82 resultados para Managing Diversity


Relevância:

20.00% 20.00%

Publicador:

Resumo:

The impact of Petrochemical Special Economic Zone (PETZONE) activities on the health status of Jafari Creek was studied by assessing the changes in macroinvertebrate assemblages in nine sites during September 2006- January 2008. Furthermore to evaluate the ecological status of the Jafari Creek the WFD indices (i.e. AMBI, M-AMBI) were used. The relationship between spatial pattern of macro invertebrate assemblages and ambient factors (i.e. water temperature, salinity, pH, dissolved oxygen, turbidity, electrical conductivity, total dissolved solid, total hardness, total nitrogen, ammonia, total phosphorous, chemical oxygen demand, biological oxygen demand, sediment grain size distribution, sediment organic content, heavy metals contents) was measured. Background Enrichment indices, Contamination factor and Contamination degree, were used to assess the health status in the study area based on Nickel, Lead, Cadmium and Mercury contents of the sediments. The macrobenthic communities had a low diversity and were dominated by opportunistic taxa, and the AMBI and M-AMBI indices need to be calibrated before using in Persian Gulf and its coastal waters. The BIO-ENV analysis identified pH, dissolved oxygen, TDS, and the total organic content of sediments as the major environmental variables influencing the infaunal pattern. This suggests that management should attempt to ensure minimal disturbance to environmental variables underlying the spatial variation in macroinvertebrate assemblages. Background Enrichment indices showed that the health of Jafari Creek has declined over time due to the constant discharge of heavy metals to the Creek system. Furthermore WQS index shows that the quality condition of the water column in Jafari Creek, regard to the calculated number (3) is week. These indices also identified a significant degree of pollution in the study area. The decrease in the ecological potential of Jafari Creek was best highlighted by the alteration in macrobenthic assemblages.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The Moosa Creek extends from its opening into the Persian Gulf, with some sub narrow creeks leading to it. Zangi creek is one of the main branches of Moosa creek. The creek contains numerous sources of organic pollution, including sewage outlet flows and boat waste. After establishing the Petrochemical special Economic Zone (PETZONE) in 1997 near to the Zangi Creek, the pipelines, streets and railway made it distinct from eastern and western parts of this creek. Industrial activities have released sludge and effluents in this creek along these years. A survey of the Zangi creek was performed, assessing water properties, organic pollution, and the population density, distribution and diversity of macrobenthic fauna through bi-monthly sampling from July 2006 to September 2007. Samples were collected from water near the bottom and sediment at 7 stations include 2 stations inside the distinct Zangi creek and 4 stations along a transect with 1 km distances between them in eastern free part and one reference station located at the Persian Gulf entrance to the Moosa creek. The environmental parameters such as temperature, salinity, pH, dissolved oxygen, COD, turbidity, EC and heavy metals include Hg, Cd, Pb, Ni as well as percentage silt-clay and total organic matter of the sediment were measured. The faunal population density and their distribution are discussed in relation to the environmental changes. Results showed spatial heterogeneity in faunal distribution of the Zangi creek. Nine groups of macrofauna were identified out of distinct zangi creek. Polychaets formed the dominant group (48%) followed by bivalves (13%), gastropods (10%), Decapods (2%), Tanaids (5%), and all other groups (22%). The distinct creek was heavily polluted without any macrofauna communities probably as a consequence of the high pH, COD, low salinity and heavy metals contamination specially Cd and Pb. The other stations near to the disposal site were found with macrofauna communities commonly tolerant to organic pollution, At 3 km east of the disposal site, macrofauna is comparable to the surrounded creek, whereas macrofauna still indicate environmental degradation. Farther a way, faunal density decreases and equilibrium taxa gradually replace opportunistic species, while the other stations were far from polluted area contained lower pollution and relatively healthy macrofauna. The mean biomass of macrobenthic fauna were estimated for the whole studied area. The results are considered in Minimum density and biomass in surrounded creek and maximum density and biomass in 3 km of surrounded area. Biodiversity Indices were low in surrounded creek. The Shanon-weaver information index was used to describe the spatially variations in diversity. Macrofauna density, shanon and simpson index were significantly variable between surrounded and free parts of Zangi creek (p<0.05). The numerical abundance of macrobenthose varied from 221. m-2 in polluted area to 4346 m-2 in free part of Zangi creek. The Shanon-weaver information index varied from 0.4 in distinct area to 2.9 in reference station. The physico- chemical changes between distinct and free creeks showed significant variations such as pH, salinity and EC. Salinity and EC were significantly positive correlate to macrofauna density, whereas pH and TOM percentage indicated significantly negative correlation to density. Heavy metals concentrations in sediments were higher than water samples. Concentration pattern of heavy metals in sediments and water samples were Ni>Pb>Cd>Hg. Salinity and pH were significantly correlated to metals in sediments (p<0.01). No significant correlation were found between Macrofauna density and heavy metals (p<0.05).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The article presents the environmental impacts of aquaculture and the ways to manage them. The environmental impacts include issues of recreation and aesthetics, and the usage of resources and discharge of nutrients and organic matter into the environment. Likewise, the results are also discussed, such as reduced production, disease outbreak in cultured and wild populations, and an increase of regulatory restrictions being placed on aquaculture operations.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Genetic diversity of Saccostrea cucullata in the northern coast lines of the Persian Gulf and the Sea of Oman were determined using DNA extraction and RAPD - PCR. A total of 300 samples were collected from 6 station along the coastline. Two out of six primers showed positive results namely GCG - ATC - CCC - A (Primer 1) and GTC - CAC - ACG - C (Primer 5) which were in accordance with morphometric analysis. The number of bands in the two above - mentioned primers in Khor - Tang and Chabahar station (Province of Sistan and Balouchestan) was significantly different from the number of produced bands in Dayer and Bushehr station (Province of Bushehr) as well as Gheshm and Bandar - Lengeh station (Province of Hormozgan). The cluster analisys was used to confirm the above variations. The results showed that the oyster population can be divided into two separate clusters. The first cluster included Bushehr Dayer Gheshm and Bandar - Lengeh species. The second cluster included Khor - Tang and Chabahar species. The analysis also showed that the first cluster can be divided into two Sub — cluster. Bushehr and Dayer belong to one Sub - cluster whereas Gheshm and Bandar - Lengeh form the other Sub — cluster. The formation of different vluster can be related to Physico - Chemical properties of water and climatic variations in different habitats along the Persion Gulf and the Sea of Oman. Key words: Molecular genetics, Population, RAND, PCR' Saccostrea cucullata

