Venice2012_Tues29th_1215_Atlantic

Study of a new net
for glass eel fishery
SEG Conférence – Venice May 2012
PRIOUL François
LE FLOC’H Erwann
FOUCHER Gilles
Presentation - Context
- French Good Practices Guide
- Increasing of the restocking part until 60 % for 2013
Objectives :
- Decrease mortality in catches
- Decrease injuries made by fishing gear
Increase glass eels quality
Nets description :
Experimental net
Conventional net
Method
- Gear on each side of the vessel
- The entire catch is placed in oxygenated pockets
- 10 strokes by fishing campaign
- Vessel speed : 4 knots (8km/h)
- Duration of scoop net strokes = 10 min
- Catches located in a tank of water at 5 ‰ salinity for about 12 h
10 fishing campaign planned,
performed 7 = 70 scoop net strokes,
140 catches analyzed
Average mortality made by each gear (%)
Results
30.00%
25.00%
TC
TE
20.00%
15.00%
• Mortality
13.35%
10.00%
5.00%
2.00%
0.00%
Average mortality in catches (%)
60.00%
Moy % mortes TC
50.00%
Moy % mortes TE
40.00%
30.00%
20.00%
10.00%
0.00%
1
2
3
4
Fishing campaign
5
6
7
Results
• Injuries
Injuries by the new gear
Injuries by the classic gear
0.9%
3.9%
4.6%
0.1% 0.1%
0.7%
0.6%
1.4%
13.7%
73.7%
0.1%
0.2%
0-0 (safe glass eel)
1.9%
0.2% 0.0%
0.0%
3.1%
0-0 (safe glass eel)
0-1
0-1
0-2
0-2
1-0
1-0
1-1
1-1
1-2
1-2
2-0
2-0
2-1
2-1
2-2
2-2
94.8%
10314 glass eels analyzed by indigo carmine coloration
Conclusion
Encouraging results:
Seems to increase glass eel quality in catches
Prospects
- First approach in system improvement
- Results brings elements to adapt guide of good practices
- Proposing to adapt to other kind of gear
180.0
Average production made by each gear (g)
160.0
Production
140.0
Moy poids capture TC (g)
120.0
Moy poids capture TE (g)
100.0
80.0
60.0
40.0
59.1
20.0
57.4
0.0
350.0
Average production by catches
300.0
Moy poids capture TC (g)
250.0
Moy poids capture TE (g)
200.0
150.0
100.0
50.0
0.0
1
2
3
4
5
6
7