Small Gravel Research Articles

Spawn Timing and Redd Morphology of Anadromous Coastal Cutthroat Trout Oncorhynchus clarkii clarkii in a Tributary of South Puget Sound, Washington

AbstractSpawn timing information for Coastal Cutthroat Trout Oncorhynchus clarkii clarkii is typically limited to counts of adult fish at traps and tagging studies based on few samples. These types of data have suggested a protracted spawning period that occurs between November and March. We sought to determine the spawn timing and describe the redd morphology of anadromous Coastal Cutthroat Trout in a typical coastal stream of southern Puget Sound, Washington. Skookum Creek was surveyed for live and dead Coastal Cutthroat Trout and redds once weekly from early October to early June during six spawning season (2008–2014). In total, 148 live adults and 544 redds were observed. The timing of redd construction was highly variable among years, with 50% of redd detections occurring by as early as February 13 or as late as April 27. Measurements were collected from individual redds to describe redd morphology and the habitat type utilized by spawning Coastal Cutthroat Trout. Redds were typically found in substrate composed of small gravel (1.3–3.8 cm) and large gravel (3.8–7.6 cm) and in water with an average velocity of 0.60 m/s. The pit within redds averaged 0.43 m wide × 0.48 m long. Information from this study may provide new insights that will allow fisheries managers to begin developing a species‐specific approach to monitoring anadromous Coastal Cutthroat Trout.Received July 2, 2015; accepted December 2, 2015 Published online March 31, 2016

Role of multidetector computed tomography without contrast enhancement in predicting the outcome of extracorporeal shock wave lithotripsy for urinary calculi

Objective: The aim of this study was to evaluate the role of nonenhancing computed tomography as a predictive factor for successful extracorporeal shock wave lithotripsy (ESWL) for urinary calculi to avoid the cost of ineffective ESWL. Background: Urolithiasis is a universal problem. Many methods of treatment of urolithiasis are described, among which is ESWLs. The outcome of ESWL is affected by several factors. Multidetector computed tomography (MDCT) can aid the localization of calculi and may provide accurate anatomical detail, providing valuable data such as stone size and stone density as predictors for ESWL success. Materials and methods: This study included 54 patients who presented with symptomatic renal colic and hematuria at the ESWL unit. ESWL was used as the primary treatment option for all patients. All patients were investigated by MDCT before and after ESWL treatment. Successful ESWL was defined when a patient had achieved complete clearance of the stone fragments or had small residual gravels of size less than 4 mm. ESWL failure was defined as no breakage of the stone after three sessions. Results: A high rate of ESWL success after a second session of ESWL was achieved in 26 cases (48.1%), followed by a first session in 15 cases (27.8%), with an overall success rate of 90.7% in 49 cases. Also, smaller size and density of urinary stones will increase the success rate of ESWL. Conclusion: MDCT can be used to provide valuable data on urinary stones to aid treatment decisions and predict the outcome of ESWL.

Records of repeated drought stages during the Holocene, Lake Iznik (Turkey) with reference to beachrock

The cement fabrics, subsurface nature and optically stimulated luminescence age of beachrocks along the shores of Lake Iznik in NW Turkey were studied within the context of Holocene lake level changes. With a maximum thickness of 1.5 m, the low-angle (average 5–10°) beds are composed of coarse grains and small gravels and extend up to 5 m offshore at their most lakeward extremities. Cement textures on and around the poorly-rounded grains are made up of micrite envelopes and meniscus bridges as well as acicular aragonite rims. Geoelectrical resistivity sections taken from a representative location along the beach where the beds have maximum thickness showed that the sand-buried beds are followed up to about 24 m landward. Based on the OSL ages of 33 samples, the cemented beds occurred at four drier periods of the following: Pre- and Early Holocene (dated to 15–9 ka), Holocene Climatic Optimum (7.9–5.6 ka), Middle Holocene (4.9 ka–2.8 ka) and Late Holocene (2.0 ka–0.9 ka).

Phylogenetic Relationships ofGelidiella(Gelidiales, Rhodophyta) from Madagascar with a Description ofGelidiella incrassatasp. nov.

