The Marine Big Five of Walvis Bay

Opting for wilderness and wonder
February 8, 2017
Those yellow flowers
February 10, 2017
Opting for wilderness and wonder
February 8, 2017
Those yellow flowers
February 10, 2017

Text Peter Bridgeford | Photographs Mike Lloyd

“Thar she blows,” the lookout shouted from the crow’s nest of the whaling ship.

T he telltale plumes of a whale’s blow, once spotted, sealed the animal’s fate. in the eighteenth and nineteenth centuries, rapacious American and British whalers remorselessly plundered the south-western coast of Africa in pursuit of whales. Walvis Bay, the Bay of Whales, was home to the whaling fleets during this killing frenzy.

Held in awe because of their size and mysterious lives in the deep ocean, whales elicit an excited response when seen, as in the days of Moby Dick, the classic whaling story written by Herman Melville. In Walvis Bay, whales are again being hunted, but the camera has replaced the harpoon, and today they are worth more alive than dead. Marine tour operators now patrol the environs of the bay in search of whales and other marine animals, a whale being the ultimate sighting on a marine cruise.

The harbour town has a well-established and thriving marine tour industry. Crafts from several companies – ski-boats, catamarans and kayaks – take hundreds of tourists on marine cruises every year. As in land-based tourism, the marine component also has its Big Five. These are whales, dolphins, seals, leather-back turtles and sunfish.

The two whale species normally seen in the Bay of Whales are the humpback and southern right whales. Of these leviathans, the former are more common. The most characteristic feature of humpback whales is their enormous flippers, close to one-third of their body length. The other is the humped dorsal fin, hence its common name. Both sexes average about 15 metres in length, but the females can reach up to 19 metres. These gentle giants weigh a mere 30 000 to 40 000 kilograms, although heavier specimens have been encountered.

Humpback whales are associated with elaborate songs, which can last for over 20 minutes and comprise a complex range of vocalisations, heard overlong distances. During winter in the southern hemisphere, these whales migrate from the Antarctic and along the western coast of Southern Africa to the temperate waters off Angola. Here they calve in the warmer waters before returning to feeding grounds of the chilly Antarctic, and entering Walvis Bay waters further south.

The endemic Benguela dolphin, also known as Heaviside’s dolphin, occurs along the west coast of Southern Africa. This small dolphin grows up to 1.2 metres long and attains a mass of up to 40 kilograms. An interesting snippet of history about this dolphin is its name. The skull and skin of the first specimen seen and described by scientists from the Cape of Good Hope arrived at the museum of the Royal College of Surgeons in 1828. A Captain Heaviside, a prominent naval surgeon, was mistakenly attributed as the sender, and the new species, Delphinus heavisidii, was named in honour of the esteemed surgeon. However, there were no cetaceans in Heaviside’s collection. It was Captain Heaviside, an employee of the British East India Company, who had taken the specimen to England in 1827. Because of the rules of naming scientific specimens, the spelling was not corrected when the error was eventually discovered.

Heavyside-Dolphin-Mike-Lloyd
The endemic Benguela dolphin, also known as Heaviside’s dolphin, occurs along the west coast of Southern Africa
Sea-turtle-Mike-Lloyd
Leatherback turtles can attain lengths of up to 2.5 metres and weigh over 500 kilograms
Whale-Mike-Lloyd
One of the most characteristic features of humpback whales is the humped dorsal fin, hence its common name
Mola-mola-Mike-Lloyd
Sunfish owe their scientific name, Mola mola, to their rounded body, rough texture and whitish colour, similar to a millstone
Seals-with-jackal-Mike-Lloyd
Cape fur seals, here with a black-backed jackal, are found commonly along the Namibian coast

The sea has many strange and mysterious animals living in it, with the sunfish, its name derived  from its habit of appearing to sunbathe on the ocean surface, being one of them. Moonfish is another name for this curious marine animal. With specimens weighing in at as much as 2300 kilograms, it is the heaviest bony fish in the world. It has a diameter of up to 3.3 metres, although the specimens sighted in Walvis Bay are smaller. Sunfish occur in temperate and warmer waters. They hold the record for producing the most eggs, with a female capable of laying 300 million eggs in her lifetime. These unusual fish have been found at depths of up to 600 metres. Sunfish owe their scientific name, Mola mola, to their rounded body, rough texture and whitish colour, similar to millstone, or mola in Latin. Despite their size, sunfish are harmless creatures. They feed mainly on soft-bodied jellyfish, blue bottles, squid and small fishes.

Another of the Marine Big Five searched for eagerly in the bay are leatherback turtles. Big specimens can attain lengths of up to 2.5 metres and weigh over 500 kilograms. They can dive down as deep as 1500 metres and stay under for up to nine minutes. Imagine the pressure at that depth! To put this into perspective, humans can dive about 90 metres deep, but only with special equipment. Leatherback turtles lack the horny plates of most other turtles, but the leathery skin bears seven longitudinal ridges, making identification easy. While looking formidable, their jaws are rather weak, their prey consisting mainly of sot-bodies species such as jellyfish. In the past few years, increasing numbers of leatherback turtles have been  recorded on the Namibian coast. Some of these, marked with tags, are from breeding grounds in South America.

The last of the Marine Big Five, Cape fir seals, are found commonly along the Namibian coast, with several large breeding colonies of these superbly adapted marine mammals occurring from South of Lüderitz to Cape Frio in the Skeleton Coast Park. Some are accustomed to being fed and regularly board the boats of tour operators, giving tourists a close encounter with the endearing creatures. Big bull seals can weigh as much as 360 kilograms, although the average weight is about 220 kilograms. Females are a lot smaller, attaining a mass of about 75 kilograms. An interesting aspect of Cape fur seals is their synchronised pupping season, with most young being born in late November and early December. Seals feed mainly on fish, giving rise to many commercial fisherman and surf anglers seeing the seals as competing for decreasing stocks of edible fish.

Visit the Bay of Whales and have a close encounter with the Marine Big Five. You may have the privilege of seeing the greatest show on earth, with a whale leaping out of the water in sheer exuberance.

This article was first published in the Flamingo December 2011 issue.

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