Climate Change and the World’s “Sacred Sea”—Lake Baikal, Siberia

Lake Baikal—the world\u27s largest, oldest, and most biotically diverse lake—is responding strongly to climate change, according to recent analyses of water temperature and ice cover. By the end of this century, the climate of the Baikal region will be warmer and wetter, particularly in winter. As the climate changes, ice cover and transparency, water temperature, wind dynamics and mixing, and nutrient levels are the key abiotic variables that will shift, thus eliciting many biotic responses. Among the abiotic variables, changes in ice cover will quite likely alter food-web structure and function most because of the diverse ways in which ice affects the lake\u27s dominant primary producers (endemic diatoms), the top predator (the world\u27s only freshwater seal), and other abiotic variables. Melting permafrost will probably exacerbate the effects of additional anthropogenic stressors (industrial pollution and cultural eutrophication) and could greatly affect ecosystem functioning

Lake-wide physical and biological trends associated with warming in Lake Baikal

Eutrophication and warming of lakes are occurring globally. Lake Baikal, a large ancient lake composed of three basins, has recently experienced benthic eutrophication at local sites and lake warming in the south basin. Here, we look for signals of warming and pelagic eutrophication across the entire lake using physical and biological data collected at a subset of 79 stations sampled ca. annually (1977–2003) during the period of summer stratification. Lake-wide, surface waters warmed 2.0 °C; and, consistent with this warming, the abundance of two warm-water, cosmopolitan zooplankton taxa increased between two (pelagic cladocerans) and 12-fold (Cyclops kolensis). C. kolensis increased throughout the lake, whereas cladocerans increased significantly only in the north basin. In contrast, abundance of the cold-water endemic copepod, Epischura baikalensis, that dominates the crustacean zooplankton community, did not change. With the exception of one coastal station in the north basin, there is no evidence of pelagic eutrophication. Although chlorophyll concentrations increased 46% lake-wide (0.82 to 1.20 μg/L), the increasing trend was significant only in the south basin. Surprisingly, mean Secchi transparency increased by 1.4 m lake-wide across the 26-year time series with significant deepening of water transparency occurring in the central and north basins. This suggests a decline in productivity in the north and middle basins, but an increase in the south basin. Taken together, these findings suggest that physical and biological changes associatedwithwarming have occurred in Lake Baikal, butwide-spread pelagic eutrophication in the lake\u27s three basins has not

Climate change drives widespread shifts in lake thermal habitat

Lake surfaces are warming worldwide, raising concerns about lake organism responses to thermal habitat changes. Species may cope with temperature increases by shifting their seasonality or their depth to track suitable thermal habitats, but these responses may be constrained by ecological interactions, life histories or limiting resources. Here we use 32 million temperature measurements from 139 lakes to quantify thermal habitat change (percentage of non-overlap) and assess how this change is exacerbated by potential habitat constraints. Long-term temperature change resulted in an average 6.2% non-overlap between thermal habitats in baseline (1978–1995) and recent (1996–2013) time periods, with non-overlap increasing to 19.4% on average when habitats were restricted by season and depth. Tropical lakes exhibited substantially higher thermal non-overlap compared with lakes at other latitudes. Lakes with high thermal habitat change coincided with those having numerous endemic species, suggesting that conservation actions should consider thermal habitat change to preserve lake biodiversity

Rapid and highly variable warming of lake surface waters around the globe

In this first worldwide synthesis of in situ and satellite-derived lake data, we find that lake summer surface water temperatures rose rapidly (global mean = 0.34°C decade-1) between 1985 and 2009. Our analyses show that surface water warming rates are dependent on combinations of climate and local characteristics, rather than just lake location, leading to the counterintuitive result that regional consistency in lake warming is the exception, rather than the rule. The most rapidly warming lakes are widely geographically distributed, and their warming is associated with interactions among different climatic factors - from seasonally ice-covered lakes in areas where temperature and solar radiation are increasing while cloud cover is diminishing (0.72°C decade-1) to ice-free lakes experiencing increases in air temperature and solar radiation (0.53°C decade-1). The pervasive and rapid warming observed here signals the urgent need to incorporate climate impacts into vulnerability assessments and adaptation efforts for lakes

Global data set of long-term summertime vertical temperature profiles in 153 lakes

Climate change and other anthropogenic stressors have led to long-term changes in the thermal structure, including surface temperatures, deepwater temperatures, and vertical thermal gradients, in many lakes around the world. Though many studies highlight warming of surface water temperatures in lakes worldwide, less is known about long-term trends in full vertical thermal structure and deepwater temperatures, which have been changing less consistently in both direction and magnitude. Here, we present a globally-expansive data set of summertime in-situ vertical temperature profiles from 153 lakes, with one time series beginning as early as 1894. We also compiled lake geographic, morphometric, and water quality variables that can influence vertical thermal structure through a variety of potential mechanisms in these lakes. These long-term time series of vertical temperature profiles and corresponding lake characteristics serve as valuable data to help understand changes and drivers of lake thermal structure in a time of rapid global and ecological change

Global data set of long-term summertime vertical temperature profiles in 153 lakes