We evaluated the relationships among species in the genus Gelidiella using 47 rbcL and 29 COI sequences, including those from 18 specimens collected in Madagascar. Molecular analyisis revealed the presence of three major lineages among Magalasy Gelidiella which were assigned, based on morpho-anatomical observation, to Gelidiella acerosa, G. ligulata and a so far not described species for which we here proposed the name G. incrassata. Both molecular and morphological data demonstrated the presence of three species in Madagascar: the G. acerosa complex, G. ligulata, and G. incrassata sp. nov., described here. Gelidiella incrassata was collected on small gravel from the intertidal down to a depth of 14 m on the southeast coast of Madagascar. It is distinguished by its large size (up to 7 cm), opposite to alternate ramuli, thick-walled cortical and medullary cells, and stalked tetrasporangial stichidia with irregular arrangement of tetrasporangia. Phylogenetic analyses of rbcL and COI sequences revealed the sister relationship between G. incrassata and G. fanii from southeast Asia and Hawaii. Gelidiella acerosa comprised three genetic groups in Madagascar, each being genetically distinct (pairwise distances, 4.9–8.3% for COI and 1.2–2.3% for rbcL). Further sampling of G. acerosa is needed before taxonomic revisions can be proposed. The distribution of G. ligulata is expanded to include the southwest Indian Ocean.

A New Species ofLeptochiton(Polyplacophora: Leptochitonidae) from the Southwestern Atlantic

ABSTRACT Leptochiton sanmatiensis, new species, is described from shallow-waters of Argentina. The species is characterized by having a quincuncial arrangement of tegmental granules on head valve, lateral areas of intermediate valves and postmucronal area of tail valve, and a longitudinal arrangement of these structures on the central areas of intermediate valves; each granule having a macraesthete and four micraesthetes. In addition, the new species has pectinated dorsal scales, with 14–21 ridges; a low number of ctenidia (up to six on each side in the largest specimens); and the second lateral tooth with three denticles in the cusp. The species lives on small gravel and shells.

Improving our ability to collect eggs of the threatened Australian grayling, Prototroctes maraena

Successful monitoring of fish eggs or larvae facilitates the assessment of management actions (e.g. environmental flow releases) on spawning success. Paired sets of drift nets (one at the surface and one on the bottom) were used at six sites in the Thomson River to determine whether we can improve our ability to monitor the spawning success of Australian grayling, Prototroctes maraena. Over 900 P. maraena eggs were captured, with 90% being captured in drift nets set on the bottom. All but one of the eggs were captured at two sites, which had faster flow rates and a substrate of small gravel rather than fine sediment. These results indicate that using surface drift net sets for sampling eggs in rivers with low turbulence may be ineffective and that spawning may be more likely in faster-flowing areas with gravel substrates.

КОПРОЛІТИ ХРЯЩОВИХ РИБ ІЗ ПАЛЕОГЕНОВИХ ВІДКЛАДІВ КРИМУ

First is a description of the Eocene fish coprolites Selachicoprus volgensis Khosatskyet Vialov of sections Ak-kaya and Prolom (Belogorsky region, Crimea). The data obtained are expanding information about trace fossils vertebrates Paleogene and justify their prospects further researches of Cenozoic deposits of Ukraine. Investigated two coprolites location in Belogorsk region of Crimea. The first of them is a career gap, which is located on the left bank district. Kuchuk Karasu, about 1 km south of the village Prolom and the second is near the village Bila Skelia (White Rock) on the right bank Biyuk-Karasu was open N.I. Udovychenko and luhansk paleontologists studied for over 20 years. Should be noted that maximum concentration remains of vertebrates, with whom coprolites are found, there is a layer 4 and bottom layer 6, which are composed greenish-brown sand, glauconite, calcareous concretions of small phosphorite, small grains mixed gravel and greenish-yellow calcareous clay, sandstone with very large admixture of glauconite, phosphorite concretions small. The presence of well-preserved coprolites indicates the existence of the bottom of the reservoir areas inviting waters, and the presence of dissolved phosphates, which are not allowed to chemically break down coprolites. Keywords: coprolites, Eocene, Oligocene, Crimea.

Underwater evaluation of habitat partitioning in a European river between a non‐native invader, the racer goby and a threatened native fish, the European bullhead

AbstractWe conducted underwater surveys using SCUBA gear to examine habitat and microhabitat competition between the Ponto‐Caspian racer goby Babka gymnotrachelus and native European bullhead Cottus gobio to assess the potential for competitive displacement of the native species by the invading species. In summer, 88 surveys were made in a tributary of the River Vistula within defined benthic areas across the entire width of the river bed. The occurrence of fish by total length class (small: <6 cm; large: >6 cm) and environmental conditions (depth, water velocity, substratum type, plant cover, shelter type) was recorded. We found a substantial separation between the species and size classes in relation to substratum, shelter type and water velocity. European bullheads were limited to lotic areas with stony bottoms, whereas racer gobies also occupied lentic areas over sand or mud. European bullheads usually took refuge under stones in contrast to a wider range of shelters used by racer goby, including tree roots and rubbish. In general, the breadth of habitat used by the racer goby was wider than that of the European bullhead, although habitat overlap between the species was not statistically significant except for the type of shelter occupied by small fish, selecting smaller stones. An inverse relationship was observed between small European bullheads and all racer gobies in areas where they co‐occurred, suggesting that invader may be having an adverse effect on the distribution and habitat use of small native bullheads, particularly in areas of moderate water velocities over small stones and gravel.

