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1.
The high consumption of crabs (Ucides cordatus) stimulated interest in the present study on the northern coast of Brazil, which encompasses a preserved area of mangrove forest. The objective was to describe and quantify the transfer of metals from the muddy sediments to the leaves of the Rhizophora mangle, and thence the crabs and humans. The samples were collected along two transects, while samples of hair were obtained from local habitants. The pH, interstitial salinity, Eh (mV) were measured, the granulometry and mineralogical and multi-element chemical analyses were run, and the organic material determined. The sediments are silty-clayey, composed of quartz, kaolinite, iron oxides, and illite, as well as smaller portions of smectite, pyrite, halite, and high levels of SiO2 (56.5 %), Al2O3 (18.5 %), and Fe2O3 (7 %). The elements Zn, Sr, As, and Zr are concentrated in the leaves, while the bioaccumulation of Zn, Se, Sr, and As was recorded in the crabs, of which, Se is the most concentrated in the tissue of the muscles and the hepatopancreas. The concentrations of nutrient and toxic elements were similar in all age groups (hair samples), with only Hg presenting an increasing concentration between infants and adults. The highest rates of transfer were recorded for the elements Zn and Se in the crabs and Hg in leaves and hair. The accumulation of metals in the leaves and crabs reflects the chemical composition of the sediments and low rates of sediment-vegetation-crab transfer, with the exception of Hg, which accumulated in the hair.  相似文献   

2.
To estimate species turnover rates on scales of several tens of km in deep-sea benthic animals, we analyzed spatial and inter-annual changes in species diversity and composition of cerviniids, a typical group of deep-sea harpacticoids, at stations in and around Sagami Bay, central Japan. Associations with environmental factors were also investigated. Generally, bathymetrical patterns in diversity of benthos are unimodal and peak at depths of 2,000–3,000 m. In Sagami Bay, cerviniid diversity did not follow this trend; both species richness and evenness were negatively correlated with water depth. Multivariate analyses [detrended correspondence analysis (DCA) and non-metric multi-dimensional scaling] suggested that temporal changes in species composition of cerviniids are smaller than spatial changes that occur on horizontal scales of several tens of km. Community structure does not change completely on these scales in the bathyal zone around Sagami Bay. DCA also showed that bathymetrical changes in species composition can be regulated by certain factors associated with water depth.  相似文献   

3.
Calving can be a critical period for cetaceans. Areas providing security for vulnerable calves, and high food availability for lactating females can be critical habitats requiring specific conservation measures. Here, we test the hypothesis that calving and nursing habitat could be defined for Risso’s dolphins (Grampus griseus). We investigated the spatial and temporal preferences of this species around Pico Island, Azores, using data gathered from land-based surveys and dedicated at-sea observations between 2004 and 2007. We divided observed pods into three groups: (1) those with newborn and young calves, (2) those with older calves or juveniles and (3) those consisting only of adults or sub-adults. We analysed eco-geographical variables and incorporated them into a presence-only spatial distribution model to evaluate differences in habitat suitability among the groups. We identified 694 pods of Risso’s dolphins overall. On the 267 pods observed in the first and second groups, 136 calves or juveniles were identified, of which 22 were newborns. The peak of the calving season was between June and August. The pods with newborn calves were larger and closer to shore, whereas the other groups were more widely dispersed offshore. Our results support the definition of critical habitat areas for this species, but we suggest widening the geographical coverage for better mapping around the island and throughout the archipelago generally. Conservation measures can, nevertheless, be implemented immediately, in order to reduce human impacts on a vulnerable component of the Risso’s dolphin population  相似文献   

