Two new gastropod species recently collected in the St. Naum springs situated near the southeastern edge of Lake Ohrid in North Macedonia are described. Ancylus naumiensis n. sp. molecularly belong ...to “Ancylus sp. D” of Albrecht et al. (2006) previously recorded for St. Naum springs in Macedonia and Tusemista spring in Albania. A new genus, Ohridonaumia n. gen., was created to include a new species, Ohridonaumia trajanovski n. sp.
In the DEEP core from the Lake Ohrid ICDP drilling project, the carbon isotope composition of bulk organic matter (δ13CTOC) over the last 516 ka shows a negative correlation with total organic carbon ...(TOC) and total inorganic carbon (TIC). This relationship is marked by periods of lower δ13CTOC values corresponding to higher TIC and TOC. Along with TOC/TN, the correlation between δ13CTOC and δ13CTIC suggests that most of the organic matter in the core is from aquatic primary production within the lake. The combination of TOC, TIC, and δ13CTOC is able to disentangle long-term glacial/interglacial cycles and, to a lesser extent, millennial scale climate variability. Over the longer term, δ13CTOC shows modest variability, indicating that the δ13C of the dissolved inorganic carbon (DIC) pool is stabilised by the supply of karst spring water characterised by δ13CDIC influenced by the bedrock δ13C value, and the long residence time of the lake water and well mixed upper water column promoting equilibration with atmospheric CO2. However, comparison between arboreal pollen (AP%), TIC and TOC data indicates that the δ13CTOC signal is modulated by the leaching of soil CO2 through runoff and spring discharge, changes in primary productivity, and recycling of organic matter within the lake, all affecting δ13CDIC. Exceptionally low δ13CTOC during some interglacial periods (e.g. MIS7 and MIS9) possibly indicate rapid intensification of organic matter recycling and/or increasing stratification and enhanced methanogenesis, even if the latter process is not supported by the sedimentological data.
•The organic matter δ13C in Lake Ohrid's DEEP core is most from primary productivity.•DIC from the karst springs and atmospheric CO2 equilibration dominate Lake Ohrid.•Soil CO2 drives of the organic matter δ13C over interglacial/glacial periods.
The Albanian part of Lake Ohrid is endangered by heavy metals, the source of which is mainly the old mining waste around the lake shore, but also agricultural pollution. The chromium and nickel ...concentrations were investigated in the fall season in the sediment and common reed (Phragmites australis). The peroxidation of lipids in stalks was also investigated. The study was conducted on three points of the lake: at the entrance to the city of Pogradec, the former Fe-Ni mine and the village of Lin (control point). Heavy metals were determined with the method of atomic absorption spectrometry and malondialdehyde, using the spectrophotometric method. The results showed that there was greater accumulation of nickel than chromium in both sediments and stalks in the three explored points. The sediment and plant samples taken in the part of the former Fe-Ni mines showed a higher level of investigated metals, compared to the other two research points. At this point, the difference was significant for chromium (p <0.01) compared to the village of Lin, whereas for nickel there was a significant difference (p <0.01) for the two research points compared to the reference point (Lin). Concerning the Cr and Ni levels in stalk, a significant difference (p <0.01) was observed for both metals only in the samples taken from the former Fe-Ni mines, compared to the village of Lin. Meanwhile, the increased MDA level caused by oxidative stress was higher in the plants collected at the entrance of Pogradec, not only with the checkpoint (p <0.01) but also with the plants collected in the former Ni-Fe mine.
Here we describe a new monotypic glomerid genus, Macedomeris gen. nov., with Macedomeris ivoi sp. nov. (a presumed troglobiont) as its type species. The new genus clearly differs from all other ...genera within the order Glomerida by the combination of several morphological characters: the presence of a characteristic deep lateral pit ("Ohrgrube") on both sides of the thoracic shield, the absence of striking ornamentation on tergites, the fusion of tergite 11 with the anal shield, and the lack of a large medial hump. In addition, Macedomeris gen. nov. differs from other members of the Glomerida by its general appearance, the presence of 2 or 3 vestigial ommatidia and a very wide syncoxite of a 2-segmented leg-pair 17 in the male. Notes on its ecology, troglomorphic features, and relationships with similar members of the tribe Doderiini are also given.