A paraglacial coastal gravel structure: Connell's Bank, NW Ireland

ABSTRACT Knight, J., Burningham, H., 2014. A paraglacial coastal gravel structure: Connell's Bank, NW Ireland. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 121–126, ISSN 0749-0208. Coastal gravel structures have been well documented worldwide and are formed dominantly by onshore wave transport of gravel, mainly during storm events. They are commonly observed along paraglacial coastlines where their origins are more ambiguous because of the effects of antecedent patterns of sediment supply, glacioisostatic sea-level change, and contemporary coastal processes. This paper describes the properties and polygenic origin of Connell's Bank, a small paraglacial gravel structure on the Atlantic-facing coast of NW Ireland. This feature has been shown on historical maps, air photos and satellite imagery since ca. 1850 but its outline has varied depending on seasonal migration, expansion and co...

Influence of large wood on channel morphology and sediment storage in headwater mountain streams, Fraser Experimental Forest, Colorado

Large fallen wood can have a significant impact on channel form and process in forested mountain streams. In this study, four small channels on the Fraser Experimental Forest near Fraser, Colorado, USA, were surveyed for channel geometries and large wood loading, including the size, source, and characteristics of individual pieces. The study is part of a larger effort to understand the impact of mountain pine beetle infestation on a suite of watershed properties. Here, we present baseline data collected at the onset of widespread tree mortality. Channels range from 1.5 to 2m in width, with slopes ranging from 3 to >10%. Median (D50) streambed particle sizes range from gravel to very coarse gravel. Channels are characterized as cascade, step-pool, and plane bed over varying scales. Large wood loads ranged from about 0.4 to 1.0 piece per meter length of channel, which is comparable to values reported for other Colorado sites. Much of the wood showed indications of being in place for long periods of time (decayed/rotten, broken into ramps, and partially buried in beds and banks). Nearly all surveyed reaches contained steps formed from small boulders and/or logs. Significant portions of the elevation drop in some of the reaches were made up by log steps, though the percentages varied (0 to 60%). Individual log steps trap a portion of the coarse sediment moved as bedload, forming wedge-shaped accumulations upstream of the logs. The particle size distributions for measured bedload and step accumulations largely overlapped, but more so for the coarse ends of the distributions, suggesting a trapping inefficiency for the finer component of bedload. Estimates of the total volume of sediment stored behind log steps were approximately an order of magnitude greater than the mean sediment volume exported on an annual basis, as determined from measured accumulations in weir ponds. The particle size distribution of sediment in the ponds – ranging from sand to medium gravel – is considerably finer than sediment stored in steps. The series of comparisons between storage volumes, particle size distributions, and sediment export suggests that log steps effectively trap coarse sediment moved in these small streams and act as a series of check dams that inhibit channel erosion, but may be less effective at trapping finer sediment (sand and small gravel).

The sand-deposition impact of artificial gravel beds on the protection of the Mogao Grottoes

Gravel beds can prevent sand-dust emission and weaken sand-dust flux. We used wind-tunnel experiments and field observations on artificial gravel beds above the Mogao Grottoes to quantify their impact. In the report, we identified a significant correlation between gravel roughness and its ability to trap wind-transported sand. The optimal combinations of gravel diameter and coverage were determined. The greatest roughness is achieved when small gravel coverage is 75%, medium 40% and large 45%. We found that initial wind speed and gravel coverage are the key factors controlling the amount of sand trapped by the gravel beds.

No differences between littoral fish community structure of small natural and gravel pit lakes in the northern German lowlands

Habitat loss has been identified as a major contributor to declining freshwater biodiversity, resulting in a high threat level among European fishes. Non-natural ecosystems such as pit lakes may compensate habitat loss by providing new habitat for aquatic organisms. We compared the structure of the littoral fish communities of 18 natural and 19 gravel pit lakes located in the northern German lowlands to evaluate whether artificial lakes managed by angling clubs host similar communities as typically observed in natural lakes. The fish community structure was analyzed between the lake types and along gradients of lake morphometry, productivity and littoral complexity. Although the gravel pit lakes differed in morphology (characterized by steeper littoral slopes and less structured littoral habitat), differences in fish community structure between the natural and gravel pit lakes were weak and mainly related to differences in the abundance of the dominant species perch, roach and rudd. Both lake types had similar species richness, community diversity and hosted several small-bodied and endangered species. To conclude, fish communities characteristic of small natural lakes may serve as reference for the development of gravel pit lakes. Moreover, our study reveals that recreational-fisheries management of gravel pit lakes does not result in artificial communities that deviate strongly from the communities present in natural lakes. Therefore, nature conservation and fisheries management goals can be reconciled in relation to fish in small artificial lakes managed by angling clubs.

