A review of current biological and recent environmental research on Lake Baikal from a British perspective

Lake Baikal is possibly the world's most remarkable freshwater lake (Figs1-3). It is certainly the largest in volume (23,000 km³), the deepest(maximum depth is 1632 m) and probably the most ancient.Nevertheless, from a biological point of view its most interesting aspect isthe endemic flora and fauna. Many of the species of animals and plantsoccurring in Lake Baikal today are found nowhere else in the world.Especially remarkable is the unique and diverse deep-water fauna whichis maintained by the circulation of oxygen-rich water to the greatestdepths in the lake. This water mixing is the prime feature that sets LakeBaikal apart from other deep freshwater lakes; for example, lakesTanganyika and Malawi in the African rift system possess anoxic deepwater(Beadle 1974). Despite the fascination of Lake Baikal's biota, itsisolated location in southeastern Siberia, combined with restricted accesscaused by political tensions, has until recently largely preventedinternational research on the lake

Protect the giant ibis through the pandemic

The giant ibis (Thaumatibis gigantea), Cambodia’s national bird, is edging toward extinction. The ibis’s historical range stretched across Southeast Asia, but only 194 critically endangered individuals remain, constrained to the northeastern region of Cambodia. The small population suffers from habitat loss and disturbance caused by human activities, and tensions between humans and wildlife have escalated during the coronavirus disease 2019 (COVID-19) pandemic. In April, 3 giant ibises and more than 100 other birds were poached in Cambodia’s Chhep Wildlife Sanctuary. To save the giant ibis, conservation efforts must continue, even during the pandemic

Waste management, informal recycling, environmental pollution and public health

With rapid population growth, especially in low-income and middle-income countries, the generation of waste is increasing at an unprecedented rate. For example, annual global waste arising from waste electrical and electronic equipment alone will have increased from 33.8 to 49.8 million tonnes between 2010 and 2018. Despite incineration and other waste treatment techniques, landfill still dominates waste disposal in low-income and middle-income countries. There is usually insufficient funding for adequate waste management in these countries and uptake of more advanced waste treatment technologies is poor. Without proper management, many landfills represent serious hazards as typified by the landslide in Shenzhen, China on 20 December 2015. In addition to formal waste recycling systems, approximately 15 million people around the world are involved in informal waste recycling, mainly for plastics, metals, glass and paper. This review examines emerging public health challenges, in particular within low-income and middle-income countries, associated with the informal sector. While informal recyclers contribute to waste recycling and reuse, the relatively primitive techniques they employ, combined with improper management of secondary pollutants, exacerbate environmental pollution of air, soil and water. Even worse, insufficient occupational health measures expose informal waste workers to a range of pollutants, injuries, respiratory and dermatological problems, infections and other serious health issues that contribute to low life expectancy. Integration of the informal sector with its formal counterparts could improve waste management while addressing these serious health and livelihood issues. Progress in this direction has already been made notably in several Latin American countries where integrating the informal and formal sectors has had a positive influence on both waste management and poverty alleviation

Diatom preservation: differential preservation of sedimentary diatoms in two saline lakes

The integrity of all sedimentary diatom assemblages is influenced to some degree by taphonomic processes. Recognising these processes with regard to preservation pathways for diatom assemblages and for individual species can be instructive for interpreting sediment core diatom records. Diatoms deposited in saline lakes are usually particularly exposed to both chemical and physical processes that promote poor preservation. Aspects of diatom preservation are explored in two markedly different saline lakes (one in North America and one in Egypt) and observations are used to make some initial inferences about diatom preservation. By applying dissolution indices to evaluate differences in valve preservation states between assemblages and between species in an objective manner, sedimentation processes and valve characteristics are indicated important implications for interpreting sedimentary diatom records. It is further argued that, by taking account of diatom dissolution states, both qualitative and quantitative inferences about past environments can be extended

