Nitrogen and Phosphorus Removal from Lake Kinneret Inputs

The Hula Valley was drained in 1957. The land use was modified from natural wetland and old shallow lake ecosystems to agricultural development. About half of the drained land area was utilized for aquaculture. Population size was enhanced and the diary was developed intensively resulting in the enhancement of domestic and husbandry sewage production that increased as well. The natural intact Hula Valley-Lake Kinneret ecosystem was heavily anthropogenically interrupted: The Hula was drained and Kinneret became a national source for domestic water supply. Some aspects of the environmental and water quality protection policy of the system are presented. The causation and operational management implications for the reduction of Nitrogen and Phosphorus migration from the Hula Valley are discussed. Drastic (81%) restriction of aquaculture accompanied by sewage totally removed achieved a reasonable improvement in pollution control which was also supported by the Hula Project. The implications of anthropogenic intervention in the process of environmental management design are presented.

The Peat-Organic-Soil in the Hula Valley

The main soil type, principle contributor of nutrients and available agricultural land in the Hula Valley is the organic Peat. Nevertheless, the relative contribution of Phosphorus from the Hula Valley to the Lake Kinneret inputs is lower than regional outsourcing. The Nitrogenic matter, mostly Nitrate migration from the Peat soil is significant. The implementation of efficient development is the key factor of Hula Land use. The financial beneficial success of the Hula land use is therefore dependent of Peat soil properties. The porosity of the Peat Soil is high and preferential pathway volume is low and Hydraulic Conductivity is therefore low. Consequently, the Mobile Spray Irrigation line was found as most suitable for cultivation in Peat Soil. Enhancement of Summer irrigation creating moisture elevation reduces Phosphorus migration from Peat Soil and is therefore recommended and recently implemented.

The Impact of Hula Project (1993-2018) on Nutrient Migrations

During the 1950s the Hula wetlands and old lake were drained and the land converted utilization to agriculture and ecotourism. As a result of the drainage, the Peat Soil was exposed to atmospheric oxygen. The geochemical environment was modified from reductive to oxidative and the Nitrogen in it was converted from Ammonium to Nitrate. Intensive migration of Nitrate from the Hula Valley induced a national concern of water quality deterioration in the lake which was dissipated when Nitrogen deficiency was developed in Lake Kinneret. Forty years after drainage the ecosystem structure was renovated (Hula Project, HP) aimed at agricultural management and nutrient migration reduction. The paper examines through evaluation of the ecological data record (1993-2018) the impact of hydrological changes, attributed to the HP implementation on nutrient dynamics within surface waters in the Hula Valley. It is suggested that soil moisture elevation by irrigation in summer reduced Phosphorus and enhanced Nitrate concentrations.

Impact of Helicobacter pylori virulence markers on clinical outcomes in adult populations

BACKGROUND In recent years,associations between specific virulence markers of Helicobacter pylori(H.pylori)and gastrointestinal disorders have been suggested.AIM To investigate the presence of virulence factors including vacuolating cytotoxin A genotypes(s1m1,s1m2,s2m1,and s2m2),cytotoxin-associated gene A(CagA),and urease activity in H.pylori strains isolated from Arab and Jewish populations in northern Israel and to assess associations between these factors and patients’demographics and clinical outcomes.METHODS Patients(n=108)who underwent gastroscopy at the Baruch Padeh Medical Center,Poriya due to symptomatic gastroduodenal pathologies as part of H.pylori diagnosis were enrolled in the study.Gastric biopsy specimens were collected from the antrum of the stomach.Clinical condition was assessed by clinical pathology tests.Bacteria were isolated on modified BD Helicobacter Agar(BD Diagnostics,Sparks,MD,United States).Bacterial DNA was extracted,and PCR was performed to detect CagA and vacuolating cytotoxin A genes.Urease activity was assessed using a rapid urease test.RESULTS A significant correlation was found between disease severity and patient ethnicity(P=0.002).A significant correlation was found between CagA presence and the s1m1 genotype(P=0.02),which is considered the most virulent genotype.Further,a higher level of urease activity was associated with isolates originating from the Jewish population.Moreover,higher urease activity levels were measured among CagA-/s1m1 and CagA-/s2m2 isolates.CONCLUSION Our study highlights the importance of incorporating molecular methods for detection of virulence markers of H.pylori in order to tailor optimal treatments for each patient.Further investigation should be performed regarding associations between H.pylori virulence factors and ethnicity.

