7 resultados para Stahl-Urban Company.

em Aquatic Commons


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Although maritime regions support a large portion of the world’s human population, their value as habitat for other species is overlooked. Urban structures that are built in the marine environment are not designed or managed for the habitat they provide, and are built without considering the communities of marine organisms that could colonize them (Clynick et al., 2008). However, the urban waterfront may be capable of supporting a significant proportion of regional aquatic biodiversity (Duffy-Anderson et al., 2003). While urban shorelines will never return to their original condition, some scientists think that the habitat quality of urban waterfronts could be significantly improved through further research and some design modifications, and that many opportunities exist to make these modifications (Russel et al., 1983, Goff, 2008). Habitat enhancing marine structures (or HEMS) are a potentially promising approach to address the impact of cities on marine organisms including habitat fragmentation and degradation. HEMS are a type of habitat improvement project that are ecologically engineered to improve the habitat quality of urban marine structures such as bulkheads and docks for marine organisms. More specifically, HEMS attempt to improve or enhance the physical habitat that organisms depend on for survival in the inter- and sub-tidal waterfronts of densely populated areas. HEMS projects are targeted at areas where human-made structures cannot be significantly altered or removed. While these techniques can be used in suburban or rural areas restoration or removal is preferred in these settings, and HEMS are resorted to only if removal of the human-made structure is not an option. Recent research supports the use of HEMS projects. Researchers have examined the communities found on urban structures including docks, bulkheads, and breakwaters. Complete community shifts have been observed where the natural shoreline was sandy, silty, or muddy. There is also evidence of declines in community composition, ecosystem functioning, and increases in non-native species abundances in assemblages on urban marine structures. Researchers have identified two key differences between these substrates including the slope (seawalls are vertical; rocky shores contain multiple slopes) and microhabitat availability (seawalls have very little; rocky shores contain many different types). In response, researchers have suggested designing and building seawalls with gentler slopes or a combination of horizontal and vertical surfaces. Researchers have also suggested incorporating microhabitat, including cavities designed to retain water during low tide, crevices, and other analogous features (Chapman, 2003; Moreira et al., 2006) (PDF contains 4 pages)

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EXTRACT (SEE PDF FOR FULL ABSTRACT): The data of this paper differ from the Jones and Bradley papers [of 1982-1986] in that it represents an attempt to select thermal pollution free records rather than to include all available records. The specific long-term trends that this paper is trying to avoid are those illustrated by the heat islands of fast growing urban locations. One other major difference in this paper is that all of the records reported of this study are complete for the entire study period.

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Under a joint agreement the Government of Sri Lanka and the Nichiro Fishing Company of Japan have undertaken an experimental pole and line fishery around Sri Lanka with a view to determining the feasibility of establishing a joint commercial venture. 3 Japanese vessels conducted trials during the period March 1973-October 1974. Details of the vessels and cruises are given. A variety of fish were tried as bait, and the selection of appropriate bait is discussed. Catches and catch and effort statistics are presented, with tables showing distribution of the tuna. The results of the trials were below expectations, and are in part attributed to bait availability, and unfavorable weather conditions. Seasonal variation of the type of fishery is suggested in order to take account of this, and it is concluded that a fishery based on 45/50 ft combined pole and line and drift net fishing vessels might prove feasible.

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The paper discusses aquaculture practices on the three other high-value commodities which can be cultured as an alternative to shrimp. These species are grouper, mud crab and sea bass, it also discusses milkfish aquaculture practices.

