Cause and Effect – From sharks to us

 If Sharks Disappeared by Lily Williams presents a simplified explanation of a complex process, trophic cascade, which tells us why sharks are critical for maintaining balanced, healthy oceans. This is an excellent book for demonstrating how creatures in an ecosystem are interconnected and when one component is missing the impact can have devastating consequences.

Over the last couple of years, I’ve notice a few more books at the juvenile level that portray sharks in less a scary light. I think promoting a better understanding of the important role sharks play in their ecosystems is crucial for changing out views about them.

According to William's book, it is estimated that 100 million sharks are killed every year.  This is driven by market demands for shark fins to make soup as a Chinese and Vietnamese delicacy, fishing practices that inadvertently kill sharks, as well as human fear that fosters the idea that fewer sharks is better for human safety. Overfishing has resulted in 1/4 to 1/3 of shark species being vulnerable to extinction.

As apex predators sharks help control population numbers of other species such as seals and sea lions. If their populations are left unchecked fish populations would be at risk and seals and sea lions would starve. If fish disappear, then plankton, the food that many fish eat could also over multiple, turning ocean waters into a thick sludge. Oceans would be unable to support much life and this would eventually impact animals and humans living on land.

I recommend this book for elementary grades study science topics such as life cycles, food chains, ecosystems, and sustainability issues.

Other resources I recommend are:

Sharkwater (DVD) by Rod Stewart

The Great White Shark Scientist by Sy Montgomery

Wandering Whale Sharks by Susumu Shingu

Wild Ocean: Sharks, Whales, Rays and Other Endangered SeaCreatures by Matt Dembicki (ed.)

Ocean Soul by Brian Skerry

The World Without Fish by Mark Kurlansky