Northern Shore Research Articles

POPULATION AND WATER AS DEVELOPMENT FACTORS: THE ISRAELI AND MACEDONIAN CASE

The State of Israel is located in Middle East (Western Asia) on the southeastern coastline of the Mediterranean Sea and northern shore of Red Sea, with total area of 21,640 sq km². The landscape is mixture of coastal lowland, central hillside area, Jordan Valley and Negev Desert, which occupies one-half of the total land. Taking into account the population (which at the moment of the creation of the Israeli state is 806,000 habitants), as well as, the large area of desert land, the Israelis faced two challenges: to increase the population (with aim to increase labor force and territorial settlement) and find a sustainable method to use and recycle water (as a key element for agricultural development). To accomplish the first goal, on July 5, 1950, the Israeli Assembly approved the Law of Return, which gives Jews the right to come and live in Israel, while for realization of the second goal, the largest contribution comes from the innovations of agricultural communities, known as kibbutz. The first part of the paper identifies Israel's immigration policies and Kibbutz water innovations that contributed to the development of the state. In order to find out whether population and water are factors for development in the Macedonian reality, the second part of the paper presents the situation of the population and the phenomenon of emigration, as well as the real state of the water resource and its use in agriculture. The research has demonstrated a completely different situation in the Macedonian case. While Israel is pursuing a liberal immigration policy to unite all Jews in its country, the Macedonian state faces constant emigration of its citizens to other countries. Low salaries and lack of a concrete strategy to motivate young people to stay in their country are the cause of increased emigration. Regarding the second factor, although there are good conditions for development of agriculture (such as climate, fertile soil and water) this sector is not a leader in contributing to the economy of the country and the state is ranked between the first countries to irrational use of water. The purpose of this paper is to examine how population factor and water factor-related to innovations and their use in the agricultural sector, have contributed to the development of the Israeli economy and whether Israeli experience can be applied to macedonian case.

Impact of anthropogenic activities on the enrichment of fluoride and salinity in groundwater in the Yuncheng Basin constrained by Cl/Br ratio, δ18O, δ2H, δ13C and δ7Li isotopes

Substantial concerns have been raised about the degradation of groundwater quality and their harmful effects due to salinization processes and endemic fluorosis issues in China. Yuncheng Basin is an economically important area situated in semi-arid northern China, which has suffered from severe groundwater contamination and intensive anthropogenic activities (agricultural, industrial and domestic). Twenty water quality parameters were surveyed at 85 groundwater and salt lake water sites during August 2013–September 2015. The combining using of Cl/Br mass ratio, δ2H, δ18O, δ13C, and δ7Li isotopes was employed to investigate the potential impact of anthropogenic activities which are supposed to contribute to groundwater salinization and fluoride enrichment in the Yuncheng Basin to a large extent. Results show that shallow groundwater are more vulnerable to contamination from anthropogenic processes of irrigation leaching, wastewater drainage, fertilizer utilization and Salt Lake water intrusion. Vertical irrigation recharge has been an important source of salt and fluoride for the shallow groundwater in the runoff area between Kaolao lowland and the central Basin, revealed by the high salinity (>4000 mg/L), high Cl/Br ratios (>2000), moderate high δ7Li (19.7–26.1‰), moderate δ13C (−8.1~−10.3‰) and constant δ18O and δ2H values. The contribution of over-utilization of fertilizers on high fluoride shallow saline groundwater is found in the crop land in the west part of the Salt Lake with a moderate high nitrate concentration (>10 mg/L), moderate Cl/Br ratios (332~1000) and low δ7Li value (13.8‰). Shallow groundwater in the northern part of the Salt lake polluted by wastewater, evidenced by boron concentration (>2000 μg/L), Na/K (molar ratio > 0.6), δ13C (−11~−11.1‰), and δ7Li (20.4~22.5‰), show highest fluoride concentrations. Due to over-pumping of groundwater, Salt Lake water intrusion mainly occurs in the northern shore of the lake and results in the enrichment of fluoride and salinity in some shallow groundwater with low Cl/Br ratios (around 300), high δ7Li value (c.a. 27‰), and moderate high δ18O (−8.2~−8.7‰) and δ2H (−62.2~−66.1‰) values. The influence of anthropogenic activities on deep groundwater is reflected in two possible scenarios. Increased extraction of groundwater leads to downward leakage of shallow high fluoride saline groundwater, increasing the pollution risk of deep groundwater within the depression cone in the west of Yuncheng City. The rapidly-developed drilling activities of geothermal water (δ7Li, 11~14.3‰; δ13C, −7.9~−8.4‰; [B], 709~3523 μg/L; [F], 2.1~8.2 mg/L) bring about the contamination of fresh groundwater by the underground leaking or discharge of geothermal water. Finally, a conceptual model has been developed to demonstrate the influences of anthropogenic activities on groundwater contamination along a northwest to southeast cross-section.