4.
Animals can learn to recognize and respond to dangerous, threatening factors through either individual or social learning, whereby an individual learns and acquires the defensive behaviors and avoidance responses of another. Here we show that kinship, familiarity, and relative dominance of the interacting individuals affect social learning of defensive responses to micropredators in deer mice, Peromyscus maniculatus. Brief exposure of individual male deer mice to biting flies (stable fly, Stomoxys calcitrans) induced a decrease in pain sensitivity, or analgesia, and active self-burying avoidance responses. The defensive analgesic responses and their fear/anxiety/stress associated correlates facilitate the display of behavioral avoidance responses. Preparatory analgesia and avoidance responses were evident 1–3 days later when the mice were exposed to biting flies that were altered to be incapable of biting but were not displayed to similar-sized non-biting house flies. These anticipatory avoidance and analgesic responses to biting flies were also acquired through social learning—without direct individual aversive experience with biting flies. Fly-naive mice (observers) that witnessed other mice (demonstrators) being attacked by biting flies but themselves were not bitten did not display any avoidance responses. However, when exposed 1–3 days later to altered flies with biting mouth parts removed, the observers displayed socially acquired analgesic and self-burying avoidance responses. Observers whose demonstrators were either kin (siblings) and, or members of a familiar pair (kin or non-kin) displayed enhanced social learning of defensive responses. Also, within the familiar pairs, social status affected learning with subordinate observers displaying better social learning than dominant observers. These findings indicate that kinship, familiarity and social status modulate social learning of defensive responses to, and the recognition of, dangerous and threatening stimuli, likely including that of predators.Communicated by G. Wilkinson  相似文献   

5.
Environmental Chemistry Letters - We report levels of trace elements in commercially harvested species from the Far Eastern seas of Russia from 2010 to 2018. The best studied organisms in this...  相似文献   

6.
PCB and PCT residues were measured in free‐living (FM) and cultivated mussels (CM) from ten sites in Galicia by gas chromatography with electron capture detector and capillary column. The level of PCB1260 and PCT5460 in FMs increases going from Muros‐Noya to Vigo estuarine bay. There was a trend of increase from north to south.  相似文献   

7.
Urban children remain disproportionately at risk of having higher blood lead levels than their suburban counterparts. The Westside Cooperative Organization (WESCO), located in Marion County, Indianapolis, Indiana, has a history of children with high blood lead levels as well as high soil lead (Pb) values. This study aims at determining the spatial relationship between soil Pb sources and children’s blood lead levels. Soils have been identified as a source of chronic Pb exposure to children, but the spatial scale of the source–recipient relationship is not well characterized. Neighborhood-wide analysis of soil Pb distribution along with a furnace filter technique for sampling interior Pb accumulation for selected homes (n = 7) in the WESCO community was performed. Blood lead levels for children aged 0–5 years during the period 1999–2008 were collected. The study population’s mean blood lead levels were higher than national averages across all ages, race, and gender. Non-Hispanic blacks and those individuals in the Wishard advantage program had the highest proportion of elevated blood lead levels. The results show that while there is not a direct relationship between soil Pb and children’s blood lead levels at a spatial scale of ~100 m, resuspension of locally sourced soil is occurring based on the interior Pb accumulation. County-wide, the largest predictor of elevated blood lead levels is the location within the urban core. Variation in soil Pb and blood lead levels on the community level is high and not predicted by housing stock age or income. Race is a strong predictor for blood lead levels in the WESCO community.  相似文献   

8.
Many animals use signals to communicate their social status to conspecifics, and the social control hypothesis suggests that social interactions maintain the evolutionary stability of status signals: low-quality individuals signal at a low level to prevent high-quality individuals from “punishing” them. I examined whether the numbers of decorations at bowers are socially controlled in the great bowerbird (Ptilonorhynchus nuchalis). In two populations, I supplemented males with decorations to determine whether they (a) rejected supplemental decorations and (b) experienced increased bower destruction from rivals. In contrast to the social control hypothesis, males in both populations accepted most supplemental decorations. Though the mean destruction rate did not increase during supplementation in either population, one of the study populations (Townsville) exhibited a negative correlation between the numbers of decorations naturally displayed at bowers and the change in destruction rate during the experiment. Townsville males that naturally had few decorations at their bowers also had more decorations stolen by other males during supplementation than males that naturally had many decorations. These results suggest that the numbers of decorations at bowers are an honest signal of the male's ability to defend his display site from rivals in at least one population of the great bowerbird (Townsville), but they do not support the social control hypothesis because males at both sites failed to limit signal expression. I discuss how the external nature of bower decorations and their availability in the environment may influence the costs and benefits of decoration theft and social control.  相似文献   

