Whales in Kaikoura, New Zealand

Whales in Kaikoura, New Zealand.

SPERM WHALES
(Physeter macrocephalus)

The Kaikoura coastline is a Mecca for watching marine mammals and the home of "Whale Watch".
Fur seals lounge on rocks just metres from the shore, Dusky and Hectors dolphins frolic in the sea within sight of town, while only a few kilometres further out, giant Sperm whales haunt the depths.
The Sperm whale can be seen all year round off Kaikoura and is the largest of the toothed whales. It is the third largest whale in the world, only beaten by the Blue and Fin whales.

WEIGHT: MALE 36000kg FEMALE 20000kg

LENGTH: MALE average 10-15m FEMALE average 8-11m
> 17m (max.)

Their steely gray skin is shriveled and corrugated in texture with white patches found around the lips, tail and flank. These patches generally increase with age, and sightings of pure white sperm whales, like the legendary Moby Dick, have been reported. The thick stubby flippers on each side are 1.5 metres long and are used for braking and steering. Instead of a dorsal fin there is a hump two-thirds of the way down its back followed by some uneven knobs or knuckles that run down the lower back to the tail. The beautiful and powerful tail flukes are proportionately larger than that of any other type of whale. Sperm whale head on.
One of the more unique features of the sperm whale is its unusual box like head that contains the largest brain in the world. It accounts for 1/3 of its total body length and well over a 1/3 of the whales body weight. The single blowhole is located on the left side at the front of the head. When the sperm whale blows, the spout travels to the left and forward at a 45‘ angle. Stored in its unusual shaped head is a liquid called SPERMACETI. Once thought to be a reservoir of whale sperm, it is now known this liquid helps control the whale's bouancy. On cooling the liquid becomes denser creating negative bouancy and aiding in the dive, when warmed the opposite occurs. This remarkable feature helps the whales dive to the incredible depths they achieve. At Kaikoura they dive to depths of around 1000m (3000ft) but have been tracked to depths of around 2500m (7000ft), making them by far the deepest diving whale in the world. Below 450 metres, the whales lungs are unable to store oxygen due to the surrounding water pressure. When re-oxygenating on the surface, almost all of the oxygen is transferred into the myoglobin in their muscle tissue and the haemoglobin in their 3 tonnes of blood. The whale typically dives and returns to the surface vertically, which helps to explain the relative ease with which the whalers were able to hunt them. When they dive they descend at approximately 4 knots or 7-8 kph and return to the surface at 5 knots or 9 kph. Times spent diving vary in duration.

In Kaikoura the whales spend about 45 minutes diving and then re-surface in almost the same spot to prepare for the next dive spending about 10 minutes on the surface and breathing about 6-7 times a minute while re-oxygenating. Each breath equating to approximately one minute below.

The longest dive ever recorded was 2hrs 18min ! Whale diving.

The remarkable abundance of wildlife along Kaikoura’s coastline owes its existence to the Hikurangi Trench, an underwater canyon which cuts deep into New Zealand’s continental shelf and terminates just off Kaikoura’s coastline. Nutrient rich waters rise to feed a large population of Groper, Shark and Squid on which the Sperm whale feeds. Scars found around the head of the whale suggest the squid to be anything from 12m - 45m long.

Like all toothed whales, the sperm whale uses echolocation to find its prey. A series of clicking noises are transmitted from the whale's forehead creating a forward pointing beam of sound. Upon striking a solid object they are reflected back, picked up by the whale's lower jaw and transferred to the inner ear. Echolocation is an amazingly sensitive system which enables the whale to know exactly what type of fish or squid it will next be dining on.

Sperm whales were once one of the most prolific whales in the world with an estimated population of around 2 million. During whaling times they were hunted for their SPERMACETI OIL and AMBERGRIS, found in the stomach of whales, and used to intensify the smell of perfumes.
Aerial view of whale. Unfortunately, with so many nations hunting whales, reaching international agreements on quotas was never easy. In less than 200 years, New Zealand’s once thriving whale populations had been virtually wiped out. On December 23, 1964 New Zealand’s last whale station closed.
Since that time whale numbers have been steadily recovering with population estimates for sperm whales being around 400,000. Future recovery depends on how we treat the fragile balance of the food chain, from the phytoplankton and zooplankton to the largest mammals of all. Over fishing by humans may well threaten their survival in future years.

It is hard to imagine how full of life the oceans once were.

Let's hope we don’t find, that due to our stupidity, Imagination, is all that we have left.