Identifying brumating Northern Diamondback Terrapins ( Malaclemys terrapin terrapin ) by incorporating environmental sensor and drone technology

Temporal factors influencing killifish abundance and recruitment in Gulf of Mexico salt marshes

Theoretical analysis of the effects of irrigation rate and paddy water depth on water and leaf temperatures in a paddy field continuously irrigated with running water

Based on the survey of the waters of Jiaozhou Bay in April and August 1981, this study examines the water temperature and horizontal distribution in the surface waters of Jiaozhou Bay. The results showed that in August and November, the variation range of water temperature in Jiaozhou Bay was 8.57–27.32°C, above 8.00°C, of which the interval length was 18.75°C. This indicates that in terms of water temperature changes, the water temperature in the entire waters of Jiaozhou Bay is relatively high in August and November, with more significant changes and a faster decrease. In August, the variation range of water temperature in Jiaozhou Bay was 25.19–27.32°C, of which the interval length was 2.13°C. In the northwestern coastal waters of Jiaozhou Bay, the water temperature reached 27.32°C. From the north to the south of the Bay, the variation range of water temperature was 25.19–27.32°C, of which the interval length was 2.13°C. In November, the variation range of water temperature in Jiaozhou Bay was 8.57–13.49°C, of which the interval length was 4.92°C. Outside the mouth of the Bay, a high-temperature zone was formed with a relatively high temperature of 13.49°C. From the north to the south of the Bay, the variation range of water temperature was 8.57–13.49°C, of which the interval length was 4.92°C. According to the variation of water temperature in Jiaozhou Bay, three factors influencing water temperature changes have been proposed: 1) total solar radiation energy; 2) air condition; and 3) water depth. These three factors influence changes in water temperature. In addition, a mechanism for the variation in water temperature has been suggested: 1) In June, the total solar radiation energy is the strongest, while it is weaker in December. As the total solar radiation energy increased, its heat to seawater increased. When the air temperature was higher than the water temperature, the air conduction transferred more and more heat to the surface seawater. When the water depth is small, the water temperature increases quickly; alternatively, the water temperature rises slowly when the water depth is large. Thus, the variation of total solar radiation energy, air conduction, and water depth determined the rise in water temperature. 2) In June, the total solar radiation energy is the strongest, while weaker in December. As the total solar radiation energy decreased, the heat supplied by solar radiation energy to seawater decreased. When the air temperature was lower than the water temperature, cold energy was transferred by the air conduction to the surface seawater. As the temperature becomes lower and lower than the water temperature, more cold energy is transferred through the air conduction to the surface seawater. When the water depth is small, the water temperature declines quickly; alternatively, when the water depth is large, the water temperature declines slowly. Thus, the variation of total solar radiation energy, air conduction, and water depth determined water temperature decline. Moreover, this study further confirmed the following: 1) The total radiation energy of the sun provides heat, but the amount of heat provided is different. 2) Both heat and cold energy can be transferred to surface seawater by air conduction. 3) Water depth determines the speed of changes in water temperature.

The growth, survival and proximate composition of Heteropneustes fossilis (Bloch, 1794) were studied under different water depths (30, 60, 90 and 120 cm) for a period of 10 months, with a temperature range of 31.5 to 7.8°C [(May-June; 26.5-31.5°C; Stage 1); (July-September; 28.8-32.6°C; Stage 2); (October-November; 15.5-28.4°C; Stage 3); (December-February; 7.8-15.7°C; Stage 4)] under earthen pond conditions in the humid subtropical climate of Tripura State, India. All the ponds were of equal size (168 m2; 14 m x 12 m) but with different water depths. The fishes were fed with a mixture of rice bran and mustard oil cake (1:1) @ 0.5-3% of their biomass. The growth, survival and proximate composition of fish were recorded in each stage. The average daily weight gain, feed conversion ratio, survival and proximate composition were found to be better in water depths of 60 cm and 90 cm during May to September when water temperature was ≥26.5°C. However, when water temperature was ≤21.4°C (October-February), growth and other attributes significantly reduced. Two-way ANOVA revealed that water depth and temperature, individually and interactively, affected the growth of H. fossilis. From this trial, it can be concluded that H. fossilis performs better when water depth is 60-90 cm and the ideal water temperature for the culture is 28.3-30.4°C. The study confirms the depth preference of H. fossilis under the humid subtropical condition and the information generatedwill help in the sustainable farming of this species. Keywords:Asian stingingcatfish, Water depth,Temperature, Growth, Survival, Proximate composition

