Theres a hierarchy in the ocean’s ecosystem.
We start at the bottom with primary producers such as Phytoplankton! These are microscopic plants that are produced in the waters with the right combination of nutrients and sunlight.
We then have Primary consumers; these are things such as some types of Zooplankton. These are small organisms that eat phytoplankton and because they only eat plants, they are called consumers. We might even say that they are vegan!
Next, we have secondary consumers, or predators! These are organisms that eat other organisms such as Humpback whales! Humpback whales feed on Zooplankton!
This continues up the food chain, with tertiary consumers, usually its portrayed in a triangle! But right at the top we have something we call apex predators! These are the top dogs; they eat other organisms but no other organisms eat them! A good example of Apex predator is us! We eat a variety of other animals but thankfully no one eats us!
Now my favourite game to play on tour is to ask the guests, who they think the Apex predator of the ocean is? Who do you think it is? ….. You said sharks, right? You might have even got specific and said the great white shark!
WRONG! Do you know who eats great white sharks?
KILLER WHALES!!!!!
I absolutely love the look on peoples faces when I tell them that.
We’ve talked a lot about different ecotypes in our previous blogs, but just as a recap, here in the Salish sea we have three ecotypes of Killer Whales. We’re always talking about two of them – Biggs Killer whales (Transients), who eat Marine mammals, and resident killer whales who eat fish, mostly salmon. But the third one we don’t talk a lot about; those are our Offshore Killer Whales! The reason we don’t talk about them much is because not a lot is known about them. They tend to spend more time off the continental shelf in deeper waters and a lot of that is due to their diet. Offshore killer whales eat bony fish and…. SHARKS!
This was first discovered actually off the coast of South Africa, two killer whales Port and Starboard wreaked havoc around the coast in 2015 when carcasses of Great White Sharks with their livers removed started washing up on beaches. This caused all the other great white sharks to leave the area and the shark diving tourism industry collapsed.
It was discovered that the Killer Whales flip sharks on their backs and holding them there for up to 15 minutes. Flipping a shark over induces a paralytic state known as tonic immobility. Once immobilized, the Killer Whales will prey on the shark’s liver which can account for a quarter of its body weight. Shark liver offers an extremely dense and nutritious source of calories for Killer Whales. Since then Killer Whales have been documented targeting the liver of various shark species.
In 2022 they were filmed hunting sharks with 4 other orcas, showing that this behavior is spreading amongst the population, so if I was a shark, I’d probably steer clear of Killer Whales too!