- Many whales have died from ship strikes, pollution and strandings.
- Some whales die from disease, predators and hunting.
- Another cause of whale death is netting and other human-induced causes.
Whales are large, long-lived mammals.
The blue whale is the largest animal that has ever lived on Earth – it’s bigger than a dinosaur. Estimated to live 80 to 90 years!
Bowhead whales are a relatively small species that can live to be over 200 years old.
But eventually, even for these huge and amazing animals, life comes to an end. How did the whale die? Since they live in water, will they drown?
Are there carnivores that eat whales?
Read on to find answers to these questions and learn how whales “continue” to live in the depths of the ocean after they die.
How did the whale die?
The causes of whale deaths can be natural or man-made. So how did the whale die? Human activities, including hunting, pollution and damage from large ships, kill whales.
Other causes of death could be old age, starvation, infection, complications of childbirth or being stranded.
Let’s have a look at the full list:
1. How the whale died: Ship hit
Adult whales often rest near the surface or swim slowly. With few predators, whales are less likely to retreat in fear when they see or hear a large ship on the horizon.
Just as vehicles such as cars can injure or kill pets and wildlife, large ships can also pose a threat to whales. These boats could be many times larger than a whale and move very fast.
Impact may result in concussion, internal injury or bleeding. If the whale survived the collision, the head injury could have prevented it from feeding, or it could have contracted an infection. Sick whales are more likely to strand – another cause of death discussed below.
How often do ship strikes happen? It is estimated that at least 80 whales are hit by boats each year. The scientists also used the trackers to map the whales’ movements relative to the boats.
A blue whale has been swimming around the Pacific Ocean for months, making frequent U-turns to avoid the busy shipping lanes that criss-cross it.
2. How Whales Die: Pollution
Solid and liquid pollution from human activities poses a major threat to all aquatic animals. It turns out that fishing nets are especially dangerous for whales.
Whales, big and small, get entangled. If they cannot swim to the surface, they quickly drown.
Whales also starve to death when free-floating nets are placed over their heads, preventing them from eating. In some cases, the nets can cut into the flesh of the fish or cut off the circulation of the fins, which can lead to infection.
Whales can be affected by liquid pollutants in the water or air pollution. Continued exposure may cause cancerous tumors.
Some stranded whales have also been observed with their bellies filled with plastic waste. This can lead to poisoning or starvation, as enough indigestible material is collected that the whale is not allowed to swallow more food.
Whether it’s a combination of oil spills, marine litter, and industrial pollutants like PCBs, or a combination of pollutants affecting their food supply, marine pollution is a serious threat to whales and other marine mammals.
3. How the Whale Died: Stranding
Strandings happen when whales swim into shallow water and get stuck, when they ride a wave washing up on a beach, or when the tide goes out and the whale becomes stranded on land or in shallow water.
The whale’s own weight (usually supported by water) can squeeze its organs or cause it to suffocate. The thick fat that keeps it comfortably warm in water causes it to overheat on land. Dehydration and drowning at high tide can also lead to death.
Stranded whales survive only a few hours on land. High tides or help from humans or other whales may help them reach deeper water again.
Why do whales beach themselves?
Toothed whales such as orcas swim to the beach in search of prey such as seals or penguins. Disease, injury, netting and parasitic infestation have also been observed in beach accidents.
4. How Whales Die: Predators
Adult whales, especially the larger baleen whales, rarely fear predator attacks. However, if calves move too far from their mother’s protection, they can become targets for sharks, orcas, and even polar bears.
On rare occasions, large pods of orcas have been observed hunting, killing and eating humpbacks, gray whales, and even blue whales. In the case of the blue whales, more than 50 orcas were involved in the chase.
However, the most dangerous predators of whales are humans. We will discuss it in detail below.
5. How Whales Die: Sick
Like humans and other mammals, whales can get sick. Cuts and scrapes can become infected with bacteria or parasites.
If the whale’s immune system can’t fight off the intruder, it dies.
The disease may have affected whale strandings when many beluga whales infected with toxoplasmosis stranded near the mouth of the St. Lawrence River. Whales can also die from dystocia.
6. How Whales Die: Starvation
Many types of whales migrate in search of food, fasting for months between feeding grounds. If a whale is sick or injured and unable to swim to feeding grounds at the right time, it may starve. Climate change is also a problem.
For example, humpback whales feed on the abundance of krill near Antarctica at certain times of the year. The krill cycle could change if global warming intensifies. If the migration patterns of the whales are not adapted, many could die from lack of food.
Other whales feed on schools of fish. Overfishing by humans has reduced the populations of many important fish species.
Changes in ocean waters and less plentiful food for whales can lead to starvation and lead to stranding of these amazing animals. Another reason could be that the net is stuck in their mouth and they cannot eat.
These reasons lead to the death of many whales every year.
7. How Whales Die: Hunting
The mass killing of whales for their “oil” nearly wiped out many species more than a century ago. Crews would spot a whale near the surface and shoot it with a harpoon, a barbed metal arrow attached to a rope.
A whale may tug a boat for days until it dies of exhaustion. As whaling activity has declined, some whale populations have rebounded alarmingly.
Today, whaling is illegal in most parts of the world. The exceptions are Japan, Iceland and Norway, which still hunt whales for meat, oil, blubber and cartilage. More than a thousand whales are killed by hunters every year.
These animals can also fall victim to “bycatch,” when they are caught in nets or traps for various fish species. An estimated 300,000 whales are accidentally caught each year.
Some were identified and released by responsible fishermen, while others drowned, unable to reach the surface to breathe.
What happens after death?
When a whale dies, gases from the breakdown of its tissues can cause the carcass to float. The tide may carry the body to the shore. If in deep water, it can become a “whale fall,” sinking to a depth of more than 3,300 feet.
When this happens, it can lead to some amazing things. In the depths of the deep, dark ocean, there is a lot of food. No sunlight reaches the sea floor, so plants don’t grow there. But whale falls provide the nutrients needed to sustain the entire biome.
Unlike shallow waters, the frigid ocean depths do not harbor bacteria and scavengers that quickly devour corpses. Lobsters, crabs, isopods, sea cucumbers, shrimp, diving sharks and certain fish species may be able to feed on a single whale fall for decades. In turn, they are food for other organisms.
Thus, even in death, mighty whales play an important role in their marine ecosystems.
Whales are amazing creatures, and now that you know some of the reasons why whales die, let’s review them:
|7 Common Causes of Whale Death|
|1. Ship ramming|
I am broadly interested in how human activities influence the ability of wildlife to persist in the modified environments that we create.
Specifically, my research investigates how the configuration and composition of landscapes influence the movement and population dynamics of forest birds. Both natural and human-derived fragmenting of habitat can influence where birds settle, how they access the resources they need to survive and reproduce, and these factors in turn affect population demographics. Most recently, I have been studying the ability of individuals to move through and utilize forested areas which have been modified through timber harvest as they seek out resources for the breeding and postfledging phases. As well I am working in collaboration with Parks Canada scientists to examine in the influence of high density moose populations on forest bird communities in Gros Morne National Park. Many of my projects are conducted in collaboration or consultation with representatives of industry and government agencies, seeking to improve the management and sustainability of natural resource extraction.
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