simulated live shipment of edible crab cancer pagurus: influence of temperature, air exposure...

IPIMAR

WEFTA 2008 38th WEFTA Annual Meeting Florence, Italy. 17-19 September 2008

Simulated live shipment of edible crab Cancer pagurus: influence of temperature, air exposure and anesthetic on physiological stress

Sara Barrento

Bárbara Teixeira António Marques

Paulo Vaz-Pires Maria Leonor Nunes

Sara Barrento: Simulated live shipment of edible crab Cancer pagurus: influence of temperature, air exposure and anesthetic on physiological stress WEFTA Annual Meeting FLorence, Italy 17-19 September 2008

Edible crab live trade in Portugal

Portuguese importations thousand tons

2249

1463

786

7

1

0 500 1000 1500 2000 2500

Total

UK

France

Spain

Ireland

In Southern Europe many crustaceans are traded live

In Portugal Cancer pagurus is the most popular crustacean kept live in holding facilities called “viveiros”

However... National production is insufficient


Live trade conditions

10 tons crab

Astrid K. Woll

Unloaded and discarded manually(during 2-3 hours)

Sara Barrento

Transport in vivier trucks during 24 – 48 h

Sara Barrento


Transportation conditions

- 1Kg crab/ 1L water - no filtration - just aeration - refrigeration temperature = 13-15º C

Truck tanks (24 - 48 h):

High mortalities: up to 50 %


Overall, what happens during live trade?

In the fishing vessel claws’ tendon is cut (nicking)

During transport:

– periods of air exposure – hypoxia– seawater physicochemical changes– handling and interaction with other individuals

– periods of starvation– seawater physicochemical changes– handling and interaction with other individuals

During holding:


Transportation condition alternatives

Use of anaesthetics during transportation and handling

Transport crabs in seawater at lower temperatures

Combination of:

Improve handling conditions

Transport crabs exposed to air under humid conditions at low temperatures to avoid transporting seawater

– anesthetic, – air exposure – low temperature


Anesthetics

There are only two approved by FDA (FINQUEL®, Tricaine-S®)

AQUI-S® is a candidate for FDA approval in the USA

But ...

- developed by New Zealand Institute of Crop and Food Research - active principle is isoeugenol (NZ$ 300 l-1; 3 cents/kg fish) - it is approved as a zero withdrawl fin fish, crustaceans and shellfish anaesthetic in:

New Zealand Australia

Faroe Islands Chile

either requires a 21 days post treatment withdrawal period before harvesting fish for food!


Aims

Study the effect of:

temperature sedation air exposure

in the physiological condition of crabs during simulated live shipment


Strategy

SEAWATER 1Kg/L

No AQUI-S®

Simulate present conditions

AQUI-S®

Decrease metabolism

AIR EXPOSURE

No AQUI-S® AQUI-S®

Decrease costs Decrease costs and metabolism

Simulate live shipment during 48 h, different treatments:

8 ºC, 12 ºC and 16 ºC


Strategy

Determine vigour (reactive, moribund or dead)

– serum proteins– hemocyanine concentration– glucose and lactate concentration– pH

Hemoplymph parameters:

Hemolymph sampling (1 mL): 0 h 3 h 8h 24 h 4 8 h

n = 95


WT AIR WAQ AQS

WT AIR WAQ AQS

0%

50%

100%

WT AIR WAQ AQS

0%

50%

100%

WT AIR WAQ AQS

WT AIR WAQ AQS

0%

50%

100%

WT AIR WAQ AQS

Results

Vigour and Mortality24 h 48 h

12 ºC

16 ºC

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Water Air Water AQuiS Air AquiS

Dead

Moribund

Reactive

8 ºC


Results

Vigour and Mortality

12 º C

8 º C

16 º C The effect of temperature depends on the treatment

T ºC not always increases mortality

Air exposure and temperature increases mortality

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Dead

Moribund

Reactive24 h


Results

Vigour and Mortality

AQUI-S® seems to have a negative effect at 8 ºC

AQUI-S® and low temperatures might lower too much the metabolism

This negative effect seems to be suppressed at higher temperatures

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%


Dead

Moribund

Reactive

12 ºC

8 ºC

16 ºC

24 h


Results

Glucose, proteins and hemocyanine

No significant changes were observed in:

Proteins

Hemocyanine

During the 48 h period:

Glucose – fluctuated


min (24h) 6.99

16 º C

16 º C

max (24h)=30

max (48h)=70

no change

Results

Lactate concentration and pH

WT WQS AIR AQS

Lactate

T(0h)= 10 mmol

pH

T(0)=7.23

12 º C

12 º C

no change

no change

no change

no change

max (48h)=80

min (48h) (48h)=7.03

max (48h)=70

no change

min (48h) (6.67)

max (48h)=90

min(24h) (6.99)

max (24h)=50

8 º C

8 º C

no change

no changes

no change

no changes

no change

no changes

no change

no changes


Summary

Temperature in general Lactate

pH

Air exposure caused the most striking increase of lactate and decrease of pH at temperatures above 8 ºC

Temperature in the AQUI-S® treatments seems to “buffer”:

But...

Lactate

pH

Air exposure

Seawater


Conclusions Mortalities depend on:

- transport duration (< 24 h is highly recommended)

- temperature and treatment

Best treatments (less mortality): 8 ºC – AIR 12 ºC – SEAWATER 16 ºC – seawater with AQUI-S®

AQUI-S® seems to have a negative effect at 8 ºC

Lactate and pH were the most relevant parameters - air exposure and temperatures above 8 ºC increased lactate and

decreased pH


Future perspectives

Optimize temperature and transport duration at which crabs have 0 mortality

Monitoring survival rates at holding facilities

Development of new effective transportation systems


Acknowledgements

Collective Research Project “CrustaSea: Development of best practice, grading and transportation technology in the crustacean fishery sector”, funded by the EC


Hey, George, who told you

this was a party??

simulated live shipment of edible crab cancer pagurus: influence of temperature, air exposure...

Health & Medicine

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c lactate

c aquis

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