The effects of two different net modifications on reducing discards in the trammel net fishery for prawn in Mersin Bay
| 09. Okt. 2023
Über diesen Artikel
Article Category: Original research paper
Online veröffentlicht: 09. Okt. 2023
Seitenbereich: 366 - 373
Eingereicht: 30. Apr. 2023
Akzeptiert: 28. Juni 2023
DOI: https://doi.org/10.26881/oahs-2023.3.09
© 2023 Adem Sezai Bozaoğlu, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
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Income obtained by using commercial nets (CNet) and alternative nets (GPlastic and GNet), and projected economic loss in changing from commercial to alternative nets
| Species | CNet Weight (g) | Unit Price (USD) | Income (USD) | GPlastic Weight (g) | Income (USD) | GNet Weight (g) | Income (USD) |
|---|---|---|---|---|---|---|---|
| 10290 | 3.35 | 34.47 | 16000 | 53.6 | 15850 | 53.10 | |
| 7220 | 13.35 | 96.39 | 7030 | 93.85 | 6350 | 84.77 | |
| 4190 | 8.89 | 37.25 | 4390 | 39.03 | 6160 | 54.76 | |
| 3600 | 3.35 | 12.06 | 2070 | 6.93 | 2100 | 7.04 | |
| 1980 | 3.35 | 6.63 | 4310 | 14.44 | 4810 | 16.11 | |
| 6400 | 6.67 | 42,69 | 10000 | 66.7 | 3350 | 22.34 | |
| 500 | 4.45 | 2.23 | 2200 | 9.79 | 1800 | 8.01 | |
| 100 | 3.35 | 0.34 | 1550 | 5.19 | 1400 | 4.69 | |
| 0 | 6.67 | 0 | 0 | 0 | 2200 | 14.67 | |
| Total Value (USD) | 232.06 | 289.53 | 265.49 | ||||
| Profit (%) | 24.77 | 14.41 |
All the species captured by the standard and alternative trammel nets
| (CNet) | GPlastic | GNet | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Species | CS | N | % N | W(g) | % W | N | % N | W(g) | % W | N | % N | W(g) | % W |
| D | 175 | 22.97 | 2780 | 7.19 | 88 | 12.39 | 1890 | 3.87 | 108 | 14.81 | 1620 | 3.5 | |
| D | 90 | 11.81 | 200 | 0.52 | 47 | 6.62 | 110 | 0.22 | 46 | 6.31 | 102 | 0.22 | |
| L | 59 | 7.74 | 4190 | 10.84 | 61 | 8.59 | 4390 | 8.77 | 84 | 11.52 | 6160 | 13.29 | |
| L | 120 | 15.75 | 10290 | 26.63 | 184 | 25.92 | 16000 | 31.97 | 178 | 24.42 | 15850 | 34.2 | |
| L | 168 | 22.05 | 7220 | 18.68 | 157 | 22.11 | 7030 | 14.05 | 137 | 18.79 | 6350 | 13.7 | |
| D | 54 | 7.09 | 1390 | 3.6 | 22 | 3.01 | 490 | 0.98 | 23 | 3.16 | 600 | 1.29 | |
| L | 26 | 3.41 | 1980 | 5.12 | 64 | 9.01 | 4310 | 8.61 | 71 | 9.74 | 4810 | 10.38 | |
| L | 13 | 1.71 | 6400 | 16.56 | 23 | 3.24 | 10000 | 19.98 | 8 | 1.1 | 3350 | 7.23 | |
| Scomber japonicus (chub mackerel) | L | 1 | 0.13 | 100 | 0.26 | 21 | 2.96 | 1550 | 3.1 | 18 | 2.47 | 1400 | 3.02 |
| L | 52 | 6.82 | 3600 | 9.31 | 30 | 4.23 | 2070 | 4.14 | 38 | 5.21 | 2100 | 4.53 | |
| L | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 5 | 0.69 | 2200 | 4.75 | |
| L | 4 | 0.52 | 500 | 1.29 | 13 | 1.83 | 2200 | 4.4 | 13 | 1.78 | 1800 | 3.89 | |
Removal times of discarded species from the net (sec)
| Discard species | Average removal time | CNet N | CNet removal time (sec) | GPlastic film N | GPlastic removal time (sec) | GNet N | GNet removal time (sec) |
|---|---|---|---|---|---|---|---|
| 21.20 ± 4.35 | 175 | 3710 | 88 | 1866 | 108 | 2290 | |
| 17.65 ± 3.27 | 90 | 1589 | 47 | 830 | 46 | 812 | |
| 60.70 ± 10.78 | 54 | 3278 | 22 | 1335 | 23 | 1396 |