A journey into the future
Even cold-water corals form beautiful and colorful coral reefs, calling them "animal forest", forest created by animals, explain us Dr. Jürgen Laudien and his colleagues. They play an important role in the ecosystem and offer to other marine life habitat and protection. This image corresponds to the Comau fjord in Chile, which shows us a reddish species associated with the coral.
Image: Thomas Heran
Dr. Jürgen Laudien research on ocean acidification - corals in Chile are survival artists
BREMERHAVEN. Television viewers are currently enchanted by the series "Blue Planet". When Dr. Jurgen Laudien, of the Alfred Wegener Institute (AWI) close his diving suit and submerges in the Patagonian water, he can look at equally impressive images live in. The marine biologist conduct research on cold-water corals, in a place you would not immediately associate with AWI. He is studying hard corals, some of which are growing in the Old Harbor's lab, which are causing sensation.
The sensation is a orange-colored little thing. This is how larvae of a stony coral Caryophyllia huinayensis look on the first day.
...first larvae stages
Image: Thomas Heran
Laudien and his PhD student Thomas Heran were able to document the larvae for the first time. A stroke of luck, because the scientists still have many questions about reproduction and development. We have a natural laboratory there.
... will look like this later
Image: Thomas Heran
Dr. Jürgen Laudien and Thomas Heran, mentioned that Nobody before described the reproduction of these cold-water corals in captivitys. Laudien and Heran were able to observe how the offspring initially roamed around in the tentacles of an individual. The species at the AWI aquacultures comes from the Comau Fjord in Southern Chile. Thereby the Bremerhavener visited the research station in Huinay Bay and was astonished. "It's a beautiful place", says Laudien, "you are totally in the wild". A rainforest spreads out on misty mountains that can reach more than 2000 meters, with snow caps all year round. The steep granite walls seem to grow out of the water. Laudien: "It's great to dive there and see the coral reefs".
The special feature of Comau Fjord rely in it's water, due to it becomes more acidic as one goes to inland. "That is why when we drive into the fjord, we are making a journey into the future", says Laudien. The reason why Caryophyllia huinayensis and the other two species of corals (Desmophyllum dianthus and Tethocyathus endesa) are found in water with the acidity predicted by the IPCC by the end of the century, is one of the main scientific focuses of the section. They said that the increment of carbon dioxide (CO2) will make the oceans more acidic, and cause the collapse of the ecosystems. The more carbon dioxide enters the oceans, the more carbonic acid forms. This mainly affects organisms with calcareous shell and skeletons. Stony corals are part of this, which deposit aragonite on their base and so can build huge reefs over many thousands of years.
Diver: Dr. Jürgen Laudien attaches bolts in the Comau fjord, to which plates are later attached. The marine researchers want to see the community development and how fast the plates are colonized by the stony corals.
So how does the three corals in Chile manage to grow in the acid waters of Comau Fjord? That's what Laudien and his team want to find out. "We have a natural laboratory there", says Laudien.
What's the trick?
Experiments are underway in Bremerhaven at the AWI, due to be known that corals need a lot of energy to survive in an acidic environment. This is what the marine biologists read due the necessity to increase the respiration in order to compensate the acidity of the water. But this does not seem to be a problem in the Comau Fjord. Its great abundance of zooplankton, tiny organisms that float in the water are used as food by corals, considering this their main source of energy. The mechanism is that the coral creates their own Milieu inside them to a degree that is not yet fully confirmed. Nonetheless, The fact that the three species can be found in Comau Fjord from 25 meters onwards, is another fortunate circumstance in the matters to experiment with them. The marine researchers can dive and take samples of the corals, saving in gear and logistic and therefore expensive dives. Normally, the animals growth between 250 to 2,500 meters depth, and also in the deep sea.
At the end of this year or early next year, AWI employees will travel to Chile again. Thomas Heran will scroll through his wonderful underwater footage documenting the work of scientists and underwater life in Chile's fjords. Another fact is that some years ago, blue whales appeared in front of the station, the largest animals on this planet. Laudien: There are scenes that could have been included in the films " The Blue Planet".