Basking sharks are the second largest fish in the world. Listed as globally endangered on the IUCN Red List after two centuries of exploitation for their oily livers. These friendly giants are filter feeders and can be seen feeding on zooplankton at the waters surface. In the past ten years scientists have been researching the movements of these sharks. Basking Sharks occur seasonally throughout the Atlantic where large numbers of these sharks can be found feeding off the west coast of Scotland in the North Eastern Atlantic Ocean during summer.
At-A-Glance
Scientific Name – Cetorhinus maximus
Size – Adults range from 22-40 ft/7-12m depending on sex and age.
Habitat – Highly migratory species commonly found in both the Northern & Southern Hemispheres feeding near the surface in coastal and deep, temperate waters.
Diet – Variety of zooplankton, copepods, small crustaceans, fish eggs and larvae.
Reproduction – Ovoviviparous (pups are nourished in utero via yolk sac and birthed live) with a gestation period lasting around 24 to 36 months giving birth to small litters with very large pups. They have a slow rate of reproduction which leaves them more vulnerable to extinction.
IUCN Listing – Endangered.
Protection – Listed under Appendix II of CITES and Appendix I & II of CMS. They are also listed under Annex I (Highly Migratory Species) of UNCLOS. This species is also highly protected in the UK and EU.
Bet You Didn’t Know…
- Basking sharks are filter feeders and are the second largest fish in the world. They filter thousands of gallons of water per hour through their gills while food is strained through their gill rakers. They can open their mouth up to 3.5 ft wide!
- They spend much of the summer months at the sea surface, moving slowly while feeding. This is how they earned they name “basking shark” because they’re basking in the sun’s warmth.
- Basking sharks were previously hunted for their liver oil, skin, meat, and fins until around 1995 when the last basking shark fishery in British waters closed.
Ready To Dive In?
The Hebrides Islands, Scotland: June to August
Cornwall, UK: May to August
Isle of Man, UK: May to August
Stellwagen Banks – Boston, MA: Late June
Science In The Spotlight
Advances in biologging, a technique which uses miniaturized tags attached to the study animal to record data about movements, behavior, physiology and environment, has led to a better insight into the lives of basking sharks. Many species of sharks, whales and fish have all been recorded demonstrating breaching behaviors. For example, white sharks breach when they are pursuing prey. Breaching is a highly energetic activity as it consists of the animals propelling themselves out of the water. There have been many hypothesized reasons for breaching behaviors such as epiparasite removal, hunting and courtship behaviors. Although, there has been accounts of basking sharks breaching before, this study is the first to record and describe the breaching basking sharks.
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