The Yellow Spot Pattern of Salamander (Salamandra infraimmaculata) in Various Habitats at the Southern Border of Its Distribution in Israel

The present study describes the different color-pattern phenotypes of yellow spots on the black back of Salamandra infraimmaculata in various habitats at the southern border of its distribution in Israel. At Tel Dan, we photographed 454 salamanders in moist habitats where water flows year round;100 of these were sampled to measure the percentage of yellow and black color on the back, and the number of spots on the head. At Kibbutz Sasa, 201 salamanders were photographed, of which 62 were sampled for the measurements. In Kibbutz Yehiam, 200 salamanders were photographed, and 60 were sampled for the measurements. At all sites, about a third of the salamanders were photographed more than once. For all three populations, yellow spots on the salamander back were found in one row, two rows or scattered. For two indices (proportion of yellow/black and number of spots on the head), the Dan population (under wet, running water all year round conditions) differed from the two other populations of salamanders (under semi-arid mountain conditions). The number of yellow spots on the head of the salamanders in the three populations varied from 1 to 7. In all populations, 4 spots pattern was the most common. In the Dan population, there were significantly more salamanders with 1 to 3 spots on their head than in the Sasa or Yehiam populations. No difference was found in the number of head spots for Sasa vs. Yehiam salamanders. The percentage of yellow on the black back was significantly larger for the Dan salamanders vs. the two other populations. The main question examined was whether there is an effect of the habitat conditions in isolated populations on the spot pattern on the salamander back. The answer is positive and is supported by previous studies.

Thermal conditioning of quail embryos has transgenerational and reversible long‑term effects

Background In the current context of global warming,thermal manipulation of avian embryos has received increasing attention as a strategy to promote heat tolerance in avian species by simply increasing the egg incubation temperature.However,because of their likely epigenetic origin,thermal manipulation effects may last more than one generation with consequences for the poultry industry.In this work,a multigenerational and transgenerational analysis of thermal manipulation during embryogenesis was performed to uncover the long-term effects of such procedure.Results Thermal manipulation repeated during 4 generations had an effect on hatchability,body weight,and weight of eggs laid in Japanese quails,with some effects increasing in importance over generations.Moreover,the effects on body weight and egg weight could be transmitted transgenerationally,suggesting non-genetic inheritance mechanisms.This hypothesis is reinforced by the observed reversion of the effect on growth after five unexposed generations.Interestingly,a beneficial effect of thermal manipulation on heat tolerance was observed a few days after hatching,but this effect was not transgenerational.Conclusions Our multigenerational study showed that thermal conditioning of quail embryos has a beneficial effect on post-hatch heat tolerance hampered by transgenerational but reversible defects on growth.Assuming that no genetic variability underlies these changes,this study provides the first demonstration of epigenetic inheritance of traits induced by environmental temperature modification associated with long-term impacts in an avian species.

Constitutive expression of feedback-insensitive cystathionine γ-synthase increases methionine levels in soybean leaves and seeds

Soybean （Glycine max （L.） Merr.） is a major crop that provides plant-origin protein and oil for humans and livestock. Al- though the soybean vegetative tissues and seeds provide a major source of high-quality protein, they suffer from low con- centration of an essential sulfur-containing amino acid, methionine, which significantly limits their nutritional quality. The level of methionine is mainly controlled by the first unique enzyme of methionine synthesis, cystathione y-synthase （CGS）. Aiming to elevate methionine level in vegetative tissues and seeds, we constitutively over-expressed a feedback-insensitive Arabidopsis CGS （AtD-CGS） in soybean cultivars, Zigongdongdou （ZD） and Jilinxiaoli 1 （JX）. The levels of soluble methionine increased remarkably in leaves of transgenic soybeans compared to wild-type plants （6.6- and 7.3-fold in two transgenic ZD lines, and 3.7-fold in one transgenic JX line）. Furthermore, the total methionine contents were significantly increased in seeds of the transgenic ZD lines （1.5- to 4.8-fold increase） and the transgenic JX lines （1.3- to 2.3-fold increase） than in the wild type. The protein contents of the transgenic soybean seeds were significantly elevated compared to the wild type, suggesting that the scarcity of methionine in soybeans may limit protein accumulation in soybean seeds. The increased protein content did not alter the profile of major storage proteins in the seeds. Generally, this study provides a promising strategy to increase the levels of methionine and protein in soybean through the breeding programs.