Measurement(s) : temperature of water, temperature profile Technology Type(s) : digital curation Factor Type(s) : lake location, temporal interval Sample Characteristic - Environment : lake, reservoir Sample Characteristic - Location : global Machine-accessible metadata file describing the reported data: https://doi.org/10.6084/m9.figshare.14619009Climate change and other anthropogenic stressors have led to long-term changes in the thermal structure, including surface temperatures, deepwater temperatures, and vertical thermal gradients, in many lakes around the world. Though many studies highlight warming of surface water temperatures in lakes worldwide, less is known about long-term trends in full vertical thermal structure and deepwater temperatures, which have been changing less consistently in both direction and magnitude. Here, we present a globally-expansive data set of summertime in-situ vertical temperature profiles from 153 lakes, with one time series beginning as early as 1894. We also compiled lake geographic, morphometric, and water quality variables that can influence vertical thermal structure through a variety of potential mechanisms in these lakes. These long-term time series of vertical temperature profiles and corresponding lake characteristics serve as valuable data to help understand changes and drivers of lake thermal structure in a time of rapid global and ecological change

The Present State of Human Impact on Lake Baikal

В статье охарактеризованы пять исторических стадий антропогенного воздействия на оз. Байкал. Описано физическое воздействие на озеро в результате постройки Иркутской ГЭС. Подробно рассмотрено химическое загрязнение озера в результате судоходства, туристической активности, со стоками и смывами из населенных пунктов, сточными водами и выбросами в атмосферу Байкальского ЦБК, водами, поступающими с водосборного бассейна, атмосферным переносом загрязнителей. Наибольшая часть (>83 %) загрязняющих веществ приносится водами притоков, на втором месте (>15 %) – поступления из атмосферы, третье место (<1 %) занимают загрязнения от БЦБК, на четвертом – загрязнения от других предприятий и населенных пунктов по берегам озера, затем в порядке убывания значения идут туризм и судоходство (всё вместе – около 0.5 %). Загрязнители в порядке снижения объемов их поступления в озеро можно расположить в ряд: минеральные соли, взвешенные вещества, растворенные органические вещества, сульфаты, минеральные формы азота и фосфора, нефтепродукты, серосодержащие органические соединения, тяжелые металлы и синтетические поверхностно-активные веществаFive stages of human impact on the lake Baikal are characterised. Physical influence on the lake caused by Irkutsk power plant is described. Chemical pollution due to navigation, tourism, settlements’ waste water, waste discharges to water and atmosphere by Baikal Pulp and Paper Plant, waters coming from watershed, atmospheric transfer are viewed in details. The most of contaminants (>83 %) is coming with the waters of tributaries, the second role belongs to atmospheric precipitation (>15 %), the third place is occupied by pollution from Baikal Pulp and Paper Plant (<1 %), the rest – contaminations from other enterprises and settlements at shores, tourism and navigation (together about 0.5 %). Pollutants according to decrease in volume of their input can be ranged as mineral salts, particulate matter, dissolved organic matter, sulphates, mineral forms of nitrogen and phosphorus, oil products, sulphur containing organic substances, heavy metals and synthetic surfactant

The Present State of Human Impact on Lake Baikal

В статье охарактеризованы пять исторических стадий антропогенного воздействия на оз. Байкал. Описано физическое воздействие на озеро в результате постройки Иркутской ГЭС. Подробно рассмотрено химическое загрязнение озера в результате судоходства, туристической активности, со стоками и смывами из населенных пунктов, сточными водами и выбросами в атмосферу Байкальского ЦБК, водами, поступающими с водосборного бассейна, атмосферным переносом загрязнителей. Наибольшая часть (>83 %) загрязняющих веществ приносится водами притоков, на втором месте (>15 %) – поступления из атмосферы, третье место (<1 %) занимают загрязнения от БЦБК, на четвертом – загрязнения от других предприятий и населенных пунктов по берегам озера, затем в порядке убывания значения идут туризм и судоходство (всё вместе – около 0.5 %). Загрязнители в порядке снижения объемов их поступления в озеро можно расположить в ряд: минеральные соли, взвешенные вещества, растворенные органические вещества, сульфаты, минеральные формы азота и фосфора, нефтепродукты, серосодержащие органические соединения, тяжелые металлы и синтетические поверхностно-активные веществаFive stages of human impact on the lake Baikal are characterised. Physical influence on the lake caused by Irkutsk power plant is described. Chemical pollution due to navigation, tourism, settlements’ waste water, waste discharges to water and atmosphere by Baikal Pulp and Paper Plant, waters coming from watershed, atmospheric transfer are viewed in details. The most of contaminants (>83 %) is coming with the waters of tributaries, the second role belongs to atmospheric precipitation (>15 %), the third place is occupied by pollution from Baikal Pulp and Paper Plant (<1 %), the rest – contaminations from other enterprises and settlements at shores, tourism and navigation (together about 0.5 %). Pollutants according to decrease in volume of their input can be ranged as mineral salts, particulate matter, dissolved organic matter, sulphates, mineral forms of nitrogen and phosphorus, oil products, sulphur containing organic substances, heavy metals and synthetic surfactant

Exergy as a Tool for Ecosystem Health Assessment

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