Whale Poo

Bryde’s whale

Did you know that whale poo can give us a lot of insight into what whales are eating? This activity will show you how we can use whale poo to understand the diet of Bryde’s whale (a whale seen throughout the Hauraki Gulf), and why it is important that we keep our oceans healthy if we want to look after the whales (and other sea creatures)

How big do you think a Bryde’s whale is?

Approximately how much does a whale that size need to eat each week?

How do we know what it eats?

Whale eating

Given that it does most of its eating under water, how do we know what it's eating?

Well, we collect their poo. The colour and texture of its poo changes according to their diet, which we have learnt using high-throughput gene sequencing. That means, that when we analyse the DNA in the poo, we get graphs that show us what the whale has been eating!

What does it eat? Feed the whale!

Whale feeding

Drag the food types below onto the mouth of the whale to see how we can tell what they are by the colour of the whale's poo.

Keeping our oceans healthy

It’s really important that we keep our oceans healthy, because phytoplankton need a healthy ocean to survive. Without phytoplankton, the zooplankton would have nothing to eat. Without zooplankton, the smaller fishes would have nothing to eat. Without the smaller fishes, the bigger fishes would have nothing to eat, and so on. Since whales eat plankton soup, zooplankton swarms, and fishes, then an unhealthy ocean means no whales. 

The biggest threats to our oceans are pollution, climate change and overfishing. Pollution (runoff from land) means that things like agricultural fertilizers and pesticides contaminate the ocean. Climate change causes ocean acidification. This means that calcium carbonate structure forming organisms can’t grow (including phyto- and zooplankton). Overfishing takes prey such as pilchards out of the water to be used for bait. These small fishes are actually really important food for sharks, big fish, whales, seabirds, and dolphins.