Transmission of Vector Borne Diseases

<div class="MsoNormal"> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZZotP71Md7vSjN8tpLeX-RH45vbOl0i_0Zp7zPlQpBZAU5Rp_MiGCG4VaGRzYnwfeD3Fz4a5hha3or-Y1Nn6DN5uzesGhyphenhyphenbyjwZvRgwbEbQ27Etuf5WCuRksPXyAxs7m-agWd5qsvet3k/s1600/vector-borne-diseases-in-bangladesh-8-638.jpg" imageanchor="1" style="clear: left; float: left; margin-bottom: 1em; margin-right: 1em;"><img border="0" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjZZotP71Md7vSjN8tpLeX-RH45vbOl0i_0Zp7zPlQpBZAU5Rp_MiGCG4VaGRzYnwfeD3Fz4a5hha3or-Y1Nn6DN5uzesGhyphenhyphenbyjwZvRgwbEbQ27Etuf5WCuRksPXyAxs7m-agWd5qsvet3k/s320/vector-borne-diseases-in-bangladesh-8-638.jpg" width="320" /></a></div> <b><u><span style="font-size: 14.0pt; line-height: 115%;">What is means to be vectorbrone diseases?</span></u></b><u><span style="font-size: 14.0pt; line-height: 115%;"><o:p></o:p></span></u></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></u></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                             <b><span style="color: #111111;">The disease transmitted from one individual to another by a vector</span></b><span style="color: #111111;">.</span> Vector may be vertebrate like dogs, birds or invertebrate like mosquitoes, sand flies, flies and cockroaches. The major requirements those should be fulfilled for transmission of vector borne disease are presence of parasite, vector and host. But in some diseases reservoir host is also involved. Ex: Pigs for Japanese Encephalitis. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">What are the factors those accelerate the transmission of vector borne diseases? <o:p></o:p></span></u></b></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></u></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                             <b>Urbanization</b>: Unplanned and uncontrolled urbanization in urbanize areas in developing countries, it causes serve health problems. As a result of higher consumption, waste generation is also increased.  Therefore it creates the habitats for vectors. Derange which is blocked with waste are ideal place for <b><i>Culex</i></b> mosquito breeding. Water accumulated containers like coconut cells, plastic cans, tins, discard tires and flower vases are preferable breeding place for <b><i>Aedes</i></b> mosquitoes.  Dirty and unclean condition in house prepares the habitats for rats. As a result of high population density, there is high probability to transmit disease from one individual to another rapidly. Migration of people from emerge area to none emerge areas also transmits the diseases because people in non emerge areas have no immunity for such diseases come from outside. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                             <b>Climate change</b>: As a result of global warming, climate and whether patterns are changed. So the world experiences long period of rainy seasons and long period of dry seasons. During dry season, eggs of mosquitoes hatch rapidly and larva emerges into adults rapidly. Adults are died within a short time period. Therefore life cycle of the mosquitoes is shortened.  Biting frequencies of mosquitoes also increase.  During wet season, density of the vegetation is increased. So it offers more resting sites for vectors. Continuous rain also supports to improve the both quality and quantity of the breeding sites. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                             <b>Agriculture</b>: forested areas are converted into agricultural areas. People tend to spend their most of the time in their agricultural lands. So they are exposure vectors easily. Rice fields are ideal breeding sites for the <b><i>Culex </i></b>mosquitoes due to high organic matte content. As a result of wells for agriculture and dam construction, moving water is converted into non moving water stagnant water. It is ideal place for <b><i>Anophline </i></b>mosquitoes breeding.  Since most of farmers in developing countries have lower income and less immunity for diseases, they are more prone to vector borne diseases. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                <b>Deforestation and forest related activities</b>- The conversion of forested area into human settlement, agriculture lands, and the vectors are persuaded to migrate into urbanize areas.  Deforested areas offer breeding places for vector with low salinity and low acidity compare to those in forested areas. People who worked with forest related activities like mining, collecting medicine and extracting woods are exposure vectors easily. Ex: Vectors of Yellow fever and Malaria. The first person who suffered from coetaneous Leishmaniasis was reported in Sri Lanka worked in a forest logging. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                <b>Excess usage of insecticides</b>:  As a result of excess use of insecticides, mosquitoes become resistant. So application of insecticides for controlling vector borne diseases is less effective. As an example, emerge of malaria in mid 1900 centaury in Sri Lank caused serve loss of population. So DDT was applied to kill <b><i>Anophiline</i></b> mosquitoes. Then reported cases were dropped down to near zero. But after few years, reemergence of Malaria was taken place due to less considering of the government to control and surveillance. So DDT was applied again to kill <b><i>Anophline</i></b> mosquitoes but it was not effective because mosquitoes become more resistant to DDT due to the excess usage. Then Malathine was introduced to kill <b><i>Anophilne</i></b> mosquitoes. Same thing was happen. Mosquitoes became resistant to Malathine.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                <b>Animal husbandry</b>: It offers addition feeding for mosquitoes. Therefore mosquitoes population is rapidly increased which may result in increase feeding frequencies on the human. Those animals also act as the reservoir host for some disease. Ex: Pigs for Japanese Encephalitis.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">What are the impacts of the vector borne diseases? </span></u></b><span style="font-size: 14.0pt; line-height: 115%;"><o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoListParagraphCxSpFirst" style="margin-left: 10px; mso-list: l1 level1 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">1)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Emergence of vector borne diseases in developing countries, the government has to be pumped more money on the health to control and treatment for the diseases. So it has to be spending money health rather than development. It cause economic drop down in country. <o:p></o:p></span></div> <div class="MsoListParagraphCxSpFirst" style="margin-left: 10px; mso-list: l1 level1 lfo1; text-indent: -.25in;"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 5px; mso-list: l1 level1 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;"> 2)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">As a result of serve vector borne diseases work flow of a country is reduced.  Beside the economic, thousand of human lives are lost once. If the householder suffers form a disease, he has to rest in home without going to his job for long time period. It causes the falling down of economic level of a family. Since most of people are low income in the developing countries, they are pushed into further poverty because they have to spend most of their money on health rather their other requirements. <o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 10px; mso-list: l1 level1 lfo1; text-indent: -.25in;"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 5px; mso-list: l1 level1 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;"> 3)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Outbreaks of vector borne disease among animal husbandry causes serve lose of economic burden. It causes loss of life of animals. It reduces meat yield, eggs and milk yields.<o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast"> <br /></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">How to control prevent the reemergence of vector borne diseases?<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></u></b></div> <div class="MsoListParagraphCxSpFirst" style="mso-list: l0 level1 lfo2; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">  1)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><b><span style="font-size: 14.0pt; line-height: 115%;">Biological control</span></b><span style="font-size: 14.0pt; line-height: 115%;">: It is always considered as the best method for controlling vectors among other methods. The cost is less compare to the chemical control. Ex: Cats can be used for controlling of rats. Larvivorus fishes are used for controlling mosquito’s larvae. <o:p></o:p></span></div> <div class="MsoListParagraphCxSpFirst" style="margin-left: 10px; mso-list: l0 level1 lfo2; text-indent: -.25in;"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoListParagraphCxSpMiddle" style="mso-list: l0 level1 lfo2; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">  2)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><b><span style="font-size: 14.0pt; line-height: 115%;">Maintenance of the environmental hygiene</span></b><span style="font-size: 14.0pt; line-height: 115%;">: It helps to prevent or minimize the mosquitoes breeding. Maintenance of cleaning condition in households helps to avoid offering breeding places for rats. Proper waste management prevents the formation of breeding places for mosquitoes breeding. The prevention of rainwater accumulation in discard materials also dis-encourages the mosquitoes breeding. <o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="mso-list: l0 level1 lfo2; text-indent: -.25in;"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <br /> <div class="MsoListParagraphCxSpLast" style="mso-list: l0 level1 lfo2; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">  3)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><b><span style="font-size: 14.0pt; line-height: 115%;">Mass chemotherapy</span></b><span style="font-size: 14.0pt; line-height: 115%;">: Use of chemical treatment for killing parasite is easier than the killing vector because parasites live in the human body. But vectors live in the all over the environment. So it is difficult to apply insecticides to each and every vector. It is important to finish entire chemotherapy course until the end unless some stages of parasite remain in the body become resistant. <o:p></o:p></span></div> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-65880709-1', 'auto'); ga('send', 'pageview'); </script>

