Lake Bank Research Articles

Diel bank migration of Burbot (Lota lota)

Determining the habitat use and movements by fish is critical to our understanding of aquatic ecosystem function. The objective of this study was to assess the diel movements of Burbot (Lota lota) over the open water season. We employed a high-resolution acoustic telemetry positioning system to track the movements and activity of four Burbot during the ice-free season (between June and September) in a sub-Arctic lake. Burbot underwent diel bank migration (DBM), a benthic form of diel vertical migration, where depths are transitioned in close association with the bottom rather than through the water column. During daytime, Burbot occupied deeper water, at the transition of soft, low complexity substrates and ascended along the rocky bottom lake banks to shallower water habitats at night. Increased activity rates during shallow water forays suggest active feeding events. DBM was low at the start of summer with nearly 24 h of daylight, but increased towards the mid-summer with a more pronounced night cycle, coalescing towards the fall. The DBM of Burbot is dynamic, with proximate triggers of light and temperature, and ultimate causes likely being foraging opportunities, bioenergetics gain and predator avoidance.

Oksyvos kultūra dešiniajame žemutinės Vyslos krante

Oksyvos kultūra, kaip nauja vėlyvojo ikiromėniškojo gele­žies amžiaus archeologinė kultūra, susidarė dėl keltų pasau­lio įtakos bei Pševorsko ir Jastorfo kultūrų impulsų III a. prieš Kr. (A1 periode). Kultūros vardas kilo nuo vietovės Oksywie (Oxhцft), šiandieninio Gdynės miesto dalies, apie 10 km į šiaurę nuo Gdansko, kur buvo atidengtas šios kul­tūros kapinynas. Pradžioje ši kultūra užėmė visą dešiniąją žemutinės Vyslos pusę ir sritį prie Chełmno (Kulmo). Kla­sikiniame periode A2 kultūra užėmė ir sritį Pomeranijoje. Archeologinių šaltinių duomenimis, čia buvo įsikūrusios vietinių gyventojų grupės – Pomeranijos kultūros tęsėjos. Dėl materialinės kultūros pokyčių ir galbūt gotų diktuoja­mų laidojimo papročių iš Oksyvos kultūros ikiromėniškojo laikotarpio A3 periodo pabaigoje ir romėniškojo laikotarpio B1 periodo pradžioje išsivystė Wielbarko kultūra. Archeologinę medžiagą, reprezentuojančią Oksyvos kul­tūrą šioje Vyslos srities dalyje, sudaro archyvinė medžiaga (apie radinius, aptiktus iki Antrojo pasaulinio karo) ir archeo­logijos paminklai. Svarbiausią grupę tarp prieškario kolekcijų sudaro archyvinė medžiaga, kurią surinko Waldemaras Hey­mas (Heym). Šis žmogus į archeologijos istoriją pirmiausia pateko kaip Heimatmuseum Marienwerder vadovas. Dėl Antrojo pasaulinio karo maišaties didžioji W. Hey­mo rinkinio dalis yra negrįžtamai dingusi arba išbarstyta. Likusi tik informacija apie pavienius artefaktus. Naujausi archeologiniai rinkiniai yra tik prieškario medžiagos papil­dymas. Jie nėra svarbiausia šio Vyslos srities regiono Oksy­vos kultūros kolekcijos dalis. Turimas medžiagos rinkinys reprezentuoja Oksyvos kul­tūrą visu ikiromėniškuoju laikotarpiu, t. y. nuo periodo A1 iki periodo A3. Dalis rinkinio yra iš to laikotarpio kapinynų, kaip antai Bystrzec (buv. Weisshof, Kreis Marienwerder) arba Stary Targ (buv. Altmark, Kreis Stuhm). Kapai, ku­riuose rasta ginklų (ietigalių, kalavijų, antskydžių), yra ypač svarbūs, tačiau jie žinomi tik iš A2 periodo ir A3 periodo baigiamosios stadijos. Iš minėto laikotarpio ankstyviausio horizonto galima kalbėti apie Pomeranijos varpinius kapus ir Jastorfo kultūros įtaką. Geriau pažįstama Pševorsko kul­tūros įtaka, ypač Oksyvos kultūros puodininkystei. Suma­nymas nustatyti Oksyvos kultūros gyvenviečių chronologiją pagal išlikusią medžiagą ir kaupiamą informaciją, kuri dau­giausia fragmentiška, yra sunkiai įvykdomas. Kitu atveju tai klausimas, į kurį turėtume atsakyti. Oksyvos kultūros arheologinė medžiaga iš šitos Vakarų Prūsijos srities yra svarbi bendram Oksyvos kultūros pa­veikslui identifikuoti, ji reikšminga ne tik šiam Vyslos re­gionui.Iš vokiečių kalbos vertė Mykolas Michelbertas

