Comparison of macrobenthic assemblages of three fish estuarine nurseries and their importance as foraging grounds

2011 ◽  
Vol 92 (1) ◽  
pp. 85-97 ◽  
Author(s):  
Jonathan Selleslagh ◽  
Sandric Lesourd ◽  
Rachid Amara
Keyword(s):  
Environmental Variables ◽  
Relative Importance ◽  
English Channel ◽  
Sediment Characteristics ◽  
Analysis Of Similarity ◽  
Macrobenthic Assemblages ◽  
Significant Difference ◽  
Estuary Sediment ◽  
Influencing Parameters ◽  
Macrobenthic Assemblage

Macrobenthic assemblages were examined in three fish estuarine nurseries and related to environmental variables, as well as fish and macrocrustaceans, in order to assess and compare the potential foraging ground value of these systems. Macrobenthos was sampled in spring 2007 in the Canche, Authie and Somme estuaries (eastern English Channel, France). A total of 17, 28 and 23 macrobenthic taxa, with a clear dominance of amphipods (mainly Bathyporeia sarsi), polychaetes and bivalves, were recorded in the three estuaries respectively. Although predators (fish and macrocrustaceans) were abundant, relatively high densities of macrobenthos were observed: 876.2 ± 389.1, 595.4 ± 197.2 and 854.3 ± 281.2 ind. m-2 in the Canche, Authie and Somme, respectively. No significant difference in species richness, Shannon–Wiener diversity and density (total and dominant groups) of macrobenthos was observed between the three estuaries. Although the analysis of similarity and similarity percentages analyses indicated that macrobenthic assemblage was variable between Authie and Somme, results showed that macrobenthos resource was relatively high and similar in the three estuaries. Taking into account these considerations, the present study indicated a similar relative importance of the Canche, Authie and Somme estuaries as foraging grounds for fish and macrocrustaceans during spring. Multivariate analysis showed that macrobenthic assemblages were mainly driven by salinity and sediment characteristics in the Canche and Authie estuaries while in the Somme estuary sediment characteristics were the most influencing parameters.

Hydrographic and nutrient chemistry surveys in the western English channel during 1963 and 1964

1972 ◽  
Vol 52 (4) ◽  
pp. 915-930 ◽  
Author(s):  
F. A. J. Armstrong ◽  
E. I. Butler ◽  
G. T. Boalch
Keyword(s):  
Suspended Matter ◽  
Low Temperatures ◽  
English Channel ◽  
Nitrogen And Phosphorus ◽  
Mean Values ◽  
Average Temperature ◽  
Significant Difference ◽  
Nutrient Chemistry ◽  
Phosphate Silicate ◽  
Made In

Three surveys were made in 1963 and five in 1964 in the area of the English Channel between the English and French coasts and between 3° 40' W and 5°10' W. This area had been surveyed in 1961 and 1962. Temperature and salinity were determined at o, to and 50 m and phosphate silicate and nitrate at 10 and 50 m. The results are presented graphically. Temperature and salinity were compared with Lumby's 25–year averages. The year 1963 started with unusually low temperatures and salinities higher than average. Temperature remained low in the spring, but salinity decreased. The year 1964 started with temperatures and salinities above normal, but during the rest of the year values were close to average. Nitrate in January 1964 was higher than in January 1963. Analyses of suspended matter at 12m were made for carbon, nitrogen and phosphorus on most surveys, and mean values for the whole area are given. Suspended carbon was 67 /ig C/l. in January 1963 and 51 /*g C/l. in January 1964, a significant difference. Increases in sus-pended carbon, nitrogen and phosphorus were found in spring and summer 1964.

scholarly journals Distribución de felinos en áreas naturales protegidas de Honduras

2013 ◽  
Vol 3 (1) ◽  
pp. 1
Author(s):  
Hector Orlando Portillo Reyes ◽  
Fausto Elvir
Keyword(s):  
Protected Areas ◽  
Central Region ◽  
Puma Concolor ◽  
Significant Finding ◽  
Panthera Onca ◽  
Leopardus Pardalis ◽  
Analysis Of Similarity ◽  
Significant Difference ◽  
Local Extirpation ◽  
Nmds Analysis