Transmission of Vector Borne Diseases

What is means to be vectorbrone diseases?                              The disease transmitted from one individual to another by a vector. Vector may be vertebrate like dogs, birds or invertebrate li…

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Sanitary Landfill as the Best Solution for Solid Waste Management

<div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">With the highest growth of population, higher consumption causes higher waste generation in the world. People tend to dispose their waste over there without caring about the environment.  It causes air pollution, water pollution, soil pollution, degrading aesthetic value of environment and proliferation of scavenging animals and vectors. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">What is meant to be a sanitary landfill?<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></u></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                     Waste is disposed in an engineered designed site to avoid negative consequences of the open dumping of the waste.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">What are the major components of sanitary landfill?<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></u></b></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(1)Linear system- </span></b><span style="font-size: 14.0pt; line-height: 115%;">It act as the barrier between the environment and waste pile in order to prevent derange of leachate into surrounding soil and ground water table.<b> <o:p></o:p></b></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(2) Leachate collection and monitoring system</span></b><span style="font-size: 14.0pt; line-height: 115%;">- It collect the leachate that is produced within and bottom from the waste pile and treated by using appropriate techniques.  The leachate is taken into a retention pond or treatment plant. Lechate is degraded thermo chemically or biologically. Then it is taken into wetland. Here filter bed like <b>Hapu pan</b> is used to remove the removing traces such as heavy metal.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(3) Gas collection and monitoring system</span></b><span style="font-size: 14.0pt; line-height: 115%;">- It collect the gas that is produced within and from the top of the waste pile. Then gas is also treated.  The landfill gas is used as the renewable energy. It can be directly used for home for lighting, cooking and heating. Landfill gas is also used to electricity generation. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(4)Surface water derange system</span></b><span style="font-size: 14.0pt; line-height: 115%;">- Since it collect all surface runoff water, it reduce the leachte production. It also prevents the rainwater contamination.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(5) Cover system-</span></b><span style="font-size: 14.0pt; line-height: 115%;"> At the end of each and every work day, daily cover has to be applied. Final cover is applied at the end of active period of the sanitary landfill. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <br /> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(6) Ground water and environmental monitoring system</span></b><span style="font-size: 14.0pt; line-height: 115%;">-  To prevent negative consequence on the environment, ground water quality, air quality, surface water quality is examined once a month</span>. <o:p></o:p></div> <div class="MsoNormal"> <br /></div> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQj-yzkwp9_0VSAzooc-RqYCuOSkFlAx-qbP3MT32GbNigILxBAnQj6SLUIKOG8QFxpMU_EjhDJ6xtr7pV-Z_o6Ox0EKkBn-QyA25Qe0Cv6Jda7PCZsX8iPD07QxjbsWXIztcHR2nM9dEQ/s1600/system+ground+water+and+enviroment+mmoniter.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="338" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjQj-yzkwp9_0VSAzooc-RqYCuOSkFlAx-qbP3MT32GbNigILxBAnQj6SLUIKOG8QFxpMU_EjhDJ6xtr7pV-Z_o6Ox0EKkBn-QyA25Qe0Cv6Jda7PCZsX8iPD07QxjbsWXIztcHR2nM9dEQ/s640/system+ground+water+and+enviroment+mmoniter.gif" width="640" /></a></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">Advantages of sanitary landfill over open dumpsite or control dump site<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                                  Since the bottom of the landfill is covered with a linear system, it prevents derange of lechate. So fertility of the soil is persevered. pH does not change. Metals in the soils do not mobile. Quality of the groundwater table is preserved.  After proper treatments, reaming water is released into the natural environment. Therefore it supports to maintain hydrological cycle. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                                  The landfill gas is carefully removed from the waste pile so spontaneously burring of waste dose not happen. Those burning produce a dense smoke which contains particulate martial, heavy metals, SO2, NOx. It causes serve respiratory problems in the lungs. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                                  The daily cover prevents the solid materials blowing by winds. It also prevents unpleasant odor.  The waste martial dragged and dropped by birds to nearby homes are avoided.  Therefore health of the residents is not affected. It prevents the formation of breeding place for mosquitoes which act as disease transmitted agents. Ex: <b><i>Aedes </i></b>mosquitoes prefer rainwater accumulated containers.  Final cover supports the surface vegetation. Since it prevents water infiltrating after finishing active period, it reduce the lechate production. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                                  Surface water derange system collects all the surface runoff from the site and removes. Therefore it also reduces lechate production. It prevents the rainwater contamination.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                                  The land of the sanitary landfill is covered with an appropriate fence. It prevents the entering of scavenging animals like cats, dogs, cow and rats. So it prevents the proliferation of animals and spread of disease. Ex: Dogs and cats spread Rabies. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                                  Sanitary landfill has a tire wash plant for wqaste transportation vehicles. So debris bounded to the tires is prevented to spread into the nearby areas<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">.                                 The property value nearby residents is preserved near the sanitary landfill. Property value near open dump site is degraded.  Even nearby peoples tend to sell their properties and move into better areas.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                                  Health of the worker of sanitary land fill is maintained at a good level. Therefore their economic level dose not fails. But in the case of open dumpsite or control dumpsite, health of workers is very bad. They often suffer from skin disease, parasites and biting of scavengers. They have to be spending more money on their health. Therefore their economic level fails. They spend unpleasant life. <o:p></o:p></span></div> <div class="MsoNormal"> </div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                                  The life span of the sanitary landfill is higher than that of the open dumpsites depending on the size. After completed of active period of sanitary landfill, it can be gradually proceed into human usage with proper caring and maintenance like public parks. <o:p></o:p></span></div> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-65880709-1', 'auto'); ga('send', 'pageview'); </script>

