Never has a JBL expedition been so varied: pet shops in Tokyo - Japanese culture in Nikko - koi breeders in Mushigame – marine water research near Ishigaki and a jungle with freshwater biotopes at Iriomote!
A full 16 day program for 32 participants, all exhausted afterwards, but a mass of experiences richer. Even the pig ear cartilages for dinner were halfway tasty!
After Tokyo and Nikko, it was really exciting to visit the koi breeders: How much do the water values in the indoor keeping facilities differ from those in the natural ponds (mud ponds)? The koi breeders were just as interested in the results as our participants, because they have less to do with water values. At water temperatures just below 20 °C, the hardness values in the natural ponds were between 0 and 2 °dGH (KH: 0.5-2 °dKH), while we measured up to 15 °GH and 5 °KH in the indoor ponds. Heavy rainfall is bound to be one of the reasons for the extremely soft water in the natural ponds! Two of the top breeders (Kaneko and Yamamatsu Koi Farm) proudly showed us their koi, which they have been raising with JBL PROPOND koi food for two years. JBL boss Roland Böhme was very interested to hear the two koi breeders reporting that they needed less food compared to before and that the water pollution had decreased as a result. Although the koi breeders only measure the ammonium/ammonia content, the foam formation on the water surface gives them visible feedback on the protein load in the water.
After a 2500 km flight south, the JBL expedition team landed on the island of Ishigaki, surrounded by coral reefs. One half of the team continued by ferry to the jungle-covered neighbouring island of Iriomote, while the other half, who had diving licences, spent three days diving and exploring various destinations in a dive boat. Especially impressive was a manta ray cleaning station, where they were able to observe several manta rays.
After the obligatory marine water measurements (KH 5.5-7.5; pH 8.2-8.4; Ca 440 mg/l; Mg 1360-1480 mg/l; density 1.025) we examined some intact reef sections as well as some reef sections de-stroyed by storms. Some curious sea snakes especially took to the participants during their many dives. The snakes weren’t at all afraid and they searched the divers as thoroughly for fish as they did all the small holes in the reef. After three days the teams swapped over, and the divers went to the jungle island, while the snorkelers explored the reefs in shallower areas.
The highlights of the jungle island Iriomote were the small clear water streams and the brackish water biotopes. The participants spent hours in the cool 24 °C water observing scats, Stiphodon gobies, Macrobrachium shrimps and many other fish species. Only in nature are real observations possible about the space required by the animals (radius of action) and about their eating habits. In the small territories of the gobies talk immediately came round to animal activists, who consider a 60 cm aquarium unsuitable. Gobies often choose to live in much smaller areas!
The rainforest itself also had some extremely exciting inhabitants at the ready. After a long search we found the largest land crab in the world, the coconut crab. Four snake species were observed and we also spotted the only tortoise species there (Cuora flavomarginata evelynae). And, the team managed to save the life of a baby turtle: A snake had wrapped itself around it and was trying unsuccessfully to swallow it. Okay,okay - you should never interfere with nature. But you just can’t watch a turtle, which is too big to become food, being killed…
The next JBL expedition, which is open to all nature lovers, will take us to Colombia in 2021. Registration is now possible via the JBL website: Colombia Expedition First-time applicants always have priority over "repeaters".