| Literature DB >> 26788434 |
Shambhu Paudel1, Juan C Levesque2, Camilo Saavedra3, Cristina Pita4, Prabhat Pal5.
Abstract
The Ganges River dolphin (Platanista gangetica gangetica) (GRD) is classified as one of the most endangered of all cetaceans in the world and the second scarcest freshwater cetacean. The population is estimated to be less than 2,000 individuals. In Nepal's Narayani, Sapta Koshi, and Karnali river systems, survival of GRD continues to be threatened by various anthropogenic activities, such as dam construction and interactions with artisanal fisheries. A basic description of the geographic scope, economics, and types of gear used in these fisheries would help managers understand the fishery-dolphin interaction conflict and assist with developing potential solutions. The main goal was to provide new information on the artisanal fishing communities in Nepal. The specific objectives were to identify, compile, and investigate the demographics, economics, fishing characteristics, and perception of fishermen about GRD conservation in the Narayani, Sapta Koshi, and Karnali rivers so conservation managers can develop and implement a potential solution to the GRD-fishery interaction problem in Nepal. Based on 169 interviews, 79% of Nepalese fishermen indicated fishing was their primary form of income. Fishermen reported fishing effort was greater in summer than winter; greatest in the afternoon (14:30 hrs ± 0:27) and during low water level conditions; and gear was set 4.8 ± 0.2 days/week. Fishermen reported using eight different types of monofilament nets (gillnets and cast nets). Sixty percent used gillnets less than 10 m long, and nearly 30% preferred gillnets between 10 and 100 m long; a few used gillnets longer than 100 m. Most fishermen reported they believed education, awareness, and changing occupations were important for GRD conservation, but they indicated that alternative occupational options were currently limited in Nepal. Nepalese fishermen acknowledged that fisheries posed a risk to GRD, but they believed water pollution, and dam/irrigation developments were the greatest threats.Entities:
Keywords: Bycatch; Cetacean conservation; Endangered species; Fishery interactions; Ganges river dolphin
Year: 2016 PMID: 26788434 PMCID: PMC4715443 DOI: 10.7717/peerj.1563
Source DB: PubMed Journal: PeerJ ISSN: 2167-8359 Impact factor: 2.984
Figure 1Study area.
Map of interview locations in Nepal.
Demographic characteristics of fishermen from the Karnali (n = 56), Narayani (n = 60), and Sapta Koshi (n = 47) rivers.
Continuous data are shown as mean ± standard error and categorical data are shown as percentages. Differences between rivers and pairwise multiple comparisons were respectively tested with Fligner-Killeen and Dunnett-Tukey-Kramer test for continuous variables, and a Chi-square test with Yates correction (when required) was used for categorical variables. It should be noted that superscripts (a, b, c) sharing the same letter are statistically significantly different.
| Demographic characteristics | Total | Karnali river | Narayani river | Sapta Koshi river | Statistics, p-value |
|---|---|---|---|---|---|
| Age | 44.1 ± 1.1 | 38.7 ± 1.4a | 50.7 ± 1.8a,b | 42.1 ± 2.0b | FKχ2 = 6.3, p = 0.043 |
| Gender | |||||
| Male | 86.5 | 87.5a | 75.0a,b | 100.0b | χ2 = 14.2, p = 0.001 |
| Female | 13.5 | 12.5 | 25.0 | 0.0 | |
| Ethnicity | |||||
| Bote | 16.6 | 0.0a | 45.0a | 0.0a | χ2 = 283.0, p < 0.001 |
| Chaudhary | 11.0 | 10.7 | 18.3 | 0.0 | |
| Malha | 27.0 | 0.0 | 0.0 | 93.6 | |
| Sonaha | 25.2 | 73.2 | 0.0 | 0.0 | |
| Other | 20.3 | 16.1 | 36.6 | 8.3 | |
| Education level | |||||
| Illiterate | 69.4 | 82.1a | 80.0b | 42.6a,b | χ2 = 30.0, p < 0.001 |
| Primary education | 22.7 | 8.9 | 15.0 | 48.9 | |
| Secondary education | 6.8 | 7.1 | 5.0 | 8.5 | |
| Higher education | 0.6 | 1.8 | 0.0 | 0.0 | |
| Permanent local resident | 93.9 | 96.4a | 86.7a | 100.0a | χ2 = 9.1, p = 0.011 |
| Years living in the same village | 43.6 ± 0.9 | 47.7 ± 1.1a,b | 41.8 ± 1.5a | 41.1 ± 2.0b | FKχ2 = 15.3, p < 0.001 |
Characteristics of the fishing activity in the Karnali (n = 56), Narayani (n = 60), and Sapta Koshi (n = 47) rivers.