The Impact of Turbidity on Zooplankton Densities in Lake Kinneret (Israel)

Spatial survey of zooplankton community composition within the upper 10 m layer in Lake Kinneret was carried out. Samples were collected by plankton net (63 μ mesh size) and counted organisms were sorted by 2 groups: 1) Large-including Copepodite and adult Cyclopoid copepods and Cladocerans;2) Small nauplii and rotifers. It was found that in the northern part of the lake where turbidity is high, the density of small organisms is relatively lower, and in other parts of the lake where water is less turbid, large organisms are relatively less abundant. Speculative assumption about the impact of fish feeding behavior on that is presented.

Land-Use, Albedo and Air Temperature Changes in the Hula Valley (Israel) during 1946-2008

Long-Term (1946-2008) record of 35,580 measurements of daily mean air temperatures in three meteorological stations (Dan, Dafna, Kfar Blum) in the Hula Valley, within the drainage basin of Lake Kinneret (Israel) was statistically evaluated. Temperature decline after the drainage of the old Lake Hula and adjacent wetlands (1958) and increase from the mid 1980’s, after the implementation of the Hula Project aimed at continuous land green cover were verified. It was suggested that those regional climate changes were due to the change of Albedo levels: lower when land was water covered and higher after regional drainage followed by a decline when vegetation cover became intensive and continuous. Decline of Albedo levels led to higher air temperature and vice versa.

Somatolactin Transcription during Oogenesis in Female Blue Gourami (<i>Trichogaster trichopterus</i>)

Somatolactin (SL), a specific pituitary hormone belonging to the prolactin (PRL) super family, is involved in background adaptation, osmoregulation, reproduction and fatty acid metabolism. The goal of this study was to examine the gene transcription of SL changes in the ovary of blue gourami females (Trichogaster trichopterus) during oogenesis by quantitative real-time polymerase chain reaction (Real-Time PCR). Somatolactin in the pituitary was higher in females at low vitellogenesis compared to females with oocytes in maturation, and the difference was significant (p < 0.05). No significant differences were found in mRNA levels between low and high vitellogenesis, and high vitellogenesis and maturation. The findings of this and previous studies demonstrate that SL, growth hormone (GH) and PRL are involved in oogenesis in blue gourami;however, considerably more studies are required in order to separate the functions of these hormones.

Sex-Based Variation of Gene Expression in the Gonads and Fins of Russian Sturgeon (<i>Acipenser gueldenstaedtii</i>)

Russian sturgeon (Acipenser gueldenstaedtii) is a primitive freshwater fish and a source of black caviar. The genes involved in sexual determination and differentiation are still unknown and there are no molecular markers for sex identification in this species. Studying the variation of the sex-based differences in genomic sequences and in gene expression in the sturgeon may lead to markers of sex in early stages of development and advances in aquaculture, as well as provide novel insights about the evolution of reproduction, sex determination, and sexual differentiation mechanisms in vertebrates. Previous studies by our and other groups have identified differentially expressed genes in the gonads of adult female and male sturgeon. The current study aimed to test whether these genes were also differentially expressed in non-gonadal tissue, namely fins. We measured by qRT-PCR the mRNA levels of 29 known and novel sex-related genes in the gonads and fins of males (4 years old) and females (7 years old;sexual maturation is earlier in males than in females). Six genes (ATP6, IGFRM, LIA1A, S1A, NPL1A, GAPDH and SOX9) showed higher expression in female fins. However, only ATP6 mRNA levels differed in fins of males and females of the same age (4 years old). These findings underscore the impracticality of sex identification based on gene expression in non-gonadal tissue and the need for genetic sex markers in the Russian sturgeon.

