985 resultados para Sea cucumber ecology


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What is the human being? Which is its origin and its end? What is the influence of the nature in the man and what is his impact on nature? Forthe animalists, men are like other animals; freedom and rationality are not signs of superiority, nor having rights over the animals. For the ecohumanists, human beings are part of nature, but is qualitatively different and superior to animals; and is the creator of the civilization. We analyze these two ecological looks. A special point is the contribution ofecohumanists -from the first half of the Renaissance, who dealt in extenso the dignity and freedom of the human being-, of Michelangelo and finally, of Mozart, through his four insurmountable operas, which display the difficulty of physical ecology to engender so much beauty, so much wealth, so much love for the creatures and so much variety.

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[EN] Loggerhead sea turtles (Caretta caretta) originating from the Western Atlantic carry out one of the largest marine migrations, reaching the eastern Atlantic and Mediterranean Sea. It has been proposed that this transatlantic journey is simply a consequence of drifting, with the lack of a target destination and a passive dispersal with oceanic currents. This predicts that the size of the source populations and geographic distance to the feeding grounds should play important roles in defining stock composition in the eastern Atlantic and Mediterranean Sea.

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Human-environment connections are the subject of much study, and the details of those connections are crucial factors in effective environmental management. In a large, interdisciplinary study of the eastern Bering Sea ecosystem involving disciplines from physical oceanography to anthropology, one of the research teams examined commercial fisheries and another looked at subsistence harvests by Alaska Natives. Commercial fisheries and subsistence harvests are extensive, demonstrating strong connections between the ecosystem and the humans who use it. At the same time, however, both research teams concluded that the influence of ecosystem conditions on the outcomes of human activities was weaker than anticipated. Likely explanations of this apparently loose coupling include the ability of fishers and hunters to adjust to variable conditions, and the role of social systems and management in moderating the direct effects of changes in the ecosystem. We propose a new conceptual model for future studies that incorporates a greater range of social factors and their dynamics, in addition to similarly detailed examinations of the ecosystem itself.

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Thesis (Master's)--University of Washington, 2016-06

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Biodiversity and distribution of benthic meiofauna in the sediments of the Southern Caspian Sea (Mazandaran) was studied in order to introducing and determining of their relationship with the environmental factors. From 12 stations (ranging in depths 5, 10, 20 and 50 meters), sediment samples were gathered in 6 months (2012). Environmental factors of water near the bottom including temperature, salinity, dissolved oxygen and pH were measured during sampling with CTD and grain size and total organic matter percentage and calcium carbonate were measured in laboratory. In different months, the average water temperature (9.52-23.93), dissolved oxygen (7.71-10.53 mg/L), salinity (10.57±0/07 and 10.75±0/04 ppt), pH (7.44±0/29 and 7.41±0/22), EC (17.97±0/12 and 18.30±0/04μs/cm2), TDS (8.92±0/04 and 9.14±0/02 mg/L), total organic matter (5.83±1/43 and 6.25±0/97%) and calcium carbonate (2.36±0/36 and 1.68±0/19%) were measured respectively. Structure of the sediment samples mostly consisted of fine sand; very fine sand, silt and clay. From the 4 group animals (Foraminifera, Crustacea, Worms and Mollusca), there were identified 40species belong to 29 genera of 25 families. The cosmopolitan foraminifer, Ammonia beccarii caspica, was common in all sampling stations. Result showed that depth was important factor on distribution of meiofauna. Most density of foraminifera and crustacean was observed in depth of 20m and for mollusca and worms observed in 5m. Shannon diversity index decreased with depth that showed in shallow water diversity was higher than deep water. Mean of maximum and minimum Shannon index was obsorvers in depth of 5m and 50 m that was measured in order 0.93 and 0.43. Account of Shannon index showed that this area is under pressure. Account of peioleo index showed distribution in this area was not steady.

