Last week nearly the entire Dutch team of CoralGardening caught a glimpse behind the scenes of a particularly successful coral breeding program at Burgers’ Ocean in Arnhem! We were treated to a very extensive tour by Max Janse, who has been curator of the aquarium since its founding! Max made an appearance in the news a few weeks ago: Burgers’ Zoo rapidly relocated more than 300 corals to two aquariums in England ahead of Brexit (in order to avoid complications). The coral colonies grow so enthusiastically at Burgers’ Ocean that they are pruned regularly in order to avoid obstructing each other. Did you know that more than 60 European aquariums are supplied with coral cultivated in the Netherlands? (Trouw 22/1/2019 Dutch).
During our tour, Max took all the time we desired in order to answer our many questions, such as: can CoralGardening receive coral from Burgers’ Ocean?
Unfortunately, as it turns out, placing coral back into the wild is not possible. Max does not know the exact name and origin of all of the corals; for example, there are more than 4500 coral species within 31 families. He know which families the aquarium has, but pinning down the exact species is much more difficult. The introduction of so-called “exotics” or “invasive species” in locations they do not naturally belong is a possible threat to the naturally occurring species that do belong there. In the Netherlands, for instance, the native flat oyster has been expressed and replaced by the intentionally introduced Japanese oyster. Max has stated that they are working with a university to catalog and classify their coral, so who know what the future may hold!
Here are some other interesting facts from Max:
- The breeding program was utterly unsuccessful for the first 8 years, it was a process of trial and error. For example, initially there was massive problem with algae and the use of grazing fish. Until they managed to dial it in 10 years ago.
- The salt water is produced in house using groundwater and salt, but no sea salt, which is too inconsistent in its composition.
- The water for the coral aquarium is enriched with minerals, including calcium, so that the corals can for their lime skeleton more easily and flourish!
- The ecological processes in the aquarium are not always predictable. A while back the windows were found to be covered in chalky circles. Max consulted Naturalis Biodiversity Center, were in was established that the circles were foraminifera, unicellular eukaryotes. The scientist who identified them was wildly enthusiastic, because no examples of this had ever been cultivated in captivity before!
Burgers’ Ocean is indeed worth a visit! The shark basin, including a Hammerhead shark, is an impressive sight to behold, and there is a tunnel where Eagle Rays and Sting rays swim above one’s head, majestic and beautiful to behold! Unfortunately there was no time to see the newly installed Mangrove ecosystem, so I will defiantly have to to return!