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Sara Barrento [email protected]
IPIMAR
3rd Joint Trans-Atlantic Fisheries Technology ConferenceCopenhagen, 15-18 September 2009
Paulo Vaz PiresAntónio Marques Maria Leonor Nunes
Influence of animal physiological condition
Critical points in the trade chain of live crustaceans in Europe
Sara Barrento [email protected]
Live crustaceans: a globalized market
Portugal seafood consumption per capita = 57 kg (data from 2003)
Portugal: trade dominated by importation
0 500 1000 1500 2000 2500
Edible crab
Norway lobster
Homarids
Crabs
Spiny lobsters
tons
National capturesImport
Live trade of edible crab in Portugal
Edible crab represents 81%
of crustaceans
live imports
≈ 2000 tons are live traded
70 % supplied by the UK
Up to 50 %
but... mortality is high
Aims
Chracterize the import trade of live edible crab from England to Portugal and measure:
- physical damage and vigour - L-lactate- D-glucose- haemocyanin- and pH in the haemlymph prior to transport, after transport
and during recovery in stocking tanks- seawater dissolved oxygen and pH in transport tanks
Starting point: England
1Weymouth Harbour
- 7 tons of edible crab
- mortality = 30 kg
- unloading: 2
hours
England: crab tagging and sampling
260 crabs tagged (2 h)
Haemolymph sampled: - lactate - glucose - haemocyanin - pH
England: crab vigour checked
3 0 - dead 1 - moribund 2 - weak 3 - healthy 4 - very healthy
Edible crab transport
5
4 700 kg crabs/tank
30 crabs were put in the top
30 crabs were put in the bottom
1 kg/L seawater at 13 ºC without filtration
Transport: 58 h
The arrival: Portugal
Seawater in the transport tank:dissolved oxygen = 2.8 mg.L-1
pH = 7.4
The arrival: Portugal
Setúbal, Portugal
Vigour checked Haemolymph sampled
Of the 60 crabs tagged only one in the top died
6000 tons unloaded (mortality = 1 %)
5
- bottom crabs had more missing limbs than top crabs
- 9 % of males had one missing claw while females had none
- top crabs had higher lactate and lower pH values than bottom crabs
After 58 h of transport Setúbal, Portugal
Vigour checked Haemolymph sampled
Of the 60 crabs tagged only one in the top died
6000 tons unloaded (mortality = 1 %)
- bottom crabs had more missing limbs than top crabs
- 9 % of males had one missing claw while females had none
- top crabs had higher lactate and lower pH values than bottom crabs
Setúbal, Portugal
Vigour checked Haemolymph sampled
Of the 60 crabs tagged only one in the top died
6000 tons unloaded (mortality = 1 %)
- bottom crabs had more missing limbs than top crabs
- 9 % of males had one missing claw while females had none
- top crabs had higher lactate and lower pH values than bottom crabs
Setúbal, Portugal
Vigour checked Haemolymph sampled
Of the 60 crabs tagged only one in the top died
6 tons unloaded (mortality = 1 %)
Recovery in stocking tanks 96 h
6 Recovery at 16 ºC
Vigour checked Haemolymph sampled (6, 24, 48, 72, 96 h)
During recovery crabs continued to loose claws and legs
67 % of moribund crabs died against 6 % of weak crabs
Top crabs 11 %
Bottom crabs 9 %
Mortality
7.0
7.1
7.2
7.3
7.4
7.5
7.6
7.7
C 0 h 58 h 6 h 24 h 48 h 72 h 96 h
pH
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
C 0 h 58 h 6 h 24 h 48 h 72 h 96 h
Glu
cose
mm
ol/L
0.0
2.0
4.0
6.0
8.0
10.0
C 0 h 58 h 6 h 24 h 48 h 72 h 96 h
La
cta
te m
mo
l/L
Haemolymph results
Impairment of aerobioses and shift to anaerobic metabolismOnly lactate reached control values
Major critical points
Transport critical points:
- poor handling
- air exposure
- poor water quality
- high animal densities
Consequences:
- missing limbs and claws
- mortality- delayed recovery- economical losses
Conclusions
Immerse transport promotes:
hypoxiaanaerobic metabolismdifferent stress levels between
top and bottom crabsphysical damages
Possible solutions:
semi-dry transport Improve immerse transport:Suppply of oxygen to seawater Implement filtrating systems
