Germany’s flora and fauna face three huge challenges: increasing biodiversity loss, changes to and destruction of habitats, and the proliferation of non-native organisms. These ‘new’ or allochthonous species include animals and plants whose occurrence in their current habitats results from human activity which occurred in the period from 1492 onwards. These alien species compete with native species that have lived in Germany since the last ice age and also with ‘old’ or autochthonous species like the house mouse (Mus musculus), which arrived in Germany long before America was discovered.
Rapidly increasing connectivity between the continents goes hand in hand with exchange of organisms, and the routes by which aquatic alien species are transported can vary greatly. Apart from intentional introduction to increase food supply, animals arrive in the ballast water of ships, are released from aquariums or escape into native waters from captivity. More than 3,000 species are transported in ballast water every day; and every litre of ballast water contains approximately 50,000 microscopic animals and 110 million plants. While many of these newcomers do not survive the journey, some do manage to find a new home without falling prey to predators.
In Germany, several thousand introduced species have become established in more than 110 aquatic habitats. Although not all are invasive, they nonetheless compete with native species for habitats and food. One particularly invasive alien species is the American bullfrog (Lithobates catesbeianus), which the international Invasive Species Specialist Group (ISSG) lists among the top 100 of the World’s Worst Invasive Alien Species. Adult frogs grow to some 80 cm in length and one kilo in weight. Their baritone call sounds like the bellow of a bull. The bullfrog is seen as a huge threat to native amphibian populations and its distribution is difficult to control. There are only a few known occurrences in Germany at present and these have been the subject of intensive monitoring for a number of years.
The NEOBIOTA – Neue Arten in unseren Tauchgewässern (New Species in Diving Waters in Germany) project combines nature conservation with amateur sport. Its online platform provides information on various animal and plant species along with a distribution map showing current sightings. The website also contains information on research groups whose work focuses on invasive species. The NEOBIOTA Team also seeks to work with other scientists to evaluate the data. These efforts have so far resulted in two scientific studies on freshwater jellyfish in Germany.
The NEOBIOTA campaign focuses on a different group of animals and plants every year. Be it the oppossum shrimp (Mysida) which occur in large swarms, small freshwater jellyfish (Craspedacusta sowerbii) or the magnificent bryozoan (Pectinatella magnifica) which can be a small as tennis table ball or as big as a football – with every report of a new sighting in a German water body, new information is gained on the hidden lives of many aquatic organisms. Anyone who engages in water sports, be they divers, canoeists, yachtsmen or swimmers, are thus invited to report their sightings. They can all contribute to protecting and conserving not only Germany’s water bodies, but also its biodiversity.
NEOBIOTA-Online-PlattformContact: Ralph Schillkontakt@neobiota.infowww.neobiota.info
Verband Deutscher Sporttaucher (VDST) e.V. Dr. Gisela B. Fritz Natascha Schwagerus PD Dr. Ralph O. Schill