Metal accumulation in an artificially recharged gravel pit lake used for drinking water supply

Gravel pit lakes offer a variety of uses after excavation has ceased. One of those uses is the storage, infiltration, aquifer passage, and production of drinking water. We have investigated such a gravel pit lake in The Netherlands that is a state of the art drinking water production facility. The gravel pit lake is a flow-through lake, fed naturally by groundwater (~17%) and rainwater (~6%), and artificially with Meuse River water (~77%). The average concentrations of Cd, Cr, Cu, Ni, Pb and Zn in the lake's bottom sediments have increased over a 10year period. Acidifying redox reactions caused by lowering of the water table and farmland fertilization upstream from the lake explain the mobilization of metals in the soil and subsequent transport with groundwater towards the lake. Dissolved metals (Al, Cd, Cr, Cu, Fe Mn, Ni and Zn) and PO43− flow with the groundwater towards the lake, where they interact with oxygen-rich and alkaline water to (co)precipitate as Fe, Mn and Al oxides. The chemistry of the gravel pit lake water is determined by a complex interplay between the input of NO3− and PO43−, soil composition up stream, biochemical processes in the lake that supply organic material, mixing processes (artificial and natural) that determine the amount of stratification and oxygen, and redox cycling processes in the bottom sediments that influence the concentration of metals and P in the lake water. Gravel pit lakes are young compared to natural lakes and the long term influence of these lakes is still largely unknown. This study confirms that they can form a sink for metals and thus influence the metal budget of a watershed. Compared to other artificial recharge methods, infiltration in a gravel pit lake along a river has certain advantages in that the lake already exists, the transport distance for the water to be infiltrated is short, the pretreatment of the infiltrated water is simple, and the long residence time of the water in the lake and the lake bank filtration attenuates quality variations of the infiltrated river water. For drinking water production or other usage of gravel pit lakes, an integrated monitoring and management of land use, ground- and surface water as well as lake bottom sediments are needed.

Eukaryotic microbial communities in hypersaline soils and sediments from the alkaline hypersaline Huama Lake as revealed by 454 pyrosequencing

In hypersaline ecosystems, microbial assemblages are structurally distinctive and play important roles in many microbiological and ecological processes. Here, eukaryotic microorganisms in hypersaline samples were investigated by 454 pyrosequencing of internal transcribed spacer (ITS) gene libraries. In total, 4,645, 1,677, and 5,912 reads were obtained from ITS libraries of waterlogged samples, salt crusts, and saline loess from the alkaline Huama Lake in Shaanxi, China. Analyses of pyrosequencing data revealed that the dominant genera were Dunaliella, Alternaria and Chlamydomonas, which dominated the microbial assemblages in the waterlogged sediments, the salt crusts and the saline loess from the lake banks, respectively. The various infrequent species were not commonly shared by the three types of samples, demonstrating that the eukaryotic microbial compositions of the different environments were distinct. However, the micro-eukaryotic assemblages associated with similar environmental conditions shared some components and were phylogenetically related. The eukaryotic microbial community composition was correlated with the pH value of the site (p=0.001; r(2)=0.99), but not with the concentration of total nitrogen or the inorganic ions investigated in this study. The results of this study demonstrated that the hypersaline ecosystems hosted surprisingly diverse eukaryotic microbial community.