RESUMENEn Honduras ocurren cinco especies de felinos, jaguar (Panthera onca), puma (Puma concolor), ocelote (Leopardus pardalis), caucel (Leopardus wiedii) y el yaguarundí (Puma yagouaroundi). Se comparó la composición de las cinco especies de felinos en 15 áreas naturales  protegidas, las cuales se agruparon en tres regiones con diferentes zonas de vida, ecosistemas y gradientes altitudinal siendo estas; la región Moskitia, la región Central y la región Caribe. Se evaluó la detección de felinos con la presencia/ausencia en cada área. Se realizó un dendrograma y un análisis no métrico multidimensional para comparar la similitud entre áreas protegidas y especies. El hallazgo significativo es la ausencia del jaguar en las áreas protegidas de la región Central de Honduras, donde posiblemente se ha dado su extirpación. El puma, el ocelote, el caucel y el yaguarundí, se registran en las tres regiones del país. Al comparar la composición de los felinos en las tres regiones usando el análisis de similitud, este presentó diferencias significativas entre las áreas protegidas evaluadas. La región Central mostró menor composición que la región del Caribe y la Moskitia. La región de la Moskitia hondureña se muestra como la región con mayor resilencia para mantener las cinco especies de felinos.Palabras clave: Composición, conglomerados, escalamiento multi-dimesional no métrico (nmds), análisis de similitud (anosim), disimilitud, Moskitia. ABSTRACTHonduras is territory of five species of cats, jaguar (Panthera onca), puma (Puma concolor), ocelots (Leopardus pardalis), margay (Leopardus wiedii) and the yaguarundi (Puma yagouaroundi). The composition of the five cats in 15 protected areas was compared grouped in three regions:  the Moskitia, Caribbean and Central region with different life zones, ecosystems and altitudinal levels. Cat detection was evaluated by presence/absence in each protected area. Cluster analysis and non- metric multidimentional scaling were used to compare similarity between protected areas and species. The significant finding is the absence of the jaguar in protected areas in the Central Region of Honduras confirming local extirpation. Puma, ocelots, margay and the yaguarundi are present in the three regions.  Comparing composition of cats between the three region using similarity analysis this presented significant difference between protected areas. The Central region showed a lower composition in cat structure that The Caribbean and Moskitia region. The Honduran Moskitia region showed a higher resilience to maintain the five cats.Key words: Composition, conglomerates, non-metric multidimentional scaling (nmds), analysis of similarity (anosim), dissimilarity, Moskitia.

scholarly journals Detecting environment-dependent diversification from phylogenies: a simulation study and some empirical illustrations

2017 ◽  
Author(s):  
Eric Lewitus ◽  
Hélène Morlon
Keyword(s):  
Environmental Variables ◽  
Relative Importance ◽  
Species Trees ◽  
Major Goal ◽  
Explanatory Variables ◽  
Extinction Rates ◽  
Dependency Tree ◽  
Species Evolution ◽  
Abiotic Variables

AbstractUnderstanding the relative influence of various abiotic and biotic variables on diversification dynamics is a major goal of macroevolutionary studies. Recently, phylogenetic approaches have been developed that make it possible to estimate the role of various environmental variables on diversification using time-calibrated species trees, paleoenvironmental data, and maximum-likelihood techniques. These approaches have been effectively employed to estimate how speciation and extinction rates vary with key abiotic variables, such as temperature and sea level, and we can anticipate that they will be increasingly used in the future. Here we compile a series of biotic and abiotic paleodatasets that can be used as explanatory variables in these models and use simulations to assess the statistical properties of the approach when applied to these paleodatasets. We demonstrate that environment-dependent models perform well in recovering environment-dependent speciation and extinction parameters, as well as in correctly identifying the simulated environmental model when speciation isenvironment-dependent. We explore how the strength of the environment-dependency, tree size, missing taxa, and characteristics of the paleoenvironmental curves influence the performance of the models. Finally, using these models, we infer environment-dependent diversification in three empirical phylogenies: temperature-dependence in Cetacea,δ13C-dependence in Ruminantia, andCO2-dependence in Portulacaceae. We illustrate how to evaluate the relative importance of abiotic and biotic variables in these three clades and interpret these results in light of macroevolutionary hypotheses for mammals and plants. Given the important role paleoenvironments are presumed to have played in species evolution, our statistical assessment of how environment-dependent models behave is crucial for their utility in macroevolutionary analysis.