Sanitary Landfill as the Best Solution for Solid Waste Management

With the highest growth of population, higher consumption causes higher waste generation in the world. People tend to dispose their waste over there without caring about the environment.  It causes a…

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Determination of primary productivity in freshwater ecosystem

<div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">Primary productivity is the major energy fixation in the freshwater ecosystem. According to the productivity, the lake is divided into vertical and horizontal strata. Dominant photosynthetic organisms are also differ one strata to other. Primary photosynthesis of littoral zone where is the shallow water of edge of lakes is contributed by macrophysics.  Primary photosynthesis of limentic zone where is the top of the water column is dominated by the phytoplankton and algae.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         Gross primary productivity (GPP) is the total amount of the food produced by photosynthetic organism in given time in a given area.  A part of the produced food is consumed for cellular respiration. After respiration, remaining of initial produced food is defined as the Net Primary Productivity (NPP). NPP is available for the increase of the biomass of organisms. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         Dissolved Oxygen (DO) is used as the index to predict the primary productivity of the freshwater ecosystems. Dark and light bottle method and C14 method are used for determination of DO.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">Dark and light bottle method<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                              Primary productivity of the lake is measured at different depths from the water surface in two hour time interval within the day. The procedure is done by as follows.<o:p></o:p></span></div> <div class="MsoListParagraphCxSpFirst" style="mso-list: l0 level1 lfo1; tab-stops: 78.75pt; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">   1)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Water samples are collected from following depth 0cm, 25cm, 50cm, 75cm and 100cm from the surface.<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="mso-list: l0 level1 lfo1; tab-stops: 78.75pt; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">   2)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">It is allowed the bottle to fill with water completely. As soon as the bottles are filled, glass stoppers are inserted into the bottles without air bubbles under the water. <o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="mso-list: l0 level1 lfo1; tab-stops: 78.75pt; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">   3)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">After water filled, initial bottles are collected.  The light bottles and dark bottles are tied and fixed in relevant depth for 2 hour period.<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="mso-list: l0 level1 lfo1; tab-stops: 78.75pt; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">   4)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">The DO in initial, light and dark bottles is determined by using the Winkler method. <o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast" style="mso-list: l0 level1 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">   5)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">The procedure is repeated for several time intervals.<o:p></o:p></span></div> <div class="MsoNormal" style="text-indent: .5in;"> <br /></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">Calculation<o:p></o:p></span></u></b></div> <div class="MsoNormal" style="text-indent: .5in;"> <span style="font-size: 14.0pt; line-height: 115%;">Initial bottles are used to determine initial DO in each time intervals. Since the dark bottles are covered by black coat, it is not allowed light to penetrate. Therefore photosynthesis does not happen in dark bottles. Only produced DO is consumed. Only cellular respiration (CRR) is taken place.  But in the case of light bottles, it is allowed light to penetrate. Therefore the photosynthesis is continued. So both photosynthesis and cellular respiration is also taken place in the light bottles.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                      CRR= (DO) initial- (DO) dark<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                      NPP= (DO) light-(DO) initial<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                      GPP= NPP+CRR<o:p></o:p></span></div> <br /> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                                           So GPP= (DO) light-(DO) dark<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"></span></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">The variation of primary productivity Vs depth<o:p></o:p></span></u></b></div> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7zNWp8GpE7lSui9nuUXFLqEWFICaCu5GxIPr4m7WKsxCYMCv-xmbtdSTwXRZZueP9Md99kLlPPqJx3qgRuGp8BVrdrXPxMSsxQLX2lhn1Gi20Lp6muum0brfeIci1ZASPFGQ115t0OUn-/s1600/productivty+vs+depth.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi7zNWp8GpE7lSui9nuUXFLqEWFICaCu5GxIPr4m7WKsxCYMCv-xmbtdSTwXRZZueP9Md99kLlPPqJx3qgRuGp8BVrdrXPxMSsxQLX2lhn1Gi20Lp6muum0brfeIci1ZASPFGQ115t0OUn-/s400/productivty+vs+depth.jpg" width="397" /></a></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></u></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">The maximum primary productivity is recorded slight below the surface due to the higher light intensity. It causes photo-inhibition of phytoplankton and reduces primary productivity.  Primary productivity is higher in the euphotic zone where the light penetration is taken place. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"> </span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                                      With the depth, transparency of the water column is reduced. So the light penetration becomes limited. Therefore primary productivity is decreased gradually downward.  Since the primary productivity is zero or limited in the bottom due to the absence of light, DO in the bottom are carried from the top layer by the water circulation. DO is consumed largely by decomposing organisms.<o:p></o:p></span></div> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-65880709-1', 'auto'); ga('send', 'pageview'); </script>

