Tag Archive | transient orcas

How Pollution affects Orcas


Without further regulations that would either ban or place restrictions on the entry of pollutants in the oceans, wild orcas like Samish (J-14) would likely endure a bleak future. (Photo of Samish is by the Whale Museum's Killer Whale Adoption Program)

Around the world, killer whale populations are falling victim the effects of pollution mainly caused by man-made toxins. These toxins, which are usually made of various chemicals, are used on land often end up entering waterways through runoffs and eventually end up as pollution in the ocean. Various chemicals, such as flame retardants, industrial pollutants, oils, and pesticides have all been known to enter the oceans through waterways and they are all having a major impact on marine wildlife, including killer whales.

Because killer whales are known as the top predator of the ocean, it's very easy for pollutants to become concentrated and reach dangerous levels their bodies since these pollutants make their way through the marine food chain.

While wildlife experts agree on the fact that pollutants make their way through the marine food chain, some of them often get sorted into the body tissues of animals after they are ingested. For example, In the Pacific Northwest, the marine food chain is consisted of  zoo plankton feeding on phytoplankton, krill feeding on zoo plankton, salmon feeding on krill, and orcas (killer whales) feeding on the  salmon, which has become endangered because of pollution, over-fishing, and habitat loss. In the case of transient orcas,  dolphins, seals and sea lions feed on the salmon, while the mammal-eating transients feed on the very same marine mammals that feed on the salmon. This means that prey animals that contain toxins in their bodies pass them on to animals that are higher on the food chain and because of this, killer whales have been shown to have high and dangerous levels of concentrated pollutants in their bodies.

In the Pacific Northwest, resident killer whale populations in Washington and in British Columbia are among the most intoxicated marine mammals in that region due to not only being urban animals, but also, the salmon they depend on is also contaminated with pollutants. Research has also shown that resident orcas have 200 times more pollutants in their system in most humans do. (Photo of resident orca is public domain).

In Norway, studies on Norwegian herring-feeding killer whales have found that this population of killer whale has very high levels of PCBs. PCBs are type of industrial chemical that is used in transformers, oils, and insouciance. As a result, this makes Norwegian killer whales have the highest level of containments in high Arctic. (photo of Norwegian orca was taken by Jonathan Ball).

Studies done on the contamination levels of Pacific offshore killer whales have discovered to be very high because they are known to feed on large fish such as great white sharks, and tuna which can bio-accumulate containments over a period of a lifetime. (Photo of offshore orca is public domain).

Transient orcas, which specialize in feeding marine mammals, are more contaminated than resident orcas due to dietary differences. Their bodies are so full on toxins that when they are found dead on beaches, their remains are often treated as toxic hazardous waste when necropsies are performed on them. (Photo is public domain).

New Zealand is home to a small population of ray-feeding killer whales that have also been known to feed on certain species of sharks. In 2010, a study done by Dr.Ingrid Visser of the Orca Research Trust of New Zealand have shown that this population of about fewer than 200 animals are the most containment animals in the Southern Hemisphere. This could also be due to the fact that the mammals are mainly seen in harbors where such containments can mainly be found. (Photo of wild orca pod off the coast of New Zealand was taken by Dr. Ingrid Visser of the Orca Research Trust).

In the 1970’s, various pollutants were banned world wide because of the negative effects they posed both to humans and wildlife. Yet, many of these pollutants can still be seen in the form of containments and in various forms and it’s still to this day having a huge impact on marine wildlife, such as PCBs (polychlorinated biphenyls). PCBs are a type of organic compound that has a 1 to 10 chlorine atom attached to biphenyl, which is molecule composed of two benzene rings. When PCBs are ingested, they aren’t neither metabolized nor eliminated for these fat-soluble molecules go on to accumulate in fats, such as blubber. Just to make matters worse for the killer whales, the PCBs are affecting their reproductive health too and this is because they are known to be estrogen imitators and cause low sperm count in both humans and animals alike, including killer whales. Also, out in the wild, when a killer whale calf is born, chances are, it was born with toxins that have been passed on to them by the mother through the placenta  and goes on to receive these same toxins it developed before birth by nursing on the mother’s fat-rich milk. In some cases, the calf (mainly the first-born) dies likely due to heavy exposure to toxins. However, calves the mother goes on to have after that have been known to fare better because of the mother’s toxin levels decrease over time. PCBs have also been known to cause other problems too such as cause disease and developmental problems.

What can you do to reduce pollution…..

  • Reduce, Reuse and Recycle
  • Clean garbage off a beach
  • buy organically grown food to reduce the use of pesticides
  • Use biodegradable cleaning products that are plant-based.
  • Dispose paint, thinners and motor oil to prevent them from going down the drains

If you have any questions, or comments about killer whales, please email me at Animaltrainer104@aol.com and I hope you to do your part in caring for killer whales and the oceans by reducing pollution.

~Jenna~

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More Orca FAQs


While resident orcas will remain in the same pod for life, this is not the case for transient orcas. Photo of orcas Unna, Kyuqout and Tuar was taken on July 24th, 2008 by yours truly.

Hello everyone,

In response I got from Yovani Valdes regarding my first blog entry that was about frequently asked questions about orcas, I decided to add a sequal to that blog entry. This entry is all based off six of seven questions that were asked by Yovani and the one other question that I have found on yahoo.com.

1. How are new pods formed?

Females will begin to branch off from from their birth pods when they start having calves of their own. From there on, they will eventually start new lines of their own even though they will continue to travel closely with their mothers and other family members.

2. How large can pods get?

Orca pod sizes can range from two to forty animals.

3. What’s a transient pod?

Most transient orcas may have short term associations with other pods from time to time. Photo by National Geographic.

Transient orca pods are small loosely-based social structures that may consist of an adult female and two or three of her offspring. However, while the eldest male calf will remain with the mother for life, the other calves must leave her. Transient calves will leave their mother’s pod at around 5-12 years. Females have been known to travel with other transient animals who they may or may not be related too while males will travel with one group after another for time to time. However, the only exception to this rule is if female offspring fail to produce any offspring of her own and will remain with the mother for life.

4. What are the intervals between births?

Born year around, killer whale calves may nurse from their mothers for up to two years. Photo of Katina with her son Makaio was by taken by yours truly in July 2011.

 

Female orcas will give birth to a single calf every 3-5 years. On average, females will probably give birth to 4-6 calves during her lifetime.

5. When do they start breeding and until what age?

While female orcas will mature at around 7 to 10 years of age, it could be another six to nine years before they have their first calf. The average age for females to give birth for the first time is around 11-15 years. They become post-reproductive in their mid-forties.

6. Why do dorsal fins bend? 

There are a series of theories about why an orca's dorsal fin bends. photo is by Public Domain

Although it’s not really known why an orca’s dorsal fin bends, many believe that gravity may have something to do with it. For example,  when orcas dive under water, the surrounding water helps support the dorsal fin which is made of nothing more than muscle and connective tissues. Also, orcas who spend most of their time at the surface with their fins protruding out of the water has greater chances of flipping over on a long-term scale. Additionally, the collagen becomes more flexible when warm such as exposure to the sunlight. However, there are also theories about collapsed dorsal fins being genetic (there there’s evidence to support that too).  Yet because the dorsal fins of male orcas can grow up to six feet tall, the height of the fins may have a great tendency for the fins to naturally collapse or become wavy over time. However, it must be reminded that neither the shape or droop of a whale’s dorsal fin are not indicators of an orca’s health, or well-being.

If you have anymore questions about orcas and other marine mammals, feel free to email me at Animaltrainer104@aol.com

Hope you all have a great weekend everyone,

~Jenna~