Kategorie: News
Conservationists and divers take action against invasive species
An unusual conservation effort took place at Linkenheimer Baggersee “Streitköpfle” on the evening of August 12: At dusk, recreational divers and conservationists set out to hunt North American bullfrogs. This invasive species has been threatening native biodiversity in the northern Upper Rhine region for around 30 years and is considered one of the most problematic invaders of ecosystems worldwide.
The area west of Linkenheim-Hochstetten, adjacent to the Natura 2000 site “Rhine floodplain from Karlsruhe to Philippsburg,” is particularly affected. Here, the bullfrog (Lithobates catesbeianus (formerly Rana catesbeiana)) finds ideal conditions in a network of quarry ponds, backwaters, and ponds. Measuring up to 20 centimeters in length, it devours almost anything that fits into its mouth – from insects and small fish to native amphibians. Even the fist-sized tadpoles are voracious eaters and cause damage to the environment even at this early stage of development.
Its high reproduction rate and large appetite make the bullfrog a serious problem for native wildlife.
The Baden-Württemberg Nature Conservation Fund is currently funding a project to combat the bullfrog with around €152,000. Aquatil gGmbH, led by renowned zoologist Prof. Dr. Ralph Schill (University of Stuttgart), is managing the project. As part of this project, the nocturnal frogs and their tadpoles are regularly caught in and around bodies of water and killed in accordance with animal welfare regulations. These measures are coordinated by the nature conservation authorities and are based on European guidelines for dealing with invasive species. The aim is to develop effective control strategies based on a deeper understanding of the ecology, spread, and hibernation of the bullfrog.
An important part of the project is to equip adult animals with transmitters so that their movement patterns between land and water can be tracked. In addition, species detection dogs are being used for the first time in Germany to track down hibernating frogs.
State Secretary Baumann supports the helpers.
Dr. Andre Baumann, State Secretary in the Baden-Württemberg Ministry of the Environment, Climate and Energy, also supports the campaign at the Linkenheimer Baggersee. As a recreational diver, he is keen to help the divers and conservationists remove the animals.
“Every female capable of reproduction that is tracked down and removed can potentially prevent the laying of 10,000 to 20,000 eggs,” says Baumann. He praises the exemplary cooperation between civic engagement and nature conservation authorities in the fight against bullfrogs.
Background information
The “Bullfrog Control in BW” project is being carried out by Aquatil gGmbH under the direction of Prof. Dr. Ralph Schill from the University of Stuttgart. It includes telemetry studies, the use of tracking dogs, a symposium, and an information brochure. It is financed by earmarked proceeds from the GlücksSpirale lottery. Further information is available online at the following address: https://stiftung-naturschutz-bw.de/web/guest/ochsenfroschbekaempfung
The control of invasive species is also an important issue at the European level. Regulation (EU) No. 1143/2014 regulates the prevention and management of the introduction and spread of invasive alien species.