Determination of primary productivity in freshwater ecosystem

Primary productivity is the major energy fixation in the freshwater ecosystem. According to the productivity, the lake is divided into vertical and horizontal strata. Dominant photosynthetic organism…

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Mosquito Sampling Techniques

<div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">Adluts Sampling techniques<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(1)Landing collection</span></b><span style="font-size: 14.0pt; line-height: 115%;"><o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                            </span><br /> <div class="separator" style="clear: both; text-align: center;"> <span style="font-size: 14.0pt; line-height: 115%;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDe6pAZoGElmTwo_HRpPviFBv0oWD6Oj-Yx4gLhMQnWv2zzAonArXNAW4YUeM4JIfSiToAHW5Ehq2k1BB-mhZSRsnbvj-i5XQTc65D7aD-N8Ezmakit0gHn2AfVqDBWsWpOv592P753SbQ/s1600/mosquito-parts.gif" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="223" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjDe6pAZoGElmTwo_HRpPviFBv0oWD6Oj-Yx4gLhMQnWv2zzAonArXNAW4YUeM4JIfSiToAHW5Ehq2k1BB-mhZSRsnbvj-i5XQTc65D7aD-N8Ezmakit0gHn2AfVqDBWsWpOv592P753SbQ/s320/mosquito-parts.gif" width="320" /></a></span></div> <span style="font-size: 14.0pt; line-height: 115%;"> Adult mosquitoes lading on the people or animals are collected by using a vial and a polythene bag. So both zoophilic and anthopophilic misquotes can be collected. This method is used to study the biting time of mosquitoes. It is a labor consuming method. It is a time consuming method.  Diseases can be transmitted from mosquitoes into human body.<o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(2)Oviposition trap<o:p></o:p></span></b></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                             A jar with wide mouth is used as the oviposition trap.  The jar is painted in black color because mosquitoes prefer shady environments. It is used to attract gravid female mosquitoes of <b><i>Aedes</i></b> sp. Hey fusion is used as the attractor. Different species of <b><i>Aedes </i></b>mosquitoes can be attracted by changing the concentration of hey fusion. <b><i>Aedes</i></b> mosquitoes lay eggs dry surface around the sides of containers and plastic stick above the water level. Eggs have to be counted following day unless eggs hatch and larvae emerge.  It is a cheap method. Oviposition traps cannot be used for collecting other mosquitoes types expect <b><i>Aedes</i></b>. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(3)Resting box<o:p></o:p></span></b></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                            Resting boxes are made of a small wooden box which is covered with a black non reflective paper because mosquitoes attracts shady environment. Its outside is covered with a muslin cloth and one end is open.  There is high probability to mosquitoes be escape from the resting box. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(4) Sticky trap<o:p></o:p></span></b></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                              It is used to collect adult mosquitoes from the both outside and inside. It is paced in dark and shady places. Appropriate bait is used to attract the mosquitoes. It is very is to handle. It is not a labor consuming method. It is a time consuming method.  Mosquitoes can be damaged or died due to the stickiness.<o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(5)Pooter/Aspirator<o:p></o:p></span></b></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                                 Both adult female and male mosquitoes can be collected from their resting places by using pooter or aspirator. Resting palces are varying with the species. Resting place of <b><i>Aedes</i></b> mosquitoes is outside vegetation. Resting places for <b><i>Anophiline</i></b> mosquitoes is inside the houses.  Mosquitoes are drawn into the main chamber of the pooter by sucking at the mouth piece. Adult mosquitoes can be collected without any damage or minimum damage. It is a time consuming method. It is labor intensive. Diseases can be transmitted through the pooter to the user. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">Why it is very difficult to catch adult male misquotes?<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></u></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Since adult males are plant nectar feeders, they are usually caught from resting places in the vegetation by using pooter or aspiration because they can be attracted by female mosquitoes. Although female mosquitoes are also plant nectar feeders, they attract to human or animals in order fulfill their blood requirements for their eggs developments. Therefore adult female mosquitoes can be easily caught. <o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">Larvae sampling techniques<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></u></b></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(1)Siphoning<o:p></o:p></span></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                             Larva is extracted into a small tube according to a pressure gradient by siphoning. It is used to collect larva from small habitats such as tree holes. So it cannot be used for large habitats. Larval density cannot be determined. <o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(2)Pippeting<o:p></o:p></span></b></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                       It is used to collect larvae from small water bodies. So it also cannot be used to collect larvae from small water bodies. Larval density cannot be determined by using pipette.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(3)Dipping<o:p></o:p></span></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                       Larvae form the large water bodies are collected by using a scoop or a dipper. It can be used to collect larvae from different depth from surface.  Larval density can be determined by using dipping method.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">(4)Netting or funnel trap<o:p></o:p></span></b></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></b></div> <br /> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                       It is made of a nylon net which attached to iron ring. The iron ring is attached to a handle.  It used to collect larval from large water bodies like wells. It can be used to determine larval density.  Larvae from small habitats cannot be collected by using netting or funnel trap.<o:p></o:p></span></div> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-65880709-1', 'auto'); ga('send', 'pageview'); </script>