Demographic Ageing in the Mediterranean: The End of the Spatial Dichotomy Between the Shores?

The Mediterranean is too often presented as a heterogeneous geographical area. Demography has helped to create this narrative of a Mediterranean of contrasts in which the different shores are systematically opposed: a northern shore in decline, with low fertility rates and an ageing population, as opposed to the young and fertile southern and eastern shores, which are experiencing rapid growth. However, this spatial dichotomy is gradually disappearing due to demographic transition: population growth and fertility are in decline, and the disparities between the different areas of the Mediterranean are vanishing. Moreover, demographic transition automatically gives rise to an ageing population. While the varied populations of the Mediterranean are currently differentiated by their levels of ageing, it is inevitable that these levels will converge in the future. This paper studies this future convergence, including the hypothesis that the southern and eastern shores will catch up with the northern shore. It also envisages a potential challenge to the spatial dichotomy of demographic ageing in the Mediterranean. To this end, we will go beyond the national frameworks generally used for studies of the Mediterranean as a whole and examine each Mediterranean country at a sub national level. After creating demographic projections based on 4 prospective scenarios, we will use various methods (cartography, spatial statistics, etc.) to express how the southern regions will catch up, how the space will change, and how the spatial dichotomy of ageing in the Mediterranean will evolve.

Herding through Uncertainties – Principles and Practices. Exploring the Interfaces of Pastoralists and Uncertainty. Results from a Literature Review

This paper has been written as a background review for the European Research Council-funded PASTRES project (Pastoralism, Uncertainty, Resilience: Global Lessons from the Margins, pastres.org). Lessons from pastoralists, we argue, may help others working in other domains to develop more effective responses to uncertain contexts. Following prof. Scoones’ paper What is uncertainty and why does it matter?, this is one of two papers developed with a view to analyse and reflect on the interfaces and interrelationships between pastoral societies, the uncertainties that embed their livelihoods, and the related coping/adaptive principles, strategies, and practices. Through a structured review and a meta-analysis of existing literature, the environmental, market, and governance dimensions characterizing uncertainty for pastoralists are explored in six different settings: a) Central and southern Asia, with specific references to the Tibetan plateau in China and to Indian pastoralists; b) the northern and southern shores of the Mediterranean, with a focus on Morocco in the Maghreb-Mashreq region and a wider perspective on pastoralism in Mediterranean Europe; c) the eastern and western flanks of Sub-Saharan Africa drylands, with a specific focus on the Fulani and Borana pastoral groups inhabiting these regions. This paper assesses the practices and strategies pastoral communties adopt in responding to the stresses and shocks generated by the uncertainties that surround them, with a view to understand and appreciate the underpinning inspiring principles. The responses displayed and applied by pastoral communities in the different settings show in fact relevant and intriguing degrees of similarity across the regions. This helps identify a common framework and a set of overarching principles and patterns for pastoralists in dealing with risk and uncertainty. The paper concludes by indicating potential ways we could learn from pastoralists, as part of a wider conversation about embracing uncertainties to meet the challenges of our turbulent world. This endeavour is complemented by another paper that explores the diverse and constantly changing uncertainty frameworks characterising different pastoral regions of the globe.