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Bream (Abramis brava orientalis) is one of Cyprindae the Caspian Sea and its basin which has a special ecological, biological and economical role. Stock of this fish in the Caspian Sea has reduced during several years for different reason the over fishing, different industrial, agriculture, urban pollution and destroy of the spawning habitat. So that fishery company decided to recover the stock of this fish by the way of artificial reproduction of a Bream couple hunted from south coast of the Caspian Sea (Iran) and setting the fingerling to the rivers and inflow wetlands of the Caspian Sea.This activity has due to 20 tons Bream annual fishing in the Iranian South coast of the Caspian Sea (Gilan province coast and Anzali wetland), The artificial reproduction has decreased Bream population diversity of Caspian sea and Anzali wetland.So it has been declined to improve Braem population diversity by the entrance of Azerbijan republic Bream and encounter to the Caspian sea Bream. Meanwhile there is Bream in the Aras Dam Lake which had been forgotten by the Fishery Company of Iran .For this reason specifications morphometric, meristic and inter species Molecular Genetic have been surveyed in Anzali wetland,Southern coast of Caspian Sea ,Aras Darn Lake and Azerbijan republic during 2003-2005. According to the research on specifications of Morphometric and Meristic of Anzali wetland(120 species),Southern coast of Caspian Sea(90 species), Aras Dam Lake(110 species) and Azerbijan Republic(125 species)has Morphometric and Meristic differences. So that average weight and total length of Anzali wetland Bream respectively was 167 g and 23/76 cm, 102 g and 27/62 cm in Caspian Sea , 461 g and 3 5/38 cm in Aras Darn Lake and 3 4189 g and 15/21 cm in Azerbijan republic (We forced to use 1 year Bream of artificial reproduction in Iran). Also variation coefficient average Morphometric, Morphometric specification Ration and meristic in Anzali wetland Bream was 17/45, 21/56 and 4/63, in Caspian Sea bream 22/58, 15/27 and 3124, in Aras Dam lake Lake 17145. 1.5/27 and 3/57 and Azerbaijan republic Bream 22/29, 19/66 and 4/22. Also Bream of these four regions in general status had Morphometric significant differences based on One Way ANOVA Analysis. Meanwhile Anzali wetland Bream with Caspian Sea Bream from 41 Morphometric surveyed factors in 33 factors, with Aras Darn Lake Bream in 41 factors, with Azerbkjan republic Bream in 41 factors,Caspian Sea Bream with Aras Darn Lake Bream in 36 factors,with Azerbijan republic B ream in 40 factors and A ras Dam L ake Bream with Azerbijan republic Bream in 38 factors had significant statistical differences. These four regions Bream had differences according to the Morphomertric specification ration based on One Way ANOVA Analysis. Also Anzali wetland Bream was surveyed with Caspian Sea Bream from 37 factors i n 27 factors, Anzali wetland Bream with Aras Dam 1ake in 37 factors Anzali wetland Bream with Azerbijan republic Bream in 32 factors,Caspian sea bream with Arsa Dam Lake Bream in 26 factors, Caspian Sea Bream with Azerbijan republic Bream in 29 factors and Aras Dam Lake Bream with Azerbijan republic Bream in 34 factor had significant statistical differences. Based on Meristic factor of four regions bream in 16 surveyed factors in 10 factors had meaningful differences according to the One Way ANOVA Analysis. While Anzali wetland Bream was surveyed with Caspian Sea Bream from in 3 factors,Anzali wetland Bream with Aras Dam lake in 8 factors,Anzali wetland Bream with Azerbijan republic B ream in 6 factors,Caspian Sea bream with Arsa Dam Lake Bream in 6 factors,Caspian sea Bream with Azerbijan republic Bream in 3 factors and Aras Dam Lake Bream with Azerijan republic Bream in 8 factor had significant statistical differences.Meanwihle based on Factor Analysis and Discriminant Breams had differences. Also according to the resrarchs Anzali wetland Bream in 0+ age group till 5+ (6 age groups),Caspian Sea bream in 1+ - 5+(5 age groups),Aras Darn Lake Bream in 1+ - 7+ (7 age groups) and Azerbijan republic Bream for Morphometric and Meristic studies in 1+age group and for molecular Genetic reaserch were in 8+and 9+ age groups. According to the research 4 ecosystems Bream in status of same age, Aras lake Bream were bigger according to weight and length.Also in this research genetic diversity between four population was researched by PCR-RFLP technic on a piece of mitochondrion genome with the length of 3500bp contain of tRNA-leu,tRNA-glu,ND5/6,Cytb. Between 17 used enzyme. 4 enzyme, Dral, Bc11, Haefll and Banff showed diversity in totally 6 composite haplotype was detected. Maximum nucleotide diversity by the value% 0/58 in Azerbijan republic Bream by all haplotype. Aras darn Lake Bream had 2 haplotype and nucleotide diversity of %0/35.Anzali wetland and Caspian Sea Bream had no diversity. Statistical analysis by the usage of Monte Carlo with 1000 repeat showed significant differences between Azerbaijan Bream and other Bream(P<0/0001) but there was no significant difference between 3 regions Bream(P>0/5).