9.
Seasonal differences in the concentration and biochemical composition of seston have been assessed for the first time in the Humboldt Current System off northern Chile (21°S). The study comprised four seasonal surveys in the Bay of Chipana, including the summer and winter of 2006 and 2007, when El Niño 2006 and La Niña 2007 developed. Protein, lipid, carbohydrate and biogenic silica contents were measured in samples collected at four selected depths. The highest protein, lipid and carbohydrate concentrations were found at the fluorescence maximum (between 10 and 15 m depth), whereas the highest biogenic silica concentration was found 1 m above the seabed. When El Niño started developing, every variable showed low values throughout the water column; however, the lowest values were found when La Niña conditions dominated, together with low oxygen concentrations. Samples collected within the oxygen minimum zone (65 m depth) showed the lowest values for the water column and the lowest seasonal variations. After the evident decline coincident with El Niño 2006, the abundance and biochemical quality (high protein and lipid contents) of seston recovered earlier in the surface layer (upper 15 m) than at other depths.  相似文献   

10.
The environment provides many necessary services for a plethora of human activities related to that are being acknowledged as our ecosystems degrade; therefore, ecosystem-based solutions are becoming increasingly more important. Hydrologic restorations (HRs) apply this type of ecosystem approach; there are multiple examples around the Mediterranean area executed since the beginning of the twentieth century. One good example of these restoration-type solutions can be seen in the badlands of Saldaña (Palencia, Spain). This case has been particularly successful in stopping gully erosion from badlands. Despite its importance for the well-being of the inhabitants of Saldaña and surroundings, the economic effects of these services which were put into place by this HR have never been assessed. In the present study, four different and compatible ecosystem restored services have been valued in monetary terms. For their aggregation, an innovative approach has been taken using the analytic hierarchy process methodology, so the weight of each ecosystem service (ES) can be determined. The economic flow of these ESs has been calculated in terms of annual income and updated values, from which natural capital increase in the population of Saldaña can be assessed. After analysing the results, it can be concluded that the village has earned more than seven million euros, which, in turn, generates important benefits to its inhabitants.  相似文献   

11.
 Many species of the carnivorous copepod family Augaptilidae, a primarily meso- and bathypelagic group, possess specialized “buttons” on the setae of their maxilla and maxilliped, which have been thought to be a simple cuticular outgrowth. The fine structure of the button setae in three species of Euaugaptilus was examined by light- and electron microscopy from samples collected in the eastern Indian Ocean and the subtropical western North Pacific. The buttons are arranged in two rows along the inner surface of the setae. There are differences in the shape, size, and arrangement of buttons among the three species, Euaugaptiluslaticeps, E.longimanus, and E.magnus. The button setae have an elaborate internal structure consisting of “setal shaft”, “stalk”, “disc”, and “outer membrane”, with microtubule bundles in the setal lumen, but have no muscular tissues. The disc has only pin-point contact to the core of the stalk, but has connection over a wider area with the fibrous tissue surrounding the core, and the contact area between the stalk and the setal shaft is also small. These structures suggest that the disc will move freely on the apex of the core of the stalk and the stalk may be movable at its connection to the setal shaft. All these components of the button setae may function in concert to fit the surface of the discs firmly to the surface of a prey, and to absorb the energy generated by the struggling prey. Received: 30 November 1999 / Accepted: 19 May 2000  相似文献   

12.
The concentration of the estrogens 17β-estradiol, estriol, estrone, 17α-ethinylestradiol, mestranol and norethisterone and of the anthropogenic gadolinium (Gdant) has been determined in the creeks and rivers, sewage treatment plants and water works of the city of Prague. The rapid degradation of estrogens in surface water allows the estrogen concentration gradient to be used as a very precise and sensitive guideline by which to pin-point sewage leaks into surface run-off water. The rather conservative behavior of Gdant in surface and ground water documents in the present case the presence of sewage water in the surface water cycle.  相似文献   