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In Iranian Coastline water of Persian Gulf we researched about flat fishes and revision their Scientitic names, Investigated diversity species (Pleuronectiformes) around three provinces such as khouzestan, Bushehr and Hormozgen. The aim focuse on introducting major family and Species Identification for this Purpose 1311 Specimens collected. Then 36 investigation Parameters includes 18 Morphometric, 11 meristic, 7 distribution has been measured in Excel. The descriptive statistic in spss software would be able us to graph dendrograms by Clustering methods, then Design a standerd table and comparised all the datas with it six major family has been found in Iranian Coasline which named: Soleidae, Bothidae Paralichtidae, Cynoglossidae, Psettodidae, Citharidae. Some of the scientific species names such as Pseudorombus arsius, P. annulatus, P. elevatus, P.malayanus, P. triocellatus from Bothidae family Join it to Paralichtidae family and Eurylossa orientalis change It's name from Soleidae family to Brachirus onentalis. Cynoglossus, bilineatus, C.Puncticepts, C.durbaensis, Clachneri, one of the most Important Point that viewed in our samples, founding a new species (C.Sp) Which we couldn't identify it with all the known keys, then sent it to international Scientific references for this porpose. (Family Cynoglossidae); Pseudorombus annulatus, P. elevatus P.arsius, P.malayanus, paralichtodes algoensis, Poecilopstei Javanicus (Family paralichthidae) Arnoglossus aspilos,A.arabicits, Engyprosopon grandisquama, L.pectoralis, Pseudorombus navalensis, Psettina brevirictis (family Bothidae); Psettodes erumei (Family Psettodidae); Citharoides macrolepis (Family Citharidae) in khouzestan Brachirus orientalis, Parachirus marmoratus, solea elongata, Zebrias synapturides (Family Soleidae) Cynoglossus bilineatus, C.puncticeps, C.arel, C.kopsii, C. Capenis (Family cynoglossida); Pseudorombus arsius, P. elevatus, P. malayanus, Poecilopstei javanicus (Family Paralichthidae); Laeops guentheri, Arnoglossus aspilos, Engyprosopon grandisquama (Family Bothidae); Psettodes erumei (Family psettodidae) in Bushehr. Brachirus orientalis, Parachirus marmoratus (Family Soleidae); Cynoglossus arel, C.bilineatus, C.Puncticeps, C. lachheri (Family cynoglossidae); Pseudorombus arisus, P. elevatus, P. malayanus, Poecilopestie j avanicus (Family parlichthidae); Arnoylossus aspilos, A. arabicus, Laeopes guentheri (Family Bothidae); Psettodes erumei (Family Psettodidae); Citharoides macrolepis (Family Citharidae) In Hormozgan. Khozestan has the maximus diversity speices (26 species) and the minimum is Hormozgan (15 Speices). 13 species of five family has never reported inpersian Gulf but we identify them in our studies for the first time. We abserved 29 Species of six family in our studies, comparision between are resualts with other researches shows that this use is the most compelet study in Iranian coastline water of Persian Gulf.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The pharaoh Cuttlefish (Sepia Pharaonis) is the most abundant species in the persian gulf and oman sea. The stock patterns of this species was studied conserning biological, morphological and electrophoretical aspects. In addition to measuring the biological patterns; 21 quantitative and qualitative factors were measured or counted. There tissues namely muscle, eye and liver were also used for further polyacrylamide electrophoresis analysis (SDS-Page method). The densitograms of protein bands of each tissue were prepared by Gel-Scanner and also the amount of bands' areas were estimated. The results of LSD test showed that tentacle length (TL), Tentacle club length (TCL) and TCL were indicative factors which they showed significant difference between male TL and female specimen of Bushehr and Balouchestan regions. Regarding to length and weight frequencies data the results indicated that males are always bigger than females and also, the cuttlefishes of the gulf of oman are bigger than persian gulf's samples. There were found a significant sample correlation (95%) between different quantitative parameters and the most correlation (0.963) was found to be between TL and TCL; whereas the less correlation (0.384) was observed between GL and LA3. However the gill length factor illustrated the less correlation with the other factors. The results of Cluster analysis for both sexes showed that the cuttlefishes of both studied regions belongs to seperate stocks. The electrophoretic experiments of proteins showed that the protein bands of the sample tissue of muscle and eye from both sampling areas revealed significant differences; whereas the tissue of liver wasn't recognized as an indicative tissue for population studies. Taking into consideration the findings of the present study including: (1) difference in spawning season, (2) results of dendrograms, (3) observed Significant differences in one-way analysis of variance (ANOVA) for morphometric measurements, (4) differences in body length and weight, (5) ecological variations of the persian gulf and oman sea, (6) as well as the results of electrophoresis of proteins have indicatend that: "The Pharaoh cuttlefishes of Bushehr and Balouchestan waters belong to two seperate stocks. Also, it is believed that each region has propably two different populations and more studies are needed to approve this result.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

