Kategorie: News
Coral project at Bastianos Dive Resorts
In the heart of the coral triangle, on the island of Bangka at the "Bastianos Dive Resorts", in the north of Sulawesi, a coral rehabilitation was established three years ago. Coral fragments that had no chance to develop into large coral blocks on loose ground were collected and attached to iron grids. Here they could now grow without disturbance and develop a new reef.
Unfortunately, traces of human activity are already visible even in the most beautiful reefs: The idea was to reforest areas of a natural reef that had been affected by various influences without damaging healthy corals. The materials should be natural or disappear over time. Iron as a support is readily accepted by stony corals if they are fixed wobble-proof. After much experimentation and consideration, those responsible agreed on cable ties for fixing. Although this is an unnatural material (nylon), it is quickly overgrown by stony corals and disappears into the calcareous skeleton. Only the superfluous ends had to be cut off. So every 15 cm, stony coral to stony coral, could be attached to the grid.
To achieve a better washing around of the small corals, the grids were anchored on limestones (Ytong), 20-30 cm above the coral reef with iron pegs in the bottom (photo I). This had the nice side effect that fish of various species could find hiding places. After one year, most of the coral species had grown around the iron and created a solid connection (photo II). After three years, only some areas of the iron grid are still visible (photo IV).
The cable tie on a fire coral (Millepora) can only be guessed at after only one month (photo V). Fire corals do not belong to the stony corals, they are hydrozoa, but they coat the iron very quickly with lime and thus protect it from rusting too quickly (photo VI). They therefore also belong to the reef builders.
The almost 5 mm wide cable tie is covered with polyps of the fire coral and lime (photo VII). The cable tie fixing a Porites stony coral is covered with polyps and lime at the contact points after only one month, despite their slow growth (photo VIII).
The Porites polyps have also spread up to 10 mm on the Ytong after only two months (photo IX). After 6 months, the cable tie in the Purites stony coral has all but disappeared, except for the clasp (photo X).
Staghorn corals (Acropora) belong to the fast growing stony corals. They can grow up to 15 cm in length per year. Due to their loose structure, they provide many hiding places for small damselfish and juvenile fish (photo XI). Unfortunately, the lower sections, in some species, also die off just as quickly, so that they sink into each other and do not form a stable unit. They fall through the grid and thus prevent reef formation. So only a few table corals and other Acropora species were included (photo XII). However, the result after two years is impressive (photo XIII).
Only when the individual coral blocks connect with each other has a new stable reef emerged (photo XIV). Different coral species or even genera fight against each other, but one is always the stronger and then overgrows the weaker one. Individual coral skeletons are thus connected to each other. Many damselfish use the bare iron bars as a place to lay their eggs and then to feed them and protect them against predators (photo XV).
A great project of the Bastianos Dive Resort. If you want to know more, you can meet representatives of the resorts at boot-2023 in Düsseldorf. The Bastianos can be found at the large Taucher.Net stand: 12 / A31.
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