Underwater Photography in the Strait of Mozambique

Nature is generous. It gives without expecting anything in return. Generally, there’s a higher-level system ensuring the balance of its parts. These underwater photographs taken in the Strait of Mozambique try to explore some of these coexistences.

Take the case of the sea anemone who has several subtenants. There’s typically a pair of anemonefish, as well as a porcelain crab, and sometimes a shrimp. While this relationship is positive for the guests, the host anemone does neither gain any profit nor suffer negative effects. However, the stinging tentacles of the anemone do not permit all and sundry to live in shelter.

The Anemone and the Porcelain Crab

Spotted porcelain crabs got their name from their creamy-white colour. They defend their territory using the pair of large claws. Impressively, a leg lost during such fightings will slowly grow back. Porcelain crabs have fine feather-like extensions on the mouthparts that allow them to filter plankton from the water.

A spotted porcelain crab (Neopetrolisthes maculatus) sits among the stinging tentacles of an anemone, Memba Bay, Strait of Mozambique.
A spotted porcelain crab (Neopetrolisthes maculatus) sits among the stinging tentacles of an anemone, Strait of Mozambique. Porcelain crabs have fine feather-like extensions on the mouthparts that allow them to filter plankton from the water, and long antennae.

Anemonefish, or clownfish, usually live in pairs in sea anemones. They bravely defend their territory – and their eggs – even against bigger fish. Juvenile anemonefish can hide in the anemone. In fact, their body is coated with mucus that protects them from the stinging tentacles of the anemone.

A juvenile twobar anemonefish, or clownfish (Amphiprion allardi) hides in the stinging tentacles of an anemone, Memba Bay, Strait of Mozambique.
A juvenile twobar anemonefish, or clownfish (Amphiprion allardi) hides in the stinging tentacles of a sea anemone, Strait of Mozambique.

Another inhabitant of sea anemones is the domino. Juveniles often form groups. The adult lose the three white spots and the black body turns to grey.

A juvenile three-spot dascyllus, or domino (Dascyllus trimaculatus) hides among the stinging tentacle of an anemone, Memba Bay, Strait of Mozambique.
A juvenile three-spot dascyllus, or domino (Dascyllus trimaculatus) hides among the stinging tentacle of an anemone, Strait of Mozambique.

The Strait of Mozambique

In the Strait of Mozambique the East African Rift system continues offshore. Just like the northern parts of the East African Rift, there’s exceptional richness in terms of biodiversity and as well as mineral resources. Indeed, Mozambique’s rich marine biology is neighboured by a huge gas field in the north. The alarming rate of global warming indicates that we humans have already taken more from nature than any higher-level system is able to compensate.

The Swahili coast of East Africa is also culturally and historically fascinating. Already two thousand years ago, the monsoon trade winds allowed ships to sail from the Red Sea along the coast to the Gulf of Aden and southwards almost to the Strait of Mozambique, across the Indian Ocean to Persia and India. People living at the coast always relied on the ocean for eating, and fishing for subsistence continues to be important. Conservation of marine life aims at preventing unsustainable fishing methods in favour of traditional fishing to prevent overfishing.

The Mozambique Channel is a 3’000 metres deep part of the Indian Ocean with the East African mainland on the west and Madagascar on the east. The Zambezi river and the major Madagascar rivers flow into the Mozambique Channel. The current in the Strait of Mozambique is relatively warm and is directed to the south where it contributes to the Agulhas current along South Africa.

Fishermen prepare the boats and head out to the Indian ocean, Strait of Mozambique.
Fishermen prepare the dugouts canoes and head out to the sea, Strait of Mozambique.

Singing Whales

Whale sharks seem to love the coastal waters of Mozambique, and humpback whales migrate from the antarctica to warmer waters to give birth and nurture their calves in winter. The siren-like glissando songs of humpback whales consists of verses with variations of a theme. If a song proves to be successful in attracting females it’s taken over by other male humpbacks. We saw them slowly moving through the bay – and we also heard them sing during our dives. Isn’t nature generous?

Sea fan, Memba Bay, Strait of Mozambique.
Sea fan and diver, Strait of Mozambique. In a depth of about 40 metres, we heard the whales sing.

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