One of the most important marine ecologic phenomenon , is the study of animal community among the bed or benthic fauna. Macrobenthoses are the graet part of the benthic faune , that are more biomasses than meiofauna and microfauna. To study polychaetes diversity of Mangroves, located in Khoore-Khooran , sampling was conducted on a bimonthly and carried out from December 2001 to October 2002. Bottom samples were collected by Van Veen grab (0.025 m2)at 6 station from 2 transect Insitu measurement of temperature , pH , Do and salinity were done . Atotal of polychaetes werw identified within study 32 Family and 43 Genus . Cirriphormia and Nephtys were the most dominant genus in the studies . The range fomumerical abundance of polychaets was between 3006 per m2 in the station A3 to 559individual per mein the station A1 and the variation was done to different bottom , texture the variable environment conditions govrtneng the different parts of each creeks as well as within creeks . Application of diversity indices (Shannon H') on the dominant polychates assambladges has higher H' in the Azar and lower 1-1/ in the Mehr . and the stations B3 has the highest H' and the station A2 has the lowest H' Application of diversity and Richness, Evennes were studied and showed that the station A3 has the lowest evenness and the most individual , and station A1 has the middle pollution.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Most of the earth's ecosystems are experiencing slight to catastrophic losses of biodiversity, caused by habitat destruction, alien species introduction, climate change and pollution (Wilcove et al., 1998). These human effects have led to the extinction of native fish species, the collapse of their populations and the loss of ecological integrity and ecosystem functioning (Ogutu-Ohwayo & Hecky, 1991; Witte et al. , 1992a; Mills et al., 1994; Vitousek et al., 1996). Food webs are macro-descriptors of community feeding interactions that can be used to map the flow of materials and nutrients in ecosystems (Jepsen & Winemiller, 2002). Comparative food web studies have been used to address theoretical questions such as 'does greater trophic connectivity increase stability?' (Cohen et al., 1990), and 'does the number of trophic levels increase with productivity?' (Briand & Cohen, 1987). Answers to such questions have obvious applications for natural resources management. From a multi-species fisheries standpoint, there is a need to understand consumer-resource dynamics within complex trophic networks.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A great part of Uganda is endowed with water bodies in the forms of rivers and open water lakes. These bodies are never alone. They are either flanked or associated with plants, which are adapted to the wet conditions. They are so characteristic that they are part and parcel of the aquatic ecosystems. They occupy various positions depending on the amount of water in the relevant habitats.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Biological diversity of an ecosystem is considered a reliable measure of the state of health of the ecosystem. In Uganda's large lakes, the Victoria and Kyoga, the past three decades have been characterized by profound changes in fish species composition following the introduction of the piscivorous Nile perch (Oguto-Ohwayo 1990). Over 300 haplochromine cichlid species comprising a wide range of trophic groups were lost along with a host of non-cichlid fishes which occupied virtually all available ecological niches and in the lakes (Witte 1992). A second major ecological event has been the gradual nutrient enrichment of the water bodies (eutrophication) from diffuse and point sources, while at the same time pollutants have also gained entrance into the water systems in pace with indusfrial development and human population increases in the lake basins. Eutrophication and pollution have drastically altered the physical and-chemical character of the water medium in which different fauna and flora thrive. In Lake Victoria these alterations have resulted in changes of algal species composition from pristine community dominated by chlorophytes and diatoms (Melosira etc) to one composed largely of blue-green algae or Cyanobacteria (Microcystis, Anabaena, Planktolyngbya etc) (Mugidde 1993, Hecky 1993).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Aquatic macro-invertebrates encompass all those organisms that be seen with unaided eyes. Most macro-invertebrates are categorised as semi-aquatic in that they are aquatic in early stages, but live as terrestrial organisms as adults, while others like gastropods, bivalves, Oligochaetae, Hirudinae and ostracods are exclusively aquatic. Some of them such as mayflies lay eggs in water and subsequent stages also live in water until adulthood when they emerge to live a terrestrial life. In others, eggs are laid near the water, while some like members of Tendipedidae (midges) lay their eggs on the leaves of aquatic macrophytes and after hatching their larvae creep into water