Past and present of Fucales from shallow and sheltered shores in Catalonia

Historical information on marine organisms needs to be incorporated to develop effective management plans and conservation targets. In the Mediterranean Sea most species of brown seaweeds of the order Fucales are threatened or endangered and need protection. Here we merge data on historical and current records to create the first reference dataset on past and present distributions of Fucales from shallow and sheltered shores of Catalonia (NW Mediterranean Sea). Most Cystoseira sensu lato populations were found in the northern shores, where the most suitable environments exist. Carpodesmia mediterranea and Cystoseira compressa are far more abundant in exposed than in shallow, sheltered shores. Populations of most of the taxa (i.e. Carpodesmia crinita, Treptacantha elegans, T. sauvageauana, T. barbata f. aurantia) have suffered an important regression and two taxa have apparently become locally extinct (Cystoseira foeniculacea, Treptacantha barbata f. barbata). Carpodesmia caespitosa is still widespread in sheltered environments from the northern shores and a previously unreported taxon has been found (T. ballesterosii var. tenuior). Our regional-scale study makes available a solid, comprehensive baseline for future monitoring and application of conservation measures for the several threatened species of Fucales.

Present Range of Tuva Mountain Vole Alticola tuvinicus Ognev, 1950 (Review of Environmental Conditions and Modeling)

This study analyzes the present distribution of the Tuva mountain voles based on literary data, museum collections, and our own materials. A bioclimatic model of potential species distribution has been constructed using 25 localities identified as having Tuva mountain voles in Russia and Mongolia. It is shown that the species range of the Tuva voles consists of three large isolated parts: the northern one, located mainly in Khakassia; southern, located in Tuva and the adjacent territory of Mongolia; and a small area on the northern shore of the Khuvsgul Lake in Mongolia. The examination of habitats of the Tuva mountain voles in the territory of Khakassia has shown that in recent decades there has been a significant decrease in the number of inhabited sites, which indicates a significant decline in population and intensification of fragmentation of the northern part of the range of the Tuva mountain vole.

Tatlısu-Çiftlikdüzü/Akanthou-Arkosykos Cypro-PPNB Orak Bıçakları

Kıbrıs’ın kuzey kıyısında, doğuya doğru uzanan Karpaz yarımadasında yer alan Tatlısu-Çiftlikdüzü/Akanthou-Arkosykos yerleşmesi 2000-2005 ve 2010-2015 yılları arasında kazılmıştır. Çalışmalara verilen aranın ardından 2016 yılında tekrar kazılmaya ve araştırılmaya başlanmıştır. Yontmataş grubunu oluşturan obsidiyenler Anadolu bağlantılı olarak çalışılırken, yerel hammaddelerin elde edilmesi ve işlenmesi de önemli araştırma konularından biri olmuştur. Yerel hammaddeler olan çakmaktaşı ve çörtten üretilmiş orak bıçakları alet grupları içerisinde iyi tanımlanmış bir grubu oluşturur. Orak bıçaklarının üzerinde bulunan silika parlaklığı orak bıçaklarının tahıllar ve saz gibi bitkilerin kesimi için kullanıldığına işaret eder. Fonksiyonunun yanı sıra teknolojik analizler bu aletlerin nasıl üretildiklerini de ortaya koymaktadır. Bu çalışma, Tatlısu topluluğunun hammadde kullanımı, aletlerini nasıl ürettikleri ve bu aletlerin bitki hasadında kullanımı ile ilgili veri oluşturmayı hedeflemektedir.

