After 20 years of civil war in Sri Lanka, the members of the JBL research team were the first to be allowed into the north of the country, which was occupied by the rebel Tamils. The destination was its untouched rainforests, rivers and streams. There are no natural lakes on Sri Lanka, but there are huge reservoirs which have developed into natural paradises. In cooperation with the well-known Sri Lankan ichthyologists, Professor Kotagama and Professor Silva, who were also on the expedition, we continued on foot, by jeep, raft, inflatable dinghy and on the back of elephants to the natural habitats of the fish and terrarium animals.
Unfortunately Sri Lanka has not been spared the effects of climate change. After months of drought the rainy season started early. The streams and rivers became raging torrents, with a milky-brown liquid instead of clear water. Each river crossing became an adventure and everyone was worried about expensive equipment such as cameras or electronic measuring instruments. Together with local fishermen, roughly half of the native fish species were located. Precise water analysis of their locations and measurements of the speed of the water current are providing us with new insights into how we can breed fish species successfully. Laws protecting native species limit or even ban the export of endemic fish and terrarium animals from Sri Lanka. Their export is only permitted if the animals have been bred for export. From the zoogeographical point of view, it is interesting to note that adjacent rivers do not have the same species of fish. All the major river systems are separated by parallel mountain ranges, effectively preventing any mixing of fish species.
In addition to aquaristic reasearch, research related to the terrarium was also on the timetable: measurements of air temperature, humidity and the composition of the ground were carried out. Terrarium specialists Rainer Nagel from Kiel and Jürgen Weisbrod from Wiesloch were able to observe monitor lizards, mountain horned dragons, radiated tortoises and skinks.
1998 was a truly black year for the Maledives: the natural phenomenon known as El Nino caused above-average high water temperatures of over 30°C. This led to the death of algae (zooanthellen) living mainly on rock coral, which usually led to the death of the coral. Known as coral bleaching, this process has sadly become notorious world-wide. After staying in the rainforest in Sri Lanka, the JBL research team travelled to the Maldives to gather their own impression of the damage and its effects on the ecosystem of the coral reef.
Their findings were shocking: all the hard corals down to a depth of about 10 m are practically 99% dead! The world-famous wealth of fish of the Maldives appears not to have suffered, however. Astonishingly all the reef inhabitants are still to be found on the reef top. This of course leads to the supposition that they obtain their food from the deeper sections of the reef which are not damaged. It is only to be hoped that these reef zones can withstand the increased demand for food in the long term without suffering any damage! Yet there is hope too: on the tips of the dead corals young corals have settled which look like young buds. The maximum size of these regrowing corals (mainly acropora species) is 13 cm. This growth coincides more or less with the experiences of marine aquarium owners who keep acropra species in their tanks. Huge shoals of fish are still to be found in the blocks of coral and under the overhangs. In the open water grey reef sharks and black-tipped reef sharks can still be observed. Even if these elegant swimmers are not exactly popular aquarium fish, they are always fascinating to observe.
During the underwater feeding trials, a new member joined the JBL team. A Napoleon wrasse, over 1 m long, joined the group and watched with interest to see if the various reef inhabitants ate the aquarium food products on offer. When a large moray eel stuck its head in the JBL MariPerls can, his patience came to an end. He snapped a whole can into his huge mouth and chewed on it until it was in shreds. It seemed to have tasted good, as he now swam from diver to diver, begging for cans. JBL is considering developing a special Napoleon wrasse food in bite-proof cans... Light measurements with laboratory luxmeters to a depth of 25 meters yielded very interesting results. Below 25 m, however, the water pressure was so strong that the luxmeter casing (in an Ewa marine underwater camera case) gave up the ghost. Teamwork was called for when it was time to zone a fringing reef. A line was unwound 30 m deep from the shore to the end of the reef, with knots every 10 m. Each team member was responsible for a 10 m section, on which all sessile organisms were identified and counted. The detailed results are to be published in specialist magazines shortly.