Eutrophication impacts littoral biota in Lake Ohrid while water phosphorus concentrations are low

Schneider, Susanne C.; Cara, Magdalena; Eriksen, Tor Erik; Goreska, Biljana Budzakoska; Imeri, Alma; Kupe, Lirika; Lokoska, Tatjana; Patceva, Suzana; Trajanovska, Sonja; Trajanovski, Sasho; Talevska, Marina; Sarafiloska, Elizabeta Veljanoska

doi:10.1016/j.limno.2013.09.002

Cited by 45 publications

(34 citation statements)

References 25 publications

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“…Although the information diatoms provide is rapid, reliable and cost efficient, the biological monitoring of Lake Ohrid still largely relies on macrophytes, invertebrates and fish, while diatoms were included only in short survey studies (e.g. Schneider et al, 2014). Despite the extensive floristic, taxonomic and palaeoecological diatom research, a systematic diatom-based ecological study on Lake Ohrid has not yet been performed.…”

Section: Implication For Diatom Ecology and Palaeoecology In Lake Ohridmentioning

confidence: 99%

Spatial patterns of diatom diversity and community structure in ancient Lake Ohrid

et al. 2018

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The extraordinary diversity in long-lived lakes is largely driven by distinct eco-evolutionary processes. With their unique biota and numerous endemic taxa, these lakes are key settings for fundamental studies related to ecology, diversity, and evolution. Here, we test how the environment shapes diatom diversity and community patterns over space in ancient Lake Ohrid. By applying Bray-Curtis similarity analyses of diatom community data, including widespread and endemic taxa, we identified two major zones: littoral and sublittoral. The latter one is being characterized with higher endemic diversity. The a and b diatom diversity and community distribution in the northern and eastern part of the lake are influenced by the presence of vertical (bathymetrical) and horizontal barriers. The zonation of the diatom communities appears driven by two large-scale factors: (i) water depth, and (ii) water chemistry, primarily, the concentration of total phosphorus, nitrogen ammonia, and conductivity. Both drivers appear to equally influence diatom diversity and community patterns. We present initial data on diatom-environment relations, where the results support earlier ecological studies emphasizing the relevance of ongoing human-induced eutrophication in the northern lake area. This study provides background information on the role of the environment in structuring contemporary diatom diversity. However, future research needs to focus on the biotic component including species competition in order to reveal the mechanisms driving spatial community dynamics in Lake Ohrid.

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Section: Implication For Diatom Ecology and Palaeoecology In Lake Ohridmentioning

confidence: 99%

Spatial patterns of diatom diversity and community structure in ancient Lake Ohrid

et al. 2018

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“…Watzin et al, 2002;Matzinger et al, 2006;Jordanoski et al, 2004Jordanoski et al, , 2005Naumoski et al, 2007;Schneider et al, 2014). Average total phosphorous (TP) concentrations of < 10 mg m −3 and Secchi depths ranging between 7 and 16 m characterise the pelagic zone of Lake Ohrid as oligotrophic.…”

Section: Site Informationmentioning

confidence: 99%

“…The concentration of Si is lowest in the trophogenic surface waters, where it is taken up by diatoms, and increases gradually to < 2 mg L −1 in bottom waters (Stanković, 1960). The littoral part of the lake ex-hibits a slightly higher trophic state (Schneider et al, 2014). These meso-to slightly eutrophic conditions in relatively shallow waters might be due to a direct input of nutrients from the catchment, higher temperatures, and increasing anthropogenic pollution over the last several decades (Kostoski et al, 2010;Schneider et al, 2014).…”

Section: Site Informationmentioning

confidence: 99%

The environmental and evolutionary history of Lake Ohrid (FYROM/Albania): interim results from the SCOPSCO deep drilling project