The effects of habitat characteristics (mangrove creek, sandflat, mudflat and seagrass meadow) water salinity, temperature, and depth on the density, spatial distribution and size distribution of juveniles of five commercially important penaied shrimp species (Metapenaus monoceros, M. stebbingi, Fenneropenaeus indicus, Penaeus japonicus and P. semisulcatus) were investigated during a high shrimp recruitment peak lasting from January to June 2002, in four contiguous habitats within a non-estuarine mangrove bay at Saco da Inhaca, Inhaca Island, Southern Mozambique. A total of 14,976 specimens representing the five species were collected by means of a 1m beam-trawl fitted with a 2 mm mesh net with a cod-end. Every two weeks corresponding with spring tides on three consecutive nights, three trawls of 50 meters each were carried out each night in each habitat at 1.40–2.15 a.m. after the daily spring tide high water peak. Species distributions among the four habitats during the six months sampled showed significant differences in habitat preference (p>0.001). Fenneropenaeus indicus, M. stebbingi and P. japonicus dominated the catches in sand flats with densities of 27 ± 0.94, 18 ± 0.98 and 7 ± 0.76 shrimp /50 m2, respectively. Metapenaeus monoceros dominated catches in mudflats at a density of 21 ± 0.78 /50 m2, followed by M. stebbingi with 13±1.2 /50 m2. Penaeus semisulcatus was almost exclusively captured in seagrass meadows at densities of 8± 0.57 /50 m2. Only the Metapeneaus species showed a wide range of habitat utilization. The differences in habitat preference emphasises spatial partitioning between shrimps, reducing competition. Multiple linear regressions of juvenile shrimp densities for each species with water depth, salinity and temperature showed some significant effects. Fenneropenaeus indicus density showed a significant negative relationship with salinity and water depth and a positive relationship with temperature and turbidity. Metapenaeus stebbingi numbers showed a significant positive correlation with increasing salinity and temperature, but a negative one with depth. Penaeus japonicus numbers were significantly related to decreasing salinity and depth. Penaeus semisulcatus abundance was significantly related to decreasing temperature, and increasing turbidity and depth. More than 50% of the total shrimps captured had carapace length of ≤ 3 mm, substantiating the nursery function of the different habitats sampled in the study. Keywords: penaeid, shrimps, juveniles, distribution, habitats, mudflats, sandflats, mangrove creek, seagrasses, Inhaca Island, Mozambique West Indian Ocean Journal of Marine Science Vol. 3 (2) 2004: pp. 163-178