Repeated occurrence of palaeo-wildfires during deposition of the Bahariya Formation (early Cenomanian) of Egypt

The Upper Cretaceous (early Cenomanian) Bahariya Formation of Egypt has an outstanding reputation for its wealth of vertebrate remains, including a variety of iconic dinosaurs, like the carnivorous Spinosaurus and Carcharodontosaurus, as well as the herbivorous Aegyptosaurus and Paralititan. Besides these dinosaur fossils, the Bahariya Formation yielded also a wealth of invertebrate and plant remains, but even today many aspects concerning the continental palaeoenvironments reflected in these deposits (including the occurrence of palaeo-wildfires) have not been studied in detail. So far six distinct macro-charcoal bearing levels could be identified within the type section of the Bahariya Formation at Gabal El Dist profile, one of the most prolific outcrops of this formation in terms of fossil occurrence located in the north of the Bahariya Oasis, Western Desert, Egypt. Most of the charcoal investigated by means of SEM originates from ferns, pointing to a considerable proportion of this plant group within the palaeo-ecosystems that experienced fires. Gymnosperms and (putative) angiosperms have less frequently been identified. The collected data present evidence that the landscapes at the northern shores of Gondwana repeatedly experienced palaeo-wildfires, adding extra proof to previous statements that the Late Cretaceous was a fiery world on a global scale.

Polycyclic aromatic hydrocarbons (PAHs) and some biomarkers in the green sea turtles (Chelonia mydas)

Selected blood biochemical parameters (Glutathione S transferase: GST; Alanine aminotransferase: ALT; Aspartate aminotransferase: AST; Lactate dehydrogenase: LD and glucose) and polycyclic aromatic hydrocarbons (PAHs) were measured in blood samples from 18 green sea turtles (Chelonia mydas) from the Iranian coastline on the northern shore of the Sea of Oman. Mean total PAH concentration in the blood samples was 17.802 ± 1.006 ng/gdw. The study found no significant correlation between blood biochemical parameters and PAHs (p > 0.01), however significant correlations were found between total PAHs and GST activity (p < 0.01). The GST activity measured in this study was useful as a first investigation into the biological effects of PAH pollution as well as in determining the bioavailability of pollution. The results suggest that PAHs might be a factor influencing a reduction in green sea turtle egg fertilization and hatching success. Further study is needed concerning the effects of PAHs and other pollutants on green sea turtles, and specifically on the potential impact on the fetal development of green sea turtles.

Effect of high salinity in grout on the performance of cement-stabilized marine clay

Constructing a soilcrete column by injecting grout into the soil is a common method of stabilizing loose soil in coastal areas. Although tap water usually is used in the grout mixture for soil improvement projects, before the cement in grout mixture has completely set, tap water will mix with in situ saline seawater. Researchers have not previously considered the behavior of clay-cement under marine conditions, especially the effect of water salinity, on the performance of soilcrete. The goals of this study were to investigate the effect of the use of naturally saline seawater in grout preparation on the mechanical, physical and microstructural behavior of cement-stabilized marine clay. Marine clay and seawater samples were prepared along the northern shore of the Persian Gulf. Tap water as low salinity water, brackish water as medium salinity water (50% tap water and 50% seawater) and natural seawater as high salinity water were used. Specimens were prepared using the deep mixing method recommendations for laboratory soilcrete tests. Macroscopic evaluation was performed by unconfined compressive strength and indirect Brazilian tension test. The physical aspects of the plasticity of the soilcrete specimens with regard to the Atterberg limits and changes in the particle size distribution caused by cement bonding were evaluated by hydrometer testing. For the micromechanical study, SEM images were prepared from selected specimens. The results show that the use of natural seawater does not reduce the strength in comparison with tap water. Specimens containing brackish water (50% seawater and 50% tap water) showed maximum strength due to flocculation in the structure of the clayey cluster in comparison with tap water. The compressive strength ranged from 1.5 to 5 MPa for clay-cement specimens made of natural soil and seawater. The ratio of tensile strength to compressive strength of these specimens was 0.15–0.25. The results show that the unconfined compressive strength of soilcrete specimens constructed under field conditions was 30% that of specimens constructed under laboratory conditions.

Geomorphology and typing of the Lake Ladoga shores with the use of dron

The use of an unmanned aerial vehicle (UAV) with a photo-video camera in the shore of Lake Ladoga in 2015 showed its high efficiency for studying the geomorphology of the shores. A number of features of the morphology of the Ladoga shores in several areas have been revealed, including: the structure of the submerged coastal slope on shallow banks has been refined; the main fracture systems for a number of crystalline massifs on the northern shore of the lake have been determined. A new map of the Ladoga Lake shores types was created. The integration of the method of terrestrial and aerial geomorphological surveys with subsequent generalization of the results to space survey data is an effective addition to the method of geomorphological studies of the coasts.