Heavy metal pollution and macrobenthic assemblages in soft sediments in two Sydney estuaries, Australia

1998 ◽  
Vol 49 (6) ◽  
pp. 533 ◽  
Author(s):  
Jonathan S. Stark
Keyword(s):  
Heavy Metals ◽  
Environmental Variables ◽  
Spatial Scales ◽  
Organic Matter Content ◽  
Matter Content ◽  
Soft Sediments ◽  
Lead And Zinc ◽  
Macrobenthic Assemblages ◽  
Order Of Magnitude ◽  
Copper Lead

The influence of heavy metals (copper, lead and zinc) associated with urban runoff, on assemblages of macrofauna in intertidal soft sediments was studied in two estuaries in the Sydney region. The patterns of distribution and abundance of fauna and assemblages was found to vary significantly at several spatial scales: within bays in an estuary, between bays within an estuary and between bays from different estuaries. Significant differences were found in concentrations of heavy metals in sediments, but there was very little difference among bays in other environmental variables: grain-size characteristics and organic matter content of sediments. Bays polluted by heavy metals had significantly different assemblages to unpolluted bays, were generally less diverse and were characterized by an order-of-magnitude greater abundance of capitellids, spionids, nereids and bivalves. Unpolluted bays had greater abundance of crustaceans and several polychaete families, including paraonids and nephtyids and were generally more diverse. There was a significant correlation between patterns of assemblages and concentrations of heavy metals, but not with other environmental variables.

Consistent patterns of variation in macrobenthic assemblages and environmental variables over multiple spatial scales using taxonomic and functional approaches

2016 ◽  
Vol 120 ◽  
pp. 191-201 ◽  
Author(s):  
Puri Veiga ◽  
Ana Catarina Torres ◽  
Fernando Aneiros ◽  
Isabel Sousa-Pinto ◽  
Jesús S. Troncoso ◽  
...  
Keyword(s):  
Environmental Variables ◽  
Spatial Scales ◽  
Multiple Spatial Scales ◽  
Macrobenthic Assemblages

scholarly journals Space Is More Important than Season when Shaping Soil Microbial Communities at a Large Spatial Scale

mSystems ◽  
2020 ◽  
Vol 5 (3) ◽  
Author(s):  
Kaoping Zhang ◽  
Manuel Delgado-Baquerizo ◽  
Yong-Guan Zhu ◽  
Haiyan Chu
Keyword(s):  
Seasonal Variation ◽  
Microbial Community ◽  
Spatial Scale ◽  
Environmental Variables ◽  
Soil Microbial Communities ◽  
Spatiotemporal Variation ◽  
Relative Importance ◽  
Large Spatial Scale ◽  
Environmental Covariates ◽  
Soil Microbial

ABSTRACT The relative importance of spatial and temporal variability in shaping the distribution of soil microbial communities at a large spatial scale remains poorly understood. Here, we explored the relative importance of space versus time when predicting the distribution of soil bacterial and fungal communities across North China Plain in two contrasting seasons (summer versus winter). Although we found that microbial alpha (number of phylotypes) and beta (changes in community composition) diversities differed significantly between summer and winter, space rather than season explained more of the spatiotemporal variation of soil microbial alpha and beta diversities. Environmental covariates explained some of microbial spatiotemporal variation observed, with fast-changing environmental covariates—climate variables, soil moisture, and available nutrient—likely being the main factors that drove the seasonal variation found in bacterial and fungal beta diversities. Using random forest modeling, we further identified a group of microbial exact sequence variants (ESVs) as indicators of summer and winter seasons and for which relative abundance was associated with fast-changing environmental variables (e.g., soil moisture and dissolved organic nitrogen). Together, our empirical field study’s results suggest soil microbial seasonal variation could arise from the changes of fast-changing environmental variables, thus providing integral support to the large emerging body of snapshot studies related to microbial biogeography. IMPORTANCE Both space and time are key factors that regulate microbial community, but microbial temporal variation is often ignored at a large spatial scale. In this study, we compared spatial and seasonal effects on bacterial and fungal diversity variation across an 878-km transect and found direct evidence that space is far more important than season in regulating the soil microbial community. Partitioning the effect of season, space and environmental variables on microbial community, we further found that fast-changing environmental factors contributed to microbial temporal variation.

The Effect of two different protein sources in the diet upon the incidence and prevalance of lameness in dairy cattle

1989 ◽  
Vol 1989 ◽  
pp. 66-66
Author(s):  
D N Logue ◽  
A Lawson ◽  
D J Roberts ◽  
E A Hunter
Keyword(s):  
Dairy Cattle ◽  
Crude Protein ◽  
Economic Consequences ◽  
Relative Importance ◽  
The West ◽  
Significant Difference ◽  
Series Of Experiments ◽  
Relationship Of ◽  
The Relationship ◽  
Locomotion Score

