What's bigger than a bus but has prey smaller than a grain of rice? | Species at Risk Act | Wildlife & habitat | Science & policy | Species at Risk Act | Issues
Photo: What's bigger than a bus but has prey smaller than a grain of rice?

(Credit: Tin Can Forest)

By Scott Wallace, Senior Research Scientist

Five fun facts

Below are five fun facts about one of the world's most interesting sea creatures: the basking shark.

  1. Basking sharks are the world's second-largest fish (only the whale shark is bigger) and can grow to the length of a school bus, more than 12 metres from tip to tail.
  2. Basking sharks can weigh more than four tonnes — heavier than a couple of cars — yet they feed primarily on zooplankton, which are smaller than a grain of rice.
  3. Although sometimes mistaken for great white sharks, basking sharks are gentle giants with tiny teeth and are harmless to humans.
  4. The basking shark's highly adapted mouth and gill structure can filter enough water to fill an Olympic-size swimming pool every 90 minutes.
  5. The mouth of a basking shark is so unique that the structure of the mouth cavity has recently inspired the design of a more efficient hydroelectric water turbine.

Sign up for our newsletter

Where are these basking sharks?

Do you wonder why you've never seen a basking shark? Despite being found along both the Pacific and Atlantic coasts of Canada, basking sharks are rarely seen in the wild. On the Pacific coast only about one a year is officially sighted, a stark contrast to 60 years ago when schools of hundreds of basking sharks could regularly be seen.

Basking sharks faced aggressive extermination in the 1950s and '60s, and because they are often found "basking" near the surface, they can become entangled in fishing gear and hit by shipping vessels. These threats have reduced basking shark populations to the point where some have disappeared and others need protection.

What's being done?

In January, Canada's Department of Fisheries and Oceans released a policy to assist in the recovery of the basking shark. It instructs vessels on how to operate around basking sharks and how to report a sighting if you are fortunate enough to see one.

For more information about basking sharks, check out this information from the Shark Identification Network and Fisheries and Oceans Canada. And be sure to keep your eyes on the ocean for this gentle, basking giant. You can also pick up the book I wrote with Brian Gisborne, Basking Sharks: The Slaughter of B.C.'s Gentle Giants (Transmontanus, 2006).

http://www.davidsuzuki.org/issues/wildlife-habitat/science/species-at-risk-act/whats-bigger-than-a-bus-but-has-prey-smaller-than-a-grain-of-rice/

Read more