Port Said and Ismailia as Desert Marvels: Delusion and Frustration on the Isthmus of Suez, 1859-1869

In April 1859, one hundred and fifty laborers gathered on Egypt’s northern shore. When pickaxes first hit the land to be parted from the Mediterranean to the Red Sea, not only was the Suez Canal initiated, but the coastal city of Port Said was also born. Two more cities, Ismailia (1862) and Port Tewfik (1867), were later founded along the waterway. This article analyzes the ways in which the environment of the isthmus of Suez changed upon the digging of the canal as well as the ideas that germinated around such changes. By relying on published memoirs, travel accounts, and archival documents, I explore how Western contemporaries viewed the isthmus desert and constructed narratives around the urbanization and the peopling of the area. I argue that they sanctioned the myth that Western initiative alone could transform the isthmus sands into flower gardens, thus disregarding realities on the ground.

Herding through Uncertainties – Regional Perspectives. Exploring the Interfaces of Pastoralists and Uncertainty. Results from a Literature Review

This paper has been written as a background review for the European Research Council-funded PASTRES project (Pastoralism, Uncertainty, Resilience: Global Lessons from the Margins, pastres.org). Lessons from pastoralists, we argue, may help others working in other domains to develop more effective responses to uncertain contexts. Following prof. Scoones’ papers What is uncertainty and why does it matter?, this is one of two papers developed with a view to analyse and reflect on the interfaces and interrelationships between pastoral societies, the uncertainties that embed their livelihoods, and the related coping/adaptive principles, strategies, and practices. Through a structured review and a meta-analysis of existing literature, the environmental, market, and governance dimensions characterizing uncertainty for pastoralists are explored in six different settings: a) Central and southern Asia, with specific references to the Tibetan plateau in China and to Indian pastoralists; b) the northern and southern shores of the Mediterranean, with a focus on Morocco in the Maghreb-Mashreq region and a wider perspective on pastoralism in Mediterranean Europe; c) the eastern and western flanks of Sub-Saharan Africa drylands, with a specific focus on the Fulani and Borana pastoral groups inhabiting these regions. This paper provides an understanding of the constantly changing uncertainty frameworks characterising the livelihoods of pastoralists inhabiting different geographical areas of the globe.Very diverse and contrasting pastoral settings present relevant similarities and convergences when facing evolving uncertainty scenarios. The ecological uncertainties that inform pastoral strategies get reconfigured as connections and networks extend and the market and governance dimensions hold growing roles in determining the livelihoods of pastoral communities. The paper concludes by indicating potential ways we could learn from pastoralists, as part of a wider conversation about embracing uncertainties to meet the challenges of our turbulent world. This endeavour is complemented by another paper that explores the principles, strategies, and practices pastoral communities adopt with a view to cope and adapt to surrounding and embedding insecurities.

L’ouverture du chenal de la Puissance céleste sous la Chine des Tang : artifice magique ou poudre noire ?

The Channel of Heavenly Might, completed in 868, was a unique feat of late Tang hydraulic engineering. A land canal cutting across the Jiangshan peninsula on the northern shore of the Gulf of Tonkin, it provided a passage connecting two bays in the gulf and sections of the coastal shipping route between Tang China and its Protectorate of Annan (Vietnam). The architect of the channel was the protector general Gao Pian (822–887), a leading actor on the military and political stage during the declining years of the Tang. A man of many talents, Gao was an effective military commander, builder of the medieval citadels of Hanoi and Chengdu, a gifted poet and a keen intellect, versed in Daoist alchemy and the arts of esoteric strategy. The most detailed account of the excavation of the channel to have come down to us is a stele inscription by Pei Xing (ca. 825-ca. 880), author of the collection of Daoist tales titled Transmitted Singularities, and redactor of official documents and military communications for Gao Pian. A witness to the events in 868 and Gao’s confidant, Pei conveyed the public message that the general mobilised the forces of thunder and lightning, objects of a widespread religious cult in the region, to accomplish the breach of a rock formation blocking the path of the channel. Other contemporary sources suggest that Gao used an unprecedented ploy to produce a “simulacrum” of thunder. The present article puts forward the hypothesis that the feat of breaching the channel was the work of alchemists present on the staff of Gao Pian, whose craft, in association with the simultaneous development of Daoist “thunder magic”, is credited with the invention of chemical explosives in ninth-century China.