13.
The social aspects of primate reintroduction are of primary importance to the success of release programs and need to be assessed through the study of changes in social behavior over time. This study reports on the development of social structure and organization in a community of 37 chimpanzees (Pan troglodytes troglodytes) released into the wild in the Conkouati Douli National Park, Republic of Congo. Analyses of post-release monitoring data collected over 10 years on association patterns between individuals show that during the years following individual releases, chimpanzees exhibited changing social structure and organization until they stabilized in one community living in a fission–fusion system. Social organization development was directly affected by several factors including community size and experience in the wild, while social structure was affected by individual characteristics: gender, pre-release history, and release history. Similarities between social structure and organization observed in the released community and wild chimpanzee communities demonstrate that the release program is a success from a social point of view.  相似文献   

14.
15.
Gametogenesis, spawning behavior, and early development have been described in the methane-seep polychaete Hesiocaecamethanicola Desbruyères and Toulmond, 1998, the first documentation of the reproductive biology of any cold-seep polychaete species. The worms were collected at the Green Canyon site in the Gulf of Mexico (27°44.77N; 91°13.33W) in August 1997. The gonads are situated in the neuropodia in association with an intraepithelial capillary system. Oogenesis is intraovarian, with oocytes remaining in the ovary until late vitellogenesis when they are released into the coelom for final growth and differentiation. Vitellogenesis involves both autosynthetic and heterosynthetic processes and, along with ovarian structure, suggests a relatively slow process of egg formation. Sperm differentiation is intertesticular until early spermiogenesis, when spermatid tetrads complete development in the coelom. The mature spermatozoon is an ect-aquasperm consisting of a tapering, digitate acrosome, a spherical nucleus, a midpiece containing from six to eight mitochondria and glycogen stores, and two centrioles associated with the flagellum. Both sexes undergo broadcast spawning, but the males spawn exclusively through the anus, a behavior previously unknown in polychaetes. Artificial fertilization resulted in spiral cleavage and development to the trochophore stage. Oocyte size-frequency analysis of adult females indicates a wide range of oocyte sizes and vitellogenic stages, suggesting that asynchronous gametogenesis occurs. Received: 13 July 2000 / Accepted: 29 November 2000  相似文献   

16.
Pregnant mice were exposed to control (0%), low (0.1%), moderate (0.5%), and high (1%) lead (Pb) acetate in deionized drinking water from the first day of gestation to postnatal day (PND) 21. Pb concentration was determined in blood and the hippocampus at the 7th, 14th, or 21st day of neonatal mice pups. The expression of connective tissue growth factor (CTGF) and TGF-β1 mRNA and protein was also measured in the hippocampus using RT-PCR and immunohistochemistry assays. The expression of CTGF and TGF-β1 mRNA was up-regulated in hippocampus in Pb-exposed groups. These results were further confirmed by immunohistochemistry staining. Data suggest that CTGF and TGF-β1 genes are differentially regulated and are affected by Pb.  相似文献   

17.
In the last decade the habit of smoking the hubbly-bubbly has increased sharply in many regions, including Europe, North America and Australia. Jordan is considered as having one of the highest consumptions of hubbly-bubbly in the world with respect to the general population. Our investigation was initiated due to the increasing trend of cancer cases in the last 10 years. The aim of this study was to determine the radioactive content in tobacco products available in the Jordanian market together with the related supplies. This study showed that all 13 samples investigated contained one or more radionuclides, from 210Pb, 40K, 137Cs, 238U, and 226Ra. Most of the samples contained natural potassium 40K and uranium 238U, lead 210Pb was found in three samples, while radium 226Ra was present only in one sample. Five samples contained the anthropogenic 137Cs. The estimated daily intake of U was found in the range between 4.4 and 115.8?µg per day (0.05–1.43 Becquerel (Bq) per day 238U), with geometric mean of 17.3?µg per day (0.2?Bq per day 238U). The geometric mean of U daily intake found represents 25% of the reference dose (RfD) value, where the highest determined U content represents 165% of the RfD value. This study demonstrated that a water vessel of hubbly-bubbly trapped less than 1.5% of the total U in Ma’assel samples. It is misleading to the public to indicate that a water vessel serves as an active filter for toxic and radiotoxic elements.  相似文献   