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Mnemiopsis leidyi one species of phylum Ctenophora, is a native species in America. It has most likely moved across the Atlantic in the ballast water of cargo ships to the Black sea in 1982, and then to the Caspian Sea thought the Volga-Don Channel, in Nov 1999. The population of M. leidyi rows rapidly and by end of 2000, the entire sea was teeming with them. This survey was arranged In order to study the relationship between the invasion of M. leidyi and sharp decline in main stocks pelagic fish such as Kilka. Dietary analysis was conducted on Anchovy Killka (Clupeonella engrauliformis) and M. leidyi from August 2001 to October 2002 in two stations, located at the costal water near Babolsar (52.38° E ,36.42° N ) and Noshahar (51.33° E,36.39° N) in the Caspian Sea province of Mazandaran, Iran. M. leidyi was caught by plankton net, at three vertical strata of both station at surface 5 in, 10m, and 15 m the Kilka was caught by fisheries boat at Babolasar fishery harbour. Samples of M. leidyi were not fixed in its common fixative, we used 96% Ethanol In order to study of M. leidyi digestion system some alive samples, directly, were studied by the fluorescence microscope which was connected to a computer prepared specially for this process. In many cases, the light was directly reflected on the sample and microscopic image was prepared in dark background. We found that there were some common organisms in diet of both species. The Schoener index analysis reflected these similarities, as values more than critical level of overlap (>89 in Babolsar samples and >84 in Noshahar samples) were found. Results from this study suggests that M. leidyi and Anchovy have a similar feeding niche and computation between them is one of the reasons to decline in anchovy stocks. Economical effects of M. leidyi s invasion in research area were studied by data on kilka caught before and after introducing M. leidyi.

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The Mediterranean Sea constitutes a unique environment to study cold-seep ecosystems due to the presence of different geodynamic settings, from an active margin along the Mediterranean Ridge (MR) to a passive margin in the Nile Deep-Sea Fan (NDSF). We attempted to identify the structure of benthic communities associated with the Napoli and Amsterdam mud volcanoes (MVs) located on the MR and to establish the links between faunal distribution and environmental conditions at different spatial scales. Comparison between the 2 MVs revealed that the faunal distribution seemed to be mainly controlled by the characteristics of the microhabitats. On both geological structures, the variability between the different microhabitats was higher than the variability observed between replicates of the same microhabitat, and the distribution of macro-fauna was apparently linked to gradients in physico-chemical conditions. The peripheral sites from Napoli were generally more oxygenated and harboured lower species richness than the active sites. The reduced sediment microhabitat from Amsterdam presented the highest methane concentrations and was mainly colonised by symbiont-bearing vesicomyid bivalves and heterotrophic dorvilleid polychaetes. Overall, a higher taxonomic diversity was observed on Napoli. Sub-stratum type was hypothesised to be the second factor influencing faunal distribution. The results of this study highlight the high heterogeneity of faunal communities associated with seep ecosystems within this region and the need to pursue investigations at various spatial and temporal scales.

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This is especially well supported by down core variation Zn concentration. As Caspian Sea water intrudes into the Bay, it may be concluded that some part of pollution has sea origin. The geochemical index (Igeo) was reformulated for the area of study using chemical partitioning as well as Pb-210 results. The newly developed geochemical index is indicative of low to medium pollution intensity in the Bay of Gorgan. Thus, any additional pollution into the area of study may leave adverse effects on the aquatic ecology of Bay of Gorgan. Further, lithogenous and non-lithogenous inputs of metals into the Bay were assessed. For this purpose and through chemical partitioning, association of metals with different sedimentary phases was determined. The overall results show that about 114th total metal concentration have been added into the Bay of Gorgan through human activities.

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Increasing abundance of non-commercial sprats and decreasing biomass and landings of commercial anchovies and sardines justify the need to study the feeding ecology and trophic niche overlap of these planktivorous species in the Gulf of Lions. Their diet has been investigated on the basis of stomach content and stable isotope analyses in 2011 and 2012 according to different depths and regions in the study area. The main prey were Corycaeidae copepods, Clauso/Paracalanus, Euterpina acutifrons and Microsetella, for sprats and small copepods, such as Microsetella, Oncaea and Corycaeidae, for anchovies and sardines. This is the first time that the diet of sprats is described in the Gulf of Lions. Sprats fed on a larger size spectrum of prey and seem to be more generalist feeders compared to anchovies and sardines. Ontogenetic changes as well as spatial and temporal variations of the diet occurred in the three species. Stable isotope analysis revealed mobility of sardines and sprats among feeding areas while anchovies exhibited preferred feeding areas. Sprats showed a higher relative condition assessed by C/N ratios than sardines and anchovies. Our results showed an overlap of the trophic niches for the three species, indicating a potential trophic competition in the Gulf of Lions.