ABSTRACT
Geoarchaeological investigations on the northeastern shore of Lake Ohrid revealed 3.5 m thick deepwater lacustrine sediments overlying terrestrial vegetation macrofossils, worked wood and ...abundant potsherds dated to the Late Bronze Age (LBA). Distinct contact of deepwater sediment with the sub‐aerial weathered limestone bedrock point to a sudden increase in lake level. According to radiocarbon data, catastrophic flooding occurred shortly after 1214 yr bc. Because the area is located in a highly active seismic zone, we propose that this event was caused by tectonically induced, metre‐scale coseismic subsidence related to faults bordering the Ohrid alluvial plain. Moreover, this event coincides well with a dramatic switch in the habitation and settlement strategy in the region. More important, however, is the finding that the age of the proposed massive tectonic event and change in habitation lies within the interval of the proposed ‘earthquake storm’ in the eastern Mediterranean dated to 1225–1175 bc. As the Ohrid‐Korça zone belongs to the same tectonic province, a relationship between the abovementioned earthquakes and the proposed event can be expected. This research therefore might provide the first direct evidence of a large‐scale earthquake event linkable to the LBA collapse of Europe's first urban civilisation in the Aegean.
We investigate the modern hydrology of Lake Ohrid (Macedonia/Albania) using a combined hydrological and isotope-based modelling approach and present a new evaluation of contemporary water balance and ...palaeoclimate estimates. The combined model is able to estimate hydrological components that cannot be directly measured, and indicates that sublacustrine spring inflow is in the order of 50% higher than previous estimates and groundwater outflow comprises approximately a third of overall water outflow. In combination with sediment core oxygen isotope data, we used the combined model to quantitatively reconstruct past climate, in particular precipitation, during the early Holocene and last glacial period. Calculated precipitation in the early Holocene was higher than the value for present day and was approximately 44% lower than present during the last glacial, assuming the majority of precipitation fell as snow. The estimated amount of precipitation in the last glacial would have been high enough to provide refugial conditions at Lake Ohrid and to support the continuous existence of arboreal vegetation in the catchment. The improved understanding of the modern isotope hydrology of Lake Ohrid is fundamental for explaining the systematics of past isotope variation and providing context for extended sediment records from the lake, which will provide longer-term palaeoclimate reconstructions covering multiple glacial-interglacial cycles.
•We provide a new evaluation of contemporary water balance for Lake Ohrid.•Sublacustrine spring inflow is 50% higher than previous estimates, groundwater outflow comprises a third of total output.•Early Holocene precipitation is calculated to have been 26% higher than present, and 44% lower during the last glacial.•Last glacial precipitation was high enough to support arboreal vegetation in the catchment and provide refugial conditions.
The period corresponding to Marine Isotope Stages 9 (MIS 9) offers the opportunity to study orbital and sub-orbital scale climate variability under boundary conditions different from those of better ...studied intervals such as the Holocene and the Last Interglacial. Yet, it is poorly represented in independently-dated continental archives around the Mediterranean Region. Here, we present a speleothem stable isotope record (δ18O and δ13C) from the Former Yugoslavian Republic of Macedonia (F.Y.R.O.M., southern Balkans), which consists of two periods of growth broadly covering the ca. 332 to 292ka and the ca. 264 to 248ka intervals (MIS 9e-b and late MIS 8). We interpret the speleothem δ18O as mostly related to regional hydrology, with variations that can be interpreted as due to changes in rainfall amount, with higher/lower values associated to drier/wetter condition. This interpretation is corroborated by a change in mineralogical composition between aragonite and calcite at ca. 328ka, which marks increasing precipitation at the onset of MIS 9 and occurs within a trend of decreasing δ18O values. Also the comparison with the multiproxy climate record available from the nearby Lake Ohrid seems to support the proposed interpretation. The MIS 9e interglacial appears to be characterized by wettest conditions between ca. 326 and 321ka, i.e. lasting ca. 5kyr. Decreasing precipitation and enhanced millennial scale variability matches the glacial inception (MIS9 d to b), with drier events at ca. 319ka (ca. 2kyr long) and 310ka (ca. 1kyr long), and a major rainfall reduction between 306 and 298ka. The latter is followed by a prominent wetter period between 298 and 295ka, for which carbon data values suggest high infiltration rate. Rainfall decreases again after 295ka, and remain low until the growth interruption at ca. 292ka. Resumption of the growth and progressive soil development, expressed by the carbon isotope record, occurred during the late part of MIS 8. Despite the rather high temporal uncertainty (average 6ka), the speleothem hydrological record complements the environmental information provided by the Lake Ohrid record and also fits well to the framework of regional and extra-regional variability, showing similarities with pollen records from southern and western Europe, both at orbital and at sub-orbital time scale.
