What is the reason we get such an abundance of marine wildlife here in Kaikōura? Why do you need to come here to view sperm whales?
We have a deep submarine canyon situated close to shore and major currents merge into this canyon and it produces a highly productive underwater system. The convergence of sub-tropical and sub-Antarctic currents helps bringing nutrients from the seabed to the surface.
This productive canyon supports the whole food chain, starting from the smaller plankton and all the way up to the greater whales. Phytoplankton is the start of the food chain and an extremely important part in our ecosystem. Phytoplankton alone produces at least 50% of the oxygen around our planet and absorbs a huge amount of carbon dioxide from the atmosphere. Every second breath that you take, thank the oceans and phytoplankton!
Sperm whales are extremely deep divers and are generally only found in deeper waters. As the canyon system sits close to shore it is the perfect place to get out into deeper waters in a very short time!
This canyon is known as the Kaikōura canyon; it is situated close to the South Bay marina where the Whale Watch boats leave from. You only need to travel about 3 nautical miles to get to the start of this submarine canyon system. The closest point to land is around Goose bay which is just south of Kaikōura, here the canyon starts less than 1 nautical mile from shore.
The effects of an earthquake
The average depth of the canyon is 1100 metres and the deepest point on the inside of the canyon was a 1600 metre hole pre-earthquake. When the 7.8 earthquake hit Kaikōura in 2016 there was a massive shift underwater and the canyon saw a big change of depths. The canyon deepened by up to 50 metres but the deep hole of 1600 metres seems to have filled up and can no longer be found on our new marine charts.
Hikurangi marine reserve
Connected to the Kaikōura canyon is the Hikurangi trench and it stretches on for hundreds of nautical miles along the east coast of New Zealand. A big part of the Kaikōura canyon is taken up by Hikurangi marine reserve. This reserve is a no-take area and no marine life is to be disturbed or removed. Many rivers and streams flows into the marine reserve and helps to create this extremely nutrient rich area which supports a great variety of wildlife. Apart from seeing sperm whales in the marine reserve, you can also find many New Zealand fur seals, dusky and hector’s dolphins and a large variety of seabirds.
View the long term exhibition of the Kaikōura earthquake when you visit the Kaikōura museum.
Hikurangi marine reserve