18.
Recent theoretical work has highlighted the importance of multi-scale forcing of the flow for altering the nature of turbulence energy transfer and dissipation. In particular, fractal types of forcing have been studied. This is potentially of real significance in environmental fluid mechanics where multi-scale forcing is perhaps more common than the excitation of a specific mode. In this paper we report the first results studying the detail of the wake structure behind fences in a boundary layer where, for a constant porosity, we vary the average spacing of the struts and also introduce fractal fences. As expected, to first order, and in the far-wake region, in particular, the response of the fences is governed by their porosity. However, we show that there are some significant differences in the detail of the turbulent structure between the fractal and non-fractal fences and that these override differences in porosity. In the near wake, the structure of the fence dominates porosity effects and a modified wake interaction length seems to have potential for collapsing the data. With regards to the intermittency of the velocities, the fractal fences behave more similarly to homogeneous, isotropic turbulence. In addition, there is a high amount of dissipation for the fractal fences over scales that, based on the energy spectrum, should be dominated by inter-scale transfers. This latter result is consistent with numerical simulations of flow forced at multiple scales and shows that what appears to be an “inertial regime” cannot be as production and dissipation are both high.  相似文献   

19.
SUMMARY

A cross-section survey of five states in Nigeria was derived through a stratified random sampling technique in 1999–2000 to assess the contribution of traditional knowledge in environmental conservation. Data were collected through a combination of questionnaire survey and discussions with stakeholders, with field assessment of herb gardens. Interviews were held with 1953 respondents composed of women, men and youths drawn from 20 settlements in 10 local government areas in the savanna and rainforest ecological zones.

The results derived from data analysis indicated that: (i) the rural communities were willing to accept integrated rural land-use practices that would conserve species and habitats, sustain the rural economy and the socio-cultural lifestyles of the people; (ii) the people at the local level had some basic knowledge about species and habitats, and have been conserving the forests with traditional land tenure rights; and (iii) environmental projects acceptable to the rural communities must be beneficial to the people, participatory, integrated with traditional knowledge and based on local needs.  相似文献   

20.
The diversity and community composition of phosphorus accumulating organisms (PAOs) in the sediments of the Sanshiliujiao Lake reservoir in Pingtan island, Fujian Province, were investigated by terminal restriction fragment length polymorphism (T-RFLP) methods combined with the construction of clone libraries. The diversity of PAOs in summer samples was significantly higher than that in winter. The dominant terminal restriction fragments (T-RFs) of PAOs were in the range of 200 to 300 bp in summer, while they were in the range of 150 to 200 bp in winter. Cloning sequencing and phylogenetic analysis showed that the main phyla of PAOs in the sediment of the Sanshiliujiao Lake reservoir were Proteobacteria, Actinobacteria, and Acidobacteria. Anaeromyxobacter, Azospirillum, Microlunatus phosphovorus, and Burkholderia were the dominant genera in the summer samples. Anaeromyxobacter, Methylobacterium, Solibacter, Azospirillum, and Microlunatus phosphovorus were the dominant genera in sediment samples in winter. The results of this study demonstrated that the diversity and community composition of PAOs in the sediments of the Sanshiliujiao Lake reservoir had specific seasonal characteristics. Various forms of phosphorus also showed their influence on the diversity of PAOs, especially Fe/Al-P. Our findings lays a scientific foundation for the future disclosure of microbial mechanisms involved in the phosphorus metabolic cycle in the sediments of reservoirs. © 2018 Science Press. All rights reserved.  相似文献   

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