Removal of cyanobacteria and cyanotoxins during lake bank filtration at Lagoa do Peri, Brazil

Bank filtration is presented as a barrier for cyanobacteria and their metabolites (cyanotoxins and odor compounds). Retention of cyanobacteria is supported by column and bench studies using sandy materials. Most of the removal is in the first decimeters of infiltration, where physical and biological processes take place. Cyanotoxin removal is a very complex process including sorption and/or biodegradation. Sorption depends on the type of cyanotoxin and the sediments/aquifer composition. Biodegradation depends on the type of cyanotoxin, redox conditions, previous contact with the cyanotoxin, type and content of natural organic matter, and temperature. Pilot studies at the Lake Lagoa do Peri in Brazil demonstrated the effectiveness of bank filtration in removing phytoplankton and Cylindrospermopsis raciborskii (105–106 cells/mL) before reaching a sampling well at 12-m depth located 20 m from the lakeshore. Column experiments confirmed biomass removal predominantly in the upper 2 cm of infiltration. No saxitoxins (STXs) were found in the well water and a high retention of neo-STX and STX was determined by isotherm experiments. The sorption linear coefficient (Kd 13–16 L/kg) was found to better represent the sorption processes than the Freundlich coefficient (Kf 6.5–12 L/kg).

Vodní měkkýši nově vzniklého jezera Most v severních Čechách [Freshwater molluscs of the Most, a newly created lake in Northern Bohemia (Czech Republic)

This paper summarizes the knowledge of freshwater mollusc fauna of the Most Lake. It was created in 2008–2013 by flooding of the majority of the former coal quarry of Ležáky (Northern Bohemia). This water reservoir originated in the area of 311 ha and with the maximum depth of 75 m it is the largest water body of the area. The research was conducted in summer 2013, when the water level was about 0.5 m bellow the final expected level. In total, only six species of freshwater molluscs (five gastropods, one bivalve) were found at 11 sites. Two autochtonous molluscs (Radix auricularia and Gyraulus crista) and four allochtonous species (Physella acuta, Gyraulus parvus, Menetus dilatatus and Dreissena polymorpha) were found. The occurrence of all species except D. polymorpha was scattered, while the latter occurred in numerous populations sometimes with more than 80 specimens per 10 cm². Most of the molluscs were found on stones of the lake banks or at areas of shallow water. The results obtained during this research have recorded mollusc assemblages at the first successional stages of this artificial lake, thus enabling future comparison.

Mark Twain's Homes and Literary Tourism

Mark Twain's Homes and Literary Tourism

Variation in the Diet of the Mexican Black-bellied GartersnakeThamnophis melanogaster: Importance of Prey Availability and Snake Body Size

We describe the diet of Thamnophis melanogaster on the Mexican plateau, including geographic variation between populations in the Lerma and Tula drainages (represented by 39 localities), annual and seasonal variation in an isolated population in the Nazas drainage, and sexual and size-related variation in all three drainages. The Mexican Black-bellied Gartersnake inhabits banks of streams, rivers, canals, ponds, and lakes, where it captures fishes, leeches, crayfishes, tadpoles, earthworms, and frogs by foraging underwater. There was no geographic variation between the Lerma and Tula populations in proportions of prey taxa consumed, but whereas primary and secondary tadpole stages were consumed by snakes in Lerma, only secondary stages were consumed by snakes in Tula. Crayfishes, novel prey for this genus, were consumed over a restricted zone in the contiguous headwaters of the Lerma and Tula drainages. Interannual and seasonal variation in proportions of annelids and anurans ingested was documented in the Nazas population, and attributed to temporal change in relative abundance of prey taxa and snake size classes. Snake size was a major determinant of diet in all three drainages, affecting proportions of different prey taxa consumed and the upper limits on the mass of ingested prey. In the three drainages, sexes were similar in body size and consumed the same prey taxa in similar proportions and masses. We discuss proximate and functional determinants of diet and suggest that the observed interannual and seasonal variation observed in Mexican Black-bellied Snakes is due mostly to temporal variation in prey availability and proportions of snake size classes.

