Subterranea Croatica, Vol. 15 No. 2, 2017.
Professional paper
The Preliminary Report on Natural Sciences Research During the Cave Diving Expedition to the Red Lake 2017
Roman Ozimec
; ADIPA – Society for Research and Conservation of Croatian Natural Diversity, Zagreb, Croatia
Branko Jalžić
; Croatian biospeleological society, Zagreb, Croatia
Dušan Jelić
; Biota j.d.o.o., Zagreb, Croatia
Abstract
The Red Lake (Crveno jezero) is a complex karst phenomenon, a partially submerged pit with a vertical difference of 526,9 m, surface area of 27 000 m2 and a water column range from 232 to 315 m with the deepest point being four meters below sea level. The maximum accumulation of water is 8,24 million m3.
The lake is located near the town of Imotski in the county ofSplit-Dalmatia. It has been protected since 1964 as a Geomorphological natural monument. Today, it is a part of the Natura 2000 network of protected areas number HR2000934 and is managed by the Public Institution for Management of Protected Natural Values in Split-Dalmatia county.
The geomorphology and the depth of the lake make undertaking scientific research extremely difficult and complex. Research was started by the Austrian biologist Rudolf Kner and was continued through the 19th and 20th centuries by many other researchers. In 1998 the Croatian Speleological Federation organised an international cave diving expedition. Systematic geomorphological and hydrological research in the 21st century has been carried out by Ivo Andrić, Ognjen Bonacci and the local “Crveno jezero“ Diving Club.
The 2017 Red Lake Cave Diving Expedition took place in May 2017 and the primary goal was to send a diver to the bottom of the lake whilst the secondary goal was scientific research. The French cave diver Frederic Swierczynski was able to dive to the bottom of the lake 245 m down. He made a video of the whole dive and collected a sample of substrate for the scientific team. Comprehensive natural sciences research of Red Lake was led by Roman Ozimec and Branko Jalžić.
During the course of five days an eight-member team carried out the following research: microclimatological, ecological, bacteriological, protistological, algaeological, mycological, lichenological, bryological, floristic and faunal, all of which was thoroughly photographed.
A well conserved and variable population of the endemic spotted minnow (Delminichthys adspersus) was found, along with the largest specimens of the species ever recorded. Another species of fish, The Illyrian Spined Loach (Cobitis illyrica) was also recorded. Moss from the genus Fontinalis which grows around the lake is home to many terrestrial and aquatic organisms such as: snails (Gastropoda), flatworms (Tricladida), leeches (Hirudinea), isopods (Isopoda), spiders (Araneae), centipedes (Chilopoda), pseudoscorpions (Pseudoscorpiones), beetles (Coleoptera), whereas many planktonic organisms live in the water column such as, phytoplankton (Dinophyta), rotifers (Rotatoria), water fleas (Cladocera) and copepods (Copepoda) among which were discovered species new to science. The first subterranean organisms from the groups of amphipods (Amphipoda) and oligochaetes (Oligochaeta) were recorded at the bottom of the lake among which were more species that are new to science.
All of the results, including scientific papers, will be included in the popular scientific monograph “Red Lake”.
Keywords
Biospeleology; Cave Diving; Red Lake
Hrčak ID:
197121
URI
Publication date:
1.12.2017.
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