Because environmental conditions within a given basin are different for each season and at different water depth, knowledge of the life history and depth distribution of target species is important for environmental and palaeoenvironmental interpretations based on ostracod species assemblages and/or the geochemical compositions of their valves. In order to determine the distribution of species with depth as well as the life history of species from Lake Geneva, a one-year sampling campaign of living ostracods was conducted at five sites (2, 5, 13, 33 and 70 m water depth) on a monthly basis in the Petit-Lac (western basin of Lake Geneva, Switzerland). Based on the results, the different species can be classified into three groups. Littoral taxa are found at 2 and 5 m water depth and include, in decreasing numbers of individuals,Cypridopsis vidua(O. F. Müller, 1776),Pseudocandona compressa(Koch, 1838),Limnocythere inopinata(Baird, 1843),Herpetocypris reptans(Baird, 1835),Potamocypris smaragdina(Vávra, 1891),Potamocypris similis(G. W. Müller, 1912),Plesiocypridopsis newtoni(Brady & Robertson, 1870),Prionocypris zenkeri(Chyzer & Toth, 1858) andIlyocyprissp. Brady & Norman, 1889. Sublittoral species are found in a majority at 13 m water depth and to a lesser extend at 33 m water depth and include, in decreasing numbers of individuals,Fabaeformiscandona caudata(Kaufmann, 1900),Limnocytherina sanctipatricii,Candona candida(O. F. Müller, 1776) andIsocypris beauchampi(Paris, 1920). Profundal species are found equally at 13, 33 and 70 m water depth and includes, in decreasing numbers of individuals,Cytherissa lacustris(Sars, 1863),Candona neglectaSars, 1887 andCypria lacustrisLilljeborg, 1890. The occurrence ofLimnocytherina sanctipatricii(Brady & Robertson, 1869) is restricted from late winter to late spring when temperatures are low, whileC. vidua,L. inopinata,P. smaragdina,P. similis,P. newtoniandIlyocyprissp. occur predominantly from spring to early autumn when temperatures are high. Individuals ofC. neglecta,C. candida,F. caudata,P. compressa,C. lacustris,H. reptansandCp. lacustrisoccur throughout the year with juveniles and adults occurring during the same period (C. neglectaat 70 m,C. lacustrisat 13, 33 and 70 m, andH. reptansat 2, 5 and 13 m water depth) or with juveniles occurring during a different period of the year than adults (C. neglectaat 13 and 33 m andC. candida,F. caudataandP. compressaat their respective depth of occurrence). Among the environmental parameters investigated, an estimate of the relationship between ostracod autoecology and environmental parameters suggests that in the Petit-Lac: (i) water temperature and substrate characteristics are important factors controlling the distribution of species with depth, (ii) water temperature is also important for determining the timing of species development and, hence, its specific life history, and (iii) water oxygen and sedimentary organic matter content is less important compared to the other environmental parameter monitored.

Soil temperature plays very important role in bio chemical processes, root water uptake and also evapotranspiration. This parameter is influenced by environmental factors such as soil moisture content. Recently water shortage has led to adopt intermittent irrigation in Sepidroud Irrigation network in Gilan province, north of Iran. In this method, different submergence depth is applied, which change the root zone (soil and water) temperature. The aim of this study was to investigate the effects of water depth on soil and water temperature in a paddy field. Paddy minis lysimeters, based on completely randomized block design with 5 treatments of constant level of water in the field, (5, 2.5, 0, -5 and -10 cm of the soil surface) in three repetitions. Measurements were including soil temperature at the depths of 5 and 10 cm from soil surface (T5 and T10) and water temperature in the morning and evening. The results showed that T5 was significantly more that T10 .In the morning, water temperature, at and below surface (non-submerged treatments) was lower than soil temperature at the same depth, while in the evening, water temperature was more than soil temperature at the same depth. In daily scale, the water temperature was more than soil temperature at the same depth. Soil temperature was decreased by reduction of soil water depth. In general, the presence of a thin layer of the water on soil surface had a cooling effect on soil but as the water reaches the soil surface, the soil environment becomes much warmer. The reduction of the submergence depth 10 cm below the surface significantly affected the made microclimate of the soil colder, by 1.5◦ Celsius in average.