Failure probability of laminated architectural glazing due to combined loading of wind and debris impact

Building façades are vulnerable to wind and wind-borne debris during extreme weather conditions like hurricanes. Laminated glazing is widely used as window glazing material to ensure the integrity of the building interiors. Wind-borne debris has been classified as small-hard and large soft missiles representing small gravel to large wooden bars that constitute the debris impacting the glazing during severe storms. Failure of laminated window glazing due to combined effect of wind and debris is studied. Stress analysis is done using finite element code ABAQUS. This is used in conjunction with a mechanics based statistical model to predict the cumulative probability of inner glass ply breakage in laminated glazing. A parametric study involving failure probability of inner glass ply for different geometry of laminated glazing is also performed.

Effect pf Thermoplastic Polymer Waste (PET) in Lightweight Concrete

Contruction concrete that use of insulation wall in building construction faces some problems such as having high weight, very reflective sound, heat transfer (the effectiveness of heat conductivity) incompetence and mechanical properties (strength) constraints. The sounds which impinge the wall cannot be absorbed efficiently but instead gives high reflection. This causes some noise of high echo in a room. So a good acoustic insulation must be efficient in absorbing the sound. This project proposes lightweight concrete as a replacement for insulation wall. This lightweight concrete will be developed using thermoplastic polymer waste which is recycled plastic bottles, sand, water, and cement. This research used thermoplastic polymer waste which is PET (Polyethylene Terephthalate) material as the reinforcement material to replace small gravel in lightweight concrete. All its composition percentage of raw materials was divided into different samples composition. Its composition determines the performances of the samples in density, porosity and mechanical properties.

자갈 섞인 모래의 건조밀도 계산에 관한 실험 연구

Various sizes of gravels are included in the most field soils that are utilized for civil constructions. Especially, the small amounts of gravel are often included in selected soils for backfill materials, earth dams, and subbase ground. In such cases, the small amounts of mixed gravel and its shape may influence the determination of dry density of soils, which results in an inaccurate degree of compaction for soils in the field. In this study, a dry density of sand with various gravel contents (0, 10, 17, 23, 29 and 33%) and three different sizes (2.0-2.36, 3.35-4.75, 5.6-10.0 mm) was experimentally investigated for compacted or loosely packed conditions. The loosely packed sand with gravels was simulated by pouring sand into compaction mould and its density was determined. When a 33% of gravel content was mixed with sand, its dry density increased up to 15-20% for compacted specimen and 20-23% for loosely packed specimen. When a gravel content and size were the same, a dry density of compacted specimen was higher than that of loosely packed specimen. Even though the same gravel content was used, a dry density of sand with big gravels was higher than that of sand with small gravels for compacted specimen and for loosely packed specimen.

Microhabitat use of the diamond darter

AbstractThe only known extant population of the diamond darter (Crystallaria cincotta) exists in the lower 37 km of Elk River, WV, USA. Our understanding of diamond darter habitat use was previously limited, because few individuals have been observed during sampling with conventional gears. We quantified microhabitat use of diamond darters based on measurements of water depth, water velocity and per cent substrate composition. Using spotlights at night‐time, we sampled 16 sites within the lower 133 km of Elk River and observed a total of 82 diamond darters at 10 of 11 sampling sites within the lower 37 km. Glides, located immediately upstream of riffles, were the primary habitats sampled for diamond darters, which included relatively shallow depths (<1 m), moderate‐to‐low water velocities (often < 0.5 m·s−1) and a smooth water surface. Microhabitat use (mean ± SE) of diamond darters was estimated for depth (0.47 ± 0.02 m), average velocity (0.27 ± 0.01 m·s−1) and bottom velocity (0.15 ± 0.01 m·s−1). Substrate used (mean ± SE) by diamond darters was predominantly sand intermixed with lesser amounts of gravel and cobble: % sand (52.1 ± 1.6), % small gravel (12.2 ± 0.78), % large gravel (14.2 ± 0.83), % cobble (19.8 ± 0.96) and % boulder (1.6 ± 0.36). Based on our microhabitat use data, conservation and management efforts for this species should consider preserving glide habitats within Elk River. Spotlighting, a successful sampling method for diamond darters, should be considered for study designs of population estimation and long‐term monitoring.