Continuous data are shown as mean ± standard error and categorical data are shown as percentages. Differences between rivers and pairwise multiple comparisons were tested with Fligner-Killeen and Dunnett-Tukey-Kramer test respectively for continuous variables, and a Chi-square test with Yates correction was used for categorical variables. It should be noted that superscripts (a, b, c) sharing the same letter are statistically significantly different.
| Fishing activity characteristics | Total | Karnali river | Narayani river | Sapta Koshi river | Statistics, p-value |
|---|---|---|---|---|---|
|
| |||||
| Fishing is main occupation (%) | 78.5 | 75.0a | 70.0b | 93.6b | χ2 = 9.3, p = 0.009 |
| Years of experience fishing | 36.9 ± 1.1 | 35.5 ± 1.53a | 43.0 ± 2.0a,b | 30.7 1.5b | FKχ2 = 17.7, p < 0.001 |
| Age started fishing | 13.6 ± 0.3 | 15.2 ± 0.1a | 11.4 ± 0.5a,b | 14.5 ± 0.7b | FKχ2 = 35.8, p < 0.001 |
| Occupation of father (%) | a | b | a | χ2 = 10.2, p = 0.006 | |
| Fisher | 77.9 | 75.0 | 31.7 | 93.6 | |
| Other | 22.1 | 25.0 | 68.3 | 6.4 | |
|
| |||||
| Days fishing per week | 4.8 ± 0.2 | 5.0 ± 0.2a | 3.7 ± 0.3b | 6.2 ± 0.7c | FKχ2 = 14.0, p < 0.001 |
| Time spent fishing per day in winter (h) | 3.1 ± 0.1 | 2.8 ± 0.1a | 2.6 ± 0.2b | 4.1 ± 0.2a,b | FKχ2 = 18.8, p < 0.001 |
| Time spent fishing per day in summer (h) | 5.2 ± 0.2 | 3.7 ± 0.1a | 3.6 ± 0.1b | 9.0 ± 0.4a,b | FKχ2 = 50.3, p < 0.001 |
| Effective number of months fishing | 3.3 ± 0.1 | 2.6 ± 0.2a | 2.6 ± 0.1b | 5.1 ± 0.2a,b | FKχ2 = 20.5, p < 0.001 |
|
| |||||
| Monthly earnings from fishing ($) | 60.2 ± 2.6 | 26.0 ± 2.3a,b | 78.0 ± 3.7a | 78.2 ± 2.5b | FKχ2 = 26.8, p < 0.001 |
| Annual earnings from fishing ($) | 233.5 ± 16.3 | 84.0 ± 3.8a | 208.1 ± 18.0a | 418.6 ± 33.4a | FKχ2 = 38.5, p < 0.001 |
| Monthly earnings from other activities ($) | 101.1 ± 9.9 | 41.8 ± 2.0a | 171.0 ± 23.9a | 82.1 ± 3.5a | FKχ2 = 32.2, p < 0.001 |
| Secondary occupation | a | a | a | FKχ2 = 191.1, p < 0.001 | |
| Agricultural labor | 47.9 | 5.4 | 71.7 | 68.1 | |
| Gold filtering | 25.8 | 75.0 | 0.0 | 0.0 | |
| Fishing unbanned areas | 3.1 | 0.0 | 0.0 | 10.6 | |
| Daily wages | 9.8 | 0.0 | 26.7 | 0.0 | |
| Other | 10.4 | 17.9 | 1.7 | 10.7 | |
Fishery description in the Karnali (n = 56), Narayani (n = 60), and Sapta Koshi (n = 47) rivers.