Aeolianites reveal Pleistocene marine history of Bermuda

AbstractBermuda is a reef atoll along the northern edge of Caribbean coral province. Although investigated by seismic and some shallow drilling, the Pleistocene marine depositional geohistory is poorly constrained. Islands along the southern rim are built by tropical calcareous aeolianites that range in age from Holocene to early Pleistocene (ca 880 kyr). These dunes are composed of particles that were derived from adjacent Pleistocene marine environments at the time of formation. Thus, the aeolianites should contain a record of marine deposition through the Early to Late Pleistocene. Carbonate grains from all aeolian deposits can, via Ward cluster analysis, be separated into two distinct groups: (i) a Halimeda‐rich group; and (ii) a crustose coralline‐rich group. Distribution of these two groups is interpreted to broadly reflect low‐energy (lagoonal) and high‐energy marginal reef (coralline algae and cup‐reef) environments, respectively. Unlike the beach sources, coral particles are perplexingly absent in the aeolianites. This conundrum is interpreted to partly reflect the domal nature of Bermudan corals, which are not incorporated into aeolian deposits due to their relatively large size. Aeolianites from Marine Isotope Stages 7, 9 and 11 record sediments produced in adjacent shallow marine settings that were similar to those present today. The spatially consistent sediment trends are not, however, present in aeolianites from Marine Isotope Stage 5E, where the aeolian bioclastic components are uniformly rich in Halimeda along both southern and northern shores. Such a distribution, where coralline‐rich sediments would be expected, suggests an extrinsic oceanographic control, interpreted herein to be elevated seawater temperature brought in by the Gulf Stream. This interpretation is consistent with palaeozoological studies of Bermuda, as well as North America, the Mediterranean, Japan and Western Australia.

Contemporary Dynamics of the Sea Shore of Kaliningrad Oblast

Abstract The article presents estimations of coastline retreat and advance in Kaliningrad Oblast at 85 monitoring points for a ten-year period of 2007–2017, based on monitoring data supplemented with satellite image analysis. The mean annual rate of coastline retreat and advance was estimated in general for each of the four major morpholithodynamic segments of the coastline: the Vistula (−0.2 m/year) and Curonian (−0.4 m/year) spits, as well as the western (−0.5 m/year) and northern (−0.2 m/year) shores of the Sambia Peninsula. The analysis of the shore protection measures implemented in Kaliningrad Oblast from 2007 to 2017 showed that the length of protected shore segments increased by 30% to 14.5 km, which is 10% of the total coastline. The obtained scheme of long-term mean annual rates of coastline retreat and advance clearly demonstrates an uneven distribution of eroded segments along the shores of Kaliningrad Oblast, however the sea shore of Kaliningrad Oblast is mainly susceptible to erosion (44%). Accumulative segments of the shore make up only 17% of the total coastline, and the remaining 39% of the shore is relatively stable. The results obtained demonstrate that the long-term mean annual rate of coastline retreat has decreased to −0.3 m/year from −1 m/year in the earlier period of 2000–2010. The general condition of the entire coastline of Kaliningrad Oblast can therefore be described as relatively sustainable]. The changes are related to several factors, such as an increase in the length of protected shore segments, the resumption of sand pulp dumping in the beach area by the Amber Mining Plant, and an increase in the amount of analytical data from an expanded local monitoring network.

Three More Voices Papers for This Special Issue of New Solutions-Environmental Justice in the U.S. Gulf Coast Region.

