Table 1 Overall results of the mark-recapture experiment. Total catches (C) per location, recaptures (R) of glass eels of the different groups released at the seaside (SS) and canal side (CS), fish passage efficiency at location E, G and I, average residence time at barriers (delay) and local abundance estimates. * Model assumptions that were used to estimate decrease in tagged glass eels were verified by plotting residuals versus fitted values. In addition, the data were checked for autoregressive temporal correlation. Location I had missing monitoring days after release; therefore, the GLM was not considered to be reliable for that location
| Â | Â | Multiple batch mark recapture experiment throughout the NSC | Single batch mark recapture experiment at multiple locations. | ||||||
|---|---|---|---|---|---|---|---|---|---|
Location | C (n) | R: SS; CS (n) | R: CS + SS % | Local M | R (ELFI) | R (trap) Passage efficiency | Avg. res. Time (days) | Max. days between release and recapture (days) | Local abundance estimation* |
A | 3,273 | 1;0 | 0.0 | 250 | 0 (0%) | Â | n.a. | n.a. | n.a. |
B | 109,630 | 12;8 | 0.5 | 255 | 124 (48%) | Â | 12.3 | 65 | 147,800 |
C | 28,623 | 9;4 | 0.3 | 250 | 210 (84%) | Â | 12.6 | 59 | 22,300 |
D | 43,127 | 15;5 | 0.5 | 254 | 698 (274%) | Â | 13.7 | 75 | 11,600 |
E | 467,371 | 100;106 | 5.2 | 503 | n.a. | 79% | 4.1 | 44 | 580,000 |
G | 9,142 | 1;0 | 0.0 | 216 | n.a. | 17% | 4.4 | 10 | 48,000 |
H | 15,974 | 3;2 | 0.1 | 250 | 210 (84%) | Â | 12.0 | 62 | 12,900 |
I | 16,714 | 2;0 | 0.1 | 257 | 84 (33%) | 8% | 13.4 | 42 | 28,800 |
J | 22 | 0;0 | 0.0 | n.a. | n.a. | n.a. | n.a. | n.a. | n.a. |
K | 412 | 0;0 | 0.0 | 53 | 33 (63%) | Â | 11.8 | 56 | 400 |
L | 14,810 | 5;1 | 0.2 | 250 | 92 (37%) | Â | 11.4 | 37 | 29,000 |
Total | 709,098 | 148;126 | 6.9% | Â | Â | Â | 10.6 | Â | 876,000 |