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Studying gamete biology can provide important information about a species fertilization strategy as well as their reproductive ecology. Currently, there is a lack of knowledge about how long sea bass Dicentrarchus labrax eggs can remain viable after being activated in seawater. The objectives of this study were to understand the effects of pre-incubation of fresh and overripe sea bass eggs in seawater and to determine the duration of egg receptivity. Pooled eggs (fresh and overripe) from four females were pre-incubated in seawater for 0 min (control), 0.5 min, 1 min, 3 min, 10 min and 30 min and then fertilized by pooled sperm from four males. The fresh eggs had a higher fertilization success than overripe eggs. Our results revealed a significant effect of pre-incubation time for both the fresh (P < 0.01) and overripe eggs (P < 0.01). Fertilization success of eggs significantly declined for both these treatments after 3 min of pre-incubation, which clearly indicates that sea bass eggs are able to be fertilized by sperm for up to 3 min after release into seawater. This study has particular importance for understanding fertilization strategies, reproductive potential, as well as reproductive ecology of sea bass.

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The coastal districts, as an intersection of two perfectly different ecosystems of dry land and sea, is one of the most complicated and the richest natural system on earth. Considering these areas are constantly exposed to aggregation of water pollutants and also consequence resulting from construction and development activities, they are very vulnerable. Therefore, "sensitive Coastal areas" has become a common word in the related subjects to marine environment recently. The said title relates to the areas of the coastal lines which are vulnerable to the natural condition or human actions because of ecological, social, economic, educational and research importance, also they need particular supports. The southern coasts of Caspian Sea, In Iran prominent samples are of these sensitive areas which their environment are exposed to demolition and destruction intensely, due to increasing and uncontrolled development. The first stage of protecting and managing the coastal areas is identifying sensitive Coastal areas and broadening the Coasts. In this survey, we attempted to examine a definite area in the southern coasts of Caspian Sea. In Iran, by profiting from the world experiences and concluded researches in Iran especially the concluded studies by marine environment office and the Environment protection organization on the subject of determination criteria of the sensitive ecological districts. For this purpose (In Gilan Province) Boujagh national park district which is located in the mouth of sefidroud river and also is possessed of the special ecological and environmental features and distinctions. In this survey, first they said district is divided proportionally on the basis of using a grid system in order to identify the sensitive ecological districts and broaden the coast, and then the desired indices have been determined and scored by numeral valuation method in each unit and then analysis has been done by using of the geography information system (GIS) and final has estimated economic valuation of sensitive ecological areas that is presented in this essay.

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The general purpose of this study is to investigate the degree of heavy metal accumulation in hard and soft tissue of sea urchin, and determining these tissues as the most suitable bioindicator for lead and cadmium in the environment of the sampling stations. The way of doing this assessment was MOOPAM. Samples were prepared and classified according to sea urchin organ (soft tissue, hard tissue, Tube feet, Test, Lantern Structure and spines) and then lead and cadmium were measured in them. Result of this study shows that hard tissue is a better index of lead and cadmium than soft tissue. The result of bioaccumulation of lead in the related tissue was found to be in the following order: Soft tissue=21, hard tissue=28.1, Test=20.8, Lantern Structure=20.5 and spines=23.9. The result of bioaccumulation of cadmium in the related tissue was found to be in the following order: Soft tissue=9. 7, hard tissue=5.01, Test=4.2, Lantern Structure=4.06 and spines=5.53.

