Bull lakes
| Big Bull Lake | ||
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| Great Bull Lake, April 2007 | ||
| Geographical location | approx. 5 km south of Rotenburg (Wümme) , Lower Saxony | |
| Location close to the shore | Rotenburg (Wümme) | |
| Data | ||
| Coordinates | 53 ° 3 '25 " N , 9 ° 25' 1" E | |
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| surface | 10 ha | |
| length | 500 m | |
| width | 200 m | |
| PH value | 4.9 | |
|
particularities |
Natural moor lake |
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| Little bull lake | |
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| Kleiner Bullensee, view in west direction, April 2007 | |
| Geographical location | approx. 5 km south of Rotenburg (Wümme) , Lower Saxony |
| Location close to the shore | Rotenburg (Wümme) |
| Data | |
| Coordinates | 53 ° 3 '46.4 " N , 9 ° 24' 34.5" E |
| surface | 3.8 ha |
| length | 250 m |
| width | 150 m |
|
particularities |
Natural moor lake |
The Bullenseen (two lakes : Großer and Kleiner Bullensee) originated as a relic of an Ice Age glacier in the Wümmeniederung south of Rotenburg (Wümme) and north of Kirchwalsede , Lower Saxony . Half of the bull lakes are located in the municipal areas of the city of Rotenburg (Wümme) and half of the municipality of Kirchwalsede, in the Rotenburg (Wümme) district . The Kleine Bullensee is included in the nature reserve " Großes und Weißes Moor ".
Two other lakes in the district of Rotenburg (Wümme) also bear the name Bullensee: the Bullensee near Kirchtimke a little further north, namesake for the nature reserve of the same name , and a little further south another significantly smaller lake (30 × 50 m) near Dreeßel , 7 km west from Visselhövede .
The bull lakes as a recreational area
Due to the high humic content due to the boggy environment, no fish live in the two lakes. The Kleine Bullensee and the surroundings of the Großer Bullensee have been designated a nature reserve since 1938 and are also known as a local recreation area in the greater Bremen / Rotenburg (Wümme) area. Therefore there is also a weekend house settlement here. Similarly, has EWE AG , a property on Bullensee. In addition, the DLRG (local group Rotenburg Wümme) has a rescue station with a tower on the Großer Bullensee to increase the safety of bathers on weekends.
Due to the dark, boggy water and the wide shallow water zones, the temperature rises very quickly when exposed to sunlight. In summer there are often "bath temperatures" of up to 30 ° C near the shore. Depending on the distance from the bank and the depth of the water, temperature differences of approx. 5 ° C then occur. In the official bathing water monitoring carried out between 2008 and 2010, the water of the Großer Bullensee is described as humic acid and slightly cloudy, with a pH between 4.5 and 5.
Since there were ever more exuberant celebrations by young people at the Großer Bullensee on May 1st , combined with considerable disruptions for the adjacent nature reserve, the Rotenburg (Wümme) district administration decided in 2012 to issue a general entry ban for the area on this day. The reason for the measure was the noise from drunken visitors and the fact that in the past the visitors to the celebrations had disposed of their waste in the nature reserve.
etymology
The name of the two lakes is probably derived from the Low German verb bullern , which means something like rumble or roar. From the time of superstition, the lakes could be associated with Poltergeistern or noisy swarms of ghosts.
Rewetting of the nature reserve
In recent years attempts have been made to rewet the partially drained White and Great Moor. In 2002 there was an explosion of the alga Vacuolaria virescens , but this was not directly related to this rewetting measure . However, it is unclear where the necessary nutrients came from. They may have been blown up from the bottom of the lake, brought in by the many bathers, washed in from groundwater or washed into the lake from the surrounding area due to the heavy rainfall in 2002. It is more likely, however, that bog water from the Kleiner Bullensee, whose water level is approx. 50 cm higher, and bog water from the edge zones were deliberately directed into the Grosser Bullenssee.
In order to rule out the final reason for future green algae growth, a ditch was dug around the Großer Bullensee, which is intended to hold back surface water after heavy rainfall from the neighboring moor, at least at these points. The trench is now neglected. In 2018, bog water still runs into the Großer Bullensee and the water in the lake is still cloudy. In many places an underwater carpet of plants forms.
Flora and fauna
One of the peculiarities of the flora of the Bull Lakes is the occurrence of all three sundew species that occur in Central Europe , including the rare long-leaved sundew ( Drosera anglica ). The herpetofauna is among other grass snakes ( Natrix natrix ) and in the surrounding nature reserve also reserves the viper ( Vipera berus ) and various Froschlurchpopulationen represented.
See also
Web links
- DLRG Rotenburg Wümme
- Bathing water quality in Großer Bullensee
- Bathing water atlas Lower Saxony: Bullensee (here the Great Bullensee is meant)
- www.anglermap.de: Water profile Großer Bullensee
- www.anglermap.de: Small Bullensee water profile
Individual evidence
- ↑ Bathing Waters Atlas Lower Saxony: Bullensee (determined 2008–2010, only Großer Bullensee) (accessed on November 8, 2014)
- ↑ Landkreis Rotenburg (Wümme) April 25, 2012: Nature reserve closed on May 1 ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ brown color of the Great Bull Lake; Presentation of the report. (PDF; 292 KB) Item 5 on the agenda. In: Minutes (public part) of the 8th public / non-public meeting of the Committee for the Environment, Nature Conservation and Planning on November 22, 2004 in Rotenburg, district building, large conference room. Rotenburg (Wümme) district, der Landrat, pp. 3–4 , accessed on January 10, 2015 .
- ↑ Eckhard Garve: Distribution atlas of the fern and flowering plants in Lower Saxony and Bremen. In: Nature conservation and landscape management in Lower Saxony. 43, 2007, ISSN 0933-1247 , pp. 1-507.