The importance of lameness in dairy cattle in UK in terms of its economic consequences and welfare considerations is well documented (Russel and others, 1982). While such epidemiological work has identified factors of importance in the aetiology of the various conditions associated with lameness it has been less successful in apportioning their relative importance, particularly for those conditions affecting the hoof. A series of experiments has been conducted at the West of Scotland College over the period 1983 to 1989 mainly investigating the relationship of nutrition and lameness. In one of these Manson and Leaver (1988) found a significant difference in the prevalence of lameness between two groups of cattle fed complete diets containing either 16.1 or 19.8% crude protein. They also found a significant increase in mean locomotion score (LS) and commented that further studies were needed to understand the dietary processes by which the hoof of the cow was predisposed to such problems.The objective of this experiment was to investigate the influence of the type of protein source in the concentrate upon the locomotion of the cows, the incidence and prevalence of lameness and finally on hoof hardness, shape, growth and wear.

scholarly journals Bio-Ecological Traits of Western Tubenose Goby Proterorhinus semilunaris (Heckel, 1837): A Key to Understand Its Invasion Success

Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1247 ◽  
Author(s):  
Gülşah Saç
Keyword(s):  
Standard Length ◽  
Natural Habitat ◽  
Invasion Success ◽  
Biological Traits ◽  
Relative Importance ◽  
Ecological Traits ◽  
Tubenose Goby ◽  
Significant Difference ◽  
Index Of Relative Importance ◽  
Proterorhinus Semilunaris

This study aims to contribute to the limited knowledge on the bio-ecological traits of the native Western tubenose goby, Proterorhinus semilunaris, which is considered to invade many inland waters in Europe and North America. During monthly sampling surveys from March 2012 to June 2013, the species was collected from the four stations in the Istranca River (Turkey) by electrofishing. The standard length and body weight of 310 samples varied between 1.4–6.1 cm and 0.08–7.09 g, respectively. The sex ratio of female to male was found to be 1.7:1.0, with a significant difference. The values of the exponent b in the length–weight relationship were approximately 3 for females, males, and all individuals, indicating an isometric growth. The size at first sexual maturity was 2.44 cm standard length (SL) for females and 2.29 cm SL for males. Absolute fecundity ranged from 56 to 344 eggs with a mean of 164 eggs. The food composition of the species comprised of 8 major groups: Insecta (Diptera, Ephemeroptera, Plecoptera, Odonata, Trichoptera, Coleoptera), Arachnida, Annelida, Gastropoda, Crustacea, Pisces, plant, and detritus. According to the results of modified index of relative importance (MI) and index of relative importance (IRI), insect and Diptera were the most prevalent prey for this fish. The present study has provided baseline information on the basic biological traits of the fish in its natural habitat for further understanding of this species success of invasion.

scholarly journals The Relative Importance of the Small Intestine and the Liver in Phase II Metabolic Transformations and Elimination of p-Nitrophenol Administered in Different Doses in the Rat

2020 ◽  
Vol 88 (4) ◽  
pp. 51
Author(s):  
Attila Almási ◽  
Pál Perjési ◽  
Emil Fischer
Keyword(s):  
High Pressure ◽  
Small Intestine ◽  
Phase Ii ◽  
Hepatic Function ◽  
Intestinal Lumen ◽  
Jejunal Loop ◽  
Relative Importance ◽  
Significant Difference ◽  
Metabolic Reactions ◽  
Different Doses

Intestinal and hepatic function have been investigated in phase II metabolic reactions and elimination of p-nitrophenol (PNP) in the rat. A jejunal loop was cannulated and recirculated with isotonic solutions containing PNP in different concentrations (0, 20, 100, 500, 1000 µM). Samples were obtained from the perfusate at given intervals. To investigate the metabolic and excretory functions of the liver, the bile duct was cannulated, and the bile was collected. Metabolites of PNP were determined by validated HPLC (high pressure liquid chromatography) methods. The results demonstrated the relative importance of the small intestine and the liver in phase II metabolic transformations and elimination of PNP. There were significant differences between the luminal and biliary appearances of p-nitrophenol-glucuronide (PNP-G) and p-nitrophenol–sulfate (PNP-S). The PNP-G appeared in the intestinal lumen at the lower PNP concentrations (20 µM and 100 µM) at higher rate than in the bile. No significant difference was found between the intestinal and the biliary excretion of PNP-G when PNP was administered at a concentration of 500 µM. However, a reverse ratio of these parameters was observed at the administration of 1000 µM PNP. The results indicated that both the small intestine and the liver might play an important role in phase II metabolic reactions and elimination of PNP. However, the relative importance of the small intestine and the liver can be dependent on the dose of drugs.

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