et al. 2017

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Abstract. This study reviews and synthesises existing information generated within the SCOPSCO (Scientific Collaboration on Past Speciation Conditions in Lake Ohrid) deep drilling project. The four main aims of the project are to infer (i) the age and origin of Lake Ohrid (Former Yugoslav Republic of Macedonia/Republic of Albania), (ii) its regional seismotectonic history, (iii) volcanic activity and climate change in the central northern Mediterranean region, and (iv) the influence of major geological events on the evolution of its endemic species. The Ohrid basin formed by transtension during the Miocene, opened during the Pliocene and Pleistocene, and the lake established de novo in the still relatively narrow valley between 1.9 and 1.3 Ma. The lake history is recorded in a 584 m long sediment sequence, which was recovered within the framework of the International Continental Scientific Drilling Program (ICDP) from the central part (DEEP site) of the lake in spring 2013. To date, 54 tephra and cryptotephra horizons have been found in the upper 460 m of this sequence. Tephrochronology and tuning biogeochemical proxy data to orbital parameters revealed that the upper 247.8 m represent the last 637 kyr. The multi-proxy data set covering these 637 kyr indicates longterm variability. Some proxies show a change from generally cooler and wetter to drier and warmer glacial and interglacial periods around 300 ka. Short-term environmental change caused, for example, by tephra deposition or the climatic impact of millennial-scale Dansgaard-Oeschger and Heinrich events are superimposed on the long-term trends. Evolutionary studies on the extant fauna indicate that Lake Ohrid was not a refugial area for regional freshwater animals. This differs from the surrounding catchment, where the mountainous setting with relatively high water availability provided a refuge for temperate and montane trees during the relatively cold and dry glacial periods. Although Lake Ohrid experienced significant environmental change over the last 637 kyr, preliminary molecular data from extant microgastropod species do not indicate significant changes in diversification rate during this period. The reasons for this constant rate remain largely unknown, but a possible lack of environmentally induced extinction events in Lake Ohrid and/or the high resilience of the ecosystems may have played a role.

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“…Oligotrophic Lake Ohrid is phosphorus limited (Allen and Ocevski, 1977), with an average total phosphorus (TP) concentration of 4.5 mg × m −3 (Matzinger et al, 2007) and total nitrogen (TN) concentration of 171-512 mg × m −3 (Watzin et al, 2002). The lake's silica (SI) concentration is < 200 mg × m −3 in the trophogenic zone during summer (Stanković, 1960), while the average water pH and conductivity are 8.48 and 208 µS × cm −1 , respectively (Schneider et al, 2014). The average Secchi depth is ca.…”

Section: Site Descriptionmentioning

confidence: 99%

Differential resilience of ancient sister lakes Ohrid and Prespa to environmental disturbances during the Late Pleistocene

et al. 2016

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Abstract. Ancient lakes, such as lakes Ohrid and Prespa on the Balkan Peninsula, have become model systems for studying the link between geological and biotic evolution. Recently, the scientific deep-drilling project Scientific Collaboration on Past Speciation Conditions in Lake Ohrid (SCOP-SCO) was initiated to better understand the environmental, climatic, and limnological evolution of the lake. It revealed that Lake Ohrid experienced a number of environmental disturbances during its ca. 2.0 million year long history. These are comprised of disturbances that lasted over longer periods of time ("press events") such as glacial-interglacial cycles and Heinrich events, as well as sudden and short disturbances ("pulse events") like the deposition of landslides, earthquakes, and volcanic ash depositions. The latter includes one of the most severe volcanic episodes during the Late Pleistocene: the eruption of the Campanian Ignimbrite (known as Y-5 marine tephra layer) from the Campi Flegrei caldera, dated to 39.6 ± 0.1 thousand years ago. The event is recorded by the deposition of a ca. 15 cm thick tephra layer in sediment cores of lakes Ohrid (DEEP-5045-1) and Prespa (Co1204). Coincidently, this pulse event is superimposed by the Heinrich H4 event, 40.4-38.4 thousand years ago.In the current paper, diatoms were used as proxies to compare the responses of these lakes to the Y-5 (pulse) and the H4 (press) disturbances. Based on stratigraphically constrained incremental sum of squares cluster (CONISS) and unconstrained Partitioning Around Medoids (PAM) analyses, we found little evidence that diatom community compositions in either lake responded to the H4 event. However, the Y-5 influx caused clear and rapid diatom community changes. After the initial response, community compositions in Lake Ohrid and, to a lesser extent, in Lake Prespa slowly returned to their quasi pre-disturbance state. Moreover, there is no evidence for disturbance-related extinction events. The combined evidence from these findings suggests that lakes Ohrid and Prespa likely did not experience regime shifts. It is therefore concluded that both lakes show resilience to environmental disturbance. However, it seems that Lake Ohrid is more resilient than Lake Prespa, as the recovery of diatom communities is more pronounced and its estimated recovery time is only ca. 1100 years vs. ca. 4000 years in Lake Prespa. The reasons for the differential responses remain largely unknown, but differences in geology, lake age, limnology, and intrinsic parameters of the diatom proxies may play an important role.

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Eutrophication impacts littoral biota in Lake Ohrid while water phosphorus concentrations are low

Cited by 45 publications

References 25 publications

Spatial patterns of diatom diversity and community structure in ancient Lake Ohrid

Spatial patterns of diatom diversity and community structure in ancient Lake Ohrid

The environmental and evolutionary history of Lake Ohrid (FYROM/Albania): interim results from the SCOPSCO deep drilling project

Differential resilience of ancient sister lakes Ohrid and Prespa to environmental disturbances during the Late Pleistocene

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