The aim of the present study was to describe the characteristics of Guiana dolphins (S. guianensis) group size and composition in the Paranaguá Estuarine Complex (25 degrees 15'-25 degrees 36' S and 48 degrees 02'-48 degrees 45' W), Paraná State, as well as to verify the existence of relationships between a given environmental variable (water depth, salinity, transparency and temperature) and group size. An area of around 124 km(2) was surveyed by boat from April 2006 to February 2008 in the following subsets of the estuary: Canal do Superagui (approximately 28 km(2)), Pinheiros bay (approximately 34 km(2)), part of Laranjeiras bay, which included the Guaraqueçaba sub-estuary (approximately 38 km(2)), and part of the Mixture Section of the Paranaguá Estuarine Complex (approximately 24 km(2)). In 45 survey days, a total of 147 hours were spent observing 286 groups of S. guianensis. Groups varied from two individuals to aggregations of up to 90 individuals (mean +/- SD: 11.5 +/- 14.4 individuals). Solitary individuals were seen only on five occasions (1.7% of all observations). Groups with calves (n = 247) represented 86.4% overall and were more common in all sub-areas when compared to groups without calves. Groups without calves were found in all sub-areas and were usually smaller and composed of up to 12 individuals. A usual group composition of 70% of adults and 30% of calves was observed considering all sub-areas and seasons. No correlations were found between group size and water temperature (Spearman's rank test, r = 0.0059, p = 0.9338), transparency (Spearman's rank test, r = 0.0597, p = 0.9333), depth (Spearman's rank test, r = 0.1421, p = 0.4698), and salinity (Spearman's rank test, r = -0.1938, p = 0.0665). While Guiana dolphin groups were seen in the entire surveyed area, group size varied significantly among the three main surveyed sub-areas (Kruskal Wallis, H2,196 = 29.85, p = 0.0000). Groups were larger in Laranjeiras bay and smaller in Canal do Superagui. The physical environment, risk of predation, seasonal distribution and abundance of prey are the main possible factors driving larger groups in inner and protected waters.

In this study, we examined the effects of water depth and temperature on seedling recruitment from a prairie wetland seed bank. We collected seed-bank samples from natural and restored prairie pothole wetlands in northwestern Iowa and combined them into a single sample. We examined seedling recruitment from this seed-bank sample in an experimental study using a factorial design of 4 temperature treatments (5 night and 15 day to 20 night and 30 day) and 3 water-depth treatments (0, 2, and 7 cm). Principal Components Analysis showed that both water depth and temperature had significant effects on the composition of the seedling community as measured by changes in relative stem density and biomass. Water depth had its strongest effects on stem density while temperature had its strongest effects on biomass. For the 22 most common species, stem density varied with water depth for 95% of the species and with temperature for 50% of the species. Most species with water depth responses had lower stem counts as water depth increased, and for the majority of species with temperature responses stem density increased with temperature. Total, annual, and perennial species richness was negatively correlated with water depth. Total and annual species richness was positively correlated to temperature, while perennial species richness was unresponsive to temperature. In addition, species found at low elevations as adults emerged at higher rates in the deep water treatments while species that occurred at higher elevations as adults had their highest emergence rates in the low water treatments. Our results suggest that differences in environmental conditions along coenoclines can affect the initial distribution of species emerging from the soil seed bank. Water depth sorted seedlings according to their adult water-depth tolerances, and temperature determined the proportion of annuals in the seedling community.

