Bearded dragons are nocturnal

Wrecks - new life in old ships

Hardly anything stimulates the imagination of treasure hunters, seafarers and divers more than finding a wreck. Many questions immediately arise: which ship was that? When, why and under what circumstances did it go down? Were there victims and what was it loaded? The mysterious aura and the silence of the underwater world add to the fascination of sunken ships.

The attentive observer of a wreck will notice a lot more than just its size and location, its condition and its cargo. The longer it remains on the seabed, the greater the number of marine animals that inhabit it. Some wrecks develop into habitats so rich in species that they are sometimes referred to as "artificial reefs". What makes them so attractive to marine life?

Sought-after growing areas. Most of the seabed consists of sand and mud. It is difficult or even impossible to get stuck on this mobile surface. Wrecks, on the other hand, offer a stable hard substrate and are therefore often colonized by sponges, hydrozoans, hard and soft corals, bog animals, tunicates and other sessile organisms. Over time, these animals can give old wrecks an unimagined blaze of color.

Towards the light. Large wrecks with their superstructures can rise many meters from the sea floor. This can be enough to provide light-loving species with a suitable habitat close enough to the water surface. Hard corals in particular need a lot of light because they live in symbiosis with algae. A sufficient supply of light is essential for their photosynthesis.

Hiding place and sleeping accommodation. Many fish use the abundance of space in a wreck to hide or rest there. The twilight inside cabins, cargo and engine rooms is an ideal resting place for nocturnal fish during the day. The spectrum of fish species that wrecks benefit from in this way ranges from small glass fish to moray eels. On the other hand, some diurnal fish appreciate wrecks as nocturnal sleeping places. Parrot fish disappear into crevices and cracks, puffer fish rest exposed on all kinds of structures.

Attractive hunting ground. The abundance of fish in and around wrecks attracts predatory fish, which find rich prey here. Barracudas and jacks hunt in the open water around the wreck. Inside wrecks, scorpion fish lie in wait, hunt groupers and moray eels go on their nightly hunting expeditions. But wrecks are not only popular hunting grounds for fish. Underwater photographers also get their money's worth here. From the wide-angle view of the ship's hull to macro photos of tiny details, the wreck offers the ambitious diver everything. So it is not surprising that old shipwrecks with their mysterious past and their splendid growth are among the most popular diving spots in all of the world's oceans.

Selection of recommended wreck dives:
Rainbow Warrior (25 meters, Bay of Islands, New Zealand)
SS Thistlegorm (25 meters, Shab Ali, Red Sea)
RMS Rhone (10 to 15 meters, British Virgin Islands)
Fujikawa Maru (15 to 40 meters, Truk Lagoon, Micronesia)
Constellation (10 meters, Bermuda)
SS Yongala (33 meters, Townsville, Australia)

Photos: Dr. Reinhard Kikinger

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