Continuous data are shown as mean ± standard error and categorical data are shown as percentages. Differences between rivers and pairwise multiple comparisons were tested with Fligner-Killeen and Dunnett-Tukey-Kramer test respectively for continuous variables, and a Chi-square test with Yates correction was used for categorical variables. It should be noted that superscripts (a, b, c) sharing the same letter are statistically significantly different.
| Fishing description | Total | Karnali river | Narayani river | Sapta Koshi river | Statistics, p-value |
|---|---|---|---|---|---|
|
| |||||
| Owner of one boat | 64.8 | 82.1a,b | 52.5a | 59.6b | χ2 = 11.8, p = 0.003 |
| Type of boat | a | b | a,b | χ2 = 94.3, p < 0.001 | |
| Single man traditional wooden boat | 81.0 | 100.0 | 100.0 | 17.9 | |
| More than one man modern boat | 19.0 | 0.0 | 0.0 | 82.1 | |
| Average number fishermen per vessel | 4.7 ± 0.6 | 2.1 ± 0.1a | 11.8 ± 1.1a,b | 2.3 ± 0.1b | FKχ2 = 26.8, p < 0.001 |
|
| |||||
| Fishing gear | a | a | a | χ2 = 23.8, p < 0.001 | |
| Phekuwa Jaal | 25.8 | 14.3 | 3.3 | 68.1 | |
| Maha Jaal | 24.5 | 71.4 | 0.0 | 0.0 | |
| Pakhure Jaal | 22.7 | 0.0 | 58.3 | 2.3 | |
| Other | 26.9 | 14.3 | 38.3 | 27.7 | |
| Net mesh size (cm) | 1.8 ± 0.2 | – | 1.7 ± 0.2a | 1.9 ± 0.2b | FKχ2 = 0.1, p = 0.990 |
| Net length (m) | 65.2 ± 6.7 | 170.2 ± 7.8a,b | 5.6 ± 1.2a | 14.1 ± 3.6b | FKχ2 = 9.7, p = 0.008 |
| Net width (m) | 4.6 ± 0.4 | 1.2 ± 0.1a | 9.1 ± 0.6a | 3.0 ± 0.1a | FKχ2 = 55.1, p < 0.001 |
|
| |||||
| Travel distance | 2.9 ± 0.1 | 2.6 ± 0.1a | 2.7 ± 0.2a | 3.3 ± 0.3b | FKχ2 = 4.5, p = 0.110 |
| Preferred fishing time (hrs) | 14:50 ± 0:16 | 15:52 ± 0:16a | 14:44 ± 0:32b | 13:44 ± 0:32a,b | FKχ2 = 18.8, p < 0.001 |
| Preferred fishing time | a | a | a | χ2 = 48.7, p < 0.001 | |
| Breeding time for fish | 10.4 | 12.5 | 16.7 | 0.0 | |
| High turbidity | 22.1 | 0.0 | 43.3 | 21.3 | |
| Low water season | 65.0 | 85.7 | 36.7 | 76.6 | |
| Summer season with hot water | 1.2 | 1.8 | 0.0 | 2.1 | |
| Other | 1.2 | 0.0 | 3.4 | 0.0 | |
Fishermen perception about the fishing activity and fisheries as a job in the Karnali (n = 56), Narayani (n = 60), and Sapta Koshi (n = 47) rivers.
Continuous data are shown as mean ± standard error and categorical data are shown as percentages. Differences between rivers and pairwise multiple comparisons were tested with Fligner-Killeen and Dunnett-Tukey-Kramer test respectively for continuous variables, and a Chi-square test with Yates correction was used for categorical variables. It should be noted that superscripts (a, b, c) sharing the same letter are statistically significantly different.
| Fishermen perceptions and opinions | Total | Karnali river | Narayani river | Sapta Koshi river | Statistic, p-value |
|---|---|---|---|---|---|
|
| |||||
| Perception about changes in the amount of fish caught over time | a | a | a | χ2 = 138.4, p < 0.001 | |
| Worse than before | 61.3 | 100.0 | 6.4 | 66.1 | |
| Same as before | 18.4 | 0.0 | 23.4 | 33.9 | |
| Better than before | 20.2 | 0.0 | 70.2 | 0.0 | |
| Perception about changes in the quantity of boats in the river | a | a | a | χ2 = 89.4, p < 0.001 | |
| Fewer than before | 36.8 | 78.3 | 14.9 | 10.7 | |
| Same as before | 54.0 | 10.0 | 68.1 | 89.3 | |
| More than before | 9.2 | 11.7 | 17.0 | 0.0 | |
|
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| Don’t want their children to be a fisher | 100.0 | 100.0a | 100.0b | 100.0c | χ2 = 1.6, p = 0.442 |
| Don’t think fishing is a good job | 100.0 | 100.0a | 100.0b | 100.0c | χ2 = 1.6, p = 0.442 |
| Which job they would like for their children | a | a | a | χ2 = 99.3, p < 0.001 | |
| Agriculture | 10.4 | 1.8 | 21.7 | 6.4 | |
| Fishing business | 3.7 | 3.6 | 0.0 | 8.5 | |
| Governmental job | 31.3 | 10.7 | 51.7 | 29.8 | |
| NGO | 12.3 | 3.6 | 11.7 | 23.4 | |
| Private firm | 35.0 | 80.4 | 5.0 | 19.1 | |
| Other small business | 7.4 | 0.0 | 10.0 | 12.8 | |
Fishermen perceptions about dolphin population and conservation status in the Karnali (n = 56), Narayani (n = 60), and Sapta Koshi (n = 47) rivers.