Mosquito Sampling Techniques

Adluts Sampling techniques (1)Landing collection                              Adult mosquitoes lading on the people or animals are collected by using a vial and a polythene bag. So both zoophilic an…

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Measurement of Transparency in Water

<div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">Transparency of the water is measured as the measure of turbidity. Turbidity of the water restricts the light penetration. It affects the primary productivity and distribution of organisms such as phytoplankton and fishes in the water column. Some organisms use their vision to find their food. They are interfered by the high turbidity.  Two types of turbidity are available in water such as organic turbidity and inorganic turbidity. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                              Organic turbidity is caused by dead organic materials (detritus), phytoplankton and zooplankton. Organic turbidity is considered as an index of primary productivity because higher the organic turbidity means higher number of photosynthetic organisms. So it increases the primary productivity. But since the photosynthetic organism tend to be retain near the surface in order grab maximum sunlight they restricts the depth which available for themselves to live. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         Inorganic turbidity is caused by suspended clay and slit particles. It reduces the light penetration through the water column. Therefore eventually altogether both organic turbidity and inorganic turbidity decreases the light penetration and reduces the space available for the life.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         Turbidity is measured by using two method such as sechi disk and seston weight method. <o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">Sechi disk<o:p></o:p></span></u></b></div> <br /> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                       It is a disk with 20cm diameter. It is dived into four quarts with altering black and white. The disk is lowered into the water aid in a thin rope. The depth where the white color quarts disappear is measured as the sechi depth. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqpMZvCaEO_expARrOP3CLhUcs_vFJfZl3spCLoftjrA6MUD6I0HNlXTpDVp5PLRRoU7BrggqKSXBLqHRUgjGcbUPc3IZBilCcEeJ3wIj5ukL4nq8l2-rqzHTAcuTw9R-WZH5YCdxIMig_/s1600/light+peneteration.PNG" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="288" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjqpMZvCaEO_expARrOP3CLhUcs_vFJfZl3spCLoftjrA6MUD6I0HNlXTpDVp5PLRRoU7BrggqKSXBLqHRUgjGcbUPc3IZBilCcEeJ3wIj5ukL4nq8l2-rqzHTAcuTw9R-WZH5YCdxIMig_/s640/light+peneteration.PNG" width="640" /></a></div> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">Disadvantages:<o:p></o:p></span></b></div> <div class="MsoListParagraphCxSpFirst" style="margin-left: 10px; text-align: left; text-indent: -0.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">1)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">It is not measured organic turbidity and inorganic turbidity separately. It gives reading of combination of organic turbidity and inorganic turbidity. <o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 10px; text-align: left; text-indent: -0.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">2)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Readings are user dependent because visibility changes person to person. <o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 10px; text-align: left; text-indent: -0.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">3)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Readings are influenced by external environmental factors such as solar intensity and waves.<o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast" style="margin-left: 10px; text-align: left; text-indent: -0.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">4)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">If it does not shrink straight, it does not give accurate readings. A weight is hanged to the bottom surface to direct the disk to shrink directly. <o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">Seston method<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         It supports to measure organic turbidity and inorganic turbidity both in quantity and quality. The procedure is done as follows. <o:p></o:p></span></div> <div class="MsoListParagraphCxSpFirst" style="mso-list: l1 level1 lfo3; tab-stops: 75.0pt; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "symbol"; font-size: 14.0pt; line-height: 115%;">·<span style="font-family: "times new roman"; font-size: 7pt; font-stretch: normal; line-height: normal;">        </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">The weight of nitrocellulose paper is weighed. (w1)<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="mso-list: l1 level1 lfo3; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "symbol"; font-size: 14.0pt; line-height: 115%;">·<span style="font-family: "times new roman"; font-size: 7pt; font-stretch: normal; line-height: normal;">        </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Known volume of water is filtrated through the filter paper. <o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="mso-list: l1 level1 lfo3; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "symbol"; font-size: 14.0pt; line-height: 115%;">·<span style="font-family: "times new roman"; font-size: 7pt; font-stretch: normal; line-height: normal;">        </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">The filtrate is dried at 80°c in an oven for 24 hours. Then weight of fitter paper and residue is weighed. (w2)<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="mso-list: l1 level1 lfo3; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "symbol"; font-size: 14.0pt; line-height: 115%;">·<span style="font-family: "times new roman"; font-size: 7pt; font-stretch: normal; line-height: normal;">        </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Total seston weight= (w1-w2)<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="mso-list: l1 level1 lfo3; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "symbol"; font-size: 14.0pt; line-height: 115%;">·<span style="font-family: "times new roman"; font-size: 7pt; font-stretch: normal; line-height: normal;">        </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">The filter paper and residue is burned in a Muffle Furnace at 450°-500°C for 12 hours.<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="mso-list: l1 level1 lfo3; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "symbol"; font-size: 14.0pt; line-height: 115%;">·<span style="font-family: "times new roman"; font-size: 7pt; font-stretch: normal; line-height: normal;">        </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Then weight of residue after burning is weighed.(w3)<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="mso-list: l1 level1 lfo3; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "symbol"; font-size: 14.0pt; line-height: 115%;">·<span style="font-family: "times new roman"; font-size: 7pt; font-stretch: normal; line-height: normal;">        </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Inorganic turbidity= w3<o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast" style="mso-list: l1 level1 lfo3; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-family: "symbol"; font-size: 14.0pt; line-height: 115%;">·<span style="font-family: "times new roman"; font-size: 7pt; font-stretch: normal; line-height: normal;">        </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Organic turbidity= (w1-w2)-w3<o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">Advantages:<o:p></o:p></span></b></div> <div class="MsoListParagraphCxSpFirst" style="margin-left: 10px; mso-list: l2 level1 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">1)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Readings are not influenced by eternal environmental factors.<o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast" style="margin-left: 10px; mso-list: l2 level1 lfo1; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">2)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Organic turbidity and inorganic turbidity can be measured separately. <o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <b><span style="font-size: 14.0pt; line-height: 115%;">Disadvantages:<o:p></o:p></span></b></div> <br /> <div class="MsoListParagraph" style="margin-left: 10px; mso-list: l0 level1 lfo2; text-indent: -.25in;"> <!--[if !supportLists]--><span style="font-size: 14.0pt; line-height: 115%; mso-bidi-font-family: Calibri; mso-bidi-theme-font: minor-latin;">1)<span style="font-size: 7pt; font-stretch: normal; font-variant-numeric: normal; line-height: normal;">    </span></span><!--[endif]--><span style="font-size: 14.0pt; line-height: 115%;">Errors are possible due to the instruments. <o:p></o:p></span></div> </div> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-65880709-1', 'auto'); ga('send', 'pageview'); </script>