Age models and tephrostratigraphy from two lakes on Adak Island, Alaska

Radiocarbon-based age models from two lakes on Adak Island, Alaska, were compared using correlated tephra to check the accuracy of the radiocarbon ages and to develop a regional tephrochronology. Andrew and Heart Lakes are located adjacent to and 5 km south of Mt. Moffett on the northern part of Adak Island in the central Aleutian Arc. The downcore trends in radiocarbon ages of macrofossils, the 1963 spike in plutonium (239+240Pu) activity, and a lead (210Pb) profile from Andrew Lake were modeled with smooth spline fits. Tephras were correlated based on magnetic susceptibility, particle morphology, and internal stratigraphy including color and particle size. Of the 19 pure tephras in Heart Lake and 21 in Andrew Lake, ten could be confidently correlated between the two lakes. The composite tephrostratigraphy from the two lakes includes at least 30 unique tephras deposited over 9600 years. Radiocarbon ages obtained from mixed aquatic and terrestrial macrofossils with ages hundreds of years too old were inferred for Heart Lake by correlated tephra ties to the Andrew Lake age model. The eroding tephra-soil deposits that crop out along the banks of Heart Lake, and its large shallow platform, may facilitate remobilization of previously stored sediments. Previous studies on Adak Island of archeological sites and tephra-soil outcrops described five tephras that are correlated with a subset of tephras from the lakes based on stratigraphic succession, inferred age, and physical description. Age-depth models for Heart and Andrew Lakes as well as tephrochronology for Adak Island provide geochronological context for future studies.

The effect of nest site on the nesting success of the Coot Fulica atra

The nesting success of Coots (Fulica atra) breeding at lakes and small inland water bod-ies in the Mazurian Lakeland, Poland, was estimated in 2008 and 2009. Mean nesting suc-cess, indicated by hatching, was 75%; it was highest at lakes in the vicinity of built-up areas (86%), moderate at small inland water bodies (69%) and lowest at lakes far from hu-man settlements (44%). Nesting success improved with decreasing distance to open wa-ter. Our results suggest that small inland water bodies and built-up areas along lake banks may serve as Coot refuges, acting as safeguards against predation, especially by the American Mink.

The effects of water management on annual maximum floods of Lake Como and River Adda at Lecco (Italy)

This paper presents the results of an analysis aimed to assess the impact exerted on the flood regime of Lake Como and its emissary by different kinds of waterworks in the Adda basin (Italy). This includes construction of reservoirs in the Alps, increase in flow capacity of the exutory and regulation of Lake Como. The assessment of the management effect on peak floods is of particular interest as flood damages could be particularly heavy in densely populated areas along the lake banks and in the river flood plain downstream of the lake. The analysis is carried out by comparing the annual maxima of Lake Como levels and the river Adda discharges at Lecco, at the lake exutory, in different real and hypothetical situations. Both the construction of alpine reservoirs and the improvement of flow capacity of the exutory decrease lake levels and flood discharges, while lake regulation (for irrigation and power production) increases them. The overall effect is a generalised reduction of the flood levels and a slight increase in the discharges with return periods lower than 10 years. The discharges with higher return periods, instead, remain unchanged. The difference between peak and mean daily discharges negligible in all cases disappears altogether for return periods higher than 10 years.

Prehistoric Life along the Banks of Spring Lake: Results and Analysis of the Southwest Texas State Field Schools (1996–1998) at 41HY165, San Marcos, Hays County, Texas

This report presents the results of archaeological investigations and subsequent analyses of archaeological site 41HY165, located along the banks of Spring Lake in Hays County, Texas. Excavations were conducted at 41HY165 during the 1996, 1997, and 1998 Southwest Texas State University (now Texas State University-San Marcos [Texas State]) field schools. As site 41HY165 was and still is located on property owned by Texas State (formerly Southwest Texas State University), investigations during the 1996–1998 field schools were subject to the Antiquities Code of Texas. Therefore, a Texas Antiquities Permit (Permit No. 1700) was issued by the Texas Historical Commission (THC) on May 30, 1996, with Dr. James Garber serving as Principal Investigator. The permit has since defaulted, and it is the goal of this report to close this permit.