Procjena stanja okoliša u odnosu na prostornu rasprostranjenost zooplanktonske zajednice u egipatskom jezeru Manzalah

Lake Manzalah is the largest of the four Nile Delta lakes in Egypt. It provides more than 50% of the total inland fisheries of the country. During the last two decades the Lake has been exposed to multiple changes mainly due to local human activities. Monthly zooplankton samples were collected during an integrated environmental monitoring program within the MELMARINA Project that extended from July 2003 to September 2004 to study the distribution and occurrence of zooplankton community in Lake Manzalah. Results showed that, the average zooplankton standing crop was 1277 x 103 individuals m-3 . Spring was the most productive season (2127 x 103 individuals m-3 ) representing 41.65% to the total zooplankton counts. Five groups dominated zooplankton community; Rotifera, Copepoda, Ostracoda, Protozoa and Cladocera. The meroplanktonic larvae of Polychaeta, Cirripedia, Mysidacea and Gastropoda as well as free living nematods were rarely recorded. Rotifera contributed 81.89% to the total zooplankton community. They were represented by 38 species belonging to 19 genera dominated by genus Brachionus (86.65% of the total Rotifera) followed by genus Keratella (8.68%). Keratella species has been indicated as an indicator of pollution. Copepoda (including their larval stages) was the second group in order of abundance forming about 14.28% of the total zooplankton counts and represented by seven species. Acanthocyclops americanus was the dominant species. The productivity of Lake Manzalah decreased from 1979 to become highly eutrophic lake during the present study, but with higher production than the other Egyptian lakes. Management is needed to stabilize the Manzalah lake ecosystem in a way that promotes the sustainability of the system.Jezero Manzalah najveće je od četiri jezera u egipatskom dijelu delte rijeke Nil. Iz njega se izlovljava više od 50% ukupnog ribarstva kopnenih voda u zemlji. Tijekom posljednja dva desetljeća jezero je bilo izloženo brojnim promjenama uglavnom zbog antropogenih lokalnih aktivnosti. Mjesečni uzorci zooplanktona sakupljani su za vrijeme integriranog programa praćenja stanja okoliša u sklopu projekta MELMARINA kojim se od srpnja 2003. do rujna 2004. proučavala raspodjela i učestalost zooplanktonske zajednice u jezeru Manzalah. Rezultati su pokazali da je prosječna gustoća populacije zooplanktona iznosila 1277 jedinki m-3 . Tijekom proljeća je zabilježena najveća produktivnost (2127×103 jedinki m-3 ) koja predstavlja 41.65% od ukupnog broja zooplanktona. U zooplanktonskoj zajednici prevladavalo je pet skupina: Rotifera, Copepoda, Ostracoda, Protozoa i Cladocera, dok su meroplanktonske larve Polychaeta, Cirripedia, Mysidacea i Gastropoda kao i slobodne živuće nematode rijetko zabilježene. Skupina Rotifera doprinosila je 81.89% od ukupnog broja zooplanktona. Zastupljeno je 38 vrsta koje spadaju u 19 rodova kojima dominira rod Brachionus (86.65% od ukupnog broja Rotifera). Slijedi genus Keratella (8.68%) koji se smatra pokazateljem zagađenja. Veslonošci (uključujući ličinačke stadije) su bili na drugom mjestu po zastupljenosti (14.28%), sa zabilježenih sedam vrsta, od kojih je dominantna bila Acanthocyclops americanus. Produktivnost jezera Manzalah je smanjena od 1979. godine i jezero je postalo vrlo eutrofično za vrijeme ove studije, no još uvijek je produktivnije od ostalih egipatskih jezera. Potrebno je ciljano upravljanje kako bi se stabilizirao ekosustav jezera Manzalah na način koji će unaprijediti održivost sistema

Influence of environmental and spatial variables on the distribution of surface sediment diatoms in an upland loch, Scotland