Measurement of Transparency in Water

Transparency of the water is measured as the measure of turbidity. Turbidity of the water restricts the light penetration. It affects the primary productivity and distribution of organisms such as ph…

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Variation of Oxygen in freshwater ecosystem

<div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">Why Oxygen is important for life?<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></u></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         Oxygen is the one of the limiting factor for the life. Since most of the life forms are aerobic except few, they inhibit in the water with high Oxygen content. Vertical distribution of phytoplankton and fishes are influenced by the DO. So they are restricted to surface layers of the mot water body. When Oxygen is reduced to zero or limited aerobic life forms are replaced by anaerobic life.  <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                       Oxygen is essential for cellular respiration of aerobic life.  Some of anaerobic life forms are inactive until Oxygen is available again such as Chirognomid larvae. Animals which have Hemoglobin in the blood can tolerate for low Oxygen level because hemoglobin has ability to grab, store and transport four Oxygen molecules once into inner cells in the body. Ex: <b><i>Tubifex</i></b> sp<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">Variation in the lentic ecosystem<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;"><br /></span></u></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         Lentic ecosystems are the standing water bodies such as lakes, ponds, marshes and swamps. Dissolved Oxygen content (DO) is influenced by the temperature, community respiration and decomposition. Amount of Oxygen is determined by the diffusion, water circulation (water mixing) and photosynthesis. The rate of diffusion of Oxygen in the lentic ecosystem is less compare to the atmosphere.  Water circulation determines the vertical Oxygen distribution throughout the water column. <o:p></o:p></span></div> <br /> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                               Photosynthesis is varying according to the depth as well as time of the day.  Therefore amount of Oxygen produced by photosynthesis is also followed by such fluctuations and variations. In the morning photosynthesis and DO is less due to the less solar intensity. From morning to noon, photosynthesis and DO are high due to the increasing solar intensity. The highest DO and photosynthesis is recorded in the noon due to the maximum solar intensity. DO and photosynthesis are aging decreasing from noon to evening due to the decreasing solar intensity.  <o:p></o:p></span></div> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJ149QywUDk60x8ro31VEbwAS0GYvPToH3TnS9KfN1ZuAuRL70Z0LPENWzOP0H7ezjlvA60vUWMyDnbC99HjRCw4HsvXXCuPcAW_DRUb7SpxHv_7Peo2vceAIQehw_uBsuelsnqPG1pWPq/s1600/dissolved+oxygen.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="300" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjJ149QywUDk60x8ro31VEbwAS0GYvPToH3TnS9KfN1ZuAuRL70Z0LPENWzOP0H7ezjlvA60vUWMyDnbC99HjRCw4HsvXXCuPcAW_DRUb7SpxHv_7Peo2vceAIQehw_uBsuelsnqPG1pWPq/s400/dissolved+oxygen.jpg" width="400" /></a></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">When consider the variation of DO according to the depth, maximum DO is reported slight below the water surface because photosynthesis is limited in the surface due to the photo-inhibition of photosynthetic organisms.  Photosynthesis is reduced gradually due to the decreasing light penetration. But community respiration is high. So Oxygen is largely consumed by organisms. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         At the bottom of the deep lakes, Oxygen availability is limited or zero because photosynthesis is not taken place due to the absence of light. Community respiration is also high. But large amount of Oxygen is consumed by decomposing organism. Therefore bottom of the deep lake does not support aerobic life. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         But in the case of shallow lakes, DO is high in even bottom due the high light penetration. Plant growth can be found at the bottom. Therefore large amount of oxygen is produced. Although decomposition is carried out, DO does not become limited due to the high productivity. Therefore bottom of the shallow lake supports the aerobic life. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         When the solar intensity is increasing in the absence of strong winds, a temperature gradient is created from top to the bottom. Thermociline acts as a density barrier between warm surface water and clod bottom water. It causes water stratification and prevents water mixing. Therefore DO on the surface layer is not transported to bottom layer. So bottom layer interfere with limited Oxygen supply and cannot support aerobic life anymore. But suddenly wind action can break the stratification and start the water mixing. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"> </span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         Doing the some period of the year, surface temperature falls, bottom temperature and surface temperature become similar .Therefore since there is no density barrier, water starts to missing. Oxygen availability is high throughout the water column.  It supports aerobic life.</span></div> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEijSwkIC_xJo3wUJnQmChIJn7hQou5nLC8P4sln8fx7JR4-1ErJqyAwVgVqtrBDO8CaRMW7s8LW8fLA2RngFXd_poMTHf3sHMA4AyvM5pUZsvPCRnLXQJXZUzV-xREyp-647OaovQUoREdK/s1600/aerobic+life.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="327" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEijSwkIC_xJo3wUJnQmChIJn7hQou5nLC8P4sln8fx7JR4-1ErJqyAwVgVqtrBDO8CaRMW7s8LW8fLA2RngFXd_poMTHf3sHMA4AyvM5pUZsvPCRnLXQJXZUzV-xREyp-647OaovQUoREdK/s400/aerobic+life.png" width="400" /></a></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><br /></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">Solubility of Oxygen in the water is directly affected by the water temperature. If the water temperature is high, it reduces the Oxygen solubility in the water.  Low temperatures increase the Oxygen solubility. <o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <b><u><span style="font-size: 14.0pt; line-height: 115%;">Variation in loctic ecosystem<o:p></o:p></span></u></b></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                         Loctic ecosystems are moving water bodies such as waterfalls and rivers. Since lotic water bodies are shallow compare to the lentic water bodies, DO is high throughout the water column because plant growth can be found due to the high light penetration. Turbulence increases the DO.  Stratification is rarely occurred in lotic systems, water circulation is continuously carried out. Therefore availability o Oxygen throughout the water column is high.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;"><span style="font-size: 14pt;">                         </span><span style="font-size: 14pt;">Variation of DO is taken place from upper reaches to lower reaches. DO is near saturation in upper reaches due to the fat river flow and turbulence. DO is limited is less in lower reaches due to the low rate of photosynthesis because sedminets tend to deposit due to slow flow rate. It restricts the light penetration. </span><span style="font-size: 14pt;"> </span> <o:p></o:p></span></div> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-65880709-1', 'auto'); ga('send', 'pageview'); </script>