On The Biology of Tilapia zillii (Gervais1848) in Lake Kinneret (Israel)

Fish (mostly Tilapia zillii), (TZ), mass mortality in Lake Kinneret initiated a study of the biology of TZ in Lake Kinneret. The study included several aspects: spawning and nesting behavior, feeding habits, the status of TZ in the Kinneret fishery and temperature tolerance. The merit of TZ to commercial landing fishery is negligible, but this specimen is one of the most common fishes in the lake. Several environmental factors are considered as promoters of the epilimnetic temperature decline: Jordan water inputs in winter season as a heat source parameter. ENSO (EL-NI&#209O/Southern Oscillation) acts as a cooling enhancement factor. Supportive data on the impact of ENSO were found in two terrestrial agricultural monitors in the northern and southern parts of the drainage basin. Gut content analysis of young fingerlings and an adult TZ specimen, indicated the significant contribution of benthic sources which are common in the shallows. The great adaptive capabilities of breeding TZ with various bottom habitats are demonstrated.

Chemical, Hydrological and Climatological Properties of Lake Agmon, Hula Valley (Israel), (1994-2006)

The first decade of monitoring program in Lake Agmon (Hula Valley, Northern Israel) is summarized. The presented part of the program include: water discharges, physico-chemical (pH, EC, Temperature) and chemical parameters (TP, TN, TDN, TDP, NO3, NH4, SO4, TDS, TSS,). It was found that Nitrogen concentrations decline from north to south and the opposite for Phosphorus. Resulting of re-suspension by wind direction of western-southern-eastern and averaged maximal velocities of 9 - 10 m/s is suggested. De-nitrification and particles sedimentation emphasize Lake Agmon as a sink for Nitrogen. Sulfate-Carbonates association and the production of precipitated Gypsum (CaSO4) highlight the sink property of Lake Agmon. Nevertheless Sulfate removal by the Lake Agmon hydrological system is significant.

Male Blue Gourami (Trichogaster trichopterus) Nest-Building Behavior Is Affected by Other Males and Females

In this study, we examine male blue gourami (Trichogaster trichopterus) nest-building behavior that is affected by other males and interactions under experimental conditions. Males found in the area control the territory and sexual behavior, and are influenced by the behavior of other males. The results of this study show that the sexual behavior (nest-building) of male blue gourami is affected both by the behavior and pheromones of other males. We suggest that males must defend their territories in order to prevent these two factors from interfering in nest-building.

Cannibalism, among Other Solutions of Adaption, in Habitats Where Food Is Not Available for Salamandra infraimmaculata Larvae Diet in Breeding Places in Xeric Habitats

The present study examines the inherent flexibility in the feeding responses of S. infraimmaculata larvae to various breeding places. In addition, the study examines the hypothesis that in dry conditions, the water breeding places are the limiting factor for the survival and completion of the life cycle of populations of S. infraimmaculata. In the breeding sites, the food for larvae is not available, and cannibalism is the specific adaptation for larvae to grow and complete metamorphosis. S. infraimmaculata larvae feed on various invertebrates in different habitats, and cannibalism involves the adaptation to breeding places where food is not available. The growth only by cannibalism as the only way to adapt to these habitats because no food is found in breeding places at the southern border of its distribution is described here for the first time, not only in salamanders but in other animals as well.

A Review on Modeling of Kinneret Salinity with Practical Recommendations

Two models have been developed for the evaluation and prediction of salinity changes (chloride concentration;ppm;[Cl]) in Lake Kinneret. They are: 1) RM, which is based on the Salt balance and hydrological budget of the lake;2) GM which is based on the geo-hydrological regional properties of Kinneret’s geological structure. The concept of both is partly different: RM is correlating reduction of runoffs to salinity elevation and GM relates salt flux to the aquifer yield and the impact of lake water level is neglected. Long term statistical analyses justify support to GM, excluding conditions of heavy floods. This paper is a combination of a supplemental extended temporal study and a models review. Practical conclusions on Kinneret hydrological management within a frame of constrains aimed at prevention of salinity and eutrophication increase are presented.

