What is shark liver used for by humans?

Shark liver oil has been used for various purposes throughout history, but its use is now largely considered outdated and even harmful due to concerns about sustainability and ethical issues related to shark fishing. Here's a breakdown of past and present uses:

Past Uses:

* Vitamin A: Shark liver oil was historically a significant source of vitamin A, which is essential for vision, immune function, and cell growth. It was used to treat vitamin A deficiency, which can cause blindness and other health problems.

* Medicinal Oil: Some traditional cultures believed shark liver oil had healing properties and used it to treat wounds, burns, and skin conditions.

* Lubricant: Due to its high oil content, shark liver oil was used as a lubricant for machinery and tools.

Present Uses:

* Limited Medical Use: In some cases, shark liver oil may be used in specific medical treatments, such as for eczema or psoriasis. However, these uses are limited and often replaced by safer alternatives.

* Fish Oil Supplements: Some shark liver oil capsules are still marketed as fish oil supplements. However, these products are often considered less beneficial and more expensive than other fish oil sources.

* Cosmetic Industry: Some cosmetic products may contain shark liver oil, but its use in this industry is declining.

Concerns and Alternatives:

* Sustainability: Sharks are slow-growing and late-maturing animals, making them vulnerable to overfishing. Harvesting their livers for oil can contribute to the decline of shark populations.

* Ethical Issues: Many people are concerned about the cruelty involved in shark fishing and the impact it has on marine ecosystems.

* Alternatives: There are numerous safer and more sustainable sources of vitamin A and other nutrients, such as cod liver oil, plant-based supplements, and a balanced diet.

In conclusion, while shark liver oil had historical uses, its current use is minimal and often considered unethical and unsustainable. There are safer and more ethical alternatives available for similar purposes.