Kelbe Photography

Diving The Deep Blue


IMG_0589

The deep blue dive is a long ride out from the cape coast. The warm waters of the eastern seaboard sweep down to meet the cold water of the cape coast and brings the warm water animals to feed at the interface of the two marine environments. This is a rich fishing ground and the trawlers are active, and successful in this area. The interface may move between15 and 50 kilometres off the Point depending on currents. The day we dived we were 55 kilometres off the Point, a 3 hour boat ride. The waters are clean and warm with temperatures around 21 to 22 degrees celsius which is in stark contrast with the coastal water temperatures of 8-15 degrees. The trawler activity attracts a large number of predators including sharks, birds and seals as well as game fish like tuna and other pelagic fish feeding off the bycatch. This is an area where some of the migratory midwater sharks can be found. Diving is baited with fresh tuna and brings in the Blue and short finned Mako sharks, rarely seen in other circumstances.

Cape Fur Seals


IMG_0453-Edit

Cape fur seals (Arctocephalus pusillus), often gather into colonies. While fur seals spend most of the year at sea they never fully evacuate the rookeries and mothers and pups return to them throughout the year. Cape fur seals begin to breed in the middle of October when males haul out on shore to establish territories through display, sparring and sometimes actual combat. They will fast at this time and not eat until after mating in November or December. When the females arrive they fight among themselves for territories in which to give birth. Female territories are smaller than those of males and are always located within them. Females within a male’s territory can be considered part of his harem. However males do not herd the females which are free to choose their mates and judge them based on the value of their territories. After mating females begin alternating brief periods of foraging at sea with several days ashore nursing their pups. Foraging trips last about seven days in winter and about four days in summer and autumn. When a mother returns from sea to feed her pup she emits a loud call which attracts all the nearby pups, but she only responds to her pup. She probably recognises her pup by smell. When left alone pups gather in groups and play during the evening. Pups are usually weaned at 4–6 months old. Underwater they are very quick and playful. They often nip fins, strobes and approach the dome ports with the teeth bared and mouth open but breathing out. Taking pictures is challenging as they are masters of the quick turn and direction change and the bubble blowing clouds the picture.

Blue Sharks

IMG_0620


Blue sharks (Prionace glauca), are light-bodied with long pectoral fins. The top of the body is deep blue, lighter on the sides, and the underside is white. The male blue shark commonly grows up to 3 metres, the larger females may reach 3.3 m, rarely up to 4 m. The Blue Shark is fairly elongated and slender in build and typically weighs from 25 to 55 kg (males) and from 90 to 180 kg (females). The heaviest reported weight for the species was 391 kg. They are viviparous with a yolk-sac, delivering 4 to 13 pups per litter. The gestation period is between 9 and 12 months. Females mature at 5 to 6 years of age and males at 4 to 5. Courtship is believed to involve biting by the male and mature specimens can be accurately sexed according to the presence or absence of bite scarring. Female blue sharks have adapted to the rigorous mating ritual by developing skin 3 times thicker than male.
Podcast

Shy Shark

_V5M2119


Shy sharks are common in Cape waters and are found in the kelp beds. This is the puffadder shyshark (Haploblepharus edwardsii) which is more slender than other shy sharks, with a short, broad, dorsally flattened head and a narrowly rounded snout. It is strikingly patterned with a series of dark-edged, bright orange "saddles" and numerous small white spots over its back. When threatened, the shy shark curls into a circle with its tail covering its eyes giving rise to the names "shy shark" and "doughnut". It is a predator that feeds mainly on crustaceans, polychaete worms, and small bony fishes. This shark is oviparous and females deposit egg capsules singly or in pairs onto underwater structures, so called mermaids purses.

Cow Sharks

IMG_0425


Cow sharks have a single dorsal fin and round snouts. 6 Gill Cow Sharks can reach close to 5 meters in length while their cousins, the 7 Gill Cow Shark (Notorynchus cepedianus), are smaller and are about 2.5 meters in length. The 7 Gill Cow Sharks are blotchy dark grey to white. In the cape waters the 7 Gill Cow Sharks live in the kelp beds off Simon's Town and feed on fish, including other sharks, and marine mammals. They are docile when seen in the kelp beds off Simon's town during the day. The 6 Gill Sharks are deep water sharks which come close to the surface at night in certain areas of the Western North American seaboard.

Nudibranchs

_V5M2072-Edit


Cape Town has an abundance and variety of nudibranchs many of which are described as unique to these waters. The species shown here is the Silvertip or the Medallion Silvertip Nudibranch. Some of the species can only be distinguished from one another by their eggs. This species differs from the Gas Flame Nudibranch (a common East Coast nudi) The difference lies in the fact that the cerata (pointy things on the back) are broader and have digestive tracks in them in the Silvertips. In this picture they are absent but this species has an organ between the rhinophores (the two big pointy thingson its head, chemical sensors) called the Janolus organ. This organ defines the family Janolus. The function of this organ is unknown. The animal is functionally blind having only rudimentary light receptors. It hunts using tactile stimuli but the most important is chemical scenting. The animal feeds on Bryozoans.

Seahares

_V5M2139

The Shaggy Seahare (Bursatella leachi africana) is said to be a rare sighting. We went for a shore dive looking for them off Simon’s Town, the first half of the dive we saw none, until we recognised the lumps of white to pink mops which adorned the ocean floor were, infact, the Shaggy Seahare. They were numerous and obviously mating and formed chains of mating animals. They munched their way through the sand and sea grass. Guido Zsilavecz book, “Nudibranchs Of The Cape Peninsula and False Bay” says the population fluctuates widely and they disappear as quickly as they come.


_V5M2150