Thermal regime has a critical impact on the lotic environment, as maximum temperature determines the boundaries of the occurrence of aquatic species, seasonal and diurnal water temperature variations affect their bioenergetics, while the timing of specific water temperature values during the year is important in the context of spawning and migrations. However, despite the great importance of water temperature studies in the context of environmental management and fisheries, as well as the development of accurate measurement techniques, such investigations have received relatively limited attention in Poland. The current study attempted to examine the seasonal differentiation of water temperature in lowland rivers. For this purpose, water temperature was recorded from the 1st of May 2015 to the 30th of April 2019 with a temporal resolution of 30-minutes. Digital temperature reorders used to make the measurements were distributed across six sites in Jeziorka, Świder and Utrata catchments located on the Mazovian Lowland and the Southern Podlachia Lowland near Warsaw. The hydrometeorological background of the water temperature monitoring was determined on the basis of data from the Warszawa-Okęcie station and water gauging stations. On the basis of the measurement data, mean, maximum, and minimum monthly water temperatures were calculated and presented on the background of the appropriate air temperature data, while statistical distribution of the 30-minute water temperature, aggregated in a monthly timescale, was presented on the box and whiskers plots. The Ward method was used to group months similar in terms of their thermal conditions, while the Pearson correlation coefficient was applied to evaluate the strength of the relationship between water and air temperature. The results indicate that the seasonal course of water temperature follows the course of air temperature, with the highest mean monthly water temperatures recorded in July, while the lowest in January. Statistical distribution analysis of water temperature in individual months and its grouping by the Ward method allowed to identify two periods characterized by relatively stable thermal conditions and two periods of dynamic changes of water temperature. In contrast to the maximum values of water temperature, which were observed in the summer as a result of intensive solar radiation and low streamflow rates, the greatest variability of water temperature, as indicated by reference to mean daily range and standard deviation, was found in the spring months, i.e. in April and May, while the lowest in winter, from December to February. The relationship between daily mean water temperature and air temperature, established with the use of the Pearson correlation coefficient on a monthly basis, was clearly stronger during the spring increase and the autumn fall of the water temperature, which can be linked with greater vulnerability to atmospheric heat fluxes. A definitely weaker relationship was found in the winter and summer months, when greater importance can be attached to other drivers of stream temperature, like the presence of ice cover, cloudiness, riparian shading, and groundwater inflows.

Wetland restoration can mitigate aerobic decomposition of subsided organic soils, as well as re-establish conditions favorable for carbon storage. Rates of carbon storage result from the balance of inputs and losses, both of which are affected by wetland hydrology. We followed the effect of water depth (25 and 55 cm) on the plant community, primary production, and changes in two re-established wetlands in the Sacramento San-Joaquin River Delta, California for 9 years after flooding to determine how relatively small differences in water depth affect carbon storage rates over time. To estimate annual carbon inputs, plant species cover, standing above- and below-ground plant biomass, and annual biomass turnover rates were measured, and allometric biomass models for Schoenoplectus (Scirpus) acutus and Typha spp., the emergent marsh dominants, were developed. As the wetlands developed, environmental factors, including water temperature, depth, and pH were measured. Emergent marsh vegetation colonized the shallow wetland more rapidly than the deeper wetland. This is important to potential carbon storage because emergent marsh vegetation is more productive, and less labile, than submerged and floating vegetation. Primary production of emergent marsh vegetation ranged from 1.3 to 3.2 kg of carbon per square meter annually; and, mid-season standing live biomass represented about half of the annual primary production. Changes in species composition occurred in both submerged and emergent plant communities as the wetlands matured. Water depth, temperature, and pH were lower in areas with emergent marsh vegetation compared to submerged vegetation, all of which, in turn, can affect carbon cycling and storage rates.

Abstract. To investigate variation in nitrite, nitrate, phosphate, and silicate in a spring–neap tide in a coral reef system influenced by groundwater discharge, we carried out a time-series observation of these nutrients and 228Ra, a tracer of groundwater discharge, in the Luhuitou fringing reef at Sanya Bay in the South China Sea. The maximum 228Ra, 45.3 dpm 100 L−1, appeared at low tide and the minimum, 14.0 dpm 100 L−1, appeared during a flood tide in the spring tide. The activity of 228Ra was significantly correlated with water depth and salinity in the spring–neap tide, reflecting the tidal-pumping feature of groundwater discharge. Concentrations of all nutrients exhibited strong diurnal variation, with a maximum in the amplitude of the diel change for nitrite, nitrate, phosphate, and silicate in the spring tide of 0.46, 1.54, 0.12, and 2.68 µM, respectively. Nitrate and phosphate were negatively correlated with water depth during the spring tide but showed no correlation during the neap tide. Nitrite was positively correlated with water depth in the spring and neap tide due to mixing of nitrite-depleted groundwater and nitrite-rich offshore seawater. They were also significantly correlated with salinity (R2 ≥ 0.9 and P < 0.05) at the ebb flow of the spring tide, negative for nitrate and phosphate and positive for nitrite, indicating the mixing of nitrite-depleted, nitrate- and phosphate-rich less saline groundwater and nitrite-rich, nitrate- and phosphate-depleted saline offshore seawater. We quantified variation in oxidized nitrogen (NOx) and phosphate contributed by biological processes based on deviations from mixing lines of these nutrients. During both the spring and neap tide biologically contributed NOx and phosphate were significantly correlated with regression slopes of 4.60 (R2 = 0.16) in the spring tide and 13.4 (R2 = 0.75) in the neap tide, similar to the composition of these nutrients in the water column, 5.43 (R2 = 0.27) and 14.2 (R2 = 0.76), respectively. This similarity indicates that the composition of nutrients in the water column of the reef system was closely related with biological processes during both tidal periods, but the biological influence appeared to be less dominant, as inferred from the less significant correlations (R2 = 0.16) during the spring tide when groundwater discharge was more prominent. Thus, the variability of nutrients in the coral reef system was regulated mainly by biological uptake and release in a spring–neap tide and impacted by mixing of tidally driven groundwater and offshore seawater during spring tide.

