How do you save a shark you know nothing about? | Simon Berrow

TL;DR

Basking sharks, the second-largest fish in the world, are fascinating creatures with a rich history in coastal communities and are currently facing the risk of extinction.

Transcript

Basking sharks are awesome creatures. They are just magnificent. They grow 10 meters long; some say bigger. They might weigh up to two tons. Some say up to five tons. They're the second-largest fish in the world. They're also harmless plankton-feeding animals. And they are thought to be able to filter a cubic kilometer of water every hour and can f... Read More

Key Insights

• 🦈 Basking sharks are the second-largest fish in the world and can grow up to 10 meters long and weigh up to five tons. They are harmless and feed on plankton.
• 🛢️ The liver of a basking shark contains gallons of oil, which was historically used for lighting and other purposes. They were an important resource for coastal communities.
• 📉 Basking shark populations have declined due to overfishing, with a peak in the 1950s when 1,500 sharks were killed per year. Shark finning is a major threat to shark populations worldwide.
• 🇮🇪 Ireland has a significant basking shark population and offers opportunities for studying and tagging them. Basking sharks were historically important to Irish coastal communities.
• 🌍 Basking sharks have a low genetic diversity and show little variation among populations worldwide. There is a risk of extinction due to their small population size.
• 🧪 Genetic analysis of basking sharks is limited due to the lack of samples. However, innovative methods like collecting DNA from shark slime have provided valuable data.
• 📈 Satellite tagging has revealed the movement and behavior of basking sharks. They can travel long distances, cross the equator, and serve as indicators of climate change.
• 🛑 There are movements in Europe to ban the catching and landing of basking sharks to protect their species. However, they still have no legislative protection in Ireland.

Questions & Answers

Q: How long can basking sharks grow?

Basking sharks can grow up to 10 meters long, with some individuals believed to be even larger.

Q: How much do basking sharks weigh?

Basking sharks can weigh up to two tons, although some sources suggest they can weigh up to five tons.

Q: What is the second-largest fish in the world?

Basking sharks are the second-largest fish in the world.

Q: How do basking sharks feed?

Basking sharks are harmless plankton-feeding animals that filter a cubic kilometer of water every hour. They can consume up to 30 kilograms of zoo plankton per day to survive.

Q: What was the historical significance of basking sharks to coastal communities in Ireland?

Basking sharks were important to coastal communities in Ireland for their liver oil, which was used for lighting and medicinal purposes. They were also used for fertilizer and their fins were harvested.

Q: What were the basking shark fisheries like off Achill Island?

The basking shark fishery off Achill Island peaked in the 1950s, with up to 1,500 sharks being killed each year. However, the fishery declined rapidly, indicating a depleted stock or low reproductive rates.

Q: How many sharks are killed annually compared to the number of human deaths caused by sharks?

Approximately 100 million sharks are killed each year, while only about five or six people die from shark attacks annually.

Q: What is the current status of basking sharks and their protection?

Basking sharks are listed as vulnerable under the IUCN, and there are movements in Europe to ban their catching and landing. However, they do not have legislative protection in Ireland, despite their historical and ecological importance to the country.

Summary & Key Takeaways

• Basking sharks are magnificent creatures that can grow up to 10 meters long and weigh up to five tons.

• They were historically important to coastal communities for their oil, which was used for lighting and medical purposes.

• There is concern that basking sharks are becoming depleted worldwide, and more research is needed to understand their population size and genetic diversity.