Numerical and behavioral responses of waterfowl to the invasive American mink: A conservation paradox

A behavioral response is usually the first adaptation of animals to environmental changes such as the introduction of an alien invasive species, and it seems to be the most important factor in reducing the negative impact of new predators on naive prey. This study examined changes in the abundance and behavior of breeding coots (Fulica atra) and great crested grebes (Podiceps cristatus) in response to invasion of the Mazurian Lakeland (NE Poland) by American mink (Neovison vison), first recorded here in 1984. Feral mink densities varied from 1.0 to 14.6 individuals per 10km of shoreline. Mink were responsible for the losses of 17–58% of experimental clutches (artificial nests containing chicken eggs) that were deployed. Mink destroyed more experimental clutches than other predators; the effects of mink predation were similar in reeds and on the bank. Radio-tracking showed that mink avoided lake banks near human settlements. Mink have markedly affected the breeding distribution of both species and caused a greater than 20-fold decline in coot numbers. For coots and grebes breeding distribution and nesting success were positively associated with built-up areas along lake shores and also with whether the birds were breeding in colonies. Increased brood survival of coots and grebes near human settlements is a paradox in the sense that a man-made habitat change has provided refuge from an alien predator.

Terrestrial smokers: Thermal springs due to hydrothermal convection of groundwater connected to surface water

Thermal springs are ubiquitous features whose underground kinematic structure is mostly unknown but are typically thought to originate from deep sources. We documented a type of thermal springs at the banks of a volcanic lake that are discharge zones of hydrothermal convection cells circulating groundwater within the near shore environment. The convection captures lake water through the lakebed, mixes it with deeper groundwater at velocities of 100s of m d−1, then returns the water to the lake via the spring. The convection cell is flushed in a few hours and turns over the lake's volume in a few days. Most volcanic lakes and other relatively cool surface water bodies in areas of elevated geothermal heat fluxes meet the conditions for the occurrence of local hydrothermal circulation of groundwater. The type of spring we studied, the terrestrial version of black smokers, is likely present but perhaps unrecognized at many areas.

Occurrence and risk assessment of polycyclic aromatic hydrocarbons in soil from the Tiefa coal mine district, Liaoning, China

In order to evaluate soil-associated polycyclic aromatic hydrocarbons (PAHs) pollution from coal mine activities in Tiefa coal mine, Northeast China, 16 PAHs identified as priority pollutants by US Environmental Pollution Agency were determined in mining zone soil (MZS), agricultural soil (AS), local lake bank soil (LBS), a vertical soil profile and three coal gangue samples. The total concentration of 16 PAHs (defined as Σ(16)PAH, dry weight) in surface soil ranged from 5.1 to 5642.3 ng g(-1), with an arithmetic mean of 1118.3 ng g(-1). Σ(16)PAH values at the sites from MZS are significantly higher than those found in AS and LBS. The vertical distribution of PAHs indicated that these compounds can penetrate the deeper layers of the soil, especially the low-rings compounds. A complex of petrogenic origin and pyrolytic sources was found within the study area, as suggested by the isomeric ratios of PAHs. According to principal component analysis (PCA), four factors were identified in the source contribution, including coal combustion, unburned coal particulates, coal gangue and vehicular emissions. The degree of contamination and the PAH toxicity assessment suggested that the soils of the study area have been seriously polluted and pose a high potential health risk.

SATELLITIC RADAR REMOTE SENSING STUDIES ON EVOLUTION OF JILANTAI SALINE LAKE

It is very important to study saline evolution by means of remote sensing images. Based on field survey and previous information, this paper points out that the older lake banks are discovered by Canadian Radarsat-1/S1 SAR images in Jilantai saline area are relicts of lake evolution since Late Pleistocene. On such a basis, the evolutionary process of Jilantai saline lake and the regularity of climate changes in Jilantai saline area are discussed in detail.