Signal crayfish (Pacifastacus leniusculus) are an invasive species of global significance because of their detrimental impacts on freshwater environments and native organisms. The movement of signal crayfish was continuously monitored for 150-days through a 20-m reach of an alluvial stream in the UK. Passive integrated transponder-tags were attached to crayfish, allowing their location to be monitored relative to 16 antennae which were buried beneath the river bed. The activity of crayfish was related to water depth and temperature, which were continuously monitored within the instrumented reach. Crayfish were highly nocturnal, with less than 6% of movements recorded during daylight hours. Activity declined from September and was minimal in November when water temperature was low and flow depth was high. However, relations between environmental parameters and crayfish activity had poor explanatory power which may partly reflect biological processes not accounted for in this study. Water depth and temperature had a limiting relationship with crayfish activity, quantified using quantile regression. The results extend existing data on signal crayfish nocturnalism and demonstrate that, although signal crayfish can tolerate a range of flows, activity becomes limited as water temperature declines seasonally and when water depth remains high in autumn and winter months.

Three high flow experiment releases from Glen Canyon Dam on rainbow trout and flannelmouth sucker habitat in Colorado River

Eukaryotic phytoplankton play crucial roles in ecosystem processes, and understanding their community composition and abundance is of great importance to protect the balance of aquatic ecosystems. Danjiangkou Reservoir is a canyon lake in central China that acts as the water source of the Mid-route of South-to-North Water Diversion Project. In this study, the composition of planktonic microeukaryotes from water samples with a depth ranging from 0.5 to 20 m in Danjiangkou Reservoir were investigated using high-throughput 18S rDNA gene sequencing. The environmental factors including pH, water temperature (WT), nitrate (NO3--N), ammonia (NH4+-N), total nitrogen (TN), conductivity (Cond.), water depth, and dissolved oxygen (DO) in the reservoir areas were measured, and their correlations with the abundance and diversity of eukaryotic phytoplankton were analyzed. The results of high-throughput sequencing showed that a total of 68 genera of phytoplankton belonging to 12 phyla were detected, and the phytoplankton communities were mainly composed of Dinophyceae, Bacillariophyta, and Chlorophyta. In particular, significant differences in the diversity of phytoplankton communities on a vertical distribution were found. The diversity and abundance of the phytoplankton communities in Songgang (SG), Tumen (TM), and Dangzikou (DZK) decreased with the increase in water depth, and the relationship between phytoplankton and water depth in other sampling sites was not obvious. The results of RDA showed that NO3--N, water depth, DO, pH, and WT could influence the vertical distribution of the phytoplankton community in the Danjiangkou Reservoir. Among these phytoplankton types, Dinophyceae was negatively correlated with NO3--N and water depth and positively correlated with other environmental factors. Meanwhile, Bacillariophyta was positively correlated with NO3--N and water depth and negatively correlated with other environmental factors. In addition, Chlorophyta was negatively correlated with WT, pH, and DO and not significantly correlated with water depth.