Some species, such as blue whales have not yet recovered from the impact of commercial whaling.
They all face a myriad of interacting human-induced threats — ocean noise, chemical and plastic pollution, collisions with ships, entanglement in fishing nets, poor fisheries management and climate change.
The humpback recovery in Antarctic waters is also an example of what can happen when governments come together to protect our global oceans. We have the tools and the science. All we are missing is the political will to create the spaces to allow wildlife to recover. We know the ocean can be restored.
A recent review in the journal Nature suggests that if the oceans are protected, marine life can rebound within our lifetime.
Whales are one example, others include turtles, sea otters, seals and, critically for humans, fisheries. The science is clear: this can happen and it will work.
Who knows whether all those old historical tales of humpbacks in every coastal bay are true, but I am excited to find out. Blue whales are still an endangered species and there are thought to be no more than 25, living in the world today. Blue whales: Heartbeat reduces to 2 beats per minute when feeding.
How blue whales became so big. Antarctic blue whales tracked by their sounds. These comments are now closed. What is Remembrance Day?
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