| dc.contributor.advisor | Professor Dr. Md. Jahidul Islam | |
| dc.contributor.author | ZAHAN, MST. NASRIN | |
| dc.date.accessioned | 2022-04-24T05:25:10Z | |
| dc.date.available | 2022-04-24T05:25:10Z | |
| dc.date.issued | 2017-06 | |
| dc.identifier.uri | http://localhost:8080/xmlui/handle/123456789/729 | |
| dc.description | Increase in food production is the prime-most objective of all countries, as world
population is expected to grow to nearly 10 billion by 2050. Increase in food production
is faced with the ever-growing challenges especially the new area that can be increased
for cultivation purposes is very limited (Saravi and Shokrzadeh, 2011). The increasing
world population has therefore put a tremendous amount of pressure on the existing
agricultural system so that food needs can be met from the same current resources like
land, water etc. Today, the use of pesticides has increased dramatically because of the
growing population and the demands this population. Pesticides have now become an
integral part of our modern life and are used to protect agricultural land, stored grain,
flower gardens as well as to eradicate the pests transmitting dangerous infectious
diseases. It has been estimated that globally nearly $38 billion are spent on pesticides
each year (Pan-Germany, 2012). About 0.1% of the pesticides reach the target organisms
and the remaining bulk contaminates the surrounding environment (Carriger et al.,
2006). The repeated use of persistent and non-biodegradable pesticides has polluted
various components of water, air and soil ecosystem. Different kinds of insecticides have
been used for crop protection for centuries. Pesticides are a concern for sustainability of
environment and global stability. The term pesticide covers a wide range of compounds
including insecticides, fungicides, herbicides, rodenticides, molluscicides, nematicides,
plant growth regulators and others. The introduction of synthetic insecticides in 1940,
when organochlorine (OCl) insecticides were first used for pest management. The
introduction of other synthetic insecticides organophosphate (OP) insecticides in the
1960s, carbamates in 1970s and pyrethroids in 1980s and the introduction of herbicides and fungicides in the 1970s -1980s contributed greatly to pest control and agricultural
output. | en_US |
| dc.description.abstract | Stinging catfish (Heteropneustes fossilis), Spotted snakehead (Channa punctatus),
Climbing perch (Anabas testudineus) and Tangra (Batasio tengana) were exposed to
various concentrations of chlorpyrifos (Expert 20 EC) to investigate mortality rate and
the toxicity level of the pesticide. The median lethal concentration (LC50) values of
chlorpyrifos (Expert 20 EC) on stinging catfish, spotted snakehead, climbing perch and
tangra were 23.10, 20.32, 16.61 and 13.94 ppm, respectively for 96 hours of exposure.
Mortality rate and behavioral changes of fish at different concentrations were
determined. Remarkable behavioral abnormalities were found during the exposure. Fish
performs all their body functions in water. The quality of the water in which fish are
contained is therefore very important to their livelihood. In the present study, some
physicochemical parameters such as temperature, pH, dissolved oxygen, total dissolved
solids and electrical conductivity. Studies were undertaken during the month of
November, 2017 to April, 2017 during which the physicochemical parameters were
analyzed and compared with the aquaculture water quality standard. The temperature
values remained within the standard values in the all the aquaculture pond types. pH
values of the aquaculture ponds ranged, from 4.7-6.8 as against the standard water
quality i.e., 6.5-8.0 and the pH of this experiment with presence of pesticide was 6.64-
7.30. Fish kills occurred in every month of the year but were most abundant in summer
from June through September as was the abundance of rainfall and warmer water
temperature along with the abundant use of pesticide was a major factor. Pesticides
caused a number of fish killing in ponds throughout the year. Conclusives, erratic
swimming and lethargy were symptomatic of pesticide toxicity. If an organophosphate
insecticide is the cause, the pectoral fins of the fish will be reversed. The pectoral fins of
a healthy fish point toward the tails, but the pectoral fins of a fish poisoned by insecticide
curl up and point toward the head. Fish ponds should not be built in areas adjacent to
crops that are likely to be treated with pesticides toxic to fish. | en_US |
| dc.language.iso | en | en_US |
| dc.publisher | HAJEE MOHAMMAD DANESH SCIENCE AND TECHNOLOGY UNIVERSITY, DINAJPUR. | en_US |
| dc.subject | CHLORPYRIFO | en_US |
| dc.subject | FISH SPECIES | en_US |
| dc.title | TOXICITY BIOASSAY OF CHLORPYRIFOS ON SOME LOCAL FISH SPECIES OF NORTHERN BANGLADESH | en_US |
| dc.type | Thesis | en_US |
