Aquatic insects as bio- indicators of water pollution in vellayani lake, Kerala (Record no. 291154)
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| 000 -LEADER | |
|---|---|
| fixed length control field | 05246nam a22002057a 4500 |
| 082 ## - DEWEY DECIMAL CLASSIFICATION NUMBER | |
| Classification number | 632.6 |
| Item number | SUS/AQ PG |
| 100 ## - MAIN ENTRY--PERSONAL NAME | |
| Personal name | Susmi, Sathana M R |
| 245 ## - TITLE STATEMENT | |
| Title | Aquatic insects as bio- indicators of water pollution in vellayani lake, Kerala |
| 260 ## - PUBLICATION, DISTRIBUTION, ETC. (IMPRINT) | |
| Place of publication, distribution, etc | Vellayani |
| Name of publisher, distributor, etc | Department of entomology |
| Date of publication, distribution, etc | 2023 |
| 300 ## - PHYSICAL DESCRIPTION | |
| Extent | 69p. |
| 502 ## - DISSERTATION NOTE | |
| Dissertation note | MSc |
| 520 3# - SUMMARY, ETC. | |
| Abstract | The study entitled ‘Aquatic insects as bio-indicators of water pollution in Vellayani lake, Kerala’ was carried out at Department of Entomology, College of Agriculture, Vellayani during the period 2021-2023. The objectives of the study were to assess the diversity of aquatic insects, to analyse the physicochemical parameters of water and to detect heavy metals and pesticide residues in water and aquatic insects of Vellayani lake. A total of 195 aquatic insects under five orders viz., Ephemeroptera, Odonata, Hemiptera, Coleoptera and Diptera belonging to 12 families such as Baetidae, Libellulidae, Gomphidae, Coenagrionidae, Gerridae, Nepidae, Belostomatidae, Corixidae, Hydrophilidae, Dytiscidae, Curculionidae and Chironomidae were documented from three sites viz., S1, S2 and S3 of Vellayani lake during October to December (2022), January to March (2023), April to June (2023) and July to September (2023). Identity of specimens were confirmed by taxonomists. Study revealed that the dominant order was Odonata (65) followed by Hemiptera (59), Diptera (49), Ephemeroptera (17) and Coleoptera (5). The dominant family was Chironomidae (49) followed by Gerridae (45), Libellulidae (43), Baetidae (17) and Coenagrionidae (16). Using the data generated on the population of aquatic insects, different indices were calculated. Margalef’s species richness was calculated and it was 0.96 in S1 which was considered as severely polluted whereas S2 (1.65) and S3 (1.78) were regarded as moderately polluted. Biotic Index (BI) was calculated to assess the degree of organic pollution and compared with the biotic index range proposed by Hilsenhoff. The BI range of 6.56 to 7.90 was recorded in all sites during entire sampling seasons which indicated poor to very poor water quality with substantial to severe organic pollution. Shannon-Wiener Index was calculated to assess the diversity of aquatic insects and the index range was used to evaluate the level of pollution. According to Shannon-Wiener Index, S1 (0.30 to 1.70) came under highly polluted condition whereas S2 (0.90 to 1.60) and S3 (1.00 to 1.60) under moderately polluted condition. Physicochemical parameters of water viz., pH, Total Dissolved Solids (TDS), Electrical Conductivity (EC), water temperature (WT), Dissolved Oxygen (DO), salinity, calcium, magnesium, nitrates, phosphates, and silicates were estimated twice/year using suitable protocols. All physicochemical parameters were found to be within the permissible limits except DO. The DO was low which ranged from 1.04 to 2.20 mg L-1 in all three sites. Correlation analysis was performed to find out the relationship between physicochemical parameters of water and abundance of aquatic insects. pH exhibited negative correlation with Belostomatidae (-0.269), Corixidae (-0.246), Coenagrionidae (-0.185) and Chironomidae (0.358). Water temperature showed positive correlation with Gerridae (0.349) while negative correlation with Libellulidae (-0.712) and Coenagrionidae (-0.044). Dissolved oxygen exhibited negative correlation with Chironomidae (-0.297). TDS and EC showed positive correlation with Gerridae (0.149, 0.399) while negative correlation with Hydrophilidae (-0.417, -0.270). Phosphate exhibited positive correlation with Baetidae (0.132) whereas negative correlation with Dytiscidae (-0.197). Heavy metals were analyzed in water, sediments and aquatic insects once/year using ICP-AES. Fe, Mn, Zn, Cu, Cd, Cr, Pb, Ni and Al were within the standard limits in three matrices. Geo-accumulation index was calculated to determine the magnitude of heavy metal pollution in sediments and since the values were <1, no heavy metal pollution was noticed. Bioaccumulation Factor was calculated by dividing the metal concentration in insects by sediment metal concentration and was well within the limit which revealed no heavy metal pollution in three sites in Vellayani lake. Pesticide residue analysis was carried out twice/year in water, sediments and aquatic insects from S1, S2 and S3. The mean residue level was below the limit of quantification in all sites. To conclude, among the twelve families documented, Libellulidae, Gerridae and Chironomidae were the dominant ones, and they were considered as the effective bioindicators of water pollution. The dominance of these families and the values of various indices revealed that the Vellayani lake water is moderately polluted, which was substantiated by low DO. No heavy metal pollution and pesticide residue contamination were observed in any of the sites in Vellayani lake |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Aquatic insects |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Functional feeding groups |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Bioindication |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Ephemeroptera |
| 650 ## - SUBJECT ADDED ENTRY--TOPICAL TERM | |
| Topical term or geographic name as entry element | Trichoptera |
| 700 ## - ADDED ENTRY--PERSONAL NAME | |
| Personal name | Ambily, Paul (Guide) |
| 942 ## - ADDED ENTRY ELEMENTS (KOHA) | |
| Source of classification or shelving scheme | |
| Item type | Theses |
| Not for loan | Collection code | Permanent location | Current location | Shelving location | Date acquired | Full call number | Barcode | Date last seen | Koha item type |
|---|---|---|---|---|---|---|---|---|---|
| Not For Loan | Thesis | KAU Central Library, Thrissur | KAU Central Library, Thrissur | Theses | 2024-04-08 | 632.6 SUS/AQ PG | 175972 | 2024-04-08 | Theses |