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Variation of Oxygen in freshwater ecosystem

Why Oxygen is important for life?                          Oxygen is the one of the limiting factor for the life. Since most of the life forms are aerobic except few, they inhibit in the water with h…

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Problems encounter in Aedes mosquito surveillance

<div class="MsoNormal"> <b><u>Why the results of Dengue mosquito surveillance are not very accurate?<o:p></o:p></u></b></div> <div class="MsoListParagraphCxSpFirst"> Assumptions:     All detrains are considered as containers.</div> <div class="MsoListParagraphCxSpFirst">                            All mosquitoes larvae are assumed as <i>Aedes</i> mosquitoes.</div> <div class="MsoListParagraphCxSpFirst"> <br /></div> <div class="MsoListParagraphCxSpLast" style="margin-left: 1.5in; mso-add-space: auto;"> <o:p></o:p></div> <div class="MsoNormal">                               <i>Aedes</i> surveillance are carried out during dry season, following mistakes/ errors are taken place.  Mosquito eggs are able to inactive for long time period till favorable conditions are returned. So there is high probability to results to be inaccurate.  <i>Aedes</i> misquotes are container breeders. They use clean and clear water for their eggs lying.  They also cannot be found in moving water. But some of detrains in the premises contain moving water. Therefore larvae found in the moving water cannot be <i>Aedes </i>larvae. Water containing organic matter from sinks are directed into detrains. Since <i>Aedes</i> larvae prefer clean and clear water, larvae found in organically polluted water cannot be <i>Aedes</i> larvae.  It is difficult to examine all containers in the premises. It is impossible to reach gutters and discard tires on the roof. Therefore results cannot be very accurate. The risk may be higher than the observed value. Due to the low risk, control measures may be not applied or not considered. <o:p></o:p><br /> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh11uW9SanHMkZh6DfquQhDaHPcv-0PNsJF-_6o4ze4VPpcMppjYFLGDMtJULdGdJSIjSa8vMiJhvlgU8E25jD4t-f2_rLSVVxp_CxecEcK2aIXVLYBRKCnTpCBm684f6IN2dyOTPjGGZXo/s1600/P1010022_crop.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh11uW9SanHMkZh6DfquQhDaHPcv-0PNsJF-_6o4ze4VPpcMppjYFLGDMtJULdGdJSIjSa8vMiJhvlgU8E25jD4t-f2_rLSVVxp_CxecEcK2aIXVLYBRKCnTpCBm684f6IN2dyOTPjGGZXo/s320/P1010022_crop.jpg" width="320" /></a></div>            If the </div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <b><u>Why pupae surveys are rarely done?<o:p></o:p></u></b></div> <div class="MsoNormal">                                             Because it is very difficult to identify pupae till the species level.  So it takes more time and less effective. <o:p></o:p></div> <div class="MsoNormal"> <b><u>What are the disadvantages of adult surveys?<o:p></o:p></u></b></div> <div class="MsoNormal">                                              Most of adult survey use human baits. But it is not convenient ethically because parasite can be transmitted from mosquito vector into human body. So people with low immunity, there is high probability to be suffered from diseases. It is a time consuming method. Although they active during day time, It is difficult to catch because they active only 7-10 in the morning and 3-5 in the afternoon. Adults can be collected from their resting habitats such as shady and shadow places. <o:p></o:p></div> <div class="MsoNormal"> <b><u>What are the control measures?<o:p></o:p></u></b></div> <div class="MsoNormal">                                                For high risk areas, eggs, larvae, pupae and adults are killed. Mosquito breeding is avoided or minimized. Waste should be disposed in a proper way. Water accumulation in both natural and artificial containers should be minimized. Insecticides should be applied to kill larvae and adults. Larvivorous fishes such as <i>Poecilia reticulata</i> should be introduced to reduce larvae. Chemical repellents such as citric oil and chemical applied net should be used to disturb the contact between misquotes and human. <o:p></o:p></div> <br /> <div class="MsoNormal">                                                Low risk areas are clean and no breeding places are available for mosquito breeding. For low risk area, no need to apply control measure. It is required to maintain environment hygiene in order to prevent to be high risk area. <o:p></o:p></div> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-65880709-1', 'auto'); ga('send', 'pageview'); </script>

Problems encounter in Aedes mosquito surveillance

Why the results of Dengue mosquito surveillance are not very accurate? Assumptions:     All detrains are considered as containers.                            All mosquitoes larvae are assumed as Aede…

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Human Influence on the Health of the Estuaries