Effects of Meso-Structure Characters on Fracture Properties and Fracture Mechanism in Concrete

To understand relationship between the meso-structure of non-homogeneous materials and the fracture properties, two groups of concrete specimens are designed and tested. For the two groups with the same water-cement ratio and coarse aggregate volume ratio, small and large grain size gravels are used respectively. Since both groups of materials are with the same mass ratio of coarse aggregates, the heterogeneity of the gravels distribution in concrete with larger grain size is higher than the other. The results show that the group with smaller aggregate grain size gains higher material fracture strength and fracture energy than another group. Then the concrete with more homogeneous meso-structure will reach higher fracture properties

Ecology and Status of the Redbreast Sunfish,Lepomis auritus, in Yoho Lake, New Brunswick

In Canada, Lepomis auritus (Redbreast Sunfish) is only found in southwestern New Brunswick, which is the northern limit for the species. In 1989, The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) listed it as a species of special concern due to its limited distribution, and changed the status to data deficient in 2008. The purpose of our study is to begin to build a database of ecological information for the Redbreast Sunfish in New Brunswick. The most northern population occurs in Yoho Lake. Population estimates averaged 386 from 2005 to 2007. The average total length and weight were 12.5 ± 3.1 cm and 42.6 ± 27.3 g, respectively. The length-frequency distributions were consistent over the years, suggesting a stable population structure. Most adult and juvenile sunfish were observed in areas of dense vegetation and large woody debris. Snorkeling surveys were conducted from late June to early July 2005–2007 to assess timing and habitat preference of spawning Redbreast Sunfish. The nests averaged 52.4 ± 10.1 cm in diameter and were 43.9 ± 12.2 cm deep. Nest substrate was sandy with small gravel, and only 33% of the nests were associated with a physical structure in the water column. Overall, the population of Redbreast Sunfish in Yoho Lake appears to be healthy and stable.

Analysis of Laminated Architectural Glazing Subjected to Wind Load and Windborne Debris Impact

During windstorms and hurricanes, architectural glazing is subjected to wind loading and windborne debris impact. Wind-borne debris is categorized into two types. One is small hard missile like roof gravel and the other is large soft missile representing the lumber from wood-framed buildings. Laminated architectural glazing (LAG) is the commonly used glazing in buildings where impact resistance is needed. The prefailure stress response of the LAG due to the combined loading due to wind and windborne debris impact is studied. Following the ASTM standards (E1886 and E1996), a steel ball with an impact velocity of 39.62 m/s and a wooden cylinder with an impact velocity 12.19 m/s were chosen to be representative of small and large missiles, respectively. A lateral pressure that corresponds to a wind speed of 58.11 m/s was used to represent wind loading on LAG. The effect of geometric and material properties on the stress response of a rectangular LAG is studied parametrically. Thinner outer ply would result in better prefailure stress pattern than a thicker outer ply, while thicker interlayer generally results in lower stresses in failure critical areas. The contribution of wind loading to the principal stress is between 5–10% of the combined stress with small missile case having higher percentage.

Substratum associations and depth distribution of benthic invertebrates in saline Walker Lake, Nevada, USA

Walker Lake, a terminal salt lake in western Nevada, is undergoing rapid changes because of falling lake level and rising salinity, affecting the potential habitat of benthic invertebrates that supply food to native fish and birds. Benthic invertebrate surveys were conducted within different substratum size classes and macrophyte beds in the nearshore littoral shallows ( 10 m) zones of the lake. Samples were dominated by the chironomid midges Cricotopus ornatus and Tanypus grodhausi; the damselfly Enallagma clausum; and an oligochaete worm of the genus Monopylephorus. Midges showed distinct depth preferences, with Cricotopus found primarily in the shallow littoral, and Tanypus found in the lower littoral and profundal regions. Enallagma occurred throughout the littoral region but was reduced in abundance below 10 m. Cricotopus and Enallagma were most abundant on cobble rock substratum and macrophytes. Sand and small gravel substrata supported few invertebrates except oligochaetes, which were most common in shallow littoral areas. The extent of Ruppia beds was determined using hydroacoustic sounding and showed that these beds were most well-developed in a zone from 1.25 to 5 m depth. The estimated area of productive shallow littoral zone habitat at different lake levels showed that coverage was lowest near the current surface elevation. Rising lake levels would result in expansion of suitable habitat area, and while falling levels could also expand nearshore habitat, this would likely occur on areas of poorer substratum quality and under high salinities that may inhibit growth.