5 resultados para Pest control and treatment of diseases. Plant protection

em Aquatic Commons


Relevância:

100.00% 100.00%

Publicador:

Resumo:

The dry powders of four local species namely Piper guineense Schum and Thonn, Aframomum melegueta Schum, Zingiber officinale Rose; Capsicum annum Miller at three concentrations of 15g, 20g and 25g.kg were evaluated for their insecticidal effects against the larval of the dried fish weevil Demestes maculates Degeer. All the four species showed some effectiveness with P. guineense given a 100% mortality at the end of 72 hours at the three concentrations. The other species though gave less mortality were able to slow down the rate of development of the larvae to the adult size

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Venomous Indo-Pacific lionfish (Pterois miles and P. volitans) are now established along the Southeast U.S.A. and parts of the Caribbean and pose a serious threat to reef fish communities of these regions. Lionfish are likely to invade the Gulf of Mexico and potentially South America in the near future. Introductions of lionfish were noted since the 1980s along south Florida and by 2000 lionfish were established off the coast of North Carolina. Lionfish are now one of the more numerous predatory reef fishes at some locations off the Southeast U.S.A. and Caribbean. Lionfish are largely piscivores that feed occasionally on economically important reef fishes. The trophic impacts of lionfish could alter the structure of native reef fish communities and potentially hamper stock rebuilding efforts of the Snapper –Grouper Complex. Additional effects of the lionfish invasion are far-reaching and could increase coral reef ecosystem stress, threaten human health, and ultimately impact the marine aquarium industry. Control strategies for lionfish are needed to mitigate impacts, especially in protected areas. This integrated assessment provides a general overview of the biology and ecology of lionfish including genetics, taxonomy, reproductive biology, early life history and dispersal, venom defense and predation, and feeding ecology. In addition, alternative management actions for mitigating the negative impacts of lionfish, approaches for reducing the risk of future invasions, and directions for future research are provided.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In this study, which has been done in Hormoz larve Hatchery at Kohestak in Minab at 1385, the efficiency of Ergosen and Vibromax vaccine and the effect of them on growth factors such as total length, Carapase, dry weight and the number of upper mordents of rostrum and survival of the stages of larvae and post larvae of Indian white shrimp was studied. Thus in order to comparison the effects of Vibromax and Ergosen, each of them separately, in one treatment, and in another simultaneously with one control treatment was used. Vaccination against larvae shrimps was done through Artemia. This study used four treatments with three replicates in a completely randomized design and comparison of means was done through Duncan test. Breeding larvae and post larvae of Indian white shrimp from zoa I stage to PL 15 was done in 20 litter plastic buckets. Present results indicated that the highest amount of growth and survival factors in larvae stage (from zoa to PL1), and also in stages of PL5 and PL15, in the treatment of Ergoson effect + vaccine and it was with a little difference from that treatment of Ergoson effect which was in high significance difference in regard to control treatment at α<0.01 level and treatment of vaccine effect and control treatment at α<0.01 level often have no significant difference. This research used environmental stress tests to study the quality of post larvae under experiment. Studying in this field showed that feeding vaccine to larvae of Indian shrimps which was done through Artemia nauplii enrichment ,and ergosen , in treatment of ergosen vaccine lead to more resistance of post larvaes against salinity stress tests and formalin .This case was observed in every three stages ,so that in stress formalin test 100 parts per million and also 10 and 20 salinity parts in thousands the most survival was observed in treatment of Ergosan effect+vaccine and after that in treatment of Ergoson effect and with a little difference in treatment of vaccine effect. Of course this case, in treatment of Ergoson effect + vaccine due to the synergistic properties vaccine with Ergoson was more than to other treatments, while every three treatments, in most stages had significant difference toward control treatment at α<0.01 level and the control treatment because of not having Ergoson and nauplii artemia with vaccine, having the least survival rate in this stages.