<div class="MsoNormal"> <span style="font-size: 14pt; line-height: 115%;">                        </span><br /> <div class="separator" style="clear: both; text-align: center;"> <span style="font-size: 14pt; line-height: 115%;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-4UBKxbVWFMCvnNdK0tiBI0-YvhJKiARuWXRzZEPekEL_mWUdYh0KeRsG04S5xyhRT2Q_5QN0xYt1EOuMhMmvNzqEmdc1kmu4x29GIOOGuwgB9iomFMDRQ7g5ByM47ZP2ZMWCtra2wAtq/s1600/P1010022_crop.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="240" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh-4UBKxbVWFMCvnNdK0tiBI0-YvhJKiARuWXRzZEPekEL_mWUdYh0KeRsG04S5xyhRT2Q_5QN0xYt1EOuMhMmvNzqEmdc1kmu4x29GIOOGuwgB9iomFMDRQ7g5ByM47ZP2ZMWCtra2wAtq/s320/P1010022_crop.jpg" width="320" /></a></span></div> <span style="font-size: 14pt; line-height: 115%;">An estuary is defined as a semi-enclosed coastal body of water which has free connection to the open sea. The productivity of estuaries is similar to that of the tropical </span><span style="font-size: 18.6667px; line-height: 21.4667px;">rain forests</span><span style="font-size: 14pt; line-height: 115%;">. The services of estuaries are not only limited to itself but to whole the earth. Although species richness is less, abundance is high due to the high food availability. Most of seawater species use estuaries as their feeding grounds, nurseries and breeding grounds. The existence of the estuary is affected by the activities in the catchment areas as well as in estuaries. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Aquaculture in the estuaries effects the bio-physical environment. Mangroves have to be disrupted in order to construct aquaculture ponds. Water is released back into estuaries without proper treatments. Effluents such as growth additives, insecticide and antibiotics, suspended particles, fecal matter are adversely affected to the health of estuaries. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Organic matter increase BOD and decreases DO. Therefore oxygen available for estuarine animals becomes limited. Large suspended particles that are released from aquaculture ponds increase the turbidity.  It restricts the light penetration and decreases the primary productivity. Decreasing primary productivity of estuary affects the food availability and oxygen solubility. As suspended particles also absorb heat other than water, temperature of the water column is increased. It decreases the oxygen solubility. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Animals those escape from the aquaculture ponds become threatened to estuarine animals. They compete with native animals for foods, breeding places and hiding places.  Sewage of aquaculture animals contains loads of pathogens which may cause diseases among estuarine animals. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Insecticides contain high amount of heavy metals which cause bio magnification and bioaccumulation.  As a result of bioaccumulation, animals in the higher trophic level of the food web are adversely effected .High concentration result in even death.  Nutrients such as P and N accelerated the growth of algal and harmful algal bloom (HAB). Eutrophication restricts the light penetration through the water column. Harmful substance which are produced by <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">HAB are capable of killing estuarine animals. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Aquaculture does not affect only the quality but for also quantity. Large amount of estuarine water is extracted into the ponds. It reduces the water volume of the estuary. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Human settlement development along the estuarine bank is one of human influences to convert natural habitats. Mangroves are disrupted to erect houses. It causes loss of habitat and productivity of estuaries. Because decomposition falling leaves and branches adds nutrients into the water column.                            People dispose their waste and sewage directly into the estuary. Pollutants are collected and brought into nearby islands by waves. As some animals attempt to ingest these substances and they’ll die. Most of the pollutants are non-biodegradable and remain for thousand years. Sewage adds pathogens and increases the BOD.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                           Irregular tourism also contributes to reducing the quality of estuary. Mangroves are removed to construct tourist hotels beside the estuary. All effluents from the hotels are released into the estuary aid in pipes. Boats those are involved in tourism effects to the estuarine animals. Boats those are regularly maintained in a proper way cause oil leakage.  Oil spills are difficult to remove and costly. Oil increases the water temperature and reduces the oxygen solubility. Waste from the tourist boast is also directly disposed into the estuaries. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Over exploitation of estuarine resources leads extinction of some species. When the extinction rate is higher than breeding rate of animals, it is impossible to recover from extinction.  Although it is prohibited to catch animals during their breeding season, illegal incidences are still reported around the estuaries. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Irresponsible fishing in the estuary is also major problem.  Most the fish man stops their boats in the estuary during day time. It reduces the light penetration and primary productivity near bank. It also restricts the available surface for oxygen solubility. It may result in less biodiversity. At night they release oil form those boats into the estuarine water.  Fishing gears and nets are thrown away when they get damaged. They are also non-biodegradable and affect the existence of the estuary. Animals are unable to move when they get trapped within those left overs.   <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Activates in the catchment area also contribute to the health of the estuary.  Sedimentation is directly affected by riverine flow into the estuary. Activities such as deforestation, construction of houses and roads and agriculture in catchment make the soil bare into the open environment. It increases the probability to wash away the soils by runoff. As the riverine flow rate is slow near the estuary, sediment tends to deposit. Estuarine animals are interfering with respiration because their gills are clogged by sediments.<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                      Sediments increase the turbidity of the water column and reduce the light penetration which may result in decreasing primary productivity. Continuous filling of estuarine basin tend to be shallower. It   reduces the space available for life. It restricts the navigation through estuary into upstream areas.  <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Dam construction across the rivers reduces the freshwater input of the estuary.  Estuary receives less amount of water during dry season. As the freshwater input is less, salinity increases due to the high rate of evaporation. Therefore during dry season, esurient environment is more favorable for eury-saline and hyper saline animals. During rainy season, estuary gets more fresh water than sea water. So salinity is reduced. So that estuarine environment is favorable for steno saline and eury-saline species. <o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          Dam construction disturbs the migration of animals. Eels migrate from rivers into sea through estuaries their breeding season. Salmon fish also move from sea to rivers through the estuaries during their spawning season. Amount of nutrients and sediments is also decreased due to the less freshwater input. <o:p></o:p></span></div> <br /> <div class="MsoNormal"> <span style="font-size: 14.0pt; line-height: 115%;">                          In most of the areas of the country, water requires for water treatment plant for drinking is also extracted large amount of water from the rivers. It also contribute to the environment of the estuary.<o:p></o:p></span></div> <script> (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,'script','//www.google-analytics.com/analytics.js','ga'); ga('create', 'UA-65880709-1', 'auto'); ga('send', 'pageview'); </script>

Human Influence on the Health of the Estuaries

                         An estuary is defined as a semi-enclosed coastal body of water which has free connection to the open sea. The productivity of estuaries is similar to that of the tropical rai…

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