Continuous data are shown as mean ± standard error and categorical data are shown as percentages. Differences between rivers and pairwise multiple comparisons were tested with Fligner-Killeen and Dunnett-Tukey-Kramer test respectively for continuous variables, and a Chi-square test with Yates correction was used for categorical variables. It should be noted that superscripts (a, b, c) sharing the same letter are statistically significantly different.
| Perceptions about dolphins and their conservation | Total | Karnali river | Narayani river | Sapta Koshi river | Statistic, p-value |
|---|---|---|---|---|---|
|
| |||||
| Does not know (saw or heard) of dead dolphins | 99.4 | 100.0a | 98.3b | 100.0c | χ2 = 1.7, p = 0.422 |
| Perceives to seeing dolphins often in the past | 61.3 | 28.6a,b | 73.3a | 85.1b | χ2 = 53.5, p < 0.001 |
| Perceives to rarely see dolphins now | 62.6 | 23.2a | 98.3a | 63.8a | χ2 = 70.4, p < 0.001 |
| Type of habitat where dolphins are most often sighted | a | a | a | χ2 = 104.7, p < 0.001 | |
| Deep pool (depth >3m) | 56.0 | 50.0 | 100.0 | 10.6 | |
| Confluence | 12.6 | 7.1 | 0.0 | 34.0 | |
| Straight channel (depth <3m) | 26.4 | 42.9 | 0.0 | 38.3 | |
| Meandering | 5.0 | 0.0 | 0.0 | 17.0 | |
| Type of behavior when dolphins are sighted | a,b | a | b | χ2 = 138.2, p < 0.001 | |
| Diving | 66.5 | 7.1 | 100.0 | 100.0 | |
| Showing back and snout | 31.6 | 87.5 | 0.0 | 0.0 | |
| Swimming | 1.9 | 5.4 | 0.0 | 0.0 | |
| Distance from dolphin to boat during sightings (m) | 48.1 ± 8.4 | 1.8 ± 0.1a | 131.4 ± 19.3a,b | 3 ± 0.0b | FKχ2 = 74.8, p < 0.001 |
|
| |||||
| Perceives decrease in number of dolphins over time | 89.5 | 87.5a | 100.0a,b | 78.7b | χ2 = 13.0, p = 0.002 |
| Perceived major threats to dolphins | a | a | a | χ2 = 64.7, p < 0.001 | |
| Habitat overlapped with fishermen | 10.7 | 0.0 | 28.3 | 0.0 | |
| Low depth and width of river | 32.1 | 12.5 | 36.7 | 51.2 | |
| High human disturbances | 53.5 | 85.7 | 26.7 | 48.8 | |
| Decrease in prey density | 3.7 | 1.8 | 8.3 | 0.0 | |
| Ways to conserve dolphins | a,b | a | b | χ2 = 64.3, p = 0.001 | |
| Awareness among the fishermen/river dependent communities | 53.4 | 89.3 | 30.0 | 40.4 | |
| Enterprise training facilities for river dependents | 23.3 | 1.8 | 38.3 | 29.8 | |
| Monitoring of fishing activities through watch group | 8.6 | 3.6 | 13.3 | 8.5 | |
| Punishing people engaged in illegal activities according to law | 5.5 | 0.0 | 5.0 | 12.8 | |
| Careful fishing by avoiding killing dolphins | 4.9 | 5.4 | 1.7 | 8.5 | |
| Other | 4.3 | 0.0 | 11.7 | 0.0 | |