The U.S. states along the northern shores of the Gulf of Mexico have often been described as America's Energy Colony. This region is festooned with polluting industries, storage and waste disposal sites for toxic products, and a history of generally lax approaches to environmental public health and enforcement of regulations. This issue of New Solutions includes three interviews of groups and individuals who work for Environmental Justice in the Gulf Coast region. The interviewees provide key insights into the diverse cultural texture and social fabric of the Gulf. Their range of gulf locales and population groups embody different styles of engagement and different relationships to organizing, disseminating health and environmental risk information, and advocating for social and environmental justice. Similarities among their communities in terms of health and economic disparities, climate risks, and vulnerabilities lend credence to the idea of the Gulf as a regional Environmental Justice community.

Genetic Differentiation of the Steppe Field Mouse Sylvaemus witherbyi Populations: The Results of the Mitochondrial DNA Control Region Analysis.

The degree of genetic diversity of the steppe field mouse was estimated on the basis of the mtDNA control region variability data. Polymorphism of this mtDNA marker in S. witherbyi was more pronounced than previously assumed. The steppe field mouse population from the northern shore of Lake Manych-Gudilo includes several mitochondrial lines, which may be due to the existence of several migration flows to this area from Southwest Asia.

Impacts of pen culture on alpha and beta diversity of fish communities in a large floodplain lake along the Yangtze River

Pen culture is a cumulative factor leading to water quality degradation, competition intensification, habitat alteration and fragmentation. Despite the unprecedented expansion of pen culture areas in Chinese lakes due to the increasing demands on fishery products, little is known about the potential impacts of pen culture on fish communities. Here, we addressed this issue by quantifying changes in alpha and beta diversity with its turnover and nestedness-resultant components between pen culture areas (PA) and non-pen culture areas (NPA) in a large floodplain lake lying on the northern shore of the Yangtze River. Fish communities were sampled seasonally from January 2016 to December 2016 in 16 representative sites (PA, 8; NPA, 8) of Lake Huayanghe using fyke nets. In comparing with fish communities in NPA, we demonstrated an overall loss of fish species and a significant reduction in alpha diversity (richness) in PA, which were probably due to habitat alteration and fragmentation triggered by pen culture. We reported a significantly lower overall beta diversity with its turnover component and a significantly higher nestedness-resultant component in PA. The homogenized and nested trend for fish communities in PA was triggered by the synthesized effects of abiotic and biotic factors. Net pens caused habitat fragmentation and blocked the offset effects by supplementary fish species in nearby habitats, thus resulting in a significantly lower turnover and higher nestedness-resultant component in PA. The introduction of the same cultured fish species and the decrease of the wild native fish species made the fish communities in PA become more homogenized and nested. Pen culture had resulted in a significant decline in alpha diversity and a designed homogenization for fish communities in the lake. Our study highlighted the urgent need for systematic assessment of cultured fish and effective control of pen culture areas to avoid the future fish homogenization and species loss in Chinese lakes.

Identification of subsiding areas undergoing significant magmatic carbon dioxide degassing, along the northern shore of Lake Kivu, East African Rift

We processed InSAR time series of ENVISAT ASAR descending and ascending datasets and identified two new deforming areas on the northern shore of Lake Kivu, characterized by steady ground subsidence of up to ~1 cm/year over a time period of about seven years (December 2002/January 2003–March 2010). Two distinct areas can be identified: one centered on the Rumoka volcanic cone, which built up during the 1912 eruption of Nyamulagira volcano, and a broader one centered on the Bulengo area on the northern shoreline of Lake Kivu. Both areas include high density of diffuse magmatic degassing areas (“mazuku”), which are topographic depressions in which substantial amount of carbon dioxide accumulates. The steady deflation of at least two fluid reservoirs is consistent with geodetic data but the presence of weak, porous layers, possibly connected with hydrothermal and hydrogeological processes in aquifers and Lake Kivu, could also account for the observed subsidence. The subsidence could be due to pore pressure decrease in porous layers, which may also serve as preferential pathways for escaping gases percolating from the aquifers and Lake Kivu.