•A speleothem record from the MIS9 to 8 interval from Southern Balkans•Speleothem oxygen isotope composition is related to hydrology.•Enhanced hydrological variability at orbital and millennial time scale•Good coherence with the regional and extraregional climatic framework
Multi-proxy analyses on core JO2004-1 recovered from Lake Ohrid (40°55.000
N, 20°40.297E, 705
m
a.s.l.) provide the first environmental and climate reconstruction in a mountainous area in Southern ...Europe over the last 140,000
years. The response of both lacustrine and terrestrial environments to climate change has been amplified by the peculiar geomorphological and hydrological setting, with a steep altitudinal gradient in the catchment and a karstic system feeding the lake. The karstic system was active during interglacials, leading to high carbonate production in the lake, and blocked during glacials as a result of extremely cold climate conditions with permafrost in the mountains. At the Riss–Eemian transition (Termination 2) the increase in lacustrine productivity predated forest expansion by about 10,000
years. In contrast, the Late Glacial–Holocene transition (Termination 1) was characterized by the dramatic impact of the Younger Dryas, which initially prevented interglacial carbonate production and delayed its maximum until the mid-Holocene. In contrast, forest expansion was progressive, starting as early as ca. 38,000 ago. The proximity of high mountains and the probable moderating lake effect on local climate conditions promoted forest expansion, and contributed to make the surroundings of Lake Ohrid favourable to forest refugia during the last glacial, usually steppic, period. Our study of sedimentology, mineralogy, geochemistry, magnetics, palynology and isotopes illustrates the non-linear response of terrestrial and lacustrine ecosystems to similar climate events, and demonstrates the potential of Lake Ohrid as an excellent paleoclimatic archive during the Quaternary.
Albania is situated in the western part of the Balkan Peninsula, on the eastern coast of the Adriatic and the Ionian Sea. The karst landscape in Albania covers about 6750 km², approximately 24 % of ...the Albanian territory. There are 25 karst regions in the country, 23 in carbonate rocks and 2 in evaporites. The total renewable karst water resources are estimated about 227 m³/s, representing 80 % of the groundwater resources of Albania. About 70 % of the population of the cities, including also part of the capital Tirana, obtains the water from karst springs. However, the negative human impacts often are threatening the karst groundwater resources of Albania. Several bad experiences in Albania have demonstrated that the main human negative impacts on karst water are related to: (a) urbanised areas, (b) agriculture activities, and (c) quarrying activities. Understanding the vital importance of karst waters and the necessity for intensive scientific investigations and monitoring, to evidence their high vulnerability, are still at a low level in Albania.
Lake Ohrid (Albania, Macedonia) is probably the oldest existing lake in Europe and thus of great interest for palaeo-environmental and genetic studies. Within more than 220 endemic faunal species ...known to live in the lake, ostracods are outstanding due to the potentially very long fossil record. They can provide geochemical information over a period exceeding the entire Quaternary and direct evidence for radiation. Here we discuss the ostracod record and the calcite concentration along a 10-m-long sediment core taken at 100 m water depth in the south-eastern, Albanian part of Lake Ohrid. Well preserved ostracod valves representing in-situ fauna only occur from 0 cm to 105 cm and from 476 cm to 933 cm core depth, corresponding to the last interglacial and the Holocene, respectively. Those periods are also characterized by high concentrations of endogen calcite. There is no significant difference in the faunal composition of the two periods separated by several tens of thousand years and we found non-calcitic ostracod remains, especially the strongly chitinised mandibles, throughout the glacial period. Therefore, we conclude that ostracods were present in the lake throughout the entire period represented by the sediment core, but with poor or lacking preservation of their calcite valves during the glacial period. Calcite precipitation and ostracod preservation were most likely inhibited by the complete interruption of Calcium supply from karsts springs, which were inactive during the glacial periods due to permafrost in large parts of the calcareous mountains.
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