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In this project, have been studied to determine the appropriate model to spatial, temporal and diversity of demersal fishes in the Sea of Oman, including Trichiuridae, Nemipteridae, Haemulidae, Arridae, Synodontidae, Batoidfishes, Carangidae, Scianidae, Carchariniformes and Serranidae. This research became operational from catch data during 2003 to 2013 (in 2007, due to the lack of ship failed). Processing and calculations was evaluated by using the software Excel, SPSS, Arc GIS and table curve 3D highest biomass and abundance was showed in strata A and C and 10-30 m depth layers was showed the best condition biomass. In other words, highest biomass was showed in the eastern region in the Oman Sea than the central and western regions. Batoidfishes and Trichiuridae had the highest biomass .Depth factors was showed a significant correlation with the biomass. Scianidae, Serranidae and Haemulidae were showed a large decline. Synodontidae was showed a very large increase. The largest of Shannon index belong to central and western region of the Oman Sea. The highest Shannon index was showed 10-20 and 50-100 m, respectively. The Distribution maps based on the biomass was analyzed by using Arc GIS software. So that were identified in the first time in a ten-year period and carefully catch stations any economic of aquatic group. In conclusion, the depth can be found in the pattern of distribution, abundance and diversity of fish from away the beach so that follow specific pattern.

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This project was done for identifying and survey on distribution and diversity of true crabs in inter tidal and sub tidal zones of the Gulf of Oman (Sistan and Baluchistan province) during two year from 2009 to 2010. Specimens of inter tidal zones were carried out at 10 stations and 8 stations from sub tidal. The specimens were collected by hand and dip-net from inter tidal and by trawl net from sub tidal regions, preserved in 70% alcohol and carried to the laboratory. A total of 37 species belonged to 17 families from inter tidal and 23 species belonged to 9 families from sub tidal were identified. Of which 54 species were identified up to species level. 2 species from Matutidae, 1 species from Eriphiidae, Menippidae, Pseudoziidae, Plagusidae, Varunidae, Camptandriidae, Dromiidae and Dorippidae, 2 species from Oziidae, 3 species from Epialtidae, 2 species from Majidae, 4 species from Pilumnidae, 12 species from Portunidae, 6 species from Xanthidae, 2 species from Grapsidae, 3 species from Dotillidae, 3 species from Macrophthalmidae, 3 species from Ocypodidae, 3 species from Calappidae, 2 species from Parthenopidae and 1 species from Galenidae were identified. All specimens are deposited in the Zoological Museum, University of Tehran (ZUTC). The results of the present study revealed that family Portunidae with 6 species from inter tidal and 9 species from sub tidal regions have the highest species richness among the 22 families. Maximum similarity (Sorenson's Index) was obtained among the stations Breis, Lipar, Pozm and Gordim, and minimum was obtained among the stations Chazire-Kharchang with Pasabandar, Beris, Lipar, Daria-Bozorg, Pozm and Gordim in intertidal regions. In sub tidal regions maximum similarity (Sorenson's Index) was obtained among the stations Pasa bandar with Berisand minimum was obtained among the stations Govatr with Ramin and Gordim, Ramin with Pozm. Also maximum species richness was observed at Tiss in inter tidal and Chabahar in sub tidal stations, whereas minimum was obtained at Beris, Pozm, Gordim and Lipar in inter tidal and Govatr and Pozm in sub tidal stations. Family Ocypodidae in inter tidal and Portunidae in sub tidal regions have the highest distribution. In all of the species length and Breadth of carapace showed significant relation.

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The helminthes parasites fauna of 313 specimens of Caspian herrings (Clupeonella cultriventris, Clupeonella engrauliformis, Clupeonella grimmi) caught from catching localities situated in southeast of Caspian Sea Were investigated during winter 2008 until autumn 2009. A total of 3 helminthes species were found. They were including Pseudopentagramma symmetrica from intestine (mid gut, hind gut and cecae) Bunocotyle cingulata in intestine, Mazocreas alosae the only monogenean with Marine origin in the gills of infected specimens. In addition to two zoonotic species including Contracecum sp. and Anisakis sp. in digestive system, muscle and ovary and an Acanthocephal, Corynosoma strumosum in intestine which were previously reported. We can conclude that the main characteristic of the helminthes parasites community of Clupeidae species studied is the dominance of the endoparasites species due mainly to the digenean Pseudopentagramma symmetrica and Bunocotyle cingulata and the relative scarcity of ectohelminthes fauna. In this paper the latest data of helminthes fauna and community ecology of digenean of Clupeidae species are presented and the community structure of Pseudopentagramma symmetrica is discussed.