Caratteristiche idrodinamiche del lago di Sauris

Experimental results obtained along the banks of theSauris's Lake, during two different groups of observations (full and reducedbasin), are here resumed. The agreement between observed and precedent calculated data, isvery remarkably. A new theory, moreover, is here showed and for t h e firsttime applied to an artificial lake.As the values of the periods for w-nodal oscillations (n > 1) both inthe theory and in the observation have been higher t h a n these regardinga lake with even depth, we have applied the below explained theory to theSauris's Lake.I t is considered a basin whose longitudinal section forms a right-angledtriangle; the shorter cathetus figures the dam.The theoretical and the observed results among themselves perfectlyagreed.The above mentioned theory, because of the easy applications, willbe used for others similar lakes.

Distribution and isotopic composition of n-alkanes from grass, reed and tree leaves along a latitudinal gradient in China

Living terrestrial higher plants including grass, reedand tree leaves were collected in spring and autumn of2001–2005 from salt marshes at Huatugou, Qaidam ba-sin; the Ruoergai grassland, Sichuan; the banks of theXihu Lake (West Lake), Hangzhou; the bank of theDianchi Lake, Yunnan; and Nanning in Guangxi (Fig. 1and Table 1).Immediately after collection, non-indigenous materialin leaves was removed and the leaves were washed re-peatedly with tap water and then rinsed with distilledwater. All samples were dried at room temperature andcrushed to fine powder. Powders were kept frozen untilanalysis. Powdered samples were extracted in a Soxhletapparatus with a mixture of dichloromethane-methanol(2:1, v/v). The extracts were filtered and evaporated, andthen fractionated with a column chromatography onalumina over silica gel (Duan

Spatial distribution, activity, habitat selection of American mink (Neovison vison) and polecats (Mustela putorius) inhabiting the vicinity of eutrophic lakes in NE Poland

Invasive American mink and native polecats were live-trapped over a period of six years and radio-tracked during one winter-spring season in the lakeside habitats in NE Poland. The number of mink declined whereas number of polecats was stable during 1995–2000, however, except during one winter, mink were always more abundant in the study area than polecats. Significant differences in habitat utilization between radio-collared mink and polecats were observed. Mink moved only along the lake shoreline and showed no seasonal shift in habitat selection. In winter, polecats were most frequently located close to the lake banks, but they also stayed in barns and stables. In spring, they moved further from the lakes. There was considerable interspecies overlap of mink and polecat home ranges in February, and common use of the banks of the 500 m long unfrozen canal was recorded for 4 mink and 5 polecats. The pattern of daily activity of polecat and mink differed: mink were most active at dawn and in early morning whereas polecats at dusk and in beginning of the night. Individuals of both species coexisted in this small area at relatively high densities and to some degree exploited the same habitats, particularly in the vicinity of sites with access to open water.

Endogenous abscisic acid as a key switch for natural variation in flooding-induced shoot elongation.

Elongation of leaves and stem is a key trait for survival of terrestrial plants during shallow but prolonged floods that completely submerge the shoot. However, natural floods at different locations vary strongly in duration and depth, and, therefore, populations from these locations are subjected to different selection pressure, leading to intraspecific variation. Here, we identified the signal transduction component that causes response variation in shoot elongation among two accessions of the wetland plant Rumex palustris. These accessions differed 2-fold in petiole elongation rates upon submergence, with fast elongation found in a population from a river floodplain and slow elongation in plants from a lake bank. Fast petiole elongation under water consumes carbohydrates and depends on the (inter)action of the plant hormones ethylene, abscisic acid, and gibberellic acid. We found that carbohydrate levels and dynamics in shoots did not differ between the fast and slow elongating plants, but that the level of ethylene-regulated abscisic acid in petioles, and hence gibberellic acid responsiveness of these petioles explained the difference in shoot elongation upon submergence. Since this is the exact signal transduction level that also explains the variation in flooding-induced shoot elongation among plant species (namely, R. palustris and Rumex acetosa), we suggest that natural selection results in similar modification of regulatory pathways within and between species.