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Making use of sea, as a place for dumping of wastes and other materials from human activities wasn’t forbidden before creation of the convention on the prevention of marine pollution by dumping of wastes and other matters (London Convention). Therefore, industrial countries, without any specific consideration, were dumping their wastes into the world’s seas. Many years and before the beginning of rapid development of industry, the great self- purification of seas were preventing some of discharging problems. But gradually, the increase of industrial development activities, exceeded the production of wastes and other matters, and this led to the misuse of world’s seas and oceans as a dump site. One of the most important consequences of 1972 Stockholm World Conference was to focusing world attention on threats have jeopardized marine environment balance. World countries` leaders committed in Stockholm to begin protecting the environment. Finally, this movement at marine environment section led to the creation of London Convention in the same year. London Convention was concluded for cooperating between countries at December 29, 1972 to promote effective control of all marine environment polluting resources and to prevent marine pollution by dumping wastes and other matters. Then it was opened for signature to other countries. At last, after 15 states signature, this convention was entered in to force at August 30.1975. Ratification and execution of London Convention resulted in coordinated performance of countries in marine waste management. Common actions with supports and cooperation of different international, regional, governmental and non-governmental organizations and agencies prevent marine pollution by dumping of wastes and other matters. Due to the importance of wastes in our marine and coastal areas, investigation of the performance of London Convention can identify the lack of regulations and lack of regulation supports about marine pollution prevention by dumping of wastes and other matters in Iran. Considering this issue, proper protection of seas will be achieved. London Convention has been studied here to achieve intended purposes. In first chapter, generalities about marine environment, including the importance and necessity of marine environment protection, with the focus on some internal and international resources of environmental law accompanying with marine pollution and its recourses, and finally, due to the study theme, dumping of wastes and other matters at seas with its impacts have been investigated .In the section of international measures, a brief history of marine pollution and marine environment international law with international law framework, exclusively for controlling of wastes and other material discharge at seas and oceans has been reviewed. In second chapter, obligations, amendments, and annexes of London Convention have been investigated and classified. The obligations have been categorized in to legal obligations and technical and organizational obligations. In former section, subject ,purpose, territory, exceptions, rights and duties of parties, convention amendments,… and in latter, special requirements for wastes assessment, determination of pollutants` permissible limit, site selection and type of discharge selection, design principles for marine environment quality monitoring program, and discharge license issuance mechanism have been studied. In third chapter, due to the examination of convention performance in Iran, the internal law system for marine environment conservation and its pollution has been mentioned in detail. Considering this, two issues have been compared .firstly, convention obligations with regional treaties that Iran as a party to them and secondly, Iranian internal law there of .Finally, common and different aspects of these issues have been determined. At last, recommendations and strategies for convention enforcement and conformity of its obligations with internal regulations have been presented. Furthermore, translation of convention English text has been reviewed and its protocol has been translated.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Fish cage culture is a rapid aquacultural practice of producing fish with more yield compared to traditional pond culture. Several species cultured by this method include Cyprinus carpio, Orechromis niloticus, Sarotherodon galilaeus, Tilapia zilli, Clarias lazera, C. gariepinus, Heterobranchus bidorsalis, Citharinus citharus, Distochodus rostratus and Alestes dentes. However, the culture of fish in cages has some problems that are due to mechanical defects of the cage or diseases due to infection. The mechanical problems which may lead to clogged net, toxicity and easy access by predators depend on defects associated with various types of nets which include fold sieve cloth net, wire net, polypropylene net, nylon, galvanized and welded net. The diseases problems are of two types namely introduced diseases due to parasites. The introduced parasites include Crustaseans, Ergasilus sp. Argulus africana, and Lamprolegna sp, Helminth, Diplostomulum tregnna: Protozoan, Trichodina sp, Myxosoma sp, Myxobolus sp. the second disease problems are inherent diseases aggravated by the very rich nutrient environment in cages for rapid bacterial, saprophytic fungi, and phytoplanktonic bloom resulting in clogging of net, stagnation of water and low biological oxygen demand (BOD). The consequence is fish kill, prevalence of gill rot and dropsy conditions. Recommendations on routine cage hygiene, diagnosis and control procedures to reduce fish mortality are highlighted