Population Dynamics of Cyclopoid Copepods in Lake Kinneret (Israel)

Reports on the Kinneret zooplankton in general and particularly on copepods are dealing recently with numerical densities of feeding habit classes. Nevertheless, for the evaluation of the integrated role of copepod assemblages in the entire lake ecosystem, their life cycle stages fluctuations are essential. It was not done in previous reports. Therefore, long term analysis of the cyclopoid copepods life stages dynamics in Lake Kinneret was carried out. Due to information availability, two complementary methods of density concentrations were evaluated for two consecutive data sets: 1) 1969-1985 numerical (No/L) documentation of life cycle stages of nauplii (I - III and III - V), copepodites (I, II, III, IV, V) and adults;2) 1969-2002 monthly averages of wet biomass density (g/m2) of zooplankton major groups combined with metabolic rates. nauplii densities represent June-August peaks and older stages spring decline and high levels during summer-early winter. Polynomial Regressions between Numerical annual averages of predator and Herbivore stages as well as young vs. older life stages indicate significant relations. During winter-spring season, temperatures are optimal for cyclopoid growth as a result of the high efficiency of metabolic activity and the low pressure of fish predation. The high rate of metabolism and intensive fish predation in summer enhance low densities of adult cyclopoids.

Limnological Changes in the Lake Kinneret (Israel) Ecosystem: The Beginning and Its Significance

The Lake Kinneret (Israel) ecosystem has undergone limnological changes. The trend of changes started in the mid 1990’s. The deviation from the previously known as stable long-term structure of the ecosystem included, among others, phytoplankton community structure, nutrient dynamics, zooplankton densities, water temperature increase, water level decline, and fishery management. This study is aimed at identifying ecosystem stability by focusing on three major compartments of the ecosystem: Total Dissolved Solids (TSS), Plankton (Phyto and Zoo), and Detritus (TSS minus plankton). It is suggested that although significant temporary changes of biotic and abiotic parameters were recorded and despite the existence of the normal seasonal fluctuations, the major compartments’ structural relations were not modified. The objective of the study is to analyze the process initiation of the modification trend. Previous studies and reports were focused on descriptive evaluation of the modified parameters. The expected outcome is a comprehensive evaluation of the modification process. Consequently, resulted prediction might be a tool for managers to improve management design.

Genetic Variation in <i>Salamandra</i><i>infraimmaculata</i>from Different Habitats Using Amplified Fragment Length Polymorphism

The purpose of the present study was to examine the genetic variation in Salamandra infraimmaculata from different breeding site habitats using the Amplified Fragment Length Polymorphism (AFLP) method. The results of the dendogram from a hierarchical cluster analysis show that the grouping of S. infraimmaculata as cluster 5 differs from all the other clusters, including the St1 (Tel-Dan stream) population, which was the most predictable. Five Haplogroups (Hg) were characterized. The mean number of alleles per locus in each population (Ne) ranged from 10.566 (Sp1) to 2.720 (Po6). An average estimated heterozygosity (He) by population ranged from 0.100 (Po6) to 0.186 (St1). Population St1, a permanent breeding site where water was available all year round, exhibited the highest level of polymorphism, while population Po6, from the ephemeral breeding site, exhibited the lowest level of polymorphism. Gene flow between clusters showed that clusters 3 and 4 are sources of migrants and also receive gene flow, while clusters 1 and 2 may be a source of migrants but may not receive much gene flow. A phylogenetic analysis, based on clustering using Nei’s genetic distance, demonstrated that the Tel-Dan population is located on a separate branch within its sub-population. The conclusion of the present study shows that the genetic divergence among isolated populations is not correlated to distance but is affected by the variation of habitats.

The Impact of Climate Change on Zooplankton Biodiversity Index (ZBDI) in Lake Kinneret, Israel

Climate change conditions were indicated in the watershed of Lake Kinneret: air and consequently water temperature increase, decline in rainfall, and diminish river discharges accompanied by a reduction in Epilimnetic nitrogen and a slight increase in phosphorus. It is suggested that warming trend of the Kinneret Epilimnion enhanced decline of Zooplankton Biodiversity Index (ZBDI).