The spatial distribution of surface sediment diatoms was analyzed using ArcGIS in the Round Loch of Glenhead, an acid upland lake in south-west Scotland. The assemblages were composed almost entirely of benthic species. Tabellaria quadriseptata was fairly evenly distributed across the loch but some species (Navicula madumensis, Brachysira brebissonii, Aulacoseira perglabra and Eunotia vanheurckii var 1) showed rather patchy distributions. Ordination analysis was performed to assess the influence of environmental and spatial variables on the diatom composition of the samples. Loss of ignition was significantly negatively correlated with redundancy analysis species axis 1 (r = –0.77), indicating the influence of substrate on the diatom assemblages. The positive relationship between theoretical bottom shear stress resulting from wind stress and redundancy analysis (r = 0.31) suggests wind stress also influences the spatial distribution of diatoms within the loch. Spatial variables [(principal coordinates of neighbour matrices (PCNM 1 and PCNM3) positively correlated with redundancy analysis axis 2], indicated that spatial variables, ignored in former studies, are a further influence on diatom distribution. Unique environmental and spatial variables explained 27.3% and 8.6% of diatom variability respectively. Environmental and spatial interactive variables combined explained 4.8% of variation. Although the pure contribution of spatial variables was only 8.6%, the study highlighted the importance of differences in the spatial distribution of different benthic diatom species in this upland lake

Palaeolimnological assessment of lake acidification and environmental change in the Athabasca Oil Sands Region, Alberta

13 páginas, 8 figuras, 4 tablas.Exploitation of the Athabasca Oil Sands has expanded hugely over the last 40 years. Regional emissions of oxidised sulphur and nitrogen compounds increased rapidly over this period and similar emissions have been linked to lake acidification in other parts of North America and Europe. To determine whether lakes in the region have undergone acidification, 12 lakes within the Regional Municipality of Wood Buffalo and the Caribou Mountains were selected to cover chemical and spatial gradients and sediment cores were obtained for palaeolimnological analyses including radiometric dating, diatom analysis, isotopic analysis of bulk sediment 13C and 15N, and spheroidal carbonaceous particles (SCPs). All lake sediment cores show evidence of industrial contamination based on SCPs, but there is no clear industrial signal in stable isotopes. Most lakes showed changes in diatom assemblages and sediment C:N ratios consistent with nutrient enrichment over various timescales, with potential drivers including climatic change, forest fires and anthropogenic nitrogen deposition. Only one of the 12 lakes investigated showed strong evidence of acidification with a decline in diatom-inferred pH from 6.3 to 5.6 since 1970 linked to increasing relative abundances of the acidophilous diatom species Actinella punctata, Asterionella ralfsii and Fragilariforma polygonata. Analysis of mercury (Hg) in the acidified lake showed increasing sediment fluxes over the last 20 years, a possible indication of industrial contamination. The acidified lake is the smallest of those studied with the shortest residence time, suggesting a limited capacity for neutralisation of acid inputs in catchment soils or by inlake processes.This work was funded by the NOx SOx Management Working Group of the Cumulative Environmental Management Association.Peer reviewe

Protect and regulate China's oyster resources

China has at least 30 oyster species, all of which provide valuable ecosystem services. Oysters’ filter feeding habit reduces suspended particles and nutrients. One hectare of oyster reef can clean a volume of water equivalent to nearly 15 Olympic swimming pools daily. Oysters’ excrement can stimulate denitrification by removing nitrogenous organic matter, helping to mitigate eutrophication. Natural oyster reefs provide habitat for many species, enhancing biodiversity and increasing fisheries. Oyster reefs can reduce impacts of waves caused by hurricanes and typhoons, stabilizing shorelines. Despite their ecological importance, 85% of oyster reefs globally have been degraded since the 19th century by overharvesting, coastal development, water pollution, and disease. China’s oyster reefs, especially those in Tianjin and Jiangsu, have been seriously damaged during recent decades. Urgent action by Chinese authorities is required to protect these crucial species