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Introduction of exotic fish species especially the Nile perch Lates niloticus, is believed to be responsible for the decline of fish species diversity in lakes Victoria, Kyoga and Nabugabo.About 60% of the haplochromine cichlids are thought to have become extinct from L. Victoria due to predation by the Nile perch. However there are many lakes satelite to the lakes Victoria and Kyoga basins which still have fish fauna similar to that of the main lakes. many of the satellite lakes are separated from the main lakes in, which Nile perch was introduced by extensive swamps that provide a barrier to Nile perch .A survey was carried out in a number of these satelite lakes and an inventory made of existing fish species. Their distribution and relative abundances were also determined. The lakes studied included Nawampasa, Nakuwa,Kawi Lamwa Gigate, Nyaguo, Agu, Nabugabo. Kayanja, Kaytigi, Mburo, Kachera and Wamala.Some habitats within the main lakes Victoria and Kyoga, especially those with rocky outcrops· and macrophyte cover that provide refugia for endangered species from Nile perch,were also surveyed) Various stations along the River Nile were also sampled to quantify the fish species that are still resent. Kyoga minor lakes were found to have the highest number of fish species especially of haplochromine cichlids. Many haplochromine trophic groups that were thought to be extinct from 1. Victoria still occur in these lakes.!Some of the satellite lakes, especially lakes Kayugi, Mburo and Kachera still contain .healili populations of oreochromis. I esculentus that could be used as brood stock in fish farming. Many of